Been working on the “Park Avenue Boom” for my 1/22 Scale Endeavour.
The original boom was almost 4.5 feet wide on its flat top surface.
Triangular in section, widest and deepest in its mid length.
Along the flat top of the boom were tracks running from side to side, these had stops fitted to them, to enable the shape of the Foot of the mainsail to be set to suit the prevailing conditions.
This gave the mainsail an “End plate”, to stop the air from spilling out at the bottom, very similar to the “Winglets” now seen on many Airliners.
Of course many of these new booms suffered breakages, but it was a big advantage to have one fitted at the time, no carbon fibre in 1932 !!.
My model boom has a carbon fibe tube, with triangle formers and a ply outer skin, trying to make it as strong as possible, yet keeping the weight down, the weight is winning at the moment !.
Taken a few photos, will post them as soon as possible.