The KD gun series by Oerlikon were originally developed for army air defense and was considered as one of the most successful post-World War II anti-aircraft defense weapons. Oerlikon and OTO-Melara have both produced naval versions.
The muzzle velocity of each gun is measured and this data is fed back to the gun-laying computer. Each gun has two belt feeds and can be switched between belts in about two seconds, allowing for a rapid change over for different ammunition types.
Ammunition for these weapons is produced by at least fourteen countries, including the PRC.
| Designation | Gun: Oerlikon 35 mm/90 KDC |
|---|---|
| Ship Class Used On | Iran: Mark 7 frigate
Greece: Missile Boats Japan: Patrol Boats |
| Date Of Design | about 1965 |
| Date In Service | 1972 |
| Gun Weight | N/A |
| Gun Length oa | 186.6 in (4.740 m) |
| Bore Length | Including muzzle brake: 146.1 in (3.710 m)
Without muzzle brake: 138.2 in (3.510 m) |
| Rifling Length | N/A |
| Grooves | N/A |
| Lands | N/A |
| Twist | N/A |
| Chamber Volume | N/A |
| Rate Of Fire | 550 rounds per minute per gun cyclic |
Weapon components are completely interchangeable and can be assembled for left or right feed.
| Type | Fixed |
|---|---|
| Weight of Complete Round | HE-I: 3.48 lbs. (1.58 kg)
SAPHEI-T: 3.48 lbs. (1.58 kg) APFSDS-T: 3.20 lbs. (1.45 kg) FAPDS: 3.17 lbs. (1.44 kg) AHEAD: 3.90 lbs. (1.77 kg) |
| Projectile Types and Weights | HE-I: 1.21 lbs. (0.550 kg)
SAPHEI-T: 1.21 lbs. (0.550 kg) APFSDS-T: 0.86 lbs. (0.388 kg) FAPDS: 0.83 lbs. (0.375 kg) AHEAD: 1.65 lbs. (0.750 kg) |
| Bursting Charge | HE-I: 0.24 lbs. (112 gm)
SAPHEI-T: 0.05 lbs. (22 gm) APFSDS-T: N/A (solid sub-caliber penetrator) FAPDS: N/A (solid sub-caliber penetrator) AHEAD: N/A (uses 152 3.3 gm sub-projectiles) |
| Projectile Length | Projectile: N/A
Complete Round HE-I and SAPHEI-T: (38.7 cm) APFSDS-T and FAPDS: (34.0 cm) |
| Propellant Charge | 0.73 lbs. (0.33 kg) NC 01 T 35 (single based) |
| Cartridge | 35 mm x 288 |
| Muzzle Velocity | HE-I: 3,850 fps (1,175 mps)
SAPHEI-T: 3,850 fps (1,175 mps) APDS-T: 4,724 fps (1,440 mps) FAPDS: 4,724 fps (1,440 mps) |
| Working Pressure | 24.6 tons / in2 (3,875 kg / cm2) |
| Approximate Barrel Life | N/A |
| Ammunition stowage per gun | 1 2 |
| Elevation | Distance |
|---|---|
| Surface | 8,700 yards (8,000 m) |
| AA | 5,500 yards (5,000 m) |
Optical control or local control greatly reduces these figures.
| Time | Distance |
|---|---|
| 0.96 seconds | 1,090 yards (1,000 m) |
| 2.18 seconds | 2,190 yards (2,000 m) |
| 3.80 seconds | 3,280 yards (3,000 m) |
| 6.06 seconds | 4,370 yards (4,000 m) |
| Time | Distance |
|---|---|
| 0.73 seconds | 1,090 yards (1,000 m) |
| 1.57 seconds | 2,190 yards (2,000 m) |
| 2.38 seconds | 3,280 yards (3,000 m) |
| 3.34 seconds | 4,370 yards (4,000 m) |
| Designation | Single Mount: N/A 1a |
|---|---|
| Weight | GDM-A: 10,500 lbs. (4,763 kg) without ammunition
GDM-C: 17,637 lbs. (8,000 kg) including ammunition |
| Elevation | GDM-A: -15 / +85 degrees
GDM-C: -15 / +85 degrees |
| Elevation Rate | GDM-A
70 degrees per second maximum Acceleration 130 degrees per second GDM-C
|
| Train | 360 degrees |
| Train Rate | GDM-A
120 degrees per second maximum Acceleration 160 degrees per second GDM-C
|
| Gun recoil | N/A |
- ^The single gun version used by the Japanese was manually controlled and had a sidecar for the gunner.
- ^The GDM-A is the original Oerlikon design. This mounting is mostly above the weather deck with only control and power cables going below. The mounting can be remotely controlled, locally controlled using an optical gunsight, or locally controlled using an integrated radar and computer system with an optical sight.
- ^The GDM-C version was developed as a joint project between Oerlikon and OTO-Melara. This mounting has a stalk penetrating the weather deck which include hoists running from below-deck magazines up to the gunhouse. This mounting can be controlled in the same three modes as the GDM-A mounting. The GDM-C requires two loaders plus a gunlayer if it is not in remote control mode. A US Navy Foreign Ordnance Review Team concluded about 1971 that this version was better suited to US requirements, but none were purchased.
- ^The GDM-C mount is gyrostabilized and requires a power source of 43 KW.
"Jane's Pocket Book 9: Naval Armament" edited by Denis Archer
"The Naval Institute Guide to World Naval Weapon Systems 1991/92" by Norman Friedman
"Jane's Ammunition Handbook: Ninth Edition 2000-2001" edited by Terry J. Gander and Charles Q. Cutshaw
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"Defense & Armament Heracles International" Issue #72, April 1988
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Press releases:
Oerlikon Contraves AG
OTO-Melara
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Special help by Matthew Rodchenko
19 November 2008 - Benchmark
25 November 2024 - Converted to HTML 5 format and added mounting details