In late December 2009, the 'YT 802 Valiant', the first of a new series of Z-Tech 4500-class tugs for the United States Navy Pilots was handed over to her owners.
After a shakedown period and crew training, the vessel was placed into active service in early February 2010.
This series of new tugs are being built by JM Martinac Shipbuilding, which is a sub-contractor to Pacific Tugboat Services, the prime contractor for the delivery of the vessels to the US Navy.
The design was developed by Robert Allan, Canada, and was adapted to the Navy Pilots' needs based on the now widely accepted Z-Tech 6000 hull form originally developed by the designers for the Port of Singapore.
The US Navy tugs will be based in Bremerton and Bangor, Washington, and will perform ship-handling duties for the full range of US Navy surface warships and submarines.
For this the tugs are equipped with an extensive array of underwater fendering, as well as the typical resilient style fenders for handling surface ships.
The Z-Tech 4500 class tugs have an overall length of 27.4 metres, a moulded beam of 11.65 metres, a moulded depth of five metres and a maximum loaded draught of 4.88 metres.
The propulsion machinery comprises a pair of Caterpillar 3512C, main engines, each rated 1,350kW at 1,600rpm, each driving a Schottel Model SRP 1012 steering/propulsion Z-Drive units, with 2,100mm diameter fixed pitch propellers. This combination delivered in excess of the predicted performance, providing 42 tonnes bollard pull ahead, 45 tonnes astern, and a free-running speed of 12.4 knots on trials.