MAN twin-engine system in Dalby Ouse catamaran

MAN Engines for Commercial Shipping

Thanks to the MAN D2862 LE456 twin-engine system, the catamaran Dalby Ouse can claim the title of ‘most powerful Wind Farm Supply Vessel’

© Scott Elford Photography

MAN’s International Engine Competence Centre in Nuremberg has fitted out the new flagship of Dalby Offshore’s fleet. Equipped with two MAN D2862 LE 456 V12 engines, the catamaran can call upon a total of 3300 HP (2427 kW) and accelerate to a top speed of up to 30 knots. With a length of 26 metres, the ‘Wind Farm Supply Vessel’ – WSV for short – is not only the largest vessel in the fleet of UK ship operator Dalby Offshore, it is also the most powerful in its class.

The catamaran Dalby Ouse approaching an offshore installation. © Scott Elford Photography

The 1650 HP (1213 kW) D2862 LE 456 is the second most powerful V12 engine for work boats in MAN Engines’ portfolio. The power package draws its strength from 24.24 l displacement. Thanks to its twin-engine system, the WSV can accelerate to up to 30 knots (55.6 km/h) and is in operation for up to twelve hours on working days. For particularly long journeys, the Dalby Ouse offers eleven sleeping berths: eight for passengers and three for the crew. In order to ensure that despite its function as a powerful work boat the vessel can yet offer a suitable level of travelling comfort, Dalby opted for the smooth-running MAN engine, which can maintain low noise and vibration levels even at high speeds. In addition, the engineers mounted the superstructures on springs to further optimize comfort. Other important characteristics that need to be fulfilled by WSVs include the abi¬lity to cover an appropriate operating range, to exhibit improved behaviour in strong swells and to stay in position at the wind turbine even in rough seas to allow for the technicians to cross over safely.¬ The catamaran, specially adapted for these requirements, can also transport 20 tonnes of equipment and 24 passengers plus crew members, which makes it ideal for crew transfers and supply runs to wind farms.

With two MAN D2862 LE 456 V12 engines, the Dalby Ouse’s engine room packs a total of 3300 HP (2427 kW). © Dalby Offshore Limited

This is the fifth time Dalby Offshore have opted for an MAN engine. These power packages bear a great deal of responsibility each day. The WSVs not only transport the technicians, they also act as a platform to safely carry service personnel to offshore installations. In this process it is essential to keep the catamaran pressed against the turbine in order to hold the vessel as steady as possible even in bad conditions. It has become evident over the years that the technical features of MAN’s twelve-cylinder engines are perfectly suited for precisely this task: “MAN engines have one of the best torque curves on the market. A maximum torque reached at 1200 rpm and an extremely broad torque plateau allow for a great deal of flexibility in the operating profile,” explains Andrew Mellard, General Manager of MAN Engines & Components in the UK. “This feature is crucial for the WSVs so that they can transport technicians safely to their workplace.” As well as the technical details, operating costs and access to expert contact partners on site are also key concerns for operators. This is why Steve Bartram, Operations Manager at Dalby Offshore, is extremely pleased that the choice of engine supplier was once again made in favour of the Nuremberg engine factory: “MAN’s engines have proven their reliability and efficiency, and the aftersales service in this sector is also superb,” says the Operations Manager.

© Dalby Offshore

MAN Service is not alone in being unique on the waters around Britain – the D2862 LE456 is the first of its kind to be deployed in the UK. This powerful model is ideally suited for the aluminium catamaran. Depending on the order situation, it could be in use for 2500 to 3000 hours per year, with operating time divided amongst construction, operation and maintenance of offshore installations.

Handover at Seawork 2016

The catamaran was presented to its new owners at the international maritime exhibition Seawork, held in Southampton between 14th and 16th June 2016. The new Dalby Ouse is the eighth WSV to have been handed over to ship operator Dalby Offshore by the Great Yarmouth-based shipyard Alicat Workboats. The new work boat was designed by the sister company South Boats IOW. After some smaller Dalby Offshore models having previously been fitted with the 1030 kW (1400 HP) D2862 model, the choice this time fell on the more powerful version with 184 kW (250 HP) additional power, making this order the most powerful WSV on the market to date. Andrew Mellard stated that he was particularly pleased that the past ten years had resulted in strong business relationships with Alicat Workboats and South Boats IOW, something he said all parties were proud of. Indeed, this has already yielded a number of new orders for 2017.

More about Dalby Offshore

Technical data of the D2862 LE456

Power 1213 kW/1650 HP
Engine speed 2300 rpm
Bore 128 mm
Stroke 157 mm
Cylinders (arrangement) 12 (V)
Capacity 24.24 l
Maximum torque 5510 Nm
At an engine speed of 1200–2100 rpm
Installation dimensions (L x W x H) 2139 x 1153 x 1272 mm
Weight (dry) 2380 kg
The broad torque plateau is of vital importance for WSVs in order to keep them pressed against the offshore installations and allow service personnel to board safely.