An Alternative Design of Boat Guide
If you have a Beaver you may have experienced the problem of the boat slipping off to one side during recovery on certain steeper slipways. The problem is caused by the increased angle between the boat and the trailer preventing the rear of the central keel of the hull engaging between the two centre skids until the boat is a significant way on to the trailer. Any sideways gradient on the slipway or trailer causes the boat to slip to one side.
Bill Perry and Dave Smith have previously given details of additions they have made to their trailers to prevent this problem. This article details an alternative method of achieving the same effect.
Guide timbers in place
(Click on any photograph to enlarge it)
The design consists of two pieces of timber, planed to the appropriate shape and then screwed to the outside of the two outer skids. These produce a channel to guide the boat, preventing it slipping to one side as it is recovered.
Boat in channel between guides
The pieces of timber only protrude about 4 cm above the skids and so only make contact with the curved bottom edge of the hull. They can be greased with lard along with the skids to reduce friction.
Closeup of the guide timber
This design will obviously only work if the boat hull does not overlap the outer edge of the skids on your trailer by more than a few cm although a packing piece of timber could be used to increase the width if necessary. The timbers have to be planed to fit the contours of the boat hull so this must be done whilst the boat is on the trailer so that the timber can be repeatedly offered up to check the angle is appropriate, mine is about 60 degrees.
Closeup with boat in place
The smaller timber attached to the guide timber visible in the photos is not part of the design, it is there for a different purpose.
Hull gets narrower towards the bow
The guide timbers on my trailer extend from the end of the skid to rear of the wheel arch, although they could extend further. The angle the timber is planed to must be measured close to the wheel arch and must extend along the full length even though, due to the shape of the hull, the gap increases as it gets nearer to the bow. Obviously the gap must be wide enough for the widest part of the hull to pass through as the boat is slipped on and off.
The boat just rests against the guide
Because the guide timbers only allow the boat to move sideways a few millimetres, they are subject to relatively small forces. Also because they only protrude a little above the skid they are attached to, the method of fixing does not have to be substantial. Mine are simply screwed to the skid using seven 3 inch brass wood screws at 30 cm centres. This also has the advantage that nothing protrudes on the inner edge of the skids.
The guide timber is screwed to the skid
The smaller pieces of timber are attached with a single screw close to the end of the skid. They can be turned through 180 degrees so that they protrude beyond the skids. The idea behind them is that on the occasions where the slipway is not enclosed, they can be used to trap the boat , stopping it moving sideways before it is winched on to the trailer. I have not had the need to try them out yet, so they may not work.
Whilst the design of the two smaller pieces of timber is untried, the boat guides themselves have been in use for the last three years and have worked well. They are simple and cheap to make, mine were made from a length of 8 cm x 4 cm timber rescued from the canal. Because they only make contact with the bottom edges of the hull they cannot catch on rubbing strips or corner fenders and they cannot scratch or damage paintwork or the hull. They do leave a little lard on the bottom edge of the hull sides but once afloat this can not be seen.
If you are fortunate enough to have one of the brand new Beavers then you should not suffer from the problem described at all. Ian Graham cleverly extended the central keel on the new hulls so that it will engage much sooner than previously.
