Ordnance Pamphlet OP 769, dated 15 October 1967, supersedes OP 769 (Preliminary) dated June 1943 and OP 769 1st Revision (Preliminary) dated December 1953. This technical manual reflects the configuration of the three 16-inch/50-caliber turrets in USS New Jersey (BB-62) at the scheduled completion of ship reactivation on 30 April 1968. The figures below summarize the gun, its projectiles and range tables, firing and recoil data, projectile stowage, and turret geometry. For the complete pamphlet, see the full NAVORD OP-769 turret manual (19 chapters, 4 appendices, and index).
Turret Manuals for the 16″/50
These turret maintenance manuals were printed at about the same time as OP 769 was printed and reprinted:
- SW 330-AA-MMA-010 / 0640-LP-006-3200 — Maintenance Manual for 16-Inch Three Gun Turrets, BB-61 Class. Volume 1, Description; Volume 2, Operation. 1 November 1985.
- SW-330-AA-IPB-010 / 0640-LP-381-6900 — Maintenance Manual for 16-Inch Three Gun Turrets, BB-61 Class. Volume 1, First Revision, Illustrated Parts Breakdown. 1 January 1990.
The 16″/50 Gun and Its Projectiles
The 16″/50 gun was designed to fire the projectiles listed below. The total weight of the gun with recoiling parts is 292,000 pounds. The range tables for these projectiles are calculated with the full service charge of 6 bags of powder — total weight 650 pounds, which is the standard powder charge for this gun.
Mark 8 Mod 0 AP — 2,700-pound projectile
- Length: 72″ · Radius of ogive: 144″
- Muzzle velocity (service charge): 2,425 feet per second
- Range (service charge): 40,185 yards
- Range tables: OP 770 — Range Tables, 16″ AP Mk 8 Mod 0 2700 lb · OP 1457 — Range Tables, 16″ AP Mk 8 Mod 0 2700 lb
Mark 13 Mod 0 HC — 1,900-pound projectile
- Length: 64″ · Radius of ogive: 144″
- Muzzle velocity (service charge): 2,690 feet per second
- Range (service charge): 41,622 yards
- Range tables: OP 1100 — Range Tables, 16″ HC Mk 13 Mod 0 1900 lb · OP 1091 — Antiaircraft Range Tables, 16″ HC Mk 13 Mod 0 1900 lb
Gun Firing and Recoil
- Gun firing order: L, R, C barrels
- Firing delay: 0.06 second — there is no delay for the left barrel
- Recoil period at 15° elevation: 0.43 second
- Counter-recoil period at 15° elevation: 0.90 second
Projectile Stowage
| Stowage location | Turret I | Turret II | Turret III |
|---|---|---|---|
| Upper projectile flat, outer ring | 120 | 70 | 100 |
| Lower projectile flat, outer ring | 125 | 125 | 126 |
| Each inner ring | 72 | 72 | 72 |
| Total stowage | 390 | 460 | 370 |
- Total stowed projectiles: 1,220
- Drill projectiles: 9 per turret, for a total of 27
- For a view of the projectile stowage in the turret, see 7E1 Projectile Stowage (Naval Ordnance and Gunnery, Chapter 7).
Turret Geometry — Iowa-Class Battleships
The Iowa-class battleships have an overall length of 888 feet and a beam of 108 feet.
| Turret | Centerline axis from bow | Trunnion height above waterline |
|---|---|---|
| Turret 16/1 | 224 feet | 26.15 feet |
| Turret 16/2 | 296 feet | 34.65 feet |
| Turret 16/3 | 642 feet | 28.40 feet |
The centerline of the gun trunnions is about 132″ forward of the vertical centerline of the turret. Thus the trunnion of the center gun rotates on an arc of radius 132″ from the centerline of the turret. The left and right gun trunnions, being on the same centerline as the center gun but outboard of it, rotate on a slightly larger arc.