COPY
MODIFICATION TO CERTAIN AMERICAN MERCHANT SHIPS FOR TANK LANDING.
The tanks and/or motor vehicles would be carried on the 2nd deck which would require to be lowered and possibly stiffened locally.
An opening approximately 40' long and 10'6" high would be cut in the shell plating amidships on each side for vehicles to pass through, either when being taken on board or when being disembarked. This opening would be fitted with a hinged flap door which when open would form a platform.
Two brows about 80' long by 13' wide, one each side, would be carried by the ship when tank operations are envisaged and would be stowed against the ship's side forward of the openings during passage to and from the scene of operations. The brows would be long enough to enable tanks to land on the beach if the vessels were aground or to land into T.L.Cs. should it be desired to keep the vessel afloat.
The biggest alteration is lowering the 2nd deck so that the height between this and the upper deck gives sufficient head room for the vehicles. A minimum headroom of 10'6" all fore and aft would be required, a passage-way at least 13' wide being provided on one side of the machinery casing. It is not possible to say with our present knowledge whether the existing machinery layout would permit the lowering of the 2nd deck in this area.
Openings 13' wide and 10'6" high would be necessary in the main transverse tween deck bulkheads to allow vehicles a clear passage fore and aft. These openings would have to be closed when the ship is used as a cargo carrier in order to provide the requisite transverse strength and watertight sub-division.
Although the openings in the side plating would be made watertight for the ship's ordinary service as a cargo carrier by means of the hinged steel door, these doors would not contribute to the longitudinal strength of the ship. The scantlings of the shell plating and bulwarks around the openings would be increased to compensate for the loss in strength due to the cutting of these large ports.
The above proposals would enable the ship to carry and land up to 40 ton tanks, probably 25 in number, and up to 3 ton army lorries; still heavier tanks could be dealt with by shoring the brow. The general scheme is illustrated on attached print.
It is assumed that these ships would be used after the first operation of landing and seizing the foreshore and country immediately surrounding, that is, the vessels would be Tank Landing Ships not Tank Assault Ships. A certain amount of accommodation would have to be provided for tank crews and maintenance staff and it would be necessary to devise some arrangement for ventilating the tank stowage space during the landing operation. The fitting of such accommodation and ventilation would involve taking the ships in hand a fair time before they could be used for tank carrying.
25th September, 1941.
