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Hydraulic Governor.--The two features of this governor are the effecting of remote control by a variable pressure oil system and the pulsation of the oil pressure in this system, greatly adding to the sensitiveness of control.

The governor is loaded and the speed regulated by varying the oil pressure on the system. This can be done with great accuracy from the control station. Pipes only pass through the bulkheads and water-tight integrity is easily obtained, as it is unnecessary to pass any rods or shafts of the governing system through the bulkheads with their inherent danger of jamming.

The oil pressure pulsating slightly keeps the governing system working gently, thereby preventing sticking. It is believed that the quick acting and stable governor will be of considerable importance when steaming in formation.

The governor is provided with an automatic device cutting off steam to the turbine when the maximum safe speed is exceeded. The governor maintains a practically constant speed independent of load, depending only upon the setting of the main control handle. The motor speed being limited to something less than synchronous speed, there can be no racing or throwing of propeller blades during rough weather.

Control Room and Electrical Instruments.--The control is centralized in a control room containing all the main switching apparatus, the liquid rheostats for the main motors and the regulating apparatus for the main turbines. The fact that the auxiliaries as well as the main ship's drive are electrical enables the use of electrical instruments, greatly facilitating the detection and location of irregularities in the operation of the apparatus.

Rheostats.-Automatic liquid rheostats are used during starting and reversing. The principal of their operation is shown in the sketch on Fig. 5.

A series of fixed electrodes are mounted in the upper tank, while the lower tank serves only as a reservoir for the electrolyte. Two motor-driven centrifugal pumps take their suction from the lower tank and discharge into the upper one. As the electrolyte rises in the upper tank, the resistance decreases until the overflow point is reached, when the liquid simply circulates between the two tanks.

A by-pass is provided between the two tanks, which, when open, maintains a level in the electrode tank giving maximum resistance.

The rheostat is also provided with a short-circuiting switch and with gage glasses to observe the height of the liquid in the upper tank. Cooling coils are probably also provided to limit the temperature of the liquid.

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Fig. 5.-Liquid Rheostat, U. S. S. Tennessee (Diagrammatic only).

Cables.One of the principal criticisms of electric ship propulsion for fighting ships has been in regard to its dependence on cables, whose reliability has been questioned. The arrangements of parallel circuits of cables seems to preclude the possibility of

any single cable fault seriously interfering with the operation of the ship, and there seems little reason why they should be considered more of a hazard than the main steam pipes.

The cables are of the three-core type and the specifications under which they were man

anufactured were the result of colaboration between the Navy Department and the American Institute of Electrical Engineers.

The enclosing of the cables in heavily armored runs has been under consideration, but it is not known what specific provisions are being made for the insulation, support and protection of these cables on the Tennessee.

Turbine Room Auxiliaries.-Electrically driven auxiliaries are used to a greater extent than any previous example.

The main circulating pumps are driven by 235 HP., D.C. motors of the variable speed type, permitting the accurate proportioning of circulating water to condensate with resulting economy.

LeBlanc air ejectors are used on the main condensers, while the condensate pumps are vertical electric driven centrifugals. It should be noted that all the essential auxiliary apparatus for the turbines is rotary, the development agreeing with shore experience in this particular.

It is expected to maintain a vacuum as high, if not higher, than the old combination of reciprocating air pumps and Parsons' augmenters with the air ejectors, with considerable economy in weight and space.

Operation.-While of considerable interest and possessing features radically different from the non-electrical drives, this phase of the subject is not elaborated on. It may be stated, however, that the considerable enthusiasm resulting from the favorable experiences with the Jupiter have, in a measure, favored the continuation of the experiment on a larger scale, and the extension of the scheme to the battleships and battle cruisers.

Miscellaneous Electrical Apparatus Aboard Ship.—The particulars of the other electric equipment aboard ship are not available, but it is reasonable to assume that further developments may be looked for in this connection, and that a more extensive use of electric power will be made. The description of these details would be a subject amply large for a separate consideration and is therefor omitted herein.

DISCUSSION

The Torpedoplane

(SEE Page 743, WHOLE No. 195) Rear ADMIRAL Ralph EARLE, U. S. Navy.—The general impression that will be gathered by those reading the interesting paper by Mr. Henry Woodhouse on the torpedoplane that the navy has failed to take advantage of information in its possession in regard to the practicability and desirability of dropping torpedoes from aircraft. A long editorial recently published in the New York Times gave decidedly a similar impression to the public. It is believed that the facts in the matter do not warrant such a belief on the part of those interested in the navy. The usual practice of the navy is, of course, to remain silent on subjects such as this in connection with the naval profession, but there are at least certain facts, involving experimentation of that nature, that it can do no harm to mention in a brief form.

In the spring of 1918, the British produced a successful torpedo-carrying airplane, and used for this a land machine because of the special conditions under which they could operate in the North Sea. The torpedoplane carried a torpedo weighing approximately one thousand pounds. The United States Navy has been concerned principally with the development of a seaplane for carrying the service standard small torpedo, but the seaplane requisite was of greater capacity than was easily obtainable, and, not until July, 1918, were such seaplanes available. It is worthy of mention that the Navy Department, under date of July 20, 1914, took up the problem of employing aircraft for carrying torpedoes, and study of this project was put in process, the various bureaus in the Navy Department collaborating.

There are many letters in the Department relative to utilizing seaplanes for carrying torpedoes, and the Department has had the benefit of all information it has received from abroad and from other persons interested, in the perfection of this method of discharging torpedoes.

It is, of course, not wise to state the success of what has been done with the torpedoplane in the navy further than that this matter has been cared for in the navy and satisfactory apparatus must result.

Mr. Woodhouse makes no mention of experiments carried out by the United States Government because it is assumed he had no personal knowledge in regard to the same, although in one case he does refer to a small torpedo which could be carried by a small seaplane then in use, and states that “ before the small torpedo had been perfected, however, the large airplanes had come into use, and the use for small airplanes ceased." To make this statement complete it must be borne in mind that the small

torpedo referred to was developed by private interests and proved a total failure on trial runs, only making five hundred yards at a speed of less than ten knots, the torpedo carrying but ten pounds of explosive, such a small amount as to be of no use whatever except against the very smallest of vessels.

Mr. Woodhouse's statement of the factors that govern the success of torpedoplane situation is very well put, and a careful consideration of all the factors mentioned will enable anyone familiar with experimental and development work on any apparatus to realize the difficulties which must be overcome before a thoroughly successful and practicable torpedoplane is a fact.

Naturally, it is difficult to comment properly upon possibilities of a torpedoplane, the weapon not having been tested very thoroughly by its use in war, and certainly the methods of use proposed by the United States Navy cannot be disclosed. It is necessary to look the facts in the face, however, and to recognize that there are certain limitations in the application of this weapon to naval warfare which decidedly prohibit it from becoming a revolutionary weapon which Mr. Woodhouse considers it to be. A torpedo is in the nature of a projectile moving slowly in the water, and the torpedoplane dropping such a projectile within sight of the vessel immediately discloses the character of the attack on the vessel, and this vessel, by alteration, of course, of speed, will have no difficulty in avoiding the torpedo even though it were properly directed when launched. In a fleet action against a number of ships, using many torpedoplanes, there would be the greatest chance of success of torpedoes dropped in this manner, because the ships are more or less restricted in their maneuvers both as to change in course and speed.

The weapon is certainly a good one and would probably have been used by the United States Navy had the area of the present war been nearer to the seaboard of the United States, thus rendering it possible to use the weapon. The best development of the torpedoplane seems to be in the line of utilizing the standard service torpedo of a large explosive capacity so that the hit made by them would entail serious, if not vital, damage to the target.

A Plan for Maintaining the Naval Auxiliary Reserve After

the War

(SEE WHOLE Nos. 190 AND 193) LIEUTENANT ERNEST G. DRAPER, U. S. N. R. F.-In the December, 1918, issue of the PROCEEDINGS you printed an article of mine entitled “A Plan for Maintaining the Naval Auxiliary Reserve After the War.” In the May, 1919, issue there appears a criticism of this article by Lieut. Commander R. R. Smith, U. S. N. May I be permitted to reply briefly to this criticism ?

The essence of Commander Smith's remarks is, apparently, that instead of having an Auxiliary Reserve trained by U. S. Navy officers, the same or better results can be obtained by a course of instruction for men who are now officers in the merchant marine. “I believe," writes Commander

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