Volume Three - The Pontoon Era - Proposed off-shore dock . . .

The ship can however, be balanced at 30'- 0” from the Wall by leaving water in the outer wing compartments, but this can only be done by entirely emptying all the rest of the Dock, indeed if in the completed Dock, its centre of gravity was found to differ from that at present assumed, it might not be possible to balance it at all in this position.

For the pumping trials, at any rate, it would be necessary, if a ship of 4,200 tons was to lifted, to place her in the best position, for no increase in the pumping power could ensure all the compartments emptying completely and uniformly. Placing the ship at 30'- 0” from the Wall has also the effect of bringing a 55'- 0” ship close up to the staging we have provided on the face of the Wall, from which the bilge and other shores are worked. We consider this method of working the shores of the highest utility. The top deck is already fully occupied by the large engines and boilers (even if the Babcock & Wilcox the narrowest boilers obtainable, are used), and if the standards and wheels for working the shores have to be placed there as well, they will almost entirely block up the deck, as they occur right in front of the engine and boiler houses.

On the other hand, the staging is only of wood, and could be made to fold down, when only the wheels would project a few inches. The portion of the ship that would come up against these stagings is again always above the water-line, that is to say it is not a portion that as a rule would be repaired on a Dock, and is a point for consideration whether it would not be better to put up with a slight inconvenience, if ever it became necessary to do work to the top sides of a 55'- 0” ship, rather than suffer for all time the disadvantages of a crowded and blocked deck. This is a matter however, that in no way affects the cost or general design of the Dock, but could be settled later, after conference with your Engineers. Quite possibly a compromise might be arranged, placing the ship say 31'- 3” from the Wall, for it should be observed that our general design of the central area of the Dock for a width of 5'- 0” across the centre line is strong enough to permit of the blocks being placed anywhere over this area.

We are, Gentlemen,

Yours faithfully, for Swan, Hunter, & Wigham Richardson, Ltd.

Signed W. Denton Director.