WASHINGTON, D. C. May 16, 1912.
Hon. WM. ALDEN SMITH.
Chairman Subcommittee Committee on Commerce to investigate loss of Steamer "Titanic."
MY DEAR SENATOR: Referring to my conversation with you. I beg to hand you herewith the letter which I mentioned that I received from Admiral Cone, Chief of the Bureau of Engineering, United States Navy. I think the information he has given in this letter is quite valuable, and I hope you will be able to make some use of it in your report.
Very truly, yours,
GEO. C. PERKINS.
[ Enclosure. ]
BUREAU OF STEAM ENGINEERING,
Washington, D. C., May 8, 1912.
MY DEAR SENATOR:
In replying to your letter of May 7, concerning time required to transmit signals from the bridge to the engine room and have them obeyed, I furnish you the following data concerning backing trials of the Delaware and North Dakota at the time these vessels were running ahead at about 21 knots speed. I would estimate the time required to transmit the signal from bridge to engine room not to exceed 10 seconds. On the collier Neptune, where the engines can be handled from the bridge, this 10 seconds loss of time would be eliminated.
The backing data for the Delaware is as follows:
- Starboard Engine.
Signal received to back 0 0 Engines started backing 22 10 Engines backing hard 52 60
The ship was dead in the water in l minute 52 seconds.
Ship making about 21 knots when signal to back was received.
The corresponding data for the North Dakota, which is a turbine ship, the Delaware being a reciprocating-engine ship, is as follows:
- Starboard Engine.
(Min. : Sec.)
(Min. : Sec.)
Signal received to back 0 0 Engines started backing 1:08 2:14 Engines backing hard 9.35 3:25
The ship was dead in the water in 6 minutes 56.4 seconds.The ship at time signal to back was received was making about 21 knots.
The machinery of the Titanic was a combination of reciprocating engines with turbines, with the power distributed on three shafts, the reciprocating engines being located on the outboard shafts and developing approximately 50 per cent at the full power. The backing was accomplished only with the reciprocating engines. If we allow that the backing power of these engines was equal to the ahead power, which is not the case, as on account of the effect of the back of the propellers the backing power is always less than the ahead power, the maximum possible backing power of the Titanic could not have exceeded 50 per cent of the ahead power. This being the fact, her backing possibilities were more nearly like those of the North Dakota, the turbine vessel, than those of the Delaware, the reciprocating engine ship. As pointed out in the first part of the letter, the probable saving in total time between the desire to back on the bridge and the actual backing in the engine room, which would be accomplished by fitting bridge handling apparatus for the main engines, would probably not exceed 10 seconds.
In the above trials the North Dakota was handicapped by very bad maneuvering valves. Should her valves have handled as well as the reversing gear of the Delaware, the time to bring her to a dead stop in the water would have been reduced to approximately 5 minutes. I have selected the above vessels to quote on account of their large size both being Dreadnoughts, and the speed at which they were running when the signal to back was given.
H. I. CONE,
Engineer in Chief U. S. Navy, Chief of Bureau.
Hon. GEO. C PERKINS. United States Senator,
Chairman Committee on Naval Affairs,
United States Senate, Washington, D. C.