Basic Information

Name

Romeo Class (Project 633 Class) Russian Diesel-Electric Submarine

Designation

Romeo Class

Alternate Designation

Romeo Class; Project 633 Class

Equipment Type

Diesel-Electric Submarine

Manufacturer

Lazurit Central Design Bureau

Date of Introduction

1957

Description

Romeo Class (Project 633 Class) Russian Diesel-Electric Submarine is a class of Soviet diesel-electric submarine, built between 1957 and 1961. A Chinese variant - Type 033 - was built in China from 1962 to 1984. Project 633 was a further development of the Soviet navy's post-war 611 (Zulu-) and 613 (Whiskey-class) designs. The project was undertaken by Lazurit Central Design Bureau of Gorky. Only 20 of the Soviet Union's originally intended 56 were completed between October 1957 and the end of December 1961 because of the introduction of the nuclear submarine into the Soviet Navy. By today's standards, Romeo class submarines are considered obsolete, but they still have some value as training and surveillance vessels.

Naval & Littoral Specifications

Crew 51

Beam 6.70 m

Draft 5.00 m

Variants

Chinese Type 033 Romeo-class and its variants Under the 1950 Sino-Soviet Friendship and Mutual Assistance Treaty, the Soviets passed to China (and later to North Korea) the documentation necessary to produce Romeo submarines in 1963. The Chinese variant is known as the Type 033 Romeo. A total of 84 Type 033 submarines were built in China from 1962 to 1984, plus several exported to other countries. The Chinese Type 033 incorporated some improvements over the original Romeo, including noise reduction of 20 dB. Sonar onboard was also continuously upgraded: the original Soviet sonar was first replaced by domestic Chinese Type 105 sonar, which consequently was replaced by H/SQ2-262A sonar built by No. 613 Factory. Today most of the Type 033 subs have been retired or preserved, with a few remaining in service for training purposes. A total of six Chinese Romeo class submarine variants were developed: Type 6633: Original Chinese-built Romeo, China was to have assembled these Romeos from knock-down kits provided by the Soviet Union, 6 were planned, but only 2 were completed. The construction program came to a complete stop when the USSR stopped the delivery of parts following the Sino-Soviet split. Construction of the 3rd unit at Wuhan was stopped, and available parts were diverted to complete the first pair, but many parts had to be developed indigenously. The primary improvement of Type 6633 over the original Soviet boats is the use of domestic Chinese batteries, which had slightly superior performance to that of the original Soviet batteries. Type 033: Complete domestic production in China was achieved in 1967, and subsequently the project has renamed the Type 033. However, experience from deployment of completed boats in warmer climates proved that the original Soviet refrigeration and air conditioning system designed for the subarctic and arctic area was woefully inadequate for subtropical and tropical regions, so redesigns were needed to improve refrigeration and air conditioning systems, and all boats to be stationed in tropical and subtropical regions went through such a refit. In September 1969 construction of new Type 033s, with improved air conditioning and refrigeration capability, began at Huangpu Shipyard in Guangzhou, eventually, 13 units were completed. ES5A: Upgraded Type 033, with improvements mainly involving the replacement of equipment of Soviet origin with domestic Chinese systems, which includes: QZHA―10 (Type 779) attack periscope and QDYA―10 (Type 778) general-purpose periscope. Addition of H/SQG-2 ranging sonar, Type 063 communication systems, and countermeasure systems. Domestic Chinese Type 801 sonar replaced the original Soviet MARS-24 sonar. The only difference between the Type 801 sonar and the MARS-24 sonar is that there are 24 transducer elements for the Type 801 as opposed to 12 in the original MARS 24, so the Chinese sonar had better accuracy. Domestic Chinese H/SQZ-D reconnaissance sonar (with Type 105 transducers) replaced the original Soviet system, the performance of the SQZ-D is almost identical to the original Soviet sonar it was developed from, except for the sector of the scan, which is increased by 15 degrees. Additional noise reduction measures were also adopted. This is the type China originally sold to Egypt in the 1980s. Type 033G: Development of the ES5A, with the incorporation of the capability to launch acoustic homing torpedoes; analog computers installed to achieve automation of, and speeding up of, torpedo fire control calculations that were previously manually calculated. All Chinese Romeos were converted to this standard. The NATO reporting name for this type is rumored to be the Wuhan class. Type 033G1: A single Type 033G was modified to carry 6 YJ-1 (CSS-N-4) anti-ship missiles, this variant is called Type 033G1, with the rumored NATO reporting name of Wuhan A. The missile had to be fired while the boat was surfaced, with a total exposure time on the surface of fewer than 7 minutes. The most significant improvement, however, is the reduction of the noise level by 12 dB. ES5B: Development of the Type 033G, primarily intended for export. This is an upgrade package for Romeo submarine users. The primary improvement of this class is the ability to launch wire-guided torpedoes and anti-ship missiles (AShM) while submerged. The program began in the mid-1980s, and Egypt is reported to be the only customer when China won a contract to upgrade its Romeo-class submarine fleet, including both Soviet-built and Chinese-built units. This is the last type of Chinese Romeo class submarine; with a noise reduction of 20 dB to 140 dB in comparison to the 160 dB of the original Soviet Project 633 submarines acquired by China.

System

Alternative Designation Romeo Class; Project 633 Class

Type Diesel-Electric Submarine

Builder Krasnoye Sormovo Shipyard, Gorky Wuchang Shipyard (Wuhan) Guangzhou Shipyard (Canton) Jiangnan Shipyard (Shanghai) Bohai Shipyard (Huludao) Mayang-do Naval Shipyard (North Korea) - Assembly site of North Korean kits from China.

Crew 51 total (8 Off. + 43 Enl.)

Dimensions

Length 76.6 m

Beam 6.7 m

Draft 5.0 m

Displacement, Surface 1,319 tons

Displacement, Submerged 1,712 tons

Propulsion System

Engine Name Type 37D

Engine Type Diesel-Electric drive: 2 Type 37D diesels

Engine Power 2,700 total bhp; 2 shafts

Auxiliary Power 2 Electric 100 shp creep motors

Speed, Surface 15.2 knots surface

Speed, Submerged 13 knots submerged

Range, Surface 14,000 nm at 9 kts

Range, Submerged 350 nm at 9 kts

Normal Operation Depth 270.0 m

Maximum Operation Depth 300.0 m

Torpedo Weapon Systems

Torpedo Launcher

Number of Tubes 6 forward 533-mm and 2 aft 533-mm torpedo tubes.

Torpedo (Option #1)

Name SAET-60

Type Heavy Weight Torpedo

Length 7.80 m

Diameter 533 mm

Weight, Total 1.855 kg

Explosive Warhead The SAET-60 uses an electric motor and has a 300 kg high explosive warhead with impact and proximity fuse.

Guidance System Homing Passive acoustic homing

Wire Guidance No

Power Source Silver zinc battery, 46 cells

Propulsion Twin propeller wakeless propulsion

Speed 42 kt

Maximum Range 13 km at 42 kt

Depth Up to 400 m launch depth

Basic Load 14 x SAET-60 Heavy Weight Torpedo

Torpedo (Option #2)

Name Type 53-65

Type Torpedo

Length 7.2 m

Diameter 533 mm

Weight 2,070–2,300 kg

Range 18,000 metres

Speed 83 km/h

Guidance System Wake homing

Warhead 307.6 kilograms (678 lb) high explosive

Basic Load 14 x Type 53-65 Torpedo

Mines

Note Can carry 28 mines in lieu of torpedoes.

Radar Systems

Name 1 x Snoop Plate radar

Type Surface search/navigation

Frequency INA

Range INA

Sonar Systems

Name 1 x 1 Tamir-5L Active Sonar

Type Active Sonar

Protection

Hull INA

Countermeasures INA

NBC Water Washdown System Yes

Electronic Warfare 1 x MRP-11-14 series Stop Light intercept

Image Sources

Note https://en.wikipedia.org/wiki/List_of_active_ships_of_the_Korean_People's_Navy; https://en.wikipedia.org/wiki/Romeo-class_submarine; https://naval-encyclopedia.com/cold-war/ussr/romeo-class-submarines.php