Am scurrying around looking for a future project and have decided to attempt the Vosper Brave class MT/GB. Will use a hull that is about 37" long from MTBHULLS, as that is the size that fits our usual sailing venues best. There are a number of members who have built either the Brave or the Perkasa derivative. Can anybody suggest the best electric drivetrain for this project? At this stage am thinking of triple screws, individually powered so getting a contra-rotating screw should be relatively easy. Would like to emulate the performance of the original if possible. Appreciate any advise on this project and recommendations for a successful model.
An interesting subject. There are details at http://www.bmpt.org.uk/other_boats_history/Brave%20class/pag... which may help your thinking. I do believe the third motor was mainly for slow speed use but am not sure. From a model point of view there will not be much space in a 37" hull for three motors and the necessary batteries and my 34" Perkassa runs at full scale speed on two speed 600 motors with a 9.6v 2800mA NiMh. I have seen three prop versions but the centre prop is usually free wheeling is not driven. If you really want performance then brushless and LiPo will give the best results and give plenty of room for 3 motors (28xx size), Escs and batteries. I guess your next step is to source a suitable plan for your chosen variant. I do hope you start a build blog
From memory the centre prop was used in harbour or for station keeping at sea. when required the "wing" engines were started. I remember many years ago watching one leave Yarmouth harbour on the isle of Wight and the sound was incredible.