Marine Medium Speed 

L27/38-Powered Anchor Handling Tug Supply Vessels to Operate for BP and Topaz Marine

MAN Diesel & Turbo’s medium-speed propulsion packages have gained another foothold in Middle Eastern offshore operations. After successfully completed seatrials, Abu Dhabi-based Adyard has earlier delivered the ‘Topaz Dignity’ – which is now followed by the ‘Topaz Triumph’ AHTS.

Topaz Energy and Marine, a subsidiary of Oman-based Renaissance Services SAOG and a regional leader in providing offshore support vessels and engineering services, has passed yet another milestone in its 35-year history by building two Anchor Handling Tug Supply vessels.

The two 67-metre, ’80-ton bollard pull’ vessels are ready for anchor handling tug supply services and the transportation of dry and liquid cargo to and from pipe-laying barges, drilling platforms and production platforms for offshore operations. The Topaz Dignity will operate on behalf of BP, the oil and gas major, on a long-term-contract basis in the Caspian Sea – whilst Topaz Triumph may remain in the Middle East and be operated by Topaz Marine MENA. The state-of-the-art vessels are equipped with the latest technical equipment and are custom-built for Fi-Fi Class I and DP2 operations.

Propulsion package

The twin-screw propulsion package for each vessel consists of 8-cylinder, medium-speed MAN L27/38 engines of 2,720 kW each, horizontal offset reduction gearboxes with an CPP servo oil distribution unit, and a 1,500 kW shaft alternator PTO. The gearboxes drive approximately 18-metre intermediate shafting, and 13 metre propeller tailshafts in oil-lubricated stern tubes. The MAN Alpha CP Propellers are 2,800 mm diameter ducted, turning 198 r/min at MCR. The propeller thrust and pulling power is boosted by Alpha High Thrust nozzles, customised to hull integration with a length/diameter ratio (L/D) of 0.6. The Alphatronic 2000 Propulsion Control System is configured with twin control stations on both main bridge, aft bridge and in the engine control room – including interfaces to joystick and dynamic positioning systems.

Performance

Upon completing seatrials for the Topaz Triumph – Topaz Marine, Project Manager, Stewart Smith, expressed his satisfaction with the propulsion system and vessel performance in general: “Everything fulfilled our expectations. Compared to the estimated design speed of 13.5 knots for the vessel, we even achieved a radical increased top speed of 15 knots”. Additionally, a bollard pull test verified the vessels’ pulling power specification by achieving a test result of 87 tons.

M/V Topaz Dignity and M/V Topaz Triumph Main Particulars

L oa (m) 67.4
L pp (m) 59.4
Breadth mld (m) 16.0
Depth main deck (m) 6.8
Design Draught (m) 4.8
Max. Draught (m) 5.7
Cargo deck area (m2) 400
Accommodation (persons) 42
Propulsion power (kW) 5,440
Bollard Pull (t) 80

About Topaz Energy and Marine

Topaz is a leading oilfield services company providing marine and engineering solutions to the global energy industry with a primary focus on MENA and the Caspian Sea. Headquartered in Dubai and with more than 35 years of experience in the Middle East, Topaz operates 98 offshore support vessels, and Topaz Engineering engage in shipbuilding, ship repair, and offshore construction and maintenance activities. Topaz is a wholly owned subsidiary of Renaissance Services SAOG, a publicly traded company on the Muscat Securities Market, Oman.

Aft ship view: Topaz Dignity on the slipway just prior to launching, with the Topaz Triumph underway to the right. The 2.8-metre MAN Alpha CP Propellers operate in AHT nozzles – delivering a bollard pull in excess of 80 tons

The robust and service friendly MAN L27/38 engines with good operational characteristics for offshore supply vessels and tugs have been selected as 8-cylinder 2,720-kW versions for the twin-engine, twin-screw Topaz vessels

Drawing of the 67.4-metre Topaz FiFi Class I and DP 2 newbuildings from Adyard, Abu Dhabi