how to build a catamaran free plans

How to Build a Catamaran Boat? (Step-by-Step Guide)

Building a catamaran boat from scratch is a rewarding and challenging endeavor.

It takes a combination of skill, dedication, and hard work to craft a seaworthy vessel.

In this step-by-step guide, you’ll learn how to design and size your catamaran, gather the necessary materials, cut and assemble the pieces, lay fiberglass and apply epoxy, make finishing touches, add hardware and paint, and rig the boat.

With the right tools, planning, and patience, you can make your dream of sailing in a catamaran a reality.

Table of Contents

Short Answer

Building a catamaran boat requires a lot of patience and skill.

The first step is to choose the right materials for the hull, such as fiberglass, wood or aluminum.

Then, you will need to build the frame of the boat, which includes the crossbeams and the main hull.

After that, you will need to install the decking, the rigging, and other components.

Finally, you will need to paint and varnish the boat, as well as install the outboard motor and other accessories.

Design & Size Considerations

When it comes to building a catamaran boat from scratch, the first step is to determine the design and size of the boat.

This should take into account the intended use of the boat, such as sailing, fishing, or leisurely cruising.

The size of the boat will depend on the number of passengers and the type of activities the boat will be used for.

For instance, a larger boat may be needed if passengers will be standing or participating in watersports.

The design of the boat is also important and should be chosen based on the intended use.

If you are looking to build a sailboat, you will need a design that is optimized for sailing.

On the other hand, if you are looking to build a fishing boat, you will need a design that is optimized for fishing.

There are a wide variety of boat designs available, so it is important to research and choose the one that best suits your needs.

In addition to the design and size, you will also need to consider the materials used for construction.

The most common materials for building a catamaran boat are wood, fiberglass, and epoxy.

Each material has its own advantages and disadvantages, so it is important to research them and determine which one is best for your project.

Finally, you will need to consider the cost of the project.

Building a catamaran boat from scratch can be a costly endeavor, so it is important to have a budget in mind before you begin.

The cost will depend on the type of materials used and the complexity of the design.

It is also important to factor in the cost of any tools that may be needed for the project.

By taking into account the design and size, materials, and cost of the project, you can be sure to build a catamaran boat that meets your needs and budget.

With the right amount of patience and attention to detail, you can build your own catamaran boat in no time.

Gathering Materials

Gathering the materials needed to build a catamaran boat from scratch can be a daunting task, but it is essential for creating a sturdy and safe vessel.

Before starting the building process, it is important to have an accurate and detailed plan for the boats design and size.

Once a plan is in place, it is time to begin sourcing the necessary materials.

The most common materials used to construct a catamaran boat are wood, fiberglass, and epoxy.

When choosing wood, it is best to select a species of timber that is strong and durable, such as mahogany, teak, or cedar.

Additionally, the wood should be clear and free of knots, splits, and other defects.

Fiberglass is a lightweight fabric that is resistant to water and provides additional strength to the boats hull.

Epoxy is a waterproof adhesive that is used to seal the boat and ensure that it is watertight.

It is important to ensure that the materials are of high quality, as this will help to ensure the boats longevity.

Additionally, it is important to purchase the necessary materials in the correct amount and size.

Too little or too much of a material can be a costly and time-consuming mistake.

Finally, it is important to keep any leftover materials for future repairs or modifications.

With the right materials gathered, the next step is to cut the wood and begin the assembly process.

Cutting & Assembly

Cutting and assembly are the most important steps when it comes to building a catamaran boat from scratch.

The first step is to decide the design and size of the boat.

This will determine the type of materials you need to gather and the amount of effort that needs to be put into the project.

After deciding on the design and size, you will need to cut the wood to fit the design.

This includes cutting the wood to the desired size, as well as cutting any additional pieces that may be needed to complete the design.

It is important to ensure that all the pieces fit together correctly and securely, as any mistakes could lead to a weak boat.

Once the wood has been cut, it is time to assemble the pieces together.

This involves attaching the pieces together with glue, screws, and nails, and ensuring that the pieces fit together securely.

It is important to be careful and patient when assembling the pieces, as any mistakes could result in a weak and unstable boat.

Once the frame is ready, it is time to lay the fiberglass, and apply the epoxy to seal the boat.

This is an important step, as it will make sure that the boat is waterproof and durable.

Finally, you can add the finishing touches, such as the hardware, paint, and rigging.

With the right amount of patience and attention to detail, you can have your own custom catamaran boat in no time.

Laying Fiberglass & Applying Epoxy

When laying the fiberglass and applying epoxy, it is important to take your time and be precise.

Fiberglass and epoxy are key components of a catamaran boat, as they provide the strength and waterproofing necessary to keep the boat afloat.

Start by laying the fiberglass over the frame of the boat.

Make sure to cut the fiberglass to size and overlap the edges for a strong seal.

Once the fiberglass is in place, mix the epoxy and begin to apply it.

It is important to apply the epoxy in a thin, even layer to ensure a proper seal.

Make sure to move the epoxy around to get it into all the nooks and crannies of the boat.

Allow the epoxy to cure and then you can begin to add the finishing touches.

Finishing Touches

Once the frame of the catamaran boat is built, it is time to add the finishing touches.

This includes adding the necessary hardware, painting, and rigging the boat.

Hardware: Before adding the hardware, it is important to ensure that the frame is stable and secure.

Add the appropriate hinges, screws, and nails to the frame.

Make sure that the screws and nails are the correct size and do not exceed the recommended load capacity of the frame.

Painting: Once the hardware is added, it is time to paint the boat.

Choose a paint that is suitable for the materials used in the construction.

Make sure that the paint is applied evenly and that the frame is completely dry before applying the next coat.

Rigging: The last step is to rig the boat.

This involves attaching the sails, running rigging, and standing rigging to the masts and booms.

Make sure that the rigging is properly tensioned and secured.

Once all of these steps are complete, your catamaran boat is ready to sail.

Hardware & Paint

The last step in building a catamaran boat is to add the hardware and paint.

This step is often the most rewarding, as it is the finishing touch.

Depending on the design of your boat, there are various types of hardware you may need.

Some of the most common items are cleats, winches, fasteners, and decking.

After selecting the required hardware, you will need to install them on the boat.

It is important to use the correct type of screws and bolts, and to secure them tightly.

Once the hardware is installed, it is time to apply the paint.

The type of paint and color you choose will depend on the design of your boat.

It is important to use a high-quality marine grade paint that is designed to handle the extreme environment of the ocean.

If you are up to the challenge, you can add some custom artwork or detail to your catamaran boat.

Adding the hardware and paint is the final step in building a catamaran boat.

With patience and attention to detail, you can create a beautiful and unique boat that will last for many years.

Be sure to take your time and enjoy the process of constructing your own boat.

Once you have finished the frame, fiberglass, and epoxy of your catamaran boat, you will need to move onto the rigging.

This is a crucial step in the construction process, as it will keep your boat safe and secure on the water.

When rigging a catamaran, there are a few key components that must be taken into account.

First, you will need to determine the type of rigging you will be using.

Typically, catamarans use a combination of standing and running rigging.

Standing rigging consists of cables and lines that stay in a fixed position to provide stability and strength to the boat, while running rigging consists of lines that are used to adjust the sail and mainsheet.

Additionally, you will need to choose the right type of rope and hardware for your rigging setup.

The rope should be strong and durable, and the hardware should be made of stainless steel and be corrosion-resistant.

Once you have chosen the type of rigging and hardware, you can start assembling the rigging lines.

This process involves carefully measuring and cutting the lines to the proper lengths, and then attaching them to the mast and boom.

Depending on the type of rigging setup, you may also need to attach the lines to the hulls and deck.

It is important to inspect the rigging lines and hardware regularly to ensure that everything is secure and in proper working order.

Rigging a catamaran boat can seem like a daunting task, but it is essential for the safety and comfort of your vessel.

With the right tools, materials, and attention to detail, you can successfully and safely rig your catamaran boat.

Final Thoughts

Building a catamaran boat is a rewarding experience that requires patience and attention to detail.

With the right plan, materials, and steps, you can build your own boat in no time.

Now that you know the basics of how to build a catamaran boat, why not grab your tools and get started on your very own project? With the right motivation and dedication, you can make your dream of owning a catamaran boat a reality.

James Frami

At the age of 15, he and four other friends from his neighborhood constructed their first boat. He has been sailing for almost 30 years and has a wealth of knowledge that he wants to share with others.

Catamarans and Trimarans

Catamaran and Trimaran Boat Plans make it a reality to build your own catamaran or trimaran. Multi-hulled sailing vessels are a special class of boat. A very different mind set is required when thinking about sailing a multi hull, let alone getting your head around building one.

There are some unique challenges building a multi-hull sail boat, the extra beam added by each hull for instance can create storage issues while under construction. Hartley boat plans make the build process straight forward for even amateur builders. However with all things considered, building a multi can be an amazing journey.

Fast Twin Catermaran

Lively 28 Cruising Trimaran

Lively 35 Cruising Trimaran

How To Create the Perfect Cruising Catamaran Layout

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More than ever before, sailing fans are gaining an interest in catamaran layouts and designs that define performance. Many others are also looking into either buying a cruising catamaran or designing and building one. While building a catamaran is no piece of cake, this article shows you how to create the perfect cruising catamaran layout.

To create the perfect catamaran layout, carefully consider factors like a good hull design, optimal helm station placement, boat stability, and adequate load-carrying capacity. Excellent galley positioning, ease of handling, and spacious living and sleeping quarters are also crucial.

The modern cruising catamaran is a far cry from the simple Polynesian double canoe of old. That’s because structural innovations and new composite materials have resulted in multihulls with impressive cruising abilities. Keep reading to learn more about exceptional catamaran layouts.

The Changing Trends in Catamaran Designs

The early cruising catamaran designs resulted in boats that could sail much faster than traditional sailing boats. In addition, they could glide with ease in shallow waters and required less wind and crew. Unfortunately, these cruising cats were heavy, had small, cramped interiors, and boasted somewhat challenging handling abilities.

Today’s cruising catamarans are different. They boast the utmost comfort, high speeds, and the safety of a well-designed cruising yacht. They are also more exciting, visually appealing, deliver the smoothest of rides, and sport more spacious interiors.

Have a look at the below video showcasing the top ten cruising catamarans:

Features To Look Out for in Catamaran Design Layouts

Cruising catamaran designers understand what most sailors look for in a cruising vessel. They, therefore, design cruising multihulls that address these pertinent issues and more. Some of the features you might want to consider having in your dream boat include the following:

Responsive performance. Outstanding performance allows for pleasurable cruising and ensures your safety since you have more options during difficult weather.
Excellent load-carrying ability . This allows you to have an extended cruising vacation or ocean crossing.
Boat stability . Go for lightweight, robust construction, which results in a lot of buoyancy.
A low center of gravity for smooth rides and enhanced performance. Centering weight around a low center of gravity improves the overall sailing quality, reduces pitching movement and reduces the risk of capsizing .
Adequate bridgedeck clearance to reduce slamming and provide better performance in rough conditions. A high bridgedeck also means less noise and slapping action from the waves hitting the boat bottom, thus ensuring a quieter, smoother ride.
Comfortable sailing. To enjoy a quality life on board, you need comfort while at sea. Thus, elements like gentle movement, no creaks or groans, no bridgedeck slamming, and minimal pitching are essential for quality, peaceful and restful sleep.

Now that you know what a cutting-edge catamaran features, let’s look at how to create the perfect cruising catamaran layout.

Build a Larger-Sized Catamaran

The early catamarans ranged between 36-42 feet (10.9-12.8m). At the time, this appeared to be a good size in terms of safety and ease of handling. However, the boats were heavy, and the additional drag and displacement adversely affected their performance and windward ability.

It’s now possible to make the new generation catamarans lighter, larger, and more spacious with excellent power-to-weight features. The current trend is larger-sized catamarans in the 45-50 feet (13.7- 15.2) range. Composite engineering and technologically advanced equipment such as furling systems, electric winches, and autopilot make it easier for a smaller crew to sail larger boats with confidence. And to do so without compromising safety or stability.

Get the Best Catamaran Hull Design

A cruising catamaran’s performance depends on three main aspects; its length, the sail area, and the boat’s weight. Long boats are generally fast. A light boat with more sail area is also faster than a heavier boat with less sail area. In other words, you can make a multihull faster by making it longer, lighter, or adding more sail.

However, there are exceptions to this rule; a boat with too much sail area is more likely to capsize if there are brisk winds. Also, if the boat’s design makes it too light, it’ll be unable to handle much punishment, while a hull design that’s too slim would make the vessel incapable of carrying any significant loads. But that’s not all; if the boat is too long or too large, it’ll become grossly exorbitant. Narrow hull shape might also mean smaller cabins.

Nonetheless, these three factors alone are not enough to determine a cruising catamaran’s performance. While faster boats boast finer hulls, the wetted surface area tends to increase as fineness increases; thus, fine hulls end up becoming less fast in low wind speeds. Also, very wide hulls mean a reduction in actual performance.

The Prismatic Coefficient (Cp), a measure of how full the ends of the hull get, is the most essential design hull shape factor for any catamaran. A high Cp equals high speeds, although you can still use a lower Cp if you have fine hulls. Nevertheless, the key to a good Catamaran design is a higher Cp for fast sailing.

To achieve a high Cp, there are several things you can do:

Fit bulb bows . Unfortunately, the bulb bows tend to slam in a seaway when you do this.
Have an extensive planning aft section . However, this can increase the wetted surface area, WSA and lead to additional challenges.
Flatten out the hull rocker and add a bustle aft. This helps to add displacement aft.

Build Convertible Main Living Spaces

The open cockpit is now a thing of the past. Instead, pioneering designers for catamaran manufacturers like Nautitech, Gunboat, and Catana now replace traditional-style salons, cockpits, and cabins with spacious indoor and outdoor living spaces. The concept involves merging separate saloon and cockpit areas with duplicate lounge spaces and the use of hard-wearing composite materials.

You can also design the cabin to suit your preferences. You may decide to add a cabin or remove one, add a bathroom, have the forward berth in the hull or on the wing deck.

The design enhancements boost usable space while opening up the living areas.
It reduces time and costs for interior maintenance and cleaning.
Large windows bring in more light, increasing visibility.
Luxurious, spacious, and airy owners’ cabins provide more comfortable living space.

Bulkhead Helm Stations vs. Twin Stern Steering

Many catamaran owners have traditionally preferred bulkhead steering. This helm position remains popular, but twin stern steering positions come with more advantages since they provide greater sails visibility. The twin stern positions are also best suited for racing or day sailing since they often lack adequate protection for extended cruising.

Exposed helms are not ideal for a long ocean passage. Go for a safe, secure, and well-protected helm station that provides good visibility and comfortable space for long watches. Again, it’s best to have all control lines at the helm to establish a static control station. Also, have all push-button-controlled winches, instruments, windlass, and autopilot prominently located inside the cockpit.

Twin stern steering positions give you a better view of the sails
You get a better feel for overall sailing conditions.
Twin stern steering positions lack the necessary protection for extended cruising.

Go for the Flybridge Design

The flybridge design is appealing because it offers excellent visibility, more comfort, and additional entertainment and lounging space for everyone on board. Unfortunately for smaller boats – those below 50 feet (15.24m), there is minimal protection from the elements. As such, you might want to consider adding enclosures to offer protection. The flybridge, thus the helm, remains cut off from the vessel, which makes communicating with the crew a challenge.

It provides great visibility.
It offers comfortable spacing.
It might be unsafe to move from the cockpit to the flybridge in bad weather.
It isn’t easy to communicate with the crew.

Daggerboards vs. Fixed Keels

Average cruising catamarans typically utilize fixed keels while high-performance cats have daggerboards . Fixed keels allow you to beach your catamaran easily, and your hull remains intact if a collision occurs. While you lose some angle when sailing upwind, you gain more interior space in the hulls that you can put to good use.

Daggerboards are essential in a performance cruising catamaran since they guarantee that the boat delivers good upwind sailing, including during difficult situations. During long passages, they allow you to point better upwind though the drawback is that they consume much interior space within the cruising catamaran’s hulls.

Since flying on foils ( hydrofoils ) isn’t that practical on cruising catamarans, designers of larger-sized boats have also come up with modified daggerboards. These daggerboards produce lift and prevent leeway, too, thereby improving performance significantly, as seen with the Catana 59’s curved daggerboards. These foil-like daggerboards lift the boat ever so slightly upon reaching higher speeds, making it feel less heavy and much faster.

At the end of the day, calculating the performance of a boat sailing in a wide range of varying seas and winds might not be easy – despite a daggerboard or fixed keel configuration. This is because upwind speed depends not only on the sails’ quality but also windage and the height of the bridgedeck beyond the water.

The design innovations -curved daggerboards and hydrofoils- improve catamaran performance significantly.
Daggerboards enable you to access otherwise inaccessible anchorages.
Daggerboards take up hull space in the hulls of your vessel.

Galley Up vs. Galley Down

Galley layout are becoming more and more important as more people, including families, start sailing regularly. While at sea, your galley needs to be a safe place, well-ventilated, and functional. Everything should be well-thought-out for the sailor’s comfort, including handholds to make it safer to move around the boat.

While the galley location can either be up the bridgedeck or down in the hull, galley up appears to be the most popular trend. This makes the galley the focal point of both the living space and entertainment areas.

If you have a family, this placement is ideal since you make your meals from the galley and get to spend most of your time here. Many cruising families and couples prefer this arrangement and find separating the galley down the hull unappealing. Besides, carrying hot food up and down the staircase is unsafe.

Still, galley down is ideal for charter boats since it offers a private cooking area and uses up hull space efficiently.

Having the galley on the bridgedeck is ideal for families and cruising couples.
Placing the galley on a similar level with the serving area and cockpit is safer and less tiring.
There’s better ventilation on the bridgedeck, making for comfortable cooking.
There’s less kitchen privacy galley up.
On smaller catamarans, this layout can impact the size of the saloon seating area significantly.

Production Catamaran vs. Custom

The choice of either a production catamaran or a custom design might seem pretty straightforward. Production catamarans from major brands come backed by proven designs, dependable construction, solid warranties, and many years of experience. The catamarans are easy to service, source for parts, and most – particularly the owner’s versions – hold on to their value, making them much easier to resell.

On their part, custom boats are fantastic in that you can tailor them to your exact needs. However, they might be more challenging to maintain or service. That’s because of parts unavailability and lack of construction knowledge.

Choose Quality Construction Materials

The best quality materials to use on your catamaran are both light and robust. While carbon fiber is great, plywood, plywood/epoxy, and strip-cedar are excellent materials too. What’s more, they are also affordable, so you don’t have to get too hung up on cutting-edge building materials. What matters is build quality; thus, a well-built plywood catamaran boat can last as long as a boat made from more high-tech materials.

Combining various materials also helps combat some of the issues that plague plywood boats in terms of resale value. At times, the design tends to make the boats appear pretty dated.

Plywood and strip-cedar materials are affordable and provide excellent build quality.
Plywood boats may have a lower resale value than those built with modern materials.

Consider Ease of Handling

An important factor in handling a cruising catamaran is deck layout. Most cruising catamarans sailed short-handed , so if your boat has one helm, all lines should run back here to allow for a static control station for the entire boat.

The other essential element is visibility from the helm. The 360 degrees of visibility while maneuvering, docking, or underway is crucial to your boat’s safety, as well as life and property. As such, you should be able to view both bows, or at least the pulpits and sterns, while standing at the helm. If not, you may have challenges handling the boat due to blind spots.

Consider the Load Carrying Capacity

A well-designed catamaran is enjoyable to sail in all weather conditions. It’s also much easier to handle than a monohull because of its widely spaced twin engines. But when you immerse extra hull depth, the vessel gets sluggish and moves slower, maneuvering in tight spots or when docking becomes more challenging. Furthermore, the hull submersion reduces bridge deck clearance, leading to hull slamming.

To allow for adequate load carrying capacity, you need a design that provides a generous displacement. This helps to ensure that you maintain reasonable bridge deck clearance even when fully loaded. It also allows you to avoid digging big holes in the water as you drag your transoms.

Displacement refers to the amount of buoyancy designed into the hulls, which essentially means that your boat will cruise better if its weight is less than your designed displacement.

Note that an overloaded catamaran not only loses out on performance but eventually, on safety too. To counter this, choose a lightweight catamaran with hulls bearing cored construction and interiors made of lightweight materials.

Remember, when you go cruising, you will need to carry fuel, extra water, supplies, equipment, and amenities, translating into thousands of extra pounds. Therefore, try and avoid the following design errors to ensure that your catamaran has an adequate load-carrying capacity:

Avoid putting in place too much accommodation space.
Avoid building a heavy boat ‐ use low-tech construction materials.
Avoid installing inboards in a small boat.
Lightly constructed catamarans perform faster and carry more weight.
Cored construction makes for a strong and stiff catamaran, thus enabling good performance.

Final Thoughts

A well-designed cruising catamaran is a joy to behold. Today’s modern technological advancements mean that you can buy or build a light but strong cruising catamaran. And as you can see from this article, there are many excellent cruising catamaran layouts that you can choose from.

However, whichever layout you decide on needs to fit your sailing needs and purposes to ensure you remain comfortable and safe while at sea. Above all, ensure that you go for a vessel that you can handle with ease in all weather conditions.

Owner of CatamaranFreedom.com. A minimalist that has lived in a caravan in Sweden, 35ft Monohull in the Bahamas, and right now in his self-built Van. He just started the next adventure, to circumnavigate the world on a Catamaran!

Time For a Catamaran Adventure

Isn't Time For Yours?

Building Your Own Catamaran

Building your own catamaran is another option to getting into your own boat. In this page we will go over the advantages, considerations, and a detailed history and journal of our boat-building adventure with Light Wave . We hope this will give you a clear picture of what lies ahead if you go this route, including:

Construction methods
9 essential design features
Review of the four leading catamaran designers for home builders
Construction times
Budget: How much did it cost to build a basic cruising catamaran?
Layout of our catamaran, LightWave , and lots of pictures
Carllie’s article from September 2000 Multihulls Magazine: “The Boat Builder’s Wife “
Equipment outfitting
Radio and communication outfitting
Dinghy selection and considerations
Having a boat custom-built for you

Because of the huge dollars needed to buy a new or even a used catamaran, we would never have gotten a catamaran if we hadn’t built it ourselves.

Let’s start by saying that building any type of larger boat, especially a catamaran, can be one of the most intellectually and physically challenging things you will ever do.

It has been said that building a large boat is the closest a man can come to giving birth to a baby. In other words there is going to some discomfort and pain along the way; you will question yourself on whether this was such a good idea; it’s very difficult to reverse the decision; and though friends will support you, you will be on your own most of the time with your significant other if he/she is game.

Know your boat

You will intimately know every part of your boat. You will know where every wire, hose, bolt, bulkhead, rib, and support is because you installed them!

Pride of ownership

We have often thought what it would be like to just buy a boat from a manufacturer, and know that while owners who have spent a lot of cash (or future life to pay off the lien) their often possessive and competing-with-the Joneses could not begin to compare to our quiet glow of happiness and akinship we feel with Light Wave .

Our boat is like part of the family. So much time was spent on her that we have a major emotional investment. Every time we see our vessel – from a distance at anchor or approaching her in our marina, we say, “What a pretty boat! I can’t believe we built it!” Then that sense of accomplishment settles back in and we feel we have indeed earned the privilege of all of the beautiful experiences we have had sailing, cruising, exploring the beautiful BC Coast and much further a field (or should we say “an ocean”?).

You will be able to pay for the materials as you go and “donate” your time to the cause.

Get a newer design

Many of the production boats that are out there are designs of many years ago because the manufactures have to recoup their capital investment on the mold and production setup. When you build your own you have much newer designs to draw from.

Details on Our Boat Building Adventure

We had sailed our first boat Wave Dancer for five years and had many adventures on the British Columbia coast. In May 1996, I had just returned from a little one-week solo trip in the Gulf Islands of BC when I bought the book, The Cruising Multihull by Chris White (Future link to book review on our web site).

This is the book that got me going (Carllie was not yet convinced). I must have read it a half dozen times over the next 6 months, each time becoming more convinced that this was the way to go for our next boat. It was really still pre-internet web site days so I wrote to all the designers that were listed in the back of the book. Over the next several weeks packages of information started appearing in the mailbox (there is just something about getting packages in the mail – I guess it’s the anticipation). I would pour over these preliminary printed pages with pictures and accommodation layouts. Next, I put a few dollars down to buy the information packages and study plans from the top prospects.

I waited patiently for the study plans. It was like the night before Christmas when I was kid. Oooh the wait! Finally they came, and again I carefully scrutinized the next level of detail. Things were getting a little more serious. The top contenders were:

Richard Woods
Chris White
James Wharram

Click here to read my comments and reviews on their catamaran designs as well as those of Jeff Schionning.

I remember initially drooling over the Atlantic 42 by Chris White, still one of my favorite designs. It seemed to be so seaworthy (by the way if I run into about $800,000 USD any time soon, I am going to buy an Atlantic 55). The most important piece of advice that came out of the material was from Richard Woods:

“Build the smallest boat you‘d be happy with it.”

Axiom #1: The hours to build a catamaran is in almost in direct proportion to its weight.

Which brings us to Axiom #2:

Axiom #2: It takes about 1 hour to create 1 pound of finished boat.

In our case we spent 3,500 hours ( click here for full details on the construction hours ) to build a 4,000 lb. boat (just a little less than 0.9 hours per pound). If a boat’s empty weight is 8,000 lbs., it will probably take about 6,000 hours to build.

When you think about it, you can only mix and handle so much material per hour. More boat weight, more material, more hours. Sure there are some economies of scale on a bigger boat, but usually the systems become more complex and these take longer to install.

This decision process took 8 months and I figured we’d launch in 6 months. It was now January of 1997. Little did we know it would be 26 months and 3,500 hours between the two of us until we launched on June 5, 1999. We ordered the full plans and we were off and running.

We were ready to build, but where would we start the process? First of all, we live in a tiny 480 sq. ft. apartment in Vancouver. Back-yard building wasn’t exactly an option so I found a small garage nearby that we rented for 5 months.

After about 4 months in the garage, I had made all the small parts and it was time to build the hulls. This meant that we had to go larger facilities. We found space at Shelter Island Marina and Boatyard in Richmond. This is the biggest boat yard in the Vancouver area with dozens of commercial and private projects, big and small, under way.

We were out of money by then, so we sold our first boat so we could buy resin and fiberglass. It was a traumatic time as we said goodbye to our beloved Wave Dancer . We were now committed. We than had all the foam for the hull cores, barrels of resin, and huge rolls of matting and roving needed for the fiberglass skins delivered to our “domed stadium”. We kicked ourselves many times that we didn’t take a picture of this raw material stacked in one corner of the empty shed, so we could later show “before” and “after” photos. It was time to build the hulls.

Over the next several months we proceed to join the hulls with the beams I had built in the garage, and then to install the cuddy cabin, cockpit, and decks. By the spring of 1998, it was staring to look like a catamaran. Through the spring and summer of 1998, we continued with the major structural components: mini-keels, hatches, stairs, and interior. Then we went on to the very laborious work of fairing the boat before painting. Don’t under estimate that job!

By October 1998 we were ready to prime the boat and start painting. I really thought this would go quickly. I forgot that I would have to do two more complete sandings to sand off and finish the two layers of primer application. In addition we had to fill countless pinholes – a laborious process somewhat like hiking up a mountain – each time you get to what you think is the top, you see another summit!

The boat seemed to get bigger and bigger. Believe me, there is a lot of surface area on a catamaran. I clearly remember that last sanding: I had reached the end of my physical and mental endurance – I was exhausted. I was ready to move on to the next phase – any phase but more sanding!

We now started spray-painting the hulls bright yellow. It was around this time we decided on our boat name of Light Wave . The painting took over a month: the hulls being the easy part, it was the topsides, the nonskid, and all the masking and prep that seemed to take forever. Happily, the worst of the dust was gone.

By March 1999 we were in the home stretch. The center bridge deck cabin was completed so we took a week off from our paid jobs and lived on the boat in the shed so we could work all day and not waste time commuting. March, April and May were frantic months as we finished all the final touches: engine installation, rudders, windows, deck fittings, electrical, plumbing, mast, and rigging. See our outfitting page (for more details on what we picked and why, and things we would do differently now.

Initially, our electronic systems were relatively basic but included GPS and autopilot see the following link for all our electronic outfitting choices and reasoning for more details.

It was May 22, 1999 and we decided that Saturday, June 5th would be “Launch Day” so we could send invitations to all of our friends. On the Friday night before Launch Day, we still had a number of final things to do, many of them outside. Unfortunately it was pouring rain. We were tired and very wet but the boat had to go into the water next day so we persevered on till everything was ready.

The moment of truth came as Light Wave was lowered into the water. While still in the slings of the Travelift, I jumped aboard to check for leaks. Of course there weren’t any! More food and laughs and tours of the boat for all attending. It was a great day.

Emotionally drained that night, we slept in Light Wave in the water for the first time. It was another week before we actually went out for our first trip as we had to sell the shed, setup sails, and install some final deck hardware.

To sum it up, building a catamaran was a great experience. We learned a lot. Carllie and I grew closer together through it all. We had a great time doing it. We had a beautiful catamaran to show for it. Now it was time for a catamaran adventure !

[email protected]

Schionning Designs International Pty Ltd Leaders in Multihull Design and Kit Development.

Category: Our Catamaran Build Kits

Recommended equipment.

Quality suppliers & manufacturers

The schionning team have a lot of contact with equipment suppliers and manufacturers, and hear feedback on certain brands or systems from our many customers. there are many schionnings cruising the world and testing products longevity and the customer service offered by the manufacturer., on this page we will list products and companies that we know to provide above average quality and service. it is always growing, and if your company provides equipment used on our designs and you would like to be included - please contact us., engines & drive systems.

Schionning recommend equipment of Oceanvolt Ltd HYBRID AND ELECTRIC MARINE POWER AND PROPULSION SYSTEMS

Visit: https://oceanvolt.com

Batteries, Power Management

LITHIUM POWER (VIC)

Back in 2013 I knew that my boat batteries were reaching the end of their lives, I had been researching LiFePO4 cells for a few years and decided that I should install them. Unfortunatly I was unable to find a local supplier. So Lithium Power was established.

Technical Information

The technical information page is a collection of documents (mostly in pdf format) on the materials and systems used in schionning catamarans. including data sheets, engineering information, strength comparisons of each core material and informative articles from jeff outling the design of certain system such as engine choices and main sheet systems., detailed engineering data for your research, we understand that getting your head around the process of building your own boat, or having one built, can take a little while. to gain a greater understanding of the materials used in our designs, the below data sheets have been supplied by atl composites, and contain all of the technical data you could need regarding the composites we use. in addition are articles or documents written by jeff about certain systems used on our designs and why., all technical information and data sheets on west system/duflex/durakore provided courtesy of atl composites. for more information please see the atl composites website here., documents library.

Information Sheet – CE CERTIFICATION PROCESS

Mainsheet Systems for Catamarans
Motor Choices for Schionning Designs
Weight and Weight Distribution Schionning Designs
Schionning Designs Sailing Performance and Tips
Hull Shapes and Performance – Power Designs
Outboard Engines VS Diesels – Written by Ross McCombe
An Outboard Installation That Works – Ross McCombe Follow up
Data Sheet – DUFLEX BALSA for Catamaran Kit Builds
Data Sheet – DUFLEX FOAM
Data Sheet – FEATHERLIGHT Paper Honeycomb
Data Sheet – WEST SYSTEM R105
Data Sheet – PUMP SYSTEMS
Data Sheet – MICROFIBRE BLEND 403
Data Sheet – MICROLIGHT 410
Data Sheet – MICROSPHERES 411
Information Sheet – USING FILLERS
Data Sheet – KINETIX RESIN Thixotropic
Information Sheet – DURAKORE PLANKS 413
Data Sheet – DURAKORE PLANKING 414

Kit Materials Contents

Kit materials' contents, so if you order a schionning kit, what exactly is going to arrive see an overview of the materials you will receive, and what each is used for during the build process. fibreglass cloth or tapes microspheres, microballoons or microfibers take a closer look and you can answer these questions., our schionning kits are a no nonsense, common-sense approach to building a boat. we offer great service, fast delivery and access to anything you could need for your boat straight from the supplier to your door. our construction plans and kits are sold with 100% professional boatbuilder support via phone and email, any time you're unsure or just need a second opinion, we're here..

Our kits contain all of your basic materials to build your boat to a faired shell stage, ready for painting and fit-out. We have sail-away costing estimates available for all of our standard designs, and this will give you an accurate idea of the overall cost of your project. This costing varies depending on your level of finish, as you can imagine different options vary greatly in price.

Below is a quick glance at what your Schionning Kit will include and what each item is primarily used for, we hope this is helpful and if you should require more detailed information please don’t hesitate to contact our office.

What do I actually receive?

Superlight Balsa - End-Grain Balsa - Foam - Paper Honeycomb - Western Red Cedar - SDI - End-Grain Balsa - 150kg per cubic metre Paper Honeycomb - 50kg per cubic metre Superlight Balsa - 94kg per cubic metre Western Red Cedar - 360-380kg per cubic metre - Foam

DUFLEX PRE-LAMINATED PANELS

DuFlex pre-laminated panels are the main and most important material used in our kits, predominantly in the flat panel designs, however they are used in Strip-planked designs also, though to a lesser extent. These panels are 2400mm x 1200mm and are CNC routed to speed up build time on our Wildernes X Series, as well as some of our power designs. For internal furniture, a paper honeycomb core is used instead of the end-grain balsa wood core that is used for main structural areas. The use of this is purely to save weight in the shell and therefore produce a faster, more responsive catamaran.

KINETIX LAMINATING RESIN & HARDENER

Resin Choices for Catamaran Kit Building by Schionning Designs SDI - We choose ATL Composite's resin systems for their superior quality, reliability and value for money. West System Epoxy Resins

WEST SYSTEM EPOXY RESINS

FIBREGLASS TAPES (DOUBLE BIAS)

CARBON FIBRE CLOTH

FIBREGLASS CLOTH

The kit process, building your own boat can be a daunting prospect, however to demonstrate each step in the kit assembly process, we've created this guide for you to study. as you can see our kits are the ultimate in building efficiency and have been streamlined over 30+ years to ensure that you're on the water faster and with less effort., how does it all go together.

Schionning Designs Catamaran Kit Build Process - Step 1 The first step to building your dream catamaran begins with a strongback - this is a square frame used to position the temporary frames that will be used to form the hull shape. This frame will be set up and must be square and accurate, a string or laser level can be used to achieve this.

The first step to building your dream catamaran begins with a strongback – this is a square frame used to position the temporary frames that will be used to form the hull shape. This frame will be set up and must be square and accurate, a string or laser level can be used to achieve this.

Step 2 pre-cut frame panels are erected along the strongback in sequence - catamaran building step 2 SDI

The forebeam is now installed along with the striker attachment fitting, as shown above. The bridgedeck is installed shortly after and taped onto the bulkheads with webs installed, this now completes what is a quite stiff and strong platform to work on.

Step 8 catamaran kit building - forward webs and dash will be fitted - SDI

Now that the bridgedeck is in place, the forward webs and dash will be fitted. At this stage, all furniture and internal work begins, with the main panels left off for ease of access when working.

Catamaran Kit Building Processs by Schionning Designs SDI -Step 9 The internal furniture is now installed, if you chose Kit Option 2, this furniture will be pre-cut to your previously decided upon layout. If you chose to receive blank panels, this is the period in which your internal living areas are to be built. This construction uses paper-honeycomb Duflex panels, as these are superior in weight when used non-structurally. Cabin soles, engines and daggerboard cases are also now installed.

Material Choices

Schionning material choices, solutions that work best for catamarans & why, our designs are based on cored composite construction techniques using west system epoxy resin and knitted fabrics. but given the range of today's composite technologies, which solution works best for catamarans and why written by jeff schionning, selecting the correct materials, resin choices.

It also fully protects the boat against water absorption and it can not develop the dreaded Osmosis.

We choose ATL Composite’s resin systems for their superior quality, reliability and value for money.

Having worked closely with the ATL Composites team and their products for many years, we know we can stand by their material solutions, and rely on great service should something unexpected happen.

This may not seem important but when working with a material for an extended period of time, the small things make all the difference.

CORES Which One to Use?

End-Grain Balsa – 150kg per cubic metre
Superlight Balsa – 94kg per cubic metre
Western Red Cedar – 360-380kg per cubic metre
Foam – 80kg per cubic metre

BALSA END GRAIN (150 kg/cubic metre)

Balsa has very good values and we can produce a shell using a very light laminate. It will be very stiff and very resilient to fatigue.

It has exceptional qualities including very high compression strength, extremely good sheer capabilities and fantastic sheer stiffness.

Compressive strength is the resistance to collapsing when pressure is applied perpendicular to the surface as when pushing directly onto the material with the point of your finger. Balsa is far stronger than Foam (80kg/cubic metre) in compression.

Balsa is also very strong in shear. This is when the core sample is held flat between your hands, one hand slid one way and the other slid the opposite way, when the core tears through the middle the core has failed in sheer. The amount of stretch you feel before the core shears is shear stiffness. To compensate for sheer weakness the core is made thicker. So 13mm Balsa may be equal in sheer to 19mm Foam.

(80 to 200 kg/m³)

There are many boats sailing that are built from foam as it’s mechanical properties are good for boat building.

Initially one would expect this cat shell to be lighter as it is ½ the weight of Balsa. We do have to compensate for its weaknesses and will then add to the reinforcement the reinforcement on the outside to spread that compression load over more core and need a triaxial type weave to compensate for the veneer content that runs fore and aft on the Durakore.
Secondly, we need to increase the Core thickness to compensate for the shear value, usually neutralizing the weight advantage.
We only use structural foam core that is closed-cell and cross-linked.

The end result using foam core amounts to a very similar total boat weight. Professional builders can achieve a good result but usually use vacuum bagging and very good molds to achieve this.

Secondary Issues

Balsa can absorb water. It needs extreme neglect to rot (very unusual). Water soaks along the end grain quickly. It travels very slowly across the grain. We use balsa under the waterline especially because of it’s high compression strength for beaching etc. any core type must be sealed. Damage to all cores results in the same sort of repair. Notice a damp spot remaining when drying out to anti-foul… simply grind back the surface glass exposing the core, dry it out and re-glass – it’s that easy.

Timber cores are cheaper than Foam in most cases.

A light, high tech cat returns a far better (often 2 – 3 times) re-sale than lower tech materials. Often saving $10,000 on materials initially, loses $200,000 on re-sale – a serious reality.

Our boats can be built using Balsa, Foam or Western Red Cedar. Combine strength, stiffness, lightness and cost, with ease of use – it just makes good sense!

The designs where there is a YELLOW BACKGROUND are the designs for which CUTTING FILES are available.

SEE STUDY PLANS FOR NEW LARGE FLYBRIDGE VERSION.

for additional information

HOME / INDEX PAGE

James Wharram Designs

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Self build boats.

A philosophic attitude behind the Wharram designs is that 'urban man' can, with a little financial saving and some handcraft work, create an object of beauty. This object of beauty can then, for a period of hours, days, weeks or months, carry him/her out of the urban world into a natural never-never land; the seas and oceans; to a time when the world was young; when Mankind was directly and intimately interacting with the beauty and power of nature. There are hundreds/thousands of Wharram builders or, as I prefer to call them, "Sea People", who have done or are now doing that!" - James Wharram

A well built Wharram design is a 'Functional Kinetic Sculpture'" - Hanneke Boon

Everything you need to build your own sea-going catamaran: 3 steps

Familiarise yourself with our range of designs and their unique qualities. For more detailed information read the Wharram Design Book which reviews each self-build boat model and offers a detailed introduction and understanding of the world of self-build catamarans.
Order one or more sets of our Study Plans and immerse yourself into the boat builder's mindset; evaluate the costs; the amount of time required to build your boat; where you will build it and where you will eventually launch it.
Once you have decided on the boat that is right for you to build, order the Boat Building Plans and become a member of the global family of Wharram builders and sailors. You can build a Wharram with very little experience . All Wharram building plans are drawn for the first time builder, so anyone with a modicum of practical ability can build one of our designs. Our Building Plans present quality instruction, guidance and advice for both novice and professional alike. They are all based on decades of actual building experience and thousands of ocean miles sailed, so you can be confident in your boat's capabilities and safety.

Tiki Designs

Tiki 46 sailing on a coast of rolling hills, with all sails up.

Coastal Trekkers To Long Term Live Aboards

From the car trailable Tiki 21 - winner of the 1982 Cruising World Design Competition, to the Tiki 46, a spacious ocean cruiser or charter boat, the TIKI range offers car trailable coastal trekkers to long term live aboards . Although a Tiki 21, a very popular coastal trek design, has circumnavigated, we would not recommend this for everyone! A number of Tiki 26s have also made ocean crossings, but again this is only for the experienced sailor. The larger TIKI designs of 30ft and over are craft capable of longer voyages and ocean crossings. They are designed to be less costly to build by using appropriate wood/epoxy technology and by eliminating, wherever possible, expensive metal fittings common to modern yacht design.

On the larger TIKIs the 'Deckpod' offers sheltered steering and the 'Stern Ramp' provides easy access to and from the water. The TIKIs are boats you can work and live on. The Wharram approach goes beyond simple boat design - the concept of 'Flexispace' puts emphasis on not just the physical living area, but also the 'mind space' of those on board.

Hitia Designs

Three Hitia 17s with colourful sails on the beach

Affordable Weekend Adventure Boats

The Hitia Designs are the perfect beach catamarans . They are 'coastal trekkers' and cater for those who do not want a craft for long distance or "blue water" sailing, but would like to be able to trail their boat to varied interesting coasts and lakes. Their easy economical construction, stability and speed makes for affordable weekend adventure boats . The Hitia 14 can be carried on the roof of your car and fits on the deck of a larger boat. The Hitia 17 has more stowage space and room for a tent on deck for longer excursions. These boats are ideal for small adventures and coastal treks.

Introducing: the Mana 24 'Cat Kit'

Boat In A Box

The MANA kit is sold with all the plywood cut out by CNC cutter and pre-coated with epoxy, so building the boat at home will be a bit like assembling a flat-pack . All the parts slot together perfectly so a hull can take shape in a day. Building from such a kit takes away the worry of measuring and cutting all the boat parts , which can be quite daunting to many first time builders and saves a lot of time in the early stages of building. In designing the MANA, we looked sideways into the world of camping and have combined the innovative CNC cut "flat pack" boat-building concept with the philosophy of outdoor living to create the unique MANA camper-sailer, specifically designed for trailer sailing.

The ply parts will have a first smooth coat of epoxy already applied, cutting down time in coating and sanding, so within a short time you will be able to assemble the hulls and see the boat you are building. As she is built from a pre-cut kit, we have been able to give the Mana more complex and beautiful shaping, giving her more interior volume than the Tiki designs.

Pahi Designs

Distant photo of Pahi 63 Spirit of Gaia with all sails up

The More Evocatively 'Female' Of The Wharram Designs

From the Coastal Trekking Pahi 26 to the impressive 63' flagship of the Wharram fleet 'Spirit of Gaia' - the PAHI shape is more evocatively 'Female' than the Classic Wharram designs. They are a different visual/sculptural approach to the basic design elements inherent in the Classic Designs. Constructively, they are simpler to build, using epoxy fillets instead of more difficult wood joints . They are designed to use quick growing softwood plys, coated and glassed with epoxy to achieve a durable finish. The PAHI designs were the first to use rope lashings to attach the crossbeams, giving a shock absorbing effect, without the need for metal fittings. 'Pahi' in Polynesian dialects means 'ship'.

The Pahi 42 'Captain Cook' design set fresh ocean cruising standards when she was designed in 1979. The Pahi 63 was designed in 1986 and launched in 1992 to become the new ocean going flagship for the Wharram family. During the construction of 'Spirit of Gaia' many unique new solutions to plywood and epoxy building methods were developed, which were later incorporated in the larger TIKI and ISLANDER designs.

Ethnic Designs

Amatasi being sailed by two people, deck view from stern

Traditional Pacific Sailing Craft

The Ethnic designs have been a new development at James Wharram Designs since James and Hanneke sailed extensively in the Pacific. With everything self-made these boats are lower cost to build . They cater for those who want a "traditional" Pacific sailing craft, built using appropriate modern materials and methods, but without trying to Westernise them. These designs arose after requests from Pacific Island peoples for James to design craft to overcome shortages of "traditional" building materials, but which closely reflect the cultural and ethnic origins of these craft.

Classic Designs

The Early Wharrams - Sturdy and Stable

The early 'Wharrams', now known as the Classic Designs, are recognised as beautiful, safe boats - easy to build, and easy to sail . Many anchorages around the world are graced by these Classic Designs, and of the seventeen drawn between 1957 and 1976, nine are still available, from the 16ft Maui to the 51ft Tehini. They were the first range of Wharram catamarans, designed in the 1960s and 70s, based on the sea experience of James Wharram's pioneering ocean crossings. They are sturdy, very stable, but relatively basic in design. They are built using simple plywood construction over a backbone and bulkhead frame .

BUILD YOUR RAKU CAT WITH A DuFLEX KIT BY FOLLOWING THESE NINE BASIC STEPS

Step 1. Kit Design

Work with us to finalise the details of the design you have chosen including any design options or additional modules to be included in the kit.

We will determine the laminates, the number of panels required for each laminate, create the cutting files and prepare a quote for the kit if it is not already priced.

Once the design details and pricing are confirmed you are ready to place your order.

Step 2. Unpacking

2. The kit arrives at your workshop door, usually by container, as a stack of 1.2m x 2.4m routed composite panels ready to be joined. The shipment will normally include additional reinforcements, resins, and ancilary products as specified.

Unpack the shipment and stack the panels out of the way of the space where the panels will be joined.

If you have purchased a joined kit many of the panels will already be joined up to the length that can be shipped in a container (12m).

Step 3 Joining the Panels

Set up the work space where the panels are to be joined.

The panels have a scarf join called a Z join that facilitate the join without needing tapes.

The joining can be done with a heated Z press that cures the epoxy join quickly. Alternatively they can be joined with clamping pressure.

If the panel are are being joined with the Z press you will need an elevated work bench the full length of the longest panels you are using. (image below).

If you are joining them with a clamping technique the space can be on the factory floor.

A nesting booklet is provided with the kit to show how the panels are joined (right)

Joining the panels with clamping pressure

Panels are being joined into a single long panel by painting the surfaces of the scarf join with epoxy screwing through plywood battens that have a release film applied to one side.

Joining the panels with the Z Press

Step 4 Stacking Joined Panels

Once the joins are cured the panels are stacked to one side until they are needed for the job. The inividual parts should not be cut free of the panels until they are required.

Bulkhead and floor panels will be needed before the hull sides and cabin top so they should be left to the front of the stack wherever possible.

Diuflex Kit Construction Header image step 5.

Step 5. Separating the Parts

When assembly is ready to begin the individual parts are separated from the panels by cutting the joining tabs. It is likely you will be building onto moulded hull bottoms that have been built from strip planking or another method of building moulded components. The process for building moulded components is described in another article.

Step 6. ASSEMBLY

As the joined panels are assembled onto the job you will need to apply glass tapes to the joins as specified in your plans.

Panels can be surfaced and coated inside and out with high build while they are on the workshop floor to minimise fairing time once they are assembled to the boat. The paint on the panels shown here has been kept back from the edges to provide a good bond for the tapes.

Duflex Kit Construction Assembly image-01

Smaller items such as steps, seats and dagger cases are nested into the kit and for the more complex parts diagrams are provided to assist with the assembly process.

Duflex Kit Construction Header Image Step 7

Step 7. Interior

Interior kits can be ordered with the primary kit, or they can be ordered later when final decisions have been made about the interior arrangement.

A compromise solution is to order the interior as a set of plain planels that can be cut to shape on site after finalising the layout.

Step 8 Fairing, Painting, Hardware Installation

8. The DuFLEX construction process goes a long way to minising the amount of fairing that has to be done, but inevitably any boat that has not come out of a female mould will require some level of fairing and surface preparation prior to painting.

The fillers and resin systems required for the fairing work are normally supplied as part of the kit.

Hardware installation is the same as for any other form of construction using high density core inserts or consolidated laminate in way of fittings.

Step 9. Sailing

Go Sailing. This Barefoot 40 Catamaran was built entirely with a Duflex kit in Foam/Glass and Epoxy resin systems from ATL Composites

DuFLEX Kits are manufactured and supplied world wide by ATL Composites

atlcomposites.com.au

And in Europe by VDL Composites

www.vonderlinden.de/her/28/vdL-Composites-GmbH

For more information on DuFLEX and associated Products

atlcomposites.com.au/category/27/DuFLEX

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Open Source 13-15m Catamaran Plans

Discussion in ' Projects & Proposals ' started by archie1492 , Jan 3, 2018 .

archie1492 Junior Member

Dear all, I want to create a detailed building information model for a 13 - 15 meter catamaran that is capable of being CNC cut and assembled. I need some help finding plans I can use as a basis of design. Specifically, I need the hull profile information. Section cuts through the hull will give me the ideal contours for a boat of this size. Can someone help? After weeks of searching, I still cannot find these online. For now, this is merely an exercise in my 3d modeling capability. I'd like to share my drawing work with the forum if I can get some assistance to start off. There are future possibilities I am also considering. I'm an experienced Architect & construction designer with a strong background in computer aided design. Once I've modeled the boat in 3d, I would like to flatten the various parts and create plans for the individual boat parts to be CNC cut. I would like to build a small scale model first (1:2o or perhaps 1:10) with the ultimate goal of building the boat full scale.

TANSL Senior Member

This is a very simple catamaran which, if you are interested, I can give you a lot of information. It is not a spectacular boat but it can help you in your first steps with boats. LOA = 16 m, Lbp = 14.6 m

Thanks I really appreciate it. The hull lines for the motor cat you've provided are not quite what i'm looking for. I'm specifically looking for the hull lines for a 14m catamaran sail boat. I guess there is some standard for these contours especially the area below the waterline. Check the attached document as well if anyone is interested in this.

Attached Files:

catdimension.pdf

I'm sorry, you never specified that it was a sailing catamaran. I thought that to carry out your purposes, " For now, this is merely an exercise in my 3d modeling capability ", any model was valid. Apparently, you have different purposes than, in addition to, to practice with 3D models. The better you clarify what you are really looking for, the better someone can help you.

Hi all, Here's an example of what kind of information I need to get started. Optimising Hull Lines for Performance https://www.graingerdesigns.net/the-lab/optimising-hull-lines-for-performance/ The boat shown here is a 8.5m cat sailboat. I'm looking for something a bit larger in the 14m range. Also, the images only show one of the hull profiles. I'd like profile lines for the entire boat. I will post some other images I've found online showing profile lines for smaller boats. I still cannot find any 14m hull lines. Can anyone help?

grainger_1488019480.jpg

Grainger_1488019410.jpg, grainger_1488019333.jpg, grainger_1488019265.jpg, grainger_1488019219.jpg.

Here are some other hull lines I've found online. Hope this is useful to anyone else looking for this information. Thanks!

Evergreen Lines small.jpg

Hull-lines.jpg, shark-20.jpg.

You could take any of those boats and scaleb the lines to get the desired length. Since it is only a 3D modeling exercise, you do not have to worry about anything else. You could even make a mix of 2 or 3 of those models to get the one you are looking for.

Thanks Tansl, I'd like to make the boat drawings accurate for the 14m size. Perhaps one day I will develop this into something worth building full scale. The more accurate I can draw the boat, the more I will learn about the boat design.

Maybe it does not look like it but I would like to help you. If you do not find what you want on the Internet I could draw a lines plan, strictly following your instructions, which would help you to make the 3D model. Or, if you find something similar on the internet I can adapt it to your needs and fill in the information that you indicate you need for your work. I insist that starting from the shapes of a 10 m boat you can get the shapes of a boat of 14 m, with total accuracy.

Dolfiman Senior Member

archie1492 said: ↑ I'd like to make the boat drawings accurate for the 14m size. Perhaps one day I will develop this into something worth building full scale. The more accurate I can draw the boat, the more I will learn about the boat design. Click to expand...

Cata 14m with Gene-Hull UE Catamaran 2.3_2018 01 15.ods

Gene-Hull Catamaran 2.3 User Guide_2018 01 16.pdf

Hull for cata 14m with Gene-Hull UE Catamaran 2.3_2018 01 16.pdf

Dolfiman, thanks so much! This is exactly what I was looking for. It's very interesting and probably a bit over my head at this point. I think this should work for modeling the basic hull shape. For the bridge deck and all of the stuff above the hull I can model this with a bit more creativity. Although, I'd like to learn more about understanding the center of gravity for the boat and the proper location of the mast. Are there any rules of thumb about this? Thanks again!

archie1492 said: ↑ I think this should work for modeling the basic hull shape. Click to expand...

Cata 14m V2 with Gene-Hull UE Catamaran 2.3_2018 01 15.ods

In complement to illustrate this first approach, my good friend Alain did some 3D views here attached of the hull V2 version with Multisurf (using fit for purpose ouput data in section 5. of the above file). To inspire you , some other examples of cata, more sport/day sailer oriented than the Saona 47 : - R/P 45 (Reichel-Pugh) : multihull http://reichel-pugh.com/tag/multihull/ - Dazcat 1295 : in this video, from 1:45 the launch, you can see the hulls from various angles https://www.youtube.com/watch?v=0BZF4Udda5E - SIG 45 (VPLP design) : from 1:20 you can see the winward hull fully lifted

dean 1962 New Member

archie1492 said: ↑ Dear all, I want to create a detailed building information model for a 13 - 15 meter catamaran that is capable of being CNC cut and assembled. I need some help finding plans I can use as a basis of design. Specifically, I need the hull profile information. Section cuts through the hull will give me the ideal contours for a boat of this size. Can someone help? After weeks of searching, I still cannot find these online. For now, this is merely an exercise in my 3d modeling capability. I'd like to share my drawing work with the forum if I can get some assistance to start off. There are future possibilities I am also considering. I'm an experienced Architect & construction designer with a strong background in computer aided design. Once I've modeled the boat in 3d, I would like to flatten the various parts and create plans for the individual boat parts to be CNC cut. I would like to build a small scale model first (1:2o or perhaps 1:10) with the ultimate goal of building the boat full scale. Click to expand...

Archie, I have been looking to do the same thing. Where are you at on the project? Very interested in hearing all about it. Thanks.

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Plans and Kits for Catamarans and Proas and other Multihulls

Check out my page on Advantages and disadvantages of multihulls

If you're planning a boatbuilding project you might like to check my boatbuilding resources. These are articles from my website and some outside links and build diaries.

Multihull plans in no particular order

Email me if a link is broken or if I've missed a boat. I try to keep my links good but things change quickly on the web.

I try to include most plans that I run across. I only exclude the ones that seem to be dubious, some are plagiarized or some just seem to be of terrible quality, or a website that includes pop-ups or other nasty things, that I don't dare include them. I have not personally checked all plans. Before building, do your homework.

Bruce Roberts has aluminium and fiberglass boat plans for large Catamarans
Schionning Designs has plans and kits for Cats, Trimarans and a keelboat.
From Wooden Boat Magazine plans for a 20 ft Trimaran. Also a Sailing Outrigger Canoe
Kurt Hughes has both large and small Catamarans and Trimaran plans.
Sailing Catamarans has beach cats.
Woods Designs has small and large boat plans
K-Designs has Little Tri sailing trimeran dinghy and others.
Dudley Dix Yacht Design has a large cruising catamaran
Svenson's Free Boat PLans has an old Mechanix Illustrated Hobby Kat plans along with many other boat plans
Duckworks Magazine has a whole section of small sailing multihulls.
James Wharram Designs offers plans and will build also.
Tornado Building Plans free from The Beachcats.com
Hartley Boats has a few designs for sailing cats.
Applegate Boatworks has plans for Blue Joseph, a proa
Glen L Offers plans for La Chatte, sailing Cat.
Scarab Folding Trimaran Dinghy.
Selway Fisher has a design for simple Catamarans.
Slider Cat Ray Aldridge design from Duckworks
Gary Dierking is well known in the Proa community.
Chesapeake Light Craft has many designs, well thought out plans and kits. This is Junior outrigger.
Also from CLC 2 large proas Madness, and Mbuli
Novacat 17 Plans and build photo IN German, get mr. Google to translate.
From Svenson's popular mechanix plans Cats Paw free plans
Fyne Boat Kits has several multihull designs. He also offers add-on outrigger for canoes and kayaks.
Instructable for a Polytarp Crab Claw sail for a proa
A one day proa project Maybe not quite perfect but worth looking at. Here's another instructable sailing outrigger canoe
Angus Rowboats has a sailing conversion plan with outriggers.

Too Much Choice

There are a great number of large cruising catamaran and other multihull plans out there. I think one of the reason is that building a large catamaran is easier than building a cruising size keelboat. Many designers feel confident that the home builder has a good chance of success in putting together quite a competent multihull.

I have not included all the large multihull plans and kits I have found, nor have I included many of the home made single effort catamarans that are out there.

Boats topics
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I try to be accurate and check my information, but mistakes happen. ALSO keep in mind that not all boat plans are well designed. Old Banks Dories are particularly tricky because they were notoriously unsteady until they had some weight in them. Check the boat forums, many people have built dories. I have not built these boats and I can't recommend or proscribe any.

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Catamaran Construction – Hulls, Laminates, and Composites

Post author By BJ Porter
Post date October 15, 2020
4 Comments on Catamaran Construction – Hulls, Laminates, and Composites

It’s a given that catamarans are more sensitive to weight and loading than monohulls. Catamaran builders strive to build the lightest boats they can without sacrificing strength and stiffness, and have adapted new building techniques and materials to meet this target. Cutting weight allows more passengers and gear without sacrificing performance.

And the marketing materials reflect it–they load every review and website with polysyllabic technical jargon describing the design and production choices each builder made to deliver the best boat they can.

But when you’re reading a brochure and you come across phrases like “ hand laid bidirectional GRP ” or “ vacuumed bagged e-glass with vinylester resin over a Divinycell core ” do you know what that really means?

All modern production catamarans are made with “FRP” construction (for Fiber Reinforced Polymer). Composites aren’t new–it’s just using materials together to strengthen the whole assembly. Straw was added to bricks centuries ago, and steel reinforced concrete is a staple of construction over the last century. For boats, it’s the use of stranded fibers and cured resins which make FRP different.

The term “FRP” doesn’t get into the technical detail of which fibers and which plastics, and how they’re put together to build your hull. There’s a wide variety of fiber types which can be stranded, woven, chopped or sprayed in a varied of patterns then combined with several types of resins to make hulls with different characteristics.

Some FRP techniques produce lighter, stronger shapes, while others are quicker to build and less expensive to produce. The choice of technique is a function of many factors, from the number of hulls and parts to be built, the type of parts, the budget for the project, and many design specific requirements for weight and strength.

1. FRP Basics

The principle behind all FRP construction is the same – you lay our fibers in the shape you need, then saturate them with resin, removing all the air and voids you can. Resin is left to cure, then the piece is ready to finish and use.

The reality is more complex, since building a boat isn’t like making a flat board or a simple door. You’ve got a complex shape with a designed set of curves to build. “Tooling” is the set of shapes to make the boat parts; molds to cover with fiberglass to get the right shapes.

That’s what makes FRP so effective – you can make almost anything out of it. But to do so requires a lot of choices about what you need for the project at hand.

There isn’t a “best” all around material or technique choice for all jobs, and sometimes a lower cost technique or easier to work with material may be the better solution to the problem.

A. Fiber types

Fiber choices in the last few decades have expanded past the glass fibers used in the first mass produced boats in the 1960s. FRP construction wasn’t new even then, they built the first composite boats using modern fiberglass in the 1940s.

The major fibers used in marine construction fall into three categories – glass, aramids, and carbon. The primary differences are in the strength to weight ratios of the fibers, durability, elasticity, and cost. Some construction may use blends of fiber types to combine performance characteristics.

Glass – the most common material still, because of its low cost and versatility. The most common variety used in GRP (Glass Reinforced Polymer) is “E-glass” which refers to its strand size and mineral content. Other grades have different and sometimes better mechanical properties, but may be more expensive and less appropriate for boat building use. Fiber sizes run 10 to 25 microns for E-glass, though other grades may be smaller.

Brands like Leopard, Lagoon, and most higher production volume builders use E-glass.

Aramids – this includes brand names like Kevlar, Technora and Twaron. They have higher tensile strength than E-glass, and resistant abrasion and punctures. Kevlar is a common choice for bullet proof body armor, and can built a tough, lightweight hull. The materials can be difficult to work with, as it is very tough to cut the cloth. It is often blended with carbon fiber or other materials – Catana is known for using Twaron blends in hull construction.

Carbon – the ultimate in lightweight, strong construction material. Carbon fiber is the most expensive fiber, and is available in a variety of weights, grades and strengths. Fibers are smaller than glass – down to 5 Micron.

The lightest, most expensive hulls are made from carbon, but a catamaran builder may use carbon in places other than the hull to add strength and stiffness. Carbon boards, rudders, and reinforcing structures can enhance performance without driving the price of the boat beyond reach. Carbon is the fiber of choice for many custom builds, racing cats, and Gunboat.

B. Mats, Strands, Roving, Direction, and Weights

Fibers are woven into matting and cloth for construction. Depending on the application, different weights of cloth and cloth patterns and weaves may be more appropriate for the job.

Cloth weight refers to the weight per square yard (or meter) of the cloth. A square yard of nine ounce cloth weighs nine ounces. The heavier the cloth, the stronger it is in a laminate.

Fibers carry loads along their length, so cloth weaves have directionality to their strength. Most builders use several layers of cloth with different orientations to give good universal strength to hulls. Specific FRP applications with strict load-path requirements may have more unidirectional fiber layering – for example, a chainplate manufactured from carbon fiber may use unidirectional fiber.

Cloth – fiberglass cloth is commonly used on outer layers of composites. Cloth may have unidirectional or bidirectional strength. Bidirectional cloths have maximum load strengths in two perpendicular directions. Variations on weaves like a modified twill allow a more flexible cloth for better shaping around complex molds.

Mat – is omnidirectional strands of fiber compressed into a cloth. This is often held together with a resin soluble glue, which makes mat great at conforming to mold shapes without folding and bunching as it collapses when wetted. Because the strands do not align, fiber strength is the same in all directions.

Woven Roving – a heavier cloth made from larger bundles of strands. Woven roving allows for quicker buildup of material and strand weight.

Most FRP layups include multiple layers of different cloth and mat. Finished layers may be finer cloth over courser cloth, over woven roving and mat.

Three primary resins are in common use in marine construction – polyester , vinylester , and epoxy . All resins have materials safety concerns and require care in their use and handling.

Polyester is the least expensive and requires breathing protection because of the VOC emission (Volatile Organic Compounds…nasty, smelly fumes). It doesn’t have good bonding/gluing capability, and should only be used with glass fibers for structural building. Some polyester resins are referred to as “isophthalic” resins.

Vinylester is chemically similar to a hybrid of polyester and epoxy, and performs best with fiberglass. It shouldn’t be used in high strength applications with carbon or aramid fibers. It has some adhesive qualities which polyester lacks, it shrinks less during curing, and has better impact resistance.

The added strength of vinylester coupled with increased water resistance makes it an attractive option for many catamaran builders. It costs less than epoxy, but still has better performance than polyester.

Epoxy is the most expensive, but is three times the strength of the others. It offers the best adhesion and the only resin for building structural elements with carbon and aramid. It resists water intrusion better than the other resins, resists blisters, emits no VOCs, and shrinks less. The major drawback is it is more brittle if it takes an impact.

While epoxy is “the best” in terms of strength and ease of building, there are many applications where other resins are appropriate. Budget is a big driver – a boat made from E-Glass doesn’t need epoxy resin, and considerable cost savings to meet a construction price target may drive the choice.

They can build quality boats from all material combinations, but price and performance will drive materials choices to keep some boats more affordable.

2. Cored Construction

What’s the best way to make fiberglass strong? To a point, you can make it thicker. As it gets thicker, it gets heavier. A hollow shape can take more compressive load than a solid one of the same weight, and the same principle applies to fiberglass construction.

Consider an I-Beam used in building construction. It has the same strength (or more) as a solid rectangular beam of similar mass. The compressive load on the beam is supported by the outside edges of the material, the metal in the middle doesn’t contribute much to the strength. So we can remove metal to get the “I” shape while still keeping those sides rigid, making a lighter girder with less material.

The same principle applies to cored construction with fiberglass. Making a sandwich of two layers of fiberglass with a light core between them allows for the greater strength with weight savings.

There are drawbacks – the biggest risk is damage which breaks the skin, which can let water into the core. Earlier cored construction used materials prone to saturation and rot if they got wet. Some builders opt to do cored construction above the waterline and solid below to minimize some of these risks.

But the advantages in weight savings and increased stiffness offset the drawbacks, and there may be a few other side effects like sound and temperature insulation. Like resins and fibers, core materials offer distinct advantages, disadvantages and price points.

Most builders have adopted a hybrid approach, building solid hulls below the waterline, and cored hulls and decks above. This gives a balance of weight and safety.

A. Balsa Core

Balsa is light and inexpensive. The first cored construction used balsa, but it has the disadvantage of being wood. As a natural material, if it gets wet it can rot and break down. Builders use “end grain” balsa – shorter cross cut sections – to prevent wicking of water if there is an intrusion.

B. Foam Core

Closed cell foam cores give good strength to weight savings while minimizing water intrusion. If you get water in the core, it won’t spread very far. Divinycell is a popular PVC foam core, though there are several choices with different densities and compressive strengths.

Some foam cores are not suitable for heat treatment, but infused or vacuum bagged boats like the Outremer and PDQ do well with it.

C. Honeycomb

Honeycomb cores are often the most expensive, but also give some of the best strength to weight ratios. Honeycombed cells made from resin cured aramid papers are some of the best, but also among the most costly. They offer good stiffness, but can be hard to shape. Aluminum and other resin-infused papers are other core materials builders can choose from.

3. Construction and Resin

When building a hull, there are optimal ratios of fiber to resin saturation for target strength and weight. Too little resin and you may not have enough strength (or worse, voids and gaps), and too much, and you’re just adding weight without adding strength. Resins are also a significant material cost in building the boat, so over application not only increases weight but adds cost.

There are many ways to assemble the cores, fibers and resins to build a finished laminate hull – we’re addressing the most common in boat building. Each approach has strengths and limitations, and an impact on the bottom-line cost to build the boat. Any voids or air pockets in the laminate can be disastrous; these techniques have been developed to increase saturation and reduce the risk of voids.

A. Hand Layup / Open Molding

As the name implies, this is the application of resin by hand to cloth as it’s laid into a mold. Wetting is done with a brush, and the laminate is rolled out to remove any air pockets and voids. This is the simplest way to lay up fiberglass, but also the least precise and consistent and will use the most resin.

Skilled craftsmen have built some of the finest vessels in the world this way. Though it’s more popular with monohulls, which are less sensitive to weight, many catamarans built with hand layups on open molds are still out cruising and performing well.

B. Spraying

Using chopped-strand fiber mixed with resin, a “chopper gun” can spray the mixture into a mold to lay down the composite. A consistent thickness can be difficult, but this is a low cost construction technique which makes a very resin-rich laminate. Using sprayed fibers gives lower strength in all directions compared to meticulously laid down mat and bi-directional cloth. But it is a quick technique popular with mass produced, smaller boats.

It is an excellent technique for parts with complex geometry where weight is not an issue, but you will not see it often in catamaran construction. It’s heavy with resin without any resultant increase in strength.

C. Vacuum Bagging (Wet layup)

When an open molded component has been laid up and wetted with resin, vacuum bagging takes the process a step further. After the wetting is complete, air tight plastic bagging is secured around the wetted area, and the air is pumped out of the bag. The vacuum pulls excess resin out and collapses air pockets.

The goal is to get thorough wetting and produce as strong a laminate as possible without excess resin. Knysa and Leopard are two builders that use vacuum bagging on their hulls to reduce weight.

D. Resin Infusion

For resin infusion the cloth, matting and core is laid in place dry, then sealed in an air-tight bag. A vacuum pump attaches to one side of the bag, and on the other a feed for resin. The vacuum sucks the air out of the dry cloth stack, then pulls the resin through the stack, infusing and wetting it.

Resin infusion, when done right, gives the lightest, strongest laminates with no voids and the minimum resin weight for maximum strength. SCRIMP is a variant of the resin infusion process used by some builders, including TPI which build many early Lagoon cats.

E. Pre-preg

Using pre-preg (for “Pre Impregnated”) cloth for your laminating gets rid of the resin bucket. They manufacture cloth with a partially catalyzed resin pressed into it, then it’s chilled or frozen to stop the curing process. There is no need for seperately mixed resins, and there’s no worry your resin might “go off” and harden before you’re done wetting the cloth. Instead, the cloth is assembled, vacuumed, then heated to kick off the curing process.

There are both advantages and disadvantages to using pre-preg for your laminate work. The big disadvantage is the cost; it is most expensive material to use. You also need to chill and store the cloth until you need it, though some can be at room temperature for a couple of weeks without kicking off. And you need an oven which requires some clever tricks if you’re building a forty or fifty foot boat.

But the strength to weight ratio will always be perfect. High tech honeycomb cores are best suited to pre-preg lamination, and without racing against resin cure times, you can ensure perfect cloth placement and precise layout in the build process.

The primary use for pre-preg in boating is high performance race boats. With catamarans, pre-preg may be used high load parts, like Gunboat does for foils and rudders.

4. Industry Examples

Across the catamaran building industry you’ll find almost all the above techniques and materials used, though some are less common. You aren’t likely to find chopped strand sprayed layups in ocean going cats, and hand layups can lead to heavier hulls than weight sensitive catamaran designers prefer. Most manufacturers have moved to vacuum bagging or resin infusion, with a few of the highest end boats using pre-preg for key components.

Built by Robertson & Caine in South Africa, the hull material is vacuum bagged, end-grain balsa-cored E-glass with polyester.

Hand laid, bagged vinylester over an Airex foam core in the hulls.

Earlier Prout catamarans like the Snowgoose 34 featured hand laid solid FRP hulls and decks. Over time they switched to foam or balsa cores for decks and above the waterline.

Older PDQ boats were made from vacuum bagged vinylester – solid below the waterline and cored with CoreCell foam above the waterline and in decks. Newer PDQ models switched to epoxy resin.

All glass is vacuum bagged. Below the waterline is solid E-glass and vinylester. The rest is unidirectional, bidirectional, and triaxial cloths over a Nida-Core polypropylene honeycomb core with isophthalic and vinylester resins.

The Gemini cats are built with a solid hand layup of woven roving and fiberglass mat and polyester resin. Decks are cored with end grain balsa. The Gemini 3200 introduced vinylester resin into the layup to prevent blistering.

Older Lagoons were SCRIMP infused vinylester with and end grain balsa core above the waterline and in the decks.

Newer Lagoon catamarans use polyester and vinylester resins, also infused with balsa cores above the waterline and solid below.

With a carbon fiber inner skin, Catana also uses Twaron aramid fibers in the sandwiched hull over a foam core.

Fontaine Pajot

Primary hull construction is resin-infused vinylester with a balsa cored hull and deck.

Beneath the waterline, Outremer uses a single layer, solid vinylester laminate for safety. The hulls and deck are vinylester with a Divinycell foam core. They stiffen certain components with carbon for rigidity and durability.

Gunboat hulls are epoxy infused carbon fiber with a Nomex honeycomb core. They build dagger boards and other high load components with pre-preg carbon.

Tags Buying Advice

By BJ Porter

Owner of Hallberg Rassy 53; world explorer.

4 replies on “Catamaran Construction – Hulls, Laminates, and Composites”

Excelent. Thank you for this I learned allot. Johan

Very straight forward information. Thankyou for doing this.

Damn…What an Amazingly Informative Article. *Cheers*

Outremer publish on their website that they use polyester. Not vinyl ester as you have stated.

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COLLECTIBLES AMONGST ABANDONED ITEMS SALE:

by Maxine Imrie | Jul 23, 2024 | Uncategorised

Cootamundra-Gundagai Regional Council (CGRC) has called for Expressions of Interest) EoI’s for the purchase of impounded vehicles.

The vehicles include tractors, cars, and Utes, along with a boat and trailer and a caravan. Lots 2 to 19 are located in Cootamundra and consist of two Chamberlain Countryman tractors, Fordson Major Tractor, homemade boat trailer with catamaran, Commer Trayback Truck, Suzuki motorbike, Toyota Hiace Van, 1986 Nissan Z31 Coupe, Mitsubishi panel van, Champion Gazel Caravan, and numerous cars in varying conditions. Lots 20 to 23 are located in Gundagai and consist of a Mitsubishi Outlander SUV, Toyota Corolla, Mitsubishi Triton utility, and a Great Wall dual cab utility.

Interested purchasers can view Lots 2 to 19 at CGRC Depot in Bradman Street Cootamundra on Wednesday 24 July from 10am – 2pm and on Saturday 27 July from 10am to 2pm. Lots 20 -23 can be viewed at the CGRC Gundagai Depot on Tuesday 23 July from 10am to 2pm.

All vehicles are sold AS IS, without any warranty or guarantees. Interested purchasers will need to complete the Expression of Interest- Motor Vehicle form available on the CGRC website or at Councils administration offices. Forms can be submitted at Council administration offices in Cootamundra and Gundagai, via email to [email protected] or mail to PO Box 420, Cootamundra NSW 2590. One form must be completed for each vehicle and EOI’s close at 4pm on Friday 2 August 2024.

Picture and caption:

Several vehicles in abandoned items sale are creating interest from collectors. Pictured below are just two of the items listed for purchase. The 1986 Nissan Z31 and Chamberlain Countryman Tractor are amongst the lots.

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Helping our customers through the CrowdStrike outage

Jul 20, 2024 | David Weston - Vice President, Enterprise and OS Security

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On July 18, CrowdStrike, an independent cybersecurity company, released a software update that began impacting IT systems globally. Although this was not a Microsoft incident, given it impacts our ecosystem, we want to provide an update on the steps we’ve taken with CrowdStrike and others to remediate and support our customers.

Since this event began, we’ve maintained ongoing communication with our customers, CrowdStrike and external developers to collect information and expedite solutions. We recognize the disruption this problem has caused for businesses and in the daily routines of many individuals. Our focus is providing customers with technical guidance and support to safely bring disrupted systems back online. Steps taken have included:

Engaging with CrowdStrike to automate their work on developing a solution. CrowdStrike has recommended a workaround to address this issue and has also issued a public statement. Instructions to remedy the situation on Windows endpoints were posted on the Windows Message Center . 
Deploying hundreds of Microsoft engineers and experts to work directly with customers to restore services.
Collaborating with other cloud providers and stakeholders, including Google Cloud Platform (GCP) and Amazon Web Services (AWS), to share awareness on the state of impact we are each seeing across the industry and inform ongoing conversations with CrowdStrike and customers.
Quickly posting manual remediation documentation and scripts found here .
Keeping customers informed of the latest status on the incident through the Azure Status Dashboard here .

We’re working around the clock and providing ongoing updates and support. Additionally, CrowdStrike has helped us develop a scalable solution that will help Microsoft’s Azure infrastructure accelerate a fix for CrowdStrike’s faulty update. We have also worked with both AWS and GCP to collaborate on the most effective approaches.

While software updates may occasionally cause disturbances, significant incidents like the CrowdStrike event are infrequent. We currently estimate that CrowdStrike’s update affected 8.5 million Windows devices, or less than one percent of all Windows machines. While the percentage was small, the broad economic and societal impacts reflect the use of CrowdStrike by enterprises that run many critical services.

This incident demonstrates the interconnected nature of our broad ecosystem — global cloud providers, software platforms, security vendors and other software vendors, and customers. It’s also a reminder of how important it is for all of us across the tech ecosystem to prioritize operating with safe deployment and disaster recovery using the mechanisms that exist. As we’ve seen over the last two days, we learn, recover and move forward most effectively when we collaborate and work together. We appreciate the cooperation and collaboration of our entire sector, and we will continue to update with learnings and next steps.

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What to know about Kamala Harris, leading contender to be Democratic presidential nominee

By Melissa Quinn

Updated on: July 21, 2024 / 10:35 PM EDT / CBS News

Washington — Vice President Kamala Harris has emerged as a top contender to replace President Biden at the top of Democratic ticket following his historic decision to withdraw from the 2024 race for the White House.

Mr. Biden roiled the general election campaign when he announced Sunday that he would be dropping out, ending weeks of pressure from within the Democratic Party that began after his shocking performance at the first presidential debate on June 27.

The president then threw his support to Harris, saying his decision to select her as his vice president was the best decision he's made.

"Today I want to offer my full support and endorsement for Kamala to be the nominee of our party this year," he wrote on social media . "Democrats — it's time to come together and beat Trump. Let's do this."

Harris said in a statement Sunday that she is "honored to have the President's endorsement and my intention is to earn and win this nomination."

"Over the past year, I have traveled across the country, talking with Americans about the clear choice in this momentous election," Harris said. "And that is what I will continue to do in the days and weeks ahead. I will do everything in my power to unite the Democratic Party—and unite our nation—to defeat Donald Trump and his extreme Project 2025 agenda. We have 107 days until Election Day. Together, we will fight. And together, we will win."

Harris also paid tribute to Mr. Biden, calling his decision to step aside for the 2024 race a "selfless and patriotic act."

The president initially resisted calls from some in his party to forego his bid for a second term, but relented after the drumbeat that began with a few rank-and-file lawmakers grew to include more high-profile Democrats who warned Mr. Biden's continued candidacy threatened the party's chances of not only holding onto the White House , but maintaining control of the Senate and flipping the House.

Harris, 59, is among the leading candidates to succeed Mr. Biden as the Democratic presidential nominee, though she could face some competition.

A vice president of firsts

A former senator from California, she was a one-time opponent of president's during the 2020 Democratic primary, launching her campaign on Martin Luther King Jr. Day in January 2019 and ending her presidential run in December of that year. She endorsed Mr. Biden several months later.

The president selected Harris as his running mate in August 2020, a historic pick that made her the first Black woman selected as a vice presidential candidate for a major party. She was also the first South Asian nominee on a presidential ticket and just the third woman nominated for vice president.

Harris continued to make history when she was elected vice president, becoming the first woman, first Black American and first South Asian American to serve in the position.

As vice president, Harris was tasked with overseeing tough issues including migration issues at the southern border, voting rights and abortion. She has been a steady presence on the campaign trail, frequently warning voters about the impacts a Republican president would have on abortion access.

Serving as president of the Senate, Harris broke a nearly 200-year-old record for the most tie-breaking votes cast by a vice president and presided over the historic confirmation of Supreme Court Justice Ketanji Brown Jackson, the first Black woman to serve on the nation's highest court.

Early years and personal life

Kamala Devi Harris was born Oct. 10, 1964 in Oakland, California, to Shymala Gopalan and Donald Harris. Her mother emigrated to the U.S. from India in 1960 to pursue a doctorate in endocrinology at the University of California,at Berkeley. Harris' father came to the U.S. from Jamaica in 1961 to study at Berkeley and worked as a professor at Stanford University. She has a younger sister, Maya.

Harris' mother, who was a breast cancer scientist, died in 2009 of colon cancer.

The vice president graduated from Howard University in 1986 and received her law degree from the University of California Hastings College of Law in 1989.

She and Doug Emhoff married in 2014, and her election to vice president made Emhoff the first second gentleman of the United States. Emhoff, a lawyer, has two children from a prior marriage. He is the first Jewish spouse of an American president or vice president and has taken a leading role for the Biden administration in speaking out against antisemitism.

Harris' career

Harris began working as a prosecutor in Alameda County, California, after graduating from law school and in 1998, became an assistant district attorney in San Francisco. From there, she led the San Francisco City Attorney's Division on Families and Children.

Harris was elected district attorney of San Francisco in 2003, the first woman to hold the role, and officiated the first same-sex wedding after Proposition 8, California's ballot initiative to ban gay marriage, was struck down by a federal court. She led the district attorney's office until 2010, when she was elected statewide as attorney general. Her election as the 32nd attorney general made her the first woman and first Black person to hold the position.

Harris was elected to federal office in 2016 when California voters selected her to succeed retiring Sen. Barbara Boxer in the upper chamber. During her tenure in the Senate, she served on the Judiciary and Intelligence Committees.

Just before she was sworn in as vice president in January 2021, Harris resigned from the Senate.

Kamala Harris

Melissa Quinn is a politics reporter for CBSNews.com. She has written for outlets including the Washington Examiner, Daily Signal and Alexandria Times. Melissa covers U.S. politics, with a focus on the Supreme Court and federal courts.

More from CBS News

Who has endorsed Harris for the nomination, and who hasn't?

Poll: Many Democrats back Harris, feel election chances improved after Biden exit

Read Biden's letter announcing his withdrawal from the presidential race

Kamala Harris expected to take outspoken approach on health policy

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What to know about Kamala Harris, leading contender to be Democratic
Harris continued to make history when she was elected vice president, becoming the first woman, first Black American and first South Asian American to serve in the position.

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Open Source 13-15m Catamaran Plans

archie1492 Junior Member