146 THE RAISING OF THE DRY-DOCK DEWEY. 
and end walls had to stand a pressure due to a head of water of about 26 feet. 
It was known that this would give an excessive pressure. Accordingly, as 
the water was pumped down, the walls were carefully observed, as far as 
practicable, to determine the deflection. The after end wall and the outer 
side wall aft on the sunken side buckled in slightly and have a permanent 
buckle of about 4 inches. This, however, is immaterial and does not affect 
the efficiency of the dock. It is hardly noticeable except on sighting along 
the surface. Also, in spite of the shoring, the valve house was badly buckled 
out of shape, due to the water pressure and had to be rebuilt. 
As soon as the dock was raised a careful and complete examination was 
made of the entire structure and all of its piping and fittings. A number of 
small new holes were found in the drainage and flooding piping. These 
could not admit water from the sea except in case one or more of the main 
sea valves should be open or leaky, so that these holes most likely had no 
appreciable effect on the sinking of the dock, except to make the listing more 
rapid. In fact they were hardly sufficient to even materially interfere with 
its operation and handling. The main sea valves were slightly leaky, but 
this leakage also was insufficient tocause oreven to contribute to the sinking 
of the dock. The vent pipes from the tanks were, however, found to be 
badly corroded, in many cases being reduced to a mere shell which had given 
way, thereby leaving large areas open to the sea. When the dock is up these 
vent pipes are always above the surface of the water, but when the dock had 
been lowered to take in the torpedo-boat destroyers, these vent pipes were 
mostly under water, and water entered them and gradually filled the ballast 
compartments of the dock which caused its sinking. The reason for its going 
down so rapidly is believed to be that when it once began to take a list to 
port the water from the starboard side flowed to the port side through the 
quick-acting gate valves in the drainage system which are only approximately 
water-tight, and also through the small holes in the drain piping. ‘This, of 
course, increased the list of the port side even though not admitting any 
additional water from the sea. 
I think that this article is not complete without making mention of the 
excellent and efficient work done by the divers. There were at work on the 
dock about a dozen Filipino divers and six divers who were petty officers 
on the torpedo boat fleet. These latter were under the charge of Gunner 
G. D. Samonski, U.S. Navy, himself an experienced and efficient diver. 
His and their work was in my opinion of an unusually efficient character. 
These men were at work almost day and night for five weeks. The heavy 
work of fitting the manhole covers with its long piping had to be done in a 
depth of water of about 70 feet, and some of this work was in very cramped 
