8-Inch 3-Gun Turrets Main Armament For USS Salem Class, Turret Description And Operation, July 1947 was created just after WW II.
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This publication is RESTRICTED and shall be safeguarded in accordance with the security provisions of U. S. Navy Regulations,
1920, Article 76.
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BUREAU OF ORDNANCE
WASHINGTON 25. D. C.
31 July 1947
ORDNANCE PAMPHLET 1180 (VOLUME 1)
TURRET DESCRIPTION AND OPERATION,
8-INCH THREE-GUN TURRETS, USS SALEM CLASS
1. Ordnance Pamphlet 1180 (Volume 1) describes and provides operating and maintenance instructions for the turret of the rapid-fire automatic 8-inch guns of heavy cruisers of the USS SALEM class. It includes appended general engineering data and Safety Precautions applying to the guns and to all other turret installations.
2. This publication, together with the references of paragraph three, provides complete information for all installations of the turrets. It is to be used by operating personnel, maintenance personnel ashore and afloat, personnel of installing activities, inspectors, and the Advanced Technical Service Schools, and all other training activities providing instruction concerning the gun and its mount services.
3. Ordnance Pamphlet 1180 (Volume 1) is one of a series of six volumes describing the turret, turret operation, and all of the turret installations. The other volumes are designated:
OP 1180 (Volume 2)-Guns and Slides
OP 1180 (Volume 3)-Elevating and Training Gear Drives and Controls
OP 1180 (Volume 4)-Ammunition Stowage and Hoist Equipment
OP 1180 (Volume 5)-Turret Fire Control and Electrical Installations
OP 1180 (Volume 6)-Tools, Accessories, and General Instructions for Turret Installations
4. This publication supersedes two volumes of a limited blueprint edition issued by the Naval Gun Factory for interim use of the Advanced Technical Service Schools, designated: OP 1180 (Preliminary), Chapters 1 and 2, respectively.
5. This publication is RESTRICTED and shall be safeguarded in accordance with the security provisions of U. S. Navy Regulations, 1920, Article 76.
G. F. HUSSEY, JR.
Vice Admiral, U. S. Navy
Chief of the Bureau of Ordnance
USS SALEM is the first of a new class of heavy cruisers. The hull is larger; the belt and deck armor are more extensive; and the fire power is greater than in ships of the BALTIMORE and earlier classes. The displacement is 17,000 tons. Over-all length is 716.5 feet; the beam 76.5 feet.
Anti-aircraft, secondary, and main batteries and fire control installations include new ordnance types and new arrangements.
Anti-aircraft batteries. Forty-eight minor-caliber guns comprise the defensive anti-aircraft armament. These guns are arranged in two batteries; twelve twin mounts of 20-millimeter machine guns are symmetrically located on the weather deck and in the superstructure; twelve twin mounts of 3-inch/50 caliber guns are em-placed on the weather deck and on pedestals above it.
The 3-inch mount is a new automatic, rapid-fire type, tactically replacing the 40-millimeter anti-aircraft installations of earlier ships. The mounts are located and arranged for independent or divided fire control. Four mounts are on the weather deck-two forward on centerline, and two aft at the transom. Eight are amidship-four port and four starboard-in positions that permit low-angle fire over adjacent mounts of the secondary battery.
Secondary battery. Six twin 5-inch, enclosed, dual-purpose mounts, of the same type and arrangement of earlier cruisers, comprise the secondary battery. They are located as follows: two port, two starboard on the weather deck amidship, and one before and one abaft the superstructure, on centerline at the second superstructure deck.
Main battery. The main battery consists of three 8-inch 3-gun turrets, described in this ordnance pamphlet. They are rapid-fire, automatic turrets of an entirely new design.
All three turrets are located on centerline, the gun houses of turrets I and III being immediately above the weather deck while that of turret II is at the level of the first superstructure deck. Turret centers are 157.5, 205.5, and 538.5 feet (for turrets I, II, and III respectively) from the bow. Gun trunnion axes, in the same order, are 27 feet 9 inches, 36 feet 2 inches, and 28 feet 9 inches above the 24-foot waterline. These positions and the large arcs of train provide fire concentration of nine guns on either beam, six forward and three astern.
All turrets are virtually identical. Their gun house and below-deck structures, emplacements, magazines, and Ordnance installations only differ in minor details, adapting each to its ship location and the fire control plan.
Turret structural and space arrangement plans however differ substantially from the conventional turret designs of all previous battleships and cruisers. This difference is due, in part, to the use of semifixed ammunition, for the first time in Ordnance of this size, and, in part, to the design types and details of the guns and the ammunition handling equipment. These ammunition and Ordnance equipment designs have permitted and required omission of flameproof bulkheads separating the guns, the control stations, and the powder service.
The emplacements are conventional foundation structure, barbette, and magazine designs. Their arrangements are quite similar to those of earlier heavy cruisers, differing principally in the magazine stowage provisions and powder-passing scuttles for powder cases instead of powder bags.
In their Ordnance installations, the turrets are entirely new. The guns operate automatically, and require no attendants in the gun compartment; they fire at three times the rate of the 3-gun turrets of the BALTIMORES. Other features are: comparatively fast gun laying and turret train drives; loading at all angles, while gun laying; substitution of radar range taking equipment for optical rangefinder; local radar train control; automatic fuze setting; and other original fire control arrangements for local and remote control.
Fire control installations. The ship's fire control installations comprise extensive arrangement of optical and radar director equipment, together with related computing and stabilizing devices. The system is more complex than that of any prior cruiser. It includes forward and after main battery directors; four secondary battery directors, one each located forward, port, starboard and aft; multiple directors for
the 3-inch mounts; and four plotting rooms, two each for main and secondary batteries. Plot switching arrangements permit many variations of control.
Main directors are combination radar and optical rangefinder types, adapted, with their plotting room equipments, for divided turret control or single control of all turrets, using remote automatic or remote indicating control.
Secondary directors are of two types. The ones above the superstructure, on centerline, are combination radar and optical rangefinder types of modified Mk 37 design. The other two are an all-radar type of new variation of a similar design. These directors and their switching circuits are arranged to function as auxiliary directors for the main battery.
The directors for the 3-inch battery are fast-tracking, lead computing, gun sight combinations of radar-ranging and open sight arrangement.