Major developments in 16" gun turrets began prior to the declaration of the national emergency in September 1939 so that new designs reached the service early in the war. In addition to the design changes in the new turrets, modification of older battleships was begun on December 8, 1941 when the bureau of Ordnance undertook the problem of repairing and completely modernizing the battleships damaged at Pearl Harbor.
b. Developments in 16" Guns
Development of the 16"/45 caliber three gun turret began in 1937 when the decision was made to abandon the proposed 14"/50 caliber four gun turret. As a result of tale decision no 14" turrets were procured or installed during the war, procurement being confined to equipment necessary to keep serviceable the 14" equipment already installed on battleships. Work on the new turrets, which were designed for ships of the BB55 NORTH CAROLINA class started in 1937 and the turrets were place in service in 1941. Development of the 16"/50 three gun turrets for ships of the BB61 IOWA class began in 1939 and the turrets were installed on the ships in 1943. There was very little difference between the 16"/45 and the 16"/50, the main difference
being the length of the gun barrel with the result of longer range for the 16"/50.
These turrets represented a considerable advance in design and were a major improvement over the older type 16" turrets. The main features of the new design were welded structure, heavier armor, lower silhouette, heavier projectiles, higher rate of fire, full automatic control and hydraulic operation of cradle and spanning tray. There was much more compartmentation than in previous turrets. Each gun was serviced through an independent powder train with single stage hoists. Reversible projectile hoists, permitting the movement of projectiles In either direction, were developed with the result that auxiliary hoists were eliminated. Cradles and powder trunk doors were power operated by an electric hydraulic drive. Safety precautions were preserved between the gun room and the powder handling room by the use of an electric-hydraulic interlock system. These turrets had a capacity of 400 rounds, which were carried entirely inside the turret.
The system of projectile handling was considered
by many authorities to be the most important advance in 50 years in safe and easy handling of big projectiles in large numbers. In order to accomplish this improvement projectile rings were developed which made handling possible in rough weather and safer and easier for personnel. This was done by having two projectile handling flats, each containing a projectile in the proper place to be loaded in the hoists. Firing cycle was 20 seconds with the gun at the loading position.
Guns were elevated independently, maximum elevation of 45°, depression 2°, and loading angle of 5°. Maximum rate of elevation was 12° of arc per second. Maximum rate of train was 4° of arc per second.
Another novel feature of these turrets was the arrangement for train and elevation. Receiver regulators were used for the first time in 16° turrets thus allowing fully automatic control. There were two pointer and two trainer stations, each group being in a separate compartment on one side of the gun house. The two stations permitted continued operation in case of damage to one.
The pointer and trainer transmitted signals to the gun layers and train operator. There were three gun layers and one train operator on the machinery deck who operated the speed gears, matching the pointers in the elevation and train indicators when in hand servo control, ay means of a selector the train and elevation drive mechanism could be operated either by hand servo control or Automatic control (signals from the director via the plotting room and the receiver regulators).
Hydraulic operation of cradle, spanning tray, and powder trunk door decreased the time required to operate cradle and spanning tray and load the guns, and reduced fatigue to personnel as well. Previous trouble with rammer drives and chains was eliminated in these turrets, with the development of an automatic decelerating device at each end of the rammer stroke.
The 16" turrets of the WEST VIRGINIA class and the 14"of the CALIFORNIA and TENNESSEE were modernized after Pearl Harbor by the installation of receiver regulators and new electric drive equipments which allowed automatic control. To do the Job quickly and with the least produc-
tion effort, it was necessary to select and use speed gears and regulators not designed at all for these ships. The installations were made with Arma regulators and Northern Pump Company speed gears, designed for 6"/47 turrets. All old elevating and training gear equipment had to be modified, relocated, and rearranged, and space for the equipment found in gun pits and handling rooms which were already crowded with other gear. New fire control instruments had to be installed and some new ones designed. The jobs were rushed through and the final products and performances were so successful in the Battle of the Philippines that there was a demand for similar modernization of the MARYLAND and COLORADO.
c. Production Program
From July 1, 1940 through June 30, 1945 the Bureau of Ordnance procured 16 of the 16"/50 three gun turrets at an approximate cost of $24,000,000 and 21 of the 16"/45 three gun turrets at a cost of $26,040,000. The heavy forging industry, as far as big guns concerned, "became virtually dormant following World War I. However, resumption of manufacture of 16"
guns was facilitated by the fact that the Bethlehem Steel and the Midvale Company had available certain of the boring and turning equipment. Most of it, however had been so extensively dismantled or diverted that considerable rehabilitation was required. None of the equipment used by these two companies for producing forgings had ever been abandoned. Bethlehem produced approximately two-thirds of the 16" forgings, Midvale supplying the other one-third. The Naval Gun Factory did the finishing machine work on most of these guns, although during the late days of the program a few guns were sent to the NOP, Pocatello. No unusual manufacturing obstacles were encountered to seriously hinder production.
The procurement program for 16" hydraulic turret equipment for BB's 55-66 was initiated, in a great many oases, prior to the War. The first two BB' s in this program originally employed train drives by the Northern Company. Defects in this equipment led to the substitution of Waterbury Tool Company speed gears, however, substitution was not complete as the electric controllers, electric motors, speed reducers, and many other
parts such as auxiliary pumps and filters were not exchanged. Later the Northern Pump speed units were improved and were installed in the turrets of BB's 59 and 60 along with the Waterbury Tool Company's electric controller, electric motor, speed reducer, and other components which were not exchanged on BB55 and BB56
The speed gears for the projectile hoist drives of BB's 55-60 were left over from World War I, and were reconditioned by the Naval Gun Factory for BB's 55-56, and by the Waterbury Tool Company for BB's 57-60. The Bureau procured only additional components to make these speed gears complete drives. Sets of pumps, valves, and other hydraulic components were procured from Vickers, Incorporated, while motors, controllers, magnetic brakes, and gear reducers were procured from the Reliance Electric Company.
The only 16" hydraulic equipment which did not prove satisfactory were the elevation speed gear units manufactured by the Waterbury Tool Company and installed on BB's 57-60. Several of these units went to pieces
when their bronze trunnion bearing blocks broke. Waterbury Tool Company contended that these failures were caused by the additional load imposed by the installation it receiver regulator to control their operation. The Waterbury Tool Company supplied new steel backed trunnion bearing clocks for all the equipment, but the Bureau decided to take no changes and procured replacement gears from Northern Ordnance Incorporated. This substitution did not include changing the electric motors, controllers, or auxiliary pump components. When the substitution was made, the elevation receiver regulator had to be modified from Mark 14 to Mark 10. The necessary parts for the modification were procured by proprietary procurement request under General Electric Company's service contract.
The oil filters for the elevation and train drives on BB's 55-60 were procured from the Cuno Engineering Corporation and those for BB's 61-66 were supplied by the Purolator Products Company. The Naval Gun Factory modified all the sumps of these filters. The only major OrdAlt performed on the 16" hydraulic
requirement was the addition of limit top screw centering devices on all the elevation and train drives.
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