WHAT SIZE: In order for results to be as accurate as possible, we needed to make our model as large as could be practically manhandled.  1/10^th scale meant that the completed model would weigh in at about 55lbs and measure 6 feet. That is about as bulky as one would like, when it comes to launching onto any pond, or the sea.  Inevitably most testing would be conducted by the one person working alone.

Click on this picture to see Catamaran construction

CONSTRUCTION: UPVC piping of the rainwater variety served as the submerged tubes. The first model was formed mostly of aluminium sheet on box section steel frames. For the superstructure, a male mould or plug, was made of 1/2" chipboard coated with resin. The submerged cone sections were turned in pine ( thanks Bill) and coated with resin. Dateline Marine Services (specialist model mouldings) produced the female moulds and the first impressions at a substantial discount (thanks Lloyd). The next model used ordinary 3/16" and 1/2" ply and a shaped foam core to replace the formed ally sheeting low down.

THE DAM BUSTER: Does size matter?  It certainly does, when testing out a theory on a budget.  We were not about to commit ourselves to building a solar powered boat without some persuasive evidence that the theory would work. Remember the Dam Busters?  Barnes Wallace developed his early theory for the "bouncing bomb" using ping pong balls and a catapult. Later, after convincing the Ministry of Defence that he had a good idea, Mr Wallace was allowed to use a proper test tank for some months.

 A model is an ideal way of obtaining first hand practical experience of the problems ahead.  In fact, most of the design challenges can be put to the test in this way then multiplied up.  Any problems encountered on the model should be the same as the full size vessel.