Thoughts On Turning Boats
The majority of boat designs for amateur builders nowadays are built upside down. There are good reasons for this, gravity is your friend, and long panels and planks can be laid on the building frame for fitting, especially for shorthanded work as there is no need for complicated sticks to shore up planks. Also sanding fairing and painting an upturned hull is far easier.
One of the things you will have considered is do I have enough room to build a boat? In some ways that’s only half of the question – because the other half is do I have enough room to turn a boat?
If your boat is small this can be an easy process. A small dinghy can be carried out onto the lawn and just rolled over. My adult son and I easily turned a Kernic boat built for the naval cadets in Western Australia. Kernic was about 100kg and 6m long – so relatively light when we turned it.
We didn’t need any special gear, but we did need to do some preparation so the boat didn’t get damaged in the turning process or in its new position. We screwed a sacrificial piece of pine to the sheer plank where the hull was going to be resting against the floor. This would ultimately be replaced by a rubbing strake in a lot of cases the sheer strake isn’t painted at this stage but all the other planks have been, so if it does get damaged, this can easily be repaired later and the sheer plank is easily accessible for painting. We covered the floor with old cushions and doonas where the boat would be in contact with the floor as it rolls over. Because the boat was light, one of us stood at each end and tilted the boat up until it was on edge, until we felt it was at the point of balance, and then then carefully walked around to the underside and slowly allowed the hull to roll down to its final position.
With a heavier boat, you need to plan things out a little more. Rory and I also turned Jewell which was about 500kg and again 6m long. But by the time it was turned the internal ballast was in the keel, and this gave the hull a very strong righting moment – that is – the she wanted to go over when she reached a certain point. As a result, we used lifting tackle off the roof beam and a horizontal retaining rope passed around the leg of a work bench attached to the wall to control the turn. In that situation due to the strong righting moment the rope ended up taking more strain than I’d anticipated, and began to pull the bench away from the wall. As there were only two of us I built a temporary frame to straddle the hull to allow Jewell to roll in a more controlled manner.
Easing the boat down.
This month, we turned the hull of the 10m Francois Vivier designed Pilbara schooner. Although the hull weighed about 400kg, we couldn’t use the lifting gear because of her length and how the workshop has been organised for this build. So I put the call out to the my comrades in the Old Gaffers Association in WA, as well as family and friends and had 12 able bodied people on the day. I’d prepared by giving the workshop a really good tidy up – moving all machinery that could be moved out of the way as far as possible. I also gave the floor a good sweep because we’d need our shoes to have good purchase on the floor. Unfortunately, the protective steel belting for the bilge runners and skeg and forefoot weren’t ready in time, so I screwed a couple of sacrificial pieces of pine to the bilge runners and taped old carpet to the skeg and forefoot by way of protection as well as a pine wearing board along the sheer plank where it would rest on the floor.
Jewell being turned in custom frame.
The day before, I used a trolley jack to raise the hull off the building frame and rested it on some crates, then from underneath I disassembled the entire building frame and removed it.
Then I attached two retaining ropes to the internal structure. On the day of the move we lowered the ends back down onto the floor, and began to raise the boat up on its side. Just before we reached the balance point, we realised we were going to have to walk her sideways across the floor as the workshop wasn’t wide enough for her to just be rolled. This was done by raising one end and moving it across the floor, then lowering that end and raising the other end and moving it across, and so we slowly shuffled the hull back across until there was room to lower her. Video can be seen here;
http://www.oconnorwoodenboats.com/videos/
Things were kept stable by keeping the hull just before the balance point so she always wanted to go back down to her original position and having most of the team on that side of the boat until we had enough room to roll over.
Finished the job.
When we had enough room, it was time to finish the turn. We raised the boat to its balance point. Unlike, Jewell, once this boat reached the point of balance she was reasonably stable, so there was time for most of the team to move to the other side of the boat to be there to ease her down with a couple of guys couple holding the retaining ropes. And then carefully we rolled her down onto some padding.
When turning boats the main advice I would give is to have a plan beforehand, taking into account the size and weight of your boat, the room available, and whether there is internal ballast.
As a rule the more hands the better, as long as the people assisting are aware of what is needing to be done, the last thing you need are people getting in the way .
