Type 631 replenishment tanker

History
PRC
General characteristics
Displacement:	2,300 long tons (2,300 t)
Length:	60 m (196 ft 10 in)
Beam:	10 m (32 ft 10 in)
Draught:	3.3 m (10 ft 10 in)
Propulsion:	2 × marine diesel engines, 7,200 hp (5,369 kW) 2 shafts
Speed:	10 knots (19 km/h; 12 mph)
Complement:	30

Type 631 tanker is a type of naval auxiliary ship currently in service with the People's Liberation Army Navy (PLAN).^[1] Originally designed as a type that is capable of transport both water and oil, but only the oiler version entered service with PLAN.^[1]

Type 631 tankers in PLAN service are designated by a combination of two Chinese characters followed by three-digit number. The second Chinese character is You (油), meaning oil in Chinese, because these ships are classified as oilers. The first Chinese character denotes which fleet the ship is service with, with East (Dong, 东) for East Sea Fleet, North (Bei, 北) for North Sea Fleet, and South (Nan, 南) for South Sea Fleet. However, the pennant numbers may have changed due to the change of Chinese naval ships naming convention. Type 631 can be easily distinguished from other transport oilers by its transfer stations amid ship that enables it to carry out underway replenishment missions.^[1] Another visual cue of this class is that from the bow to the midsection of the ship, there are three levels of freeboard, while all other Chinese tanker has a smooth curvy transition.^[1]

References

Ship classes of the People's Liberation Army Navy
List of active ships
Submarines (list)	Nuclear ballistic missile (SSBN) Type 096 Tang class* Type 094 Jin class Type 092 Xia class Nuclear attack (SSN) Type 095 ? class* Type 093/G Shang class Type 091 Han class Conventional ballistic missile (SSB) Type 032 Qing class Modified Project 629 Golf class: Type 6631/031+ Conventional attack (SS/SSK) Air-independent propulsion equipped submarine (SSI/SSP) Type 039A/AG/B/C (Type 041)Yuan class Hunter-killer submarine (SSK) Type 039/039G Song class Project 636 Kilo II class Project 877EKM Kilo I class ES5E/F and Type 035G/035ET/035B Ming class Medium submarines (SS) ES5C/D and Type 035/035A Ming class Project 633+/Type 6633+/033+/ES5A+/ ES5B+/Romeo class Type 033G+ Wuhan class Type 033G1 Wuhan-A class+ S class+ Midget submarines (SSM) M class+ Type 032+ Type 032-1+ Type 030+
Principal surface combatants	Aircraft carriers (CV) Chinese aircraft carrier programme Type 002 class* Type 001A class* Type 001 class Liaoning (16) Cruisers (CL) Arethusa class: HMS Aurora (12)+ Destroyers (DDG) Type 055 class* Type 052D class Type 052C Luyang II (Lanzhou) class Type 052B Luyang I class Type 052 Luhu class Type 051C Luzhou class Type 051B Luhai class Type 051DT Luda IV class Type 051G1/G2 Luda III class Type 051 Luda II class Type 051 Luda I class+ Project 956EM Sovremennyy II class Project 956 Sovremennyy I class Anshan class+ Frigates (FFG) Type 054B class* Type 054A Jiangkai II class Type 054 Jiangkai I (Ma'anshan) class Type 053H3 Jiangwei II class Type 053H2G Jiangwei I class Type 053H1G Jianghu V class Type 053H1Q Jianghu IV class Type 053H2 Jianghu III class Type 053H1 Jianghu II class Type 053H Jianghu I class
Coastal warfare vessels	Corvettes (FS) Type 056 Jiangdao class Bathurst class+ Castle class+ Flower class+ Submarine chasers (PCSC) Type 037-IS Haiqing class Type 037-I Haijiu class Type 062-I Haizhui class Type 037 Hainan class Project 122bis Kronshtadt class Coastal defence ships (K) Etorofu class+ Type C (No. 1 class)+ Type D (No. 2 class)+ Ukuru class+ Yongfeng class+ Armed merchantman (SP) Ruijin class+ Naval trawlers Missile boats (PCM) Type 022 Houbei class Type 037-II Houjian class Type 037-IG Houxin class Type 021 Houdong class Type 021 Huangfeng (Soviet Osa-I) class Type 021 Hola class C 14 China Cat class Type 024 Heku/Hegu/Houku/Hougu class Torpedo boats (PT) Type 6625/025/026/026II/R704 Huchuan class Type 027/027IIB Huzhou class+ Type 6602/6702/02/7102II+ P4 class+ P6 class+ P8 class+ Gunboats (PG) Seagoing Type 062-I Shanghai III class Type 062 Shanghai II class Type 062 Shanghai I class Type 206 Huludao class Type 55/55AShantou class+ Beihai class+ Type 53/53A/54AHuangpu class+ Yulin class+ Hashidate-class gunboat+ Type 0101+ Type 0105+ Type 0109+ Type 0112+ Type 52/52A+ Riverine (PBR) Atami class+ Falcon class+ Fushimi class+ Minquan class+ HMS Gannet+ Seta class+ Toba class+ Patrol boats (PB) Seagoing Type 026H Reconnaissance patrol combatant (PGR) Type 528 Type 865
Amphibious warfare vessels	Landing helicopter dock (LHD) or Landing helicopter assault (LHA) Type 075 LHA/LHD ? class* Amphibious transport dock (LPD) Type 071 Yuzhao class Dock landing ship (LSD) Type 072III Yuting II class Type 072A Yuting II class Landing ship helicopter (LSH) Type 073-III Yudeng class Type 073A Yunshu class Landing ship tank (LST) Type 072 Yukan class Type 072-II Yuting I class LST-542 class+ Landing ship medium (LSM) Type 271IIIA Yulü class Type 073-I Yudao class Type 073-II Yudao class Type 073-IIY Yudao class Type 074A Yubei class Type 079-I Yulian class Type 079-II Yulian class LSM-1 class+ Landing craft (LC) Landing craft infantry (LCI) LCI(L)+ Landing craft mechanized (LCM) Type 363/363A/55 LCM+ Landing craft tank (LCT) Type 068/069 Yuch'in class Type 067 Yunnan class Type 066/066K/066A Yuzhai class+ LCT Mk 5 & Mk 6+ Landing craft utility (LCU) Type 271-I Yupen class+ Type 271-II+ Type 271-IID+ Type 271III Type 074 Yuhai (Wuhu-A) class LCU 1600 series+ Air-cushioned Landing Craft (LCAC) Project 1232.2 Zubr class Type 726Yuyi class LCAC Type 724 LCAC Type 722-II Jinsha II class LCAC Type 722-I Jinsha I class LCAC Type 716-II Dagu B class LCAC Type 716-I Dagu A class LCAC+ Type 711 LCAC+ Songling LCAC+
Mine warfare vessels (MCM)	Minelayers (ML) Type 918 Wolei class Sokuten class+ Minehunters (MH) Type 081 Wochi class Type 081A Type 082 Wosao class Type 082II Wozang class Minesweepers (MS) Type 057K Lianyun class+ Type 010 Type 6605+ Type 6610+ Type 05 T-43 class+ Type 058+ Type 7102+ Type 062 Fushun class+ Minesweeping drone (MSD) Type 529 Type 312 Futi class
Auxiliary vessels	Ammunition ships (AE/AEM) Ammunition ship (AE) 400t-class Yantai class Ammunition ship, Missile/Rocket (AEM) Yuan Wang 21 Yuan Wang 22 Buoy tenders (AGL) Type 066 Type 744 Yannan class Type 911I Type 985 Type 994 Type 999 Type 999G Type 999HG Cargo ships (AK) Cargo ships (AK) Danlin class Dandao class Galați class Qiongsha class Flow-on/flow- off ship (AKF) Donghai Island class General stores issue ships (AKS) Type 904 Dayun class Type 904A Type 904B Reefer ships (AF) Dongdao class Dongleng class Roll-on/roll- off ship (AKR) Type 701 Self-propelled lighter/barge (YF) 500 cubic meter class barge Dongbo 22 class Dongbo 39 class Degaussing / deperming ships (ADG) Type 911 Type 912 Type 912I Type 912III Yanbai class Type 912IIIA Type 912IIIAH Type 915+ Type 916+ Type 918+ Type 601+ Sea Fish 16 class+ Yan Fang class+ Yerka class+ Dive tenders (YDT) Type 904I Type 904II Engineering ships Cable layers (ARC) Type 890 Youzheng class Type 911II Type 991I Type 991II Youdian class Crane ship (AB) Beiqi 346 class Beiqi 384 class Dredgers (AGD) 8-m3 class Beijun 204 class Dongjun 417 class Dongjun 433 class Dongjun 434 class Nanjun 610 class Floating pile drivers (YPD ) 36-m class floating pile driver Donggong 429 class Nangong 681 class Hospital ships (AH) Hospital ships (AH) Type 920 hospital ship Medical evacuation ships (AHP) Zhuanghe Ambulance transports (APH) Qiongsha class Cargo ship, rescue / medical evacuation (APR) Type Long March+ Ambulance craftd (YH) Beiyi 01 class Icebreakers (AGB) Type 071 Yanha class icebreaker Type 071A Type 071G Type 210 Yanbing class Type 272 Museum ships Dingyuan (replica) Zhiyuan (replica) Zhongshan Decommissioned ships Personnel transport (AP) Barracks ships (APB) Xu Xiake Dispatch boat (YFB) Beijiao 39 class Beijiao 57 class Beijiao 75 class Beijiao 77 class Dongjiao 03 class Dongjiao 82 class Nanjiao 83 class Nanjiao 90 class Transport ships (AP) Type 081 Red Flag class Troopships (APT) Beidiao 990 Qiongsha class Replenishment ship (AEFS) Type 901* Type 903 Fuchi class Type 903A Type 905 Fuqing class Type 908 Fusu (Nancang) class Repair ships (AR) Repair dry docks (ARD) 120t class Dongxiu 912 Hua Chuan No. 1 class Repair ships (AR) Type 648 Dadao class Rescue and salvage ships Heavy-lift ship (YHLC) Type 633 Rescue ships (ARS) Type 917 Salvage ships (ATS) Type 922 Type 922II Dalang class Type 922III Dalang II class Type 922IIIA Dalang II class Scientific research ships Environmental research ships (AGER) 300t-class Hydrographic survey ships (AGS) Type 068/069 Yuch'in class Type 625C Type 635 A/B/C Yanlai class Type 635II Type 636 Type 636A Type 646 Kan Yang class Type 988 Oceanographic research ships (AGOR) Xiangyanghong 5 Type 614III Type 625A/B Type 645 Beidiao 992 Zhang Jian Oceanographic surveillance ships (AGOS) Type 6610 Shuguang class Type 595 Type 639/639A Space exploration tracking ships (ARIS) Yuan Wang 1+ Yuan Wang 2+ Yuan Wang 3 Yuan Wang 4+ Yuan Wang 5 Yuan Wang 6 Yuan Wang 7 Weather ships (AGH) Type 614I Type 614II Spy ships (AGI) Type 813+ Type 814A Dadi class Type 815 Type 815G Submarine support ships Submarine rescue ships (ASR) Type 930 Hudong class Type 946 Dazhou class Type 946A Dadong class Submarine tenders (AS) Type 925 Dajiang class Type 926 Submersibles (X) Deep-submergence rescue vehicle (DSRV) Type 7103 DSRV LR7 Deep-submergence vehicle (DSV) Harmony class Jiaolong class Rainbowfish class Sea Pole class Other Submersibles (X) Osprey-class submersible Mobile diving bell QSZ-II submersible Diver propulsion vehicles (DPV) QX-50 QY-18 QY-40 QJY-001 Tankers Replenishment tanker (AOR) Beiyou 572 class Type 631 Type 905 Fuqing class Transport oiler (AOT) Dongyou 630 class Dongyou 640 class Jinyou class Leizhou class Type 620 Shengli class Type 626 Fuzhou class Type 632 Fulin class Type 637 Type 645 Guangzhou class Water tanker (AWT) Dongshui 649 class Leizhou class Nanshui 701 class Type 626 Fuzhou class Type 632 Fulin class Type 645 Guangzhou class Type 646 Technological research ships Missile range instrumentation ships (AGM) Type 830 Sonar trials ships Beidiao 993 Target ships (AGT) Chinese target ship Experiment 216 Decommissioned ships Technical research ships (AGTR) Mirage Hunter Torpedo retrievers (TR/TWR) Type 803 torpedo retriever Type 917 torpedo retriever Torpedo trials ships (YTT) Type 906 Type 907A Weapon trials ships (AVM/AGM) Yanxi class Type 909 Wuhu-B class Type 909A Dahua class Training ships (AX) Training ship (AX) Type 679 Daxing class Type 0891A Shichang class Yanxi class Decommissioned ships Training ship, sail (AXS) Brave the Wave-class Tugs (AT) Rescue Tug (ATR) Daozha class Type 830 Nantuo 181 class Sea-going Tug (ATA) Type 802 Gromovoy class Type 837 Hujiu class Type 852 Roslavl class Harbor tug (AT) 3200hp-class Beituo 617 class Beituo 625 class Beituo 632 class Beituo 659 class Beituo 699 class Beituo 702 class Beituo 715 class Haixiu 121 class Unmanned underwater vehicles (UUV) Remotely operated underwater vehicle (ROUV) 8A4 ROUV RECON-IV ROUV 7B8 ROUV Goldfish class ROUV HR-01 ROUV HR-02 ROUV JH-01 ROUV SJT-5 ROUV SJT-10 ROUV SJT-40 ROUV Seahorse ROUV Sea Dragon-I ROUV Sea Dragon-II ROUV Autonomous underwater vehicle (AUV) Arctic class ARV Explorer AUV WZODA AUV CR-01 AUV CR-01A AUV CR-02 AUV Intelligent Water class AUV Submerged Dragon 1 AUV Petrel I HUG Petrel II HUG
* = Under construction or procurement + = Retired