The NAVAL Research Laboratory is, broadly speaking, concerned with investigations in the field of physical and technical science as applied to the special requirements of the naval service.
The idea of such an institution had its inception at the time of the organization meeting of the Naval Consulting Board on October 7, 1915. The distinguished members of this board were quick to realize that in order to secure the best results from the work which they proposed to undertake along scientific and inventive lines, the construction of a suitable laboratory would be imperatively necessary.
There was not at this time, it will be remembered, any provision in the naval establishment for research work as such. Navy yards and their facilities were fully occupied with the active work of construction and maintenance of the fleet as their primary function. Anything in the nature of research or experimental work was necessarily subordinated to the exigencies of the primary function and suffered accordingly. The result, in general, was that service interest was limited to that which was finished and for sale upon the market without regard to whether or not it might be best for the naval purpose.
On March 15, 1916, Secretary Daniels, Mr. Edison, Dr. Beakeland, Mr. Coffin, Mr. Hunt, and Mr. Saunders, members of the Naval Consulting Board, appeared before the Committee on Naval Affairs of the House Representatives, and subjected themselves to a thorough examination as to the purposes of the laboratory and its necessity. They convinced the committee that substantial savings would accrue if means were provided to permit determination of naval needs by original investigation rather than by the dictum of the manufacturer.
Accordingly, there was incorporated in the appropriation act for the year ending June 30, 1917, the sum of $1,500,000 for laboratory and research work on the subjects of gun erosion; torpedo motive power; the gyroscope; submarine guns; protection against submarine, torpedo, and mine attack; improvement in submarine attachments; improvement and development in submarine engines, storage batteries, and propulsion; airplanes and aircraft; improvement in radio installations; and other necessary work of similar character for the benefit of the government service, including the construction, equipment, and operation of a laboratory; and the employment of scientific civilian assistants as might become necessary.
The enabling act was fortunately broad and comprehensive, particularly in the feature of establishing the new activity as a branch of the Secretary’s office, available to the entire naval establishment, rather than as an appendage of the technical bureaus.
Based upon a study of the considerations that should determine site, the more important of which were proximity to navigable streams; general climatic conditions and labor market; availability of other government machinery and facilities; accessibility to civilian scientists, and to institutions of parallel character, combined with secrecy and efficiency of operation, and safety from enemy assault, the laboratory was finally located at Bellevue, on the Potomac River, four miles below the Washington Navy Yard.
The principal buildings, all of which are of the most modern steel and concrete construction, include a research building 200 x 60 ft.; a machine shop 300 x 82; a foundry and smith shop; pattern shop and power plant. There is also a barracks to house the marine guard and enlisted personnel assigned to the station. The shop and laboratory equipment is elaborate in character and adequate for the service required.
General direction of the establishment centers in the office of the Technical Aide to the Secretary of the Navy, with an assistant director, a line officer supervising the physical operations on the ground. The technical personnel numbers about fifty, assisted by a shop force of about the same number.
Placed in formal commission in July, 1923, the laboratory has in the second year of operation, established a gratifying record of constructive performance which fully confirms the vision and judgment of its sponsors.
There have been organized to date a Radio Unit under the general supervision of Dr. A. H. Taylor, formerly of the university of Wisconsin; a Sound Unit under Dr. H. C. Hayes, formerly of Harvard; a Light and Heat Unit, under Dr. E. O. Hulburt, formerly of Johns Hopkins; and a Ballistic or Pressure Unit, under Dr. H. H. Moore.
1. Activities of the Radio Unit.—In radio the outstanding research achievement has been determination of the laws which govern the formation of radio waves of very high frequency, and of the mechanism of their propagation through space. This study has extended over two years. From the knowledge gained the laboratory is now in position to proceed with the development of inexpensive and relatively low power transmitting apparatus which will assure reliable communication over far greater range than is possible with an existing installation. Incidentally, it has contributed additional scientific information regarding the upper layers of the earth’s atmosphere, confirming the existence and establishing the altitude of the so-called Kennerly-Heaviside layer of maximum ionic density—in popular language, the ceiling of the sky.
The mass of experimental data from which these deductions were made was accumulated through the cooperation and assistance of amateur radio operators of the American Relay League, and their co-workers in foreign countries. These gentlemen have voluntarily given their time and services in making observations and reports on experimental transmissions, and in so doing have played an important part in advancing the radio art.
Research work of almost equal importance has been carried on in connection with piezo-electric crystals, principally quartz.
The well-known principle of crystal oscillation at fixed frequency seemed of value in controlling the frequency of radio transmitters and receivers. Before practical use of this principle could be made it was found necessary to investigate more fully the factors controlling such oscillations. While much remains to be accomplished, sufficient information is now available to permit the construction of crystal controlled transmitters and receivers.
Crystals intended for control of this character can be and are prepared at the laboratory permitting the fixation of oscillations at any desired number ranging from 20,000 to 11,000,000 per second; and such crystals will oscillate at the determined rate with a variation of only a few hundred per second. When controlled by such a crystal, a transmitter will have a fixed frequency regardless of inevitable minor changes in circuit conditions, a feature which it is impossible to obtain with apparatus not controlled in this manner.
Receivers also can be fitted with crystal control and quickly brought into step with the transmitter. By thus definitely fixing the frequency band over which transmission and reception take place, the number of channels through the ether over which communication is possible is very largely increased.
The principles enunciated have been given practical application in the construction of an experimental 10K.W. crystal controlled high frequency (4200 k.c.s.) transmitter built at the laboratory. This transmitter has been found suitable for direct night traffic with distant stations, and has been used by the Naval Communication Service in handling traffic with the west coast, Panama, Honolulu, Samoa, and European stations, thus taking practically the entire night load of the highest powered Naval Radio Station.
The economy resulting can be realized when it is considered that power costs alone have been reduced from about $12.00 to $1.00 per hour, and that the transmitter itself represented but a small fraction of the costs of the high powered station. Another 1 K.W. high frequency set has been used by the Navy Department for daylight traffic, and on occasions messages have been carried through with this set when those from a 350 K.W. arc set were indistinguishable because of static interference. It can now be authoritatively stated that a high frequency transmitting station can be built at a cost of $60,000 giving better service and longer range than present high power stations costing $2,000,000, while the cost of operation and upkeep will be correspondingly reduced.
Additional radio apparati devised to date include a heterodyne frequency meter, long and intermediate wave receivers, and an intra-fleet set. Inexpensive and compact air condensers for shore purposes have been constructed, as also apparatus for the elimination of losses in trunk circuits, and apparatus for permitting single antennae multiple reception on board ship. A field transmitting set for use by the Marine Corps has been constructed, as also an automatic recording apparatus for radio messages. Considerable work has been devoted to perfecting a better receiver for coastal radio stations, and in eliminating interference in arc sets.
Numerous patent applications in adaption of knowledge gained have been filed, insuring protection to the naval service of work done and making available to all government departments the free use of such developments.
A few months ago when the flight of the Shenandoah over the polar region was under consideration, radio apparatus of special type was developed and manufactured as an emergency measure. From data gathered in subsequent flights it has been possible to remodel at slight cost the installations originally devised, giving a steadier wave and greatly increased range of daylight communication. This data permits the design of much more efficient apparatus than heretofore thought possible for heavier-than-air craft.
Studies in high frequency communication from lighter-than-air craft have resulted in the development of apparatus insuring long range communication with less weight and power than heretofore used even for short distances. A sending and reception schedule arranged with the MacMillan Arctic Expedition has been astonishingly efficient in performance. Endeavor is also being made to eliminate reception interference on air craft due to ignition disturbances.
2. Activities of the Sound Unit.—The development of a simple sonic depth finder has been completed and one model is undergoing service tests. This depth finder will give accurate soundings as low as ten fathoms with a possibility of further reducing this to about five fathoms. The device is much simpler in design and more effective in operation than any now in use, and will cost less than one-third to manufacture and install. The saving for each installation will be about $100,000. Work is under way in development of an automatic visual indicator by means of which depth indications will be made immediately to the commanding officer without the intermediary of a special operator.
The development of more effective means of communication between vessels by the use of the underwater sound waves using both sonic and super-sonic principles is well advanced. Two barges intended for use in testing sound apparatus have been fitted up and will be moved in the near future to a location on deep water where conclusive tests will be made of installations designed and built for communication purposes during the past year.
Work on the development of a loud speaker for use in transmitting messages on board ship has been undertaken and several models built. While satisfactory as a loud speaker, it is not felt that anything so far developed will fully meet the exacting requirements imposed by conditions on board ship. Several new principles have been used in the development work. One application of experimental data so far obtained will be the design of an electro-magnetically driven fog signal replacing the present steam whistle on surface craft, and the compressed air whistle on submarines and light vessels.
The detection of air craft by acoustical methods has been given considerable attention, in extension of the work carried on by others. No actual work is considered warranted until a new and untried scheme giving promise of success presents itself.
3. Activities of the Heat and Light Unit.—This unit in the first six months after establishment is primarily concerned with investigations of a confidential character in connection with ultraviolet and infra-red rays. It has also carried on intensive investigations concerning properties of quartz crystals, and of apparatus necessary in conjunction with working quartz on a production basis.
The unit has undertaken work in connection with the sputtering of metals, the development of thermo-couples, and the use of the photo-elastic process for determining the stresses occurring in metallic structures; also in the laws underlying color combinations, shapes, and so forth, for visual flag signals.
4. Activities of the Ballistic Unit.—This unit has accomplished the development and manufacture of long range, high speed cameras for use in connection with projectiles in flight, and of shell bursts. It has developed, also, cameras for use in anti-air craft spotting. Calibration tests to determine the velocity of projectiles before leaving the muzzle of the gun, as opposed to the velocity in air have been completed. The ejection velocities of the West Virginia turret guns have been established as from thirty-five to fifty feet per second less than the muzzle velocity. Reliable information concerning the pressure developed under various conditions in the hydraulic steering gear of battleships has been obtained.
5. The Trend of Future Development.—The next step in the orderly expansion of the laboratory activities will be the establishment of a metallurgical and chemical unit.
The Limitation of Arms Conference imposed a limitation upon the size of future construction expressible in terms of weight alone, that is, displacement. Every ton which, by the use of lighter and stronger metal, can be saved in the weight of the hull structure may be applied to add to the strictly military characteristics of the design.
The investigation of metals, especially of the non-ferrous alloys with regard to lightness, strength, resistance to vibration, to corrosion, and climatic changes is one of the most important problems confronting the naval service.
Negotiations are in progress, also, for the employment of a distinguished mathematical physicist whose services are urgently required in the solution of the intricate mathematical problems arising from day to day in connection with the work of the other units.
6. Associated Activities.—The Bureau of Navigation has established at the laboratory under the supervision of selected officers a radio class, normally consisting of thirty-five enlisted men selected from the fleet. The course of instruction is twenty-two weeks. Advantage is taken of the available radio experts and equipment to instruct the students in the principles underlying the design of radio and sound apparatus. Two classes have been already graduated which have given an excellent demonstration in subsequent performance afloat.
There are normally attached to the laboratory, also, during the summer months a number of postgraduate officers which in time will make the work being carried on more familiar than it now is to the naval service.
7. Conclusion.—The outstanding characteristic of the Research Laboratory contrasted with anything existing elsewhere in the naval establishment, is that, by reason of the high character of its technical personnel, and of the shop personnel recruited for the most part from the Naval Gun Factory, it is possible to work directly from the mind of the scientist to the hand of the mechanic, eliminating entirely the drafting room. The draftsman has no place in the picture until the apparatus has passed the development stage and is ready to pass to a production basis.
Pride of performance is the going principle. No consideration of money or working hours or weather influences the personnel in the accomplishment of purpose. Much of the work herein outlined has necessarily been accomplished in the small hours of the night. The chairman of the House Committee on Naval Appropriations took the opportunity upon the occasion of the committee hearings to thank the technical staff in the name of the Congress for the splendid services it was rendering to the Navy Department and to the government of the United States.