History
PRC
Status	Active
General characteristics
Class and type	Duda class
Type	Tug
Length	31 m (101 ft 8 in)
Sensors and processing systems	Navigation radar
Electronic warfare & decoys	None
Armament	Unarmed
Aircraft carried	None
Aviation facilities	None

Duda class large harbor tug (YTB) is a class of little known naval auxiliary ship currently in service with the People's Liberation Army Navy (PLAN),^{[1][2][3][4][5]} and has received NATO reporting name Duda class,^[2][3][4][5] with exact type still remains unknown. A total of eleven of this class have been confirmed in active service as of 2022^{[1][2][3][4][5]} Unlike other tugs in Chinese service, This class is the only tug having a chimney with rectangular/square cross section, and thus easily distinguishable by the sharp edges of the chimney.^[1]

Ships of this class in PLAN service are designated by a combination of two Chinese characters followed by a three-digit number. The second Chinese character is Tuo (拖), meaning tug in Chinese, because these ships are classified as tugboats. 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 are subject to change due to changes of Chinese naval ships naming convention, or when units are transferred to different fleets. Specification:^[2][3][4][5]

• Length: 31 meter

v t e Active ships of the People's Liberation Army Navy
Submarines Nuclear ballistic missile (SSBN) Type 096* Type 094 (Jin class) Type 092 (Xia class) Nuclear attack (SSN) Type 095* Type 093/A (Shang class) Type 091 (Han class) Conventional ballistic missile (SSB) Type 032 (Qing class) Conventional attack (SS/SSK) Air-independent propulsion equipped (SSI/SSP) Type 039A/AG/B/C or Type 041 (Yuan class) Hunter-killer (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 (SS) ES5C/D and Type 035/035A (Ming class) Unclassified miscellaneous (IXSS) Chinese sailless submarine Olympics Class
Principal surface combatants Aircraft carriers (CV) Chinese aircraft carrier programme Type 004* Type 003* Type 002 (Kuznetsov Mod. class) Type 001 (Kuznetsov class) Destroyers (DDG) Type 055CG (Renhai class) Type 052D (Luyang III class) Type 052C (Luyang II class) Type 052B (Luyang I class) Type 052 (Luhu class) Type 051C (Luzhou class) Type 051B (Luhai class) Project 956EM Sovremenny II class Project 956 Sovremenny I class Frigates (FFG) Type 054B* Type 054A (Jiangkai II class) Type 054 (Jiangkai I or Ma'anshan class) Type 053H3 (Jiangwei II class) Type 053H1G (Jianghu V class) Type 053H1 (Jianghu II class)
Coastal warfare vessels Corvettes (FS) Type 056FF (Jiangdao 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 Armed merchantmen (SP) Type 113 Type 801 Type 8105 Type 8101 Type 8154 Type 792 naval trawlers Missile boats (PCM) Type 22 (Houbei class) Type 037-II (Houjian class) Type 037-IG (Houxin class) Type 021 (Houdong class) Type 021 (Huangfeng class or 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) Gunboats (PG) Type 062-I (Shanghai III class) Type 062 (Shanghai II class) Type 062 (Shanghai I class) Type 206 (Huludao class) Patrol boats (PB) Seagoing Type 026H Port security boat (PSB) Huangpu class Reconnaissance patrol combatant (PGR) Type 528 Type 865
Amphibious warfare vessels Landing helicopter dock (LHD) or Landing helicopter assault (LHA) Type 076* Type 075 (Yushen class) Amphibious transport dock (LPD) Type 071 (Yuzhao class) Dock landing ship (LSD) Type 072III (Yuting I 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) 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) Landing craft (LC) Landing craft tank (LCT) Type 068/069 (Yuch'in class) Type 067 (Yunnan class) Landing craft utility (LCU) Type 271III Type 074 (Yuhai or Wuhu-A class) Air-cushioned landing craft (LCAC) Project 1232.2 Zubr class Type 726 (Yuyi class) Type 724 Type 722-II (Jinsha II class) Type 722-I (Jinsha I class) Type 716-II (Dagu B class)
Mine warfare vessels (MCM) Minelayers (ML) Type 918 (Wolei class) Auxiliary minelayers (MMA) Type 8154 Minehunters (MH) Type 081 (Wochi class) Type 081A Type 082 (Wosao class) Type 082II (Wozang class) Minesweepers (MS) Type 010 Type 05 Minesweeping drone (MSD) Type 529 Type 312 (Futi class) Auxiliary Minesweepers (MSA) Type 801 Type 8105 Type 8101 Type 8154 Type 792
Auxiliary vessels Ammunition ships (AE/AEM) Ammunition ship (AE) Type 072 (Yantai class) Ammunition ship, Missile/Rocket (AEM) Yuan Wang 21 (operated by SSF) Yuan Wang 22 (operated by SSF) Buoy tenders (AGL) Type 066 Yuch'in class Type 744A Yannan class Type 911I Yunan/Yunnan class Type 944A Yanni class Cable layers (ARC) Type 911II Yunan/Yunnan class Type 991I Type 991II Youdian class Cargo ships (AK) Reefer ships (AF) Dongleng class Cargo ships (AK) Qiongsha class Retired landing ships/crafts Float-on/float- off ships (AKF) Modified Hansa Sonderberg class Donghai Island Zhen Hua 33 General stores issue ships (AKS) Type 904 Dayun class Type 904A Danyao class Type 904B Danyao II class Roll-on/roll- off ships (AKR) Bo Sea Pearl class Chang Da Long China Revival China Railway Bo Sea No.3 Container ships (AKX) Converted/militarized container ships Self-propelled lighters/barges (YF) 500 cubic meter Dongbo 22 Crane ship (AB) Beiqi 384 class Unidentified class: Nan-Qi 746 Degaussing / deperming ships (ADG) Type 911 Dazar class Type 912/912I/912III/Type 912IIIA Yanbai class Type 912IIIAH Yanci class Dive tenders (YDT) Longma class ARS/YDT Type 904I/904II Yanqian class AGE/YDT Dredgers (AGD) 8-m3 class Beijun 204 class Dongjun 417 class Dongjun 433 class Dongjun 434 class Nanjun 610 class Dredgers of unknown class/type: Bei-Jun 271, 273, 274, 277 & 278 Engineering ships Engineering ships of unknown class/type: Bei-Gong 275 & 276 Environmental research ships (AGER) Dulaji class Fleet Replenishment ship (AEFS) Type 901 Fuyu class Type 903 Fuchi I class Type 903A Fuchi II class Type 908 Fusu class Floating pile drivers (YPD) 36-m class floating pile driver Donggong 429 class Nangong 681 class General purpose research ships (AGE) Dubei class AGT/AGE Kandao class YFB/AGE Kantan class AGTR/AGE Type 904I & Type 904II Yanqian class YDT/AGE Type 906 Xiang Yang Hong 9 class YTT/AGE Harbor utility craft (YFU) Converted from various retired gunboats such as Type 53 and Type 55A Hospital ships (AH) Hospital ships (AH) Type 919 Anshen class Type 920 Anwei class Medical evacuation ships (AHP) Zhuanghe Ambulance transports (APH) Qiongsha class Ambulance craftd (YH) Ankang class Hydrographic survey ships (AGS) Type 55 Shantou class Type 068/069 (Yuch'in class) Type 635 A/B/C & Type 635II Yanlai class Type 636A Shupang class Type 639A Shupang class Type 646 Kanyang class Type 8101 Type 8105/Type 8154/Type 792 FT-14 AIT class Yanjiu class Icebreakers (AGB) Type 272 Museum ships PLANS Heroic Gunboat in the Toumenshan Naval Battle PLANS Liberation Minquan-class gunboat (replica) Project 183 P-6-class torpedo boat Type 021 missile boat Type 024 missile boat Type 031 ballistic submarine (SSB) Type 033 submarine (SS) Type 051 destroyer (DDG) Type 053K frigate (FFG) Type 091 submarine (SSN) Type 6607 destroyer (DDG) Oceanographic research ships (AGOR) Type 639A Shupang class Type 645 Zhang Jian Oceanographic surveillance ships (AGOS) Ruili No. 10 Type 927 Dongjian class Type 988 Personnel transport (AP) Barracks ships (APB) Daguan class AXT/APT/APB Dispatch boat (YFB/YFL) Duchuan class Dufei class Dukou class Duludao class Dumujiu class Dusso class Duzhou class Nanjiao 90 class Transport ships (AP) Type 081 Red Flag class Darong class APT/AP Troopships (APT) Daguan class AXT/APB/APT Darong class AP/APT Qiongsha class Range support & target ships (AGT) Dachou class TR/TWR/AGT Dubei class AGE/AGT Type 811 Type 917 Damen class TR/TWR/AGT Decommissioned ships 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) Datuo class ATR/ARS Haijiu 101 class Longma class YDT/ARS Type 917 Dasan class Salvage ships (ATS) Type 922II Dalang class Type 922III Dalang II class Type 922IIIA Dalang III class Spy ships (AGI) Type 814A Dadie class Type 815 Dongdiao I class Type 815G/Type 815A Dongdiao II class Type 8105/Type 8154/Type 792 FT-14 AIT class 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 Dalao class Submersibles (X) Deep-submergence rescue vehicle (DSRV) Type 7103 DSRV LR7 Deep-submergence vehicle (DSV) Harmony class Jiaolong class Rainbowfish class Sea Pole class Struggler 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) Hua Chuan Transport oiler (AOT) Fubai class Fujian class Fushi class Type 620 Shengli class Type 631 Fuchang class Type 637 Fuxiao class Water tanker (AWT) Fujian class Fushi class Jinyou class Nanshui 701 class Type 637 Fuxiao class Type 645 Guangzhou class Technological research ships Sonar trials ships Kantan class AGE/AGTR Technical research ships (AGTR) Mirage Hunter Unclassified Miscellaneous Submarine (IXSS) Chinese sailless submarine Torpedo trials craft Torpedo retrievers (TR/TWR) Dachou class AGT/TR/TWR Type 803 Type 917 Damen class AGT/TR/TWR Torpedo trials ships (YTT) Type 906 Xiang Yang Hong 9 class AGE/YTT Type 907A Tracking ship (AGM) Type 830 ATR/AGM Yuanwang class ARIS/AGM Training ships (AX) Training ship (AX) Daguan APB)/APT/AXT Type 0891A Dashi class Type 679 Daxing class Type 680 Dadu class Yanxi class ATLS/AX Training ship, sail (AXS) Type 2630 Onshore stationary training facilities Type 033 (Romeo class) Type 051/051Z (Luda class) Type 053H1Q (Jianghu-IV class) Type 6607 (Anshan class) Tugs (AT) Harbor tug (YT) Beituo 617 class Beituo 699 class Beituo 702 class Beituo 715 class Large harbor tug (YTB) Ducha class Duda class Duhast class Dupo class Rescue Tug (ATR) Bei-Tuo 739 class Datuo class ARS/ATR Dong-Tuo 835 class Haixiu 121 class Daozha class Type 830 AGM/ATR Sea-going Tug (ATA) Type 802 Gromovoy class Type 837 Hujiu class Type 852 Roslavl class Tugs of unknown class/type Bei-Tuo 153, 651, 704, 728, Dong-Tuo 845, 861, Nan-Tuo 142, 163, 168, 176, 187, 188 UAV mothershps (ATLS) Fighting Shark No.1 Yanxi class AGM/AVM/ATLS Unmanned surface vehicles (USV) CASIC USVs Chinese Sea Hunter Sky Journey 1 HUST USVs JARI USV JUST USV Ostar USVs PWT USV Shanghai University USV Type 80 demolition boat VVLAI USV WSST USVs Yunzhou USVs Unmanned underwater vehicles (UUV) Autonomous underwater vehicle (AUV) CR series Explorer series HSU-001 Intelligent Water class JUST AUVs Micro Dragon Series Orange Shark series Ostar AUVs Poseidon series Robosea AUVs Sea Clever Sea Whale series Submerged Dragon series THLMT AUVs Wukong WZODA XTDT Benthic landers CAS series Rainbowfish series Bottom crawlers Aquadrobotman series CSSC series Deepinfar series JUST series Robosea series SBSS series Sea Crab Sea Star THLMT unmanned vehicles#Underwater series VVLAI series Hybrid UUVs (Autonomous remotely -operated vehicles, ARVs) 7B8 Arctic series Hadal Hadal 1 Rainbowfish ARV Remotely operated underwater vehicle (ROUV) 8A4 8H4 Aquarobotman ROUV Deepinfar ROUVs Discovery Dragon Emperor Dragon Pearl Goldfish series JH-01 (Jiao-Hai 01) JTD-01 Deep Eel I JTML-02 JTMP series JTR series JUST ROUVs Max ROV Oceanxer ROUVs Ostar ROUVs PWT ROUV RECON-IV ROUV Robosea ROUVs SBSS ROUVs Sea Dragon series Sea Person (Hai-Ren/HR) series Sea Pole Sea Star 6000 Sea Submergence series SJT series ST-6000 THLMT ROUVs VVLAI ROUVs Walrus 1500 Underwater gliders Flying Wing Petrel series Sea Soar series Deepinfar Sea Wing series THLMT series Wave gliders CSSC series Hydrovo series Ostar series THLMT Black Pearl Weapon trials ships (AVM/AGM) Type 909 Wuhu-B class Type 909A Dahua class Type 910 Dahua-II class
* = Under construction or procurement, CG= Classified as guided missile cruiser by NATO, FF= Classified as light frigate by PLAN