| History | |
|---|---|
| Name | Beidiao 991 | 
| Namesake | North Investigation 991 | 
| Builder | CSIC | 
| Commissioned | April 2008 | 
| In service | 2008 | 
| Homeport | Dalian | 
| General characteristics | |
| Type | Multipurpose research ship (AGE) | 
| Displacement | 1,441 long tons (1,464 t) | 
| Length | 64 m (210 ft 0 in) | 
| Beam | 23 m (75 ft 6 in) | 
| Installed power | 2800 kW | 
| Propulsion | Marine Diesel | 
| Speed | 11 kt | 
| Range | 1500 nm | 
| Endurance | 7 days | 
| Complement | 32 | 
| Electronic warfare  & decoys  | None | 
Chinese Research Ship Beidiao 991 is a research ship that has served both in civilian use and in the People's Liberation Army Navy (PLAN).[1][2][3][4] It was built in the People’s Republic of China (PRC). This ship has the NATO reporting name Kandao (Chinese: 勘岛),[5][6][7][8] meaning Surveying Island.
Design
The steel-hulled Beidiao 991 adopts a Small-waterplane-area twin hull design, with a 2800 kW Integrated electric propulsion (IEP). It is the first ship with a displacement greater than one thousand tons to adopt an IEP in China.[1][2] Research activities are conducted on the 120 square meter afterdeck and the five onboard labs (two on port, two on starboard, and one at the stern).[1][2] The ship is equipped with a galley, conference room, command center, and various equipment for different scientific research missions, such as hydrographic, oceanographic, geologic and acoustic surveys.[1][2]
Initial service proved unsatisfactory: when operating in high seas. The ship suffered from excessive vibration that generated enough noise to prevent onboard scientific research equipment from working properly.[1][2] Fuel and fresh water reserves were inadequate, causing a need for frequent replenishment.[1][2]
The ship went through a major upgrade to resolve these issues,[1][2] which resulted in a Type 639 oceanographic surveillance ship that is forty percent larger with displacement reaching fifteen hundred tons.
| Type | NATO designation | Pennant No. | Name (English)  | 
Name (Chinese)  | 
Commissioned | Displacement | Fleet | Status | 
|---|---|---|---|---|---|---|---|---|
| Beidiao 991 multipurpose experimental ship (AGE) | Kandao class | Bei-Diao 991 | North Investigation 991 | 北调 991 | April 2008 | 1441 t | North Sea Fleets | Active | 
References
- 1 2 3 4 5 6 7 "Chinese research ship Beidiao 991". Sohu (in Simplified Chinese). December 17, 2017.
 - 1 2 3 4 5 6 7 "Chinese research vessel Beidiao 991" (in Traditional Chinese). December 12, 2017.
 - ↑ "Beidiao 991" (PDF) (in Simplified Chinese). September 15, 2017.
 - ↑ "Beidiao 991 research ship" (in Simplified Chinese). April 16, 2021.
 - ↑ "PLANS recognition guide 2018". July 16, 2018.
 - ↑ "PLANS recognition guide 2019". February 19, 2020.
 - ↑ "PLANS recognition guide 2020". February 19, 2020.
 - ↑ "PLANS recognition guide 2015". August 7, 2015.