Building a Bamboo Biadarka

The biadarka is a type of kayak. It is much longer and slimmer than a whitewater kayak. Designed by the native people of the Pacific Northwest it is an ocean going boat, made for riding over the waves and easy to roll back upright if capsized. Biadarkas were used for hunting otter and seal. These boats could stay out for days and travel great distances rapidley. The construction method is called "skin on frame". They are usually made from something like cedar, redwood, or spruce for the longer pieces such as stringers and keel. The ribs are usually made with slim willow shoots that can easily be bent to shape. Traditionally the framework was covered with seal skins, sewn together and stretched tight. Today they are covered with canvas or nylon. I've build a canvas covered kayay in the past but it was heavy and wide, very stable and great for kids but not very fast to paddle. I've wanted to build a biadarka for years. I love the long slim lines of the boat and the construction method. I wanted to do something a little different and try to incorporate bamboo into the project as much a possible. I was afraid to change things too much as I really wanted it to be usable. I ended up using red cedar for the gunwales and split bamboo for the ribs along with small bamboo pegs. There will be several long "stringers" that will be bamboo poles. In the pictures I am using cedar for temporary stringes and will replace them once all the ribs are in and the bow and stern pieces are complete. Tonkin bamboo is my firts choice for stringers and I believe I can harvest enough from my own groves. The boat is currently hanging from the rafters of my shop while I complete some other projects. I intend to finish it up in time for warm weather.

A Canvas Covered Boat

i started with two long boards for the gunwales, about 2" by 16'

The biadarka will be about 17 1/2 feet long when finished. The cross pieces are also red cedar. I used two dowels at each joint to secure these top frames to the gunwales. It was important to use gunwales as straight as possible as this was the basic shape of the boat.

Here I've started to insert the ribs. The long white board on top is the keel. There are about 50 ribs so there's quite a ways to go. I've got holes drilled where the ribs are inserted into the guwales. I will use a chisel to square up the holes so that the flat ribs will fit snugly. Below is a close-up of one of the mortize holes after squaring it up.

These are some of the ribs. I ran a planer over them to knock off the ridges where the nodes were(notice the scars) On the left is a piece of bamboo that will be split further into rib pieces. I used a cabinet scraper to roughly square these up and remove splinters along the split edges. I use a propane torch to heat the rib, just short of burning the bamboo and then bend the rib to shape. They bend quite easily and once they cool hold their shape. This works best with split pieces of bamboo.

Here I've inserted more ribs. Keeping them even is difficult. I got stuck for quite a while at this point. I tried a couple of methods for determingh which ribs were sticking up too much and which were too low. Finally I tied on several stringers temporarily which gave me several points to measure from. I have to whittle a little on each end to get them to fit well in the holes.

Most of the ribs have been inserted. As you look down the boat you can see that some sink in too much and some bulge out too much. Some just had to be re-heated and bent a little differently while some needed lengthening or shortening. I finally got them looking pretty good. Next I'll attach the keel and permanently tie on the stringers. Native Americans used sinew to tie the multiple parts of the boat together, along with wooden pegs. I am using something called artificial sinew which looks very natural and is incredibly strong. I've cheated and used epoxy to secure some parts. I would like to coat the entire boat with epoxy when I I finish in order to protect it from rot. In place of seal skin I will probably use cotton canvas with several coatings
of polyurethane. This gives a translucent look allowing the ribs and keel to show through. It is quite flexible and waterproof.

Bamboo, Boats, and the Internet

The first internet search I ever made was for bamboo. Boats were not long after that. With time I found a list group that one subscribed to, about biadarkas. I mostly lurked for a long time but eventually a discussion came up about using different materials for ribs and I mentioned split bamboo. I even went so far as sending some samples to one of the members. Building boats is a fascinating art and craft and with new materials today it seems anything is possible. While bamboo is hardly new we can still find new uses for it. The bamboo biadarka is one example and is just one of many building methods. For as long as I can remember my dream was to build a sailboat big enough to live on. I read many books, looked at any boat I could, and built a couple of small boats just to sort of get my feet wet. Always in the back of my mind I thought about the sailboat, changing the design and learning more and more about modern boatbuilding methods. As bamboo became a big part of my life I naturally thought about how bamboo's strengths could be used in boat construction. After reading Biadarka by George Dyson I felt bamboo would be ideal to replace the aluminum poles he used for stringers. The final result would be a long, narrow hull, ideal for use as a catamaran, which is what I wanted. With bamboo stringers, split bamboo ribs, and a strong synthetic skin the hulls would be very light, a major requirement for a fast catamaran. The large hull that Dyson built was 30 feet long. Two of these would be ideal for a catamaran and in fact Dyson shows how he made attachable amas for the large hull to create a trimaran with space for a tent. Now days I would rather play with my grandkids than go sailing. The biadarka seems like an ideal boat for exploring local lakes and rivers which is more my speed. Long and sleek, the biadarka it should be very fast on these smooth, inland waters. If I enjoy the boat as much as I hope I'll have to refurbish the older boats as they are ideal for youngsters as they are wide and stable.