A three-year, 29-vessel contract came to an end as the last tug of the huge Serco contract was named 'SD Deborah' on December 3, 2010.
Due to be deployed at Devenport, one of the main bases of the British Royal Navy, the 'SD Deborah' was the smallest ASD tug in the order, which has included pilot boats, tug, high-speed craft, barges and a worldwide support vessel. 'SD Deborah' is one of four sister tugs.
The 16 Damen vessel types included in the order ranged between 12 metres and 86 metres. They have been built at Damen-owned shipyards in the Netherlands, Poland and Romania.
In December 2007, Serco placed the multi-vessel order with Damen Shipyards Gorinchem to enable the international services group to support the British Royal Navy at its bases in Portsmouth, Devonport and the Clyde.
Serco operates and owns 110 vessels at the three naval ports under a 15-year contract.
The 'SD Deborah' is designed to be a highly manoeuvrable vessel in a relatively small operating area. 'SD Deborah' has two Rolls Royce US 155CP, fully steerable propulsion units and it is fitted with a bow thruster.
Thrusters of this type, in combination with controllable pitch propellers, make the 'SD Deborah' highly manoeuvrable during all towing and pushing operations.
The vessel has achieved a bollard pull of 23.8 tonnes and a speed of 11.5 knots during sea trials.
Two Caterpillar 3508B diesel main engines generate 1,491kW. The tug can transport up to 12 passengers, as well as cargo and it can transfer fresh water and provide fire fighting and water spraying facilities.
The ASD Tug 2009 is the smallest ASD tug built by Damen and despite its size the vessel is capable of assisting both surface vessels and submarines.
Other details include special grey fendering rather than the traditional black, and the tug is fitted with underwater fendering for when it has to work alongside submarines.
The contract was handled by SD Marine Services, the procurement company of Serco under a Private Finance Initiative (PFI) contract with the British Ministry of Defence. This is the first PFI ever carried out in the marine industry.
Most of the 29 vessels are being used to replace older tonnage so Serco could also sell its old vessels through the Damen subsidiary, Damen Trading.