Having taken the plunge an bought a twin cylinder steam engine, the Graupner LST-L unit described in last October's issue of "Model Boat", a suitable model was needed. Something appropriate for stream power but the popular choice of an open launch did not appeal, after a little thought, a model based upon the the early Torpedo Boats looked promising.
The only drawback was their slim hulls which did not appear to be a good match for a bulky and weighty model steam plant. After a long cycle of sketch designs, calculations and back to the drawing board, a model length of 40 inches seemed to work. It gave a beam of 4 inches which was just wide enough for the boiler but the draught had to be increased to keep the steam plant below deck level. This resulted in a final model weight of 11 pounds which was greater than originally intended but at least allowed for enough lead ballast inside the hull to ensure it always knew which way to float!
The hull was constructed in my favoured "open top box" method but using a thick timber bottom sheet and plywood sides. This makes it a tough model and strong enough to cope with the large deck openings. The original vessels had a simple if not sparse appearance which greatly helped to keep the top weight down. The model ended up around 1/30 to 1/40 scale and hopefully looks the part.
The first sailing trial was undertaken without the main deck fitted. This avoided having the deck blown off when the safety valve operated. The model was quickly modified to feature a suitable deck opening which is hidden under the searchlight base. The second run was in public and I must be getting there as the model ran perfectly for the 25 minutes a full burners gas tank will last.
I'm still moving up the learning curve with this model but recognise the need for the extra preparation/attention that steam power needs before, during and after each sailing run. Perhaps this is why some people love steam power whilst others avoid it like the plague?
Glynn Guest