142 THE RAISING OF THE DRY-DOCK DEWEY. 
are over the keel blocks.) It was then noticed that the forward end of the 
sunken side was beginning tocome up very slowly, and the operation was 
continued until the dock reached the position shown in Figs. 1 and 2, Plate 73, 
and Figs. 1 and 2, Plate 74. This position was reached about 9.30 A. M. 
At this time the whole forward end was coming up rapidly. The starboard 
_ after corner was going down, and the port after corner was coming up very 
slowly. At this time the pump was drawing water from tanks Nos. 4, 6, and 
7 forward, but practically none from Nos. 4, 6, and 7 aft. Both end pon- 
toons were completely shut off by the stop valves. Both No. 1 tanks on the 
high side were practically empty of water. The whole forward end pontoon 
was completely full of water. It will be noted from the figures that the 
water in the forward end pontoon was beginning to be lifted above the surface. 
The weight of the end pontoon together with the water in it was inthe 
neighborhood of 7,000 tons, and it was considered dangerous to continue 
this operation further. To have done so would surely have resulted in 
straining the dock and probably in tearing off the end pontoon. At the 
time the operation was stopped, no deflection of the dock structure could 
be noticed and there was no sign of giving way of the bolts securing the end 
pontoon to the side walls of the center pontoon. Furthermore, this opera- 
tion alone would not have raised the dock, for the reason that as soon as 
the forward compartments were emptied, the pump suction would have 
drawn air, after which the suction to the after tanks would have been lost 
and the after end could not have been lifted by that means. It was then 
planned to introduce compressed air in the after pontoon, in order to lift 
the after end of the dock. It was, however, doubtful whether the dock 
could be satisfactorily raised in this manner as this also would have lifted 
the high side first, and it was feared that severe strains might have been 
put on the dock due to the fact that the port after corner would have served 
as a pivot while the rest of the dock was raising first. However, it was 
decided to attempt this with the idea of discontinuing it if the action of the 
dock was not satisfactory. For this purpose the dock’s pump had to be 
kept going from time to time, in order to keep the low side from sinking 
through leakage. About 4.30 P. M. it was found that the dock’s own pump 
was in such bad condition due to having been working in mud and salt water 
and at an excessive inclination and also due tothe breaking of the oiling gear, 
that it needed overhauling. It was accordingly stopped for repairs which 
were not completed until about midnight, at which time the port side wasjust 
sinking below the surface. This method of lifting the dock was then aban- 
doned, it being considered a dangerous one even with the assistance of com- 
pressed air, and the action of the compressed air being very uncertain. 
