2:1 scale pontoon crane built from web photos, sent to me by French constructor Jacques Vuye.
The basis of the model is SML 28 of around 1928, which I have shown before at SELMEC.
The model is driven by a French MO motor mark 2 from a battery box containing three cells. This motor is geared to drive the motions of the crane by a series of worm and pinion reductions to the two winding drums, the slewing drive and the luffing screw.
The model is very tricky to build and get to work smoothly due to the worm gears on the central drive shaft; this is a particular failing of the design and still needs work to cure jamming problems.
At present there are no detailed instructions available.