Yno 231 - Western Monarch

Hull No. 231 built by Ulstein Verft AS for Western Geophsysical Company a subsidiary of Western Atlas International Inc.

Yno 231 Western Monarch

The UT 747 Seismic Research Vessel is designed by Ulstein International AS in close cooperation with Western Geophsysical. The UT 747 concept is designed in compliance with advanced and demanding requirements, setteing new dimension into the industry. Executed as Ulstein Verft yard no. 231. The UT 747 M/V "Western Monarch" is taken by Western Geophsysical as "the State of the Art" Seismic Vessel. 
The UT 747 is providing an extremely stable and silent working plattform, comprizing provision for comprehensive seismic equipment packages and spacious computer processing facilities.


The vessel is powered by a centralized diesel electric power plant. Propulision and compressors are all electrically driven, giving a high level of availability and redunancy. Shipboard and hydroacoustic noise is carefully controlled. Special measures are taken from design stage and throughout the building program in order to ensure the extremely low noise level. All major rotating machinery installations are resiliently mounted, and vibration characteristics of the steel structure and hull is made without interference from machinery and propulsion plant.

2017: Still active - IMO 9010149. Manager and owner: Westerngeco, London, UK. Flag: Panama


The vessel is built to Det norske Veritas Class +1A1, ICE-C, E0, HELDK and to international rules and regulations as applicable for the subject type of vessel. Further the vessel satisfies IMO Res. A.468 (XII) as a general maximum noise level, with additional reduction of noise level in laboratories and related areas.


Length over all 92,5 m 
Length between pp 80,0 m 
Breadth moulded 20,0 m 
Depth Main Deck 9,0 m 
Design draught 6,4 m 
Scantling draught 6,9 m


Gross tonnage (1969) below 5200 GRT 
DW (6,4 m) approx 2250 tonnes 
DW (6,9 m) approx 2925 tonnes 
Fuel oil (Incl. tks) approx 1600 m3 
WB approx 995 m3 
FW approx 150 m3 
Cable oil, clean oil 20 m3 
Cable oil, dirty oil 20 m3 
Work deck area (Main deck) 1175 m2 (12650 Sq.ft) 
Recording room area 273 m2 
Helideck CAA/DnV


Accommodation 61 persons in total, of which: 
- 5 suits with dayroom, bedroom and bathroom 
- 2 one-man cabines 
- 16 two-man cabines 
- 11 two-man bedrooms, attached to dayrooms 
- 1 two-bed hospital


Trial Speed (5,5 m) 16,0 knots 
Design pull, 5 kn 40 tonnes


Bergen Diesel 
Main gen sets 3 x BD 32 G8, each of 3200kW/6600V/60Hz 
Ulstein Propeller 
Twin screw propulsion comprimizing 2 x 2500 AGSC-2T 
Controllable pitch propulsiion plants, each with Low noise, 4 bladed skewed CP-propeller, driven throug a single input, 
single output reduction gearbox
1 off Bow thruster 150 TV, 800 Hp el. driven 
2 off High lift rudders 
2 off Passive stab tank sys. 
2 off Main Propeller motors 2700kW/6600/60Hz 2-speed 
1 off Aux generator Cummins 600kW/6600/60Hz 
2 off Clean power 60 kW/230V/60Hz 
3 off Air compressors, El-driven Ariel capacity 2200 SCFM 
2 off Life boats, 61 persons 
Life rafts as per Solas 
1 off MOB 23 
1 off Work Boat 
Windlasses: Type AV-45/50-4G K3


Ulstein Marine Electronics 
Electric remote control system main Propeller 
Joystick control system 
Electronic remote controll system 
Bow thruster 
Brigde control consoles 
Engine room console 
Starters for e.motor 
El-test board 
Engine room telegraph 
Microprocessor based alarm system 
(with dead man system and printers) 
Roll indicator


Radio Equipment 
Inmarsat JRC JUE 45A MKI Voice/Telec/Fax Radio 
Skanti TT 32oo Radio Telex System Skanti 3000 (2) 
Skanti RT 2047 
Jotron Ground to Aircraft 
Panasonic 450 MHZ Cellular Telephone 
Trane & Trane standard C Inmarsat


Navigation / Equipment 
Radar Furuno FAR-2822 X-band 
Radar Furuno FAR 2830S S-band 
Tokyo Keiko Gyro kompass system 
Roberson AP9 MKII Autopilot 
Furuno FSN-50 Transitt Satelitt 
Furuno LC GP500 GPS Satelitt 
Furuno FD 525 VHF 
Furuno TDC-318 Direction Finder 
Furuno Fax 208A Weather faxmile RCVR 
Ben Marine Electromagnetic Log