I am considering making a model of the 10 segment Advanced Base Sectional Dock used by the USN during WWII. The model should be relatively easy because the docks are relatively simple, except for the 2 traveling cranes. The model can also be made quite sturdy and would make a good way to display and to actually transport other ship models in

I collected an extensive array of photos, including the segments linked together functioning as a floating dock, separated while being commissioned, towed and prepared to be erected as a float dock.
However, although there are photos showing the dock sections separated and floating high in the water, I've never found a picture actually showing what the bottom of the pontoon sections look like. I plant to do a full hull model so I need to know what the bottom looks like. Also, exactly how are the dock sections connected to each other? There seems to be two circular couplings on each side each pontoon section. But it seems these couplings are somewhat small to ensure the pontoons would hold together with no relative movement under the weight of a 58,000 ton battleship load.
Does anyone know of any drawings of these floating docks in public domain I can consult?