Boats
(Click the images for a larger view)
River Murray Paddle Steamer
This is a model of a River Murray paddle steamer. The prototype, called "Blanche" was built by Geoffrey Wallace (my great grandfather) in 1869 and her registered home port was Milang, South Australia. She was used for carrying mail and passengers from Milang to Meningie and formed part of the "overland" route from Adelaide to Melbourne in the days of the stage coaches.
The model is completely scratch built and is 1.3 metres long. The engine is a double-acting twin-cylinder oscillating engine, like the original. The engine and rudder are radio controlled and the craft is capable of reversing.
The boiler is spirit fired with a capacity of 470 ml. Operating pressure is 140 kPa (20 psi) and it runs for 35 minutes on one fill.
Here is a close-up of the engine. There is a 2:1 gear reduction to the paddle shaft.
Motor-sailer
This radio controlled yacht is a scaled-down "Starlet", which was one of the earliest RC yacht designs published. I built this with my son Robin. We made it into a motor sailor by fitting a small propeller and motor. It is entirely scratch built, including a home-made winch from a geared-down servo.
Father & son
1 metre racing yacht
This radio controlled yacht is a 1 metre, the first ever taken from a mould owned by a colleague. I built this with my son Tim, who chose the colours from the Adelaide Crows football team. For the yachting experts in my audience, the keel is very shallow to suit a local pond. It is also too narrow and the boat has a lot of leeway, especially with the current rig. Finally, she has too much freeboard. Nevertheless, she was fun to build and we will enjoy making the necessary modifications.
Deep sea steam trawler
This steamboat is based on a British north sea trawler. The engine is a single-acting oscillating engine, and the boiler is spirit fired, as with the paddle steamer above. Since the engine cannot be stopped or reversed, I made a simple variable-pitch propeller. She is remarkably maneouverable. The fibreglass hull was made from scratch, starting with a foam plug. Most of the superstructure is made of polystyrene sheet, with tinplate lining to protect it from the heat. This picture was taken before she was fully detailed.
Here is a close-up of the variable pitch propeller. Email me if you would like to have a drawing.
This is a view of the engine compartment. The white PTFE disk is the actuator for the pitch control push rod.
Ocean-going tug
I built this tug with Robin. The design is "Seaforth Conquerer", a North Sea oil rig anchor-handling tender, from 'Model Boats" May 1983. The hull is planked from 1/32" plywood and covered with one layer of glass cloth.
This is the engine room. There are two motors driving two propellor shafts via 3:1 belt reductions. The main batteries are 4 x D size NiCads in the forward compartment. The AA cells are reserved for the receiver. Another view of the engine room shows the planking and ribs . I place some lead masses on the floor to trim the vessel. The twin propellors and rudders make her highly manoeuverable, especially with this motor controller. The servo rotates a barrel with 4 cams that actuate four limit switches. This arrangement connects the motors in series for low speed and in parallel for high speed, in both forward and reverse directions. It is very efficient, because no battery power is wasted in resistors. Also, if one propellor is jammed on debris, in series-mode the other picks up the whole voltage and you can motor home.
"Engineers work to the nearest thou. Builders work to the nearest inch. And boat-builders work to the nearest boat".