The steel-hulled boat is the Authority’s largest vessel that, in addition to its moorings duties, is also available for hire to assist moving heavy loads in Dartmouth Harbour. The new engines were installed by Oxley Marine Engineering, and the existing PRM 750D gearboxes were reused.

The repower was undertaken to replace Hercules’ aging Perkins 6.354 engines that, while they had provided years of trouble-free service, had reached the end of their cost-effective life. This record of reliability was, understandably, a major consideration when deciding on the replacement engines. However, according to Nick Oxley of Oxley Marine Engineering, engine build quality, price and the low operating cost were the deciding factors in the engines’ favour. The marine engineering company goes on to report that the Authority has also confirmed that the engines are smoother and quieter, plus there is a marked absence of emissions, particularly when compared with Hercules’ original engines.

Installation of the six-cylinder, six-litre, naturally aspirated replacement engines was straightforward thanks to their compact dimensions. A bonus is that the servicing regime has been greatly simplified due to the engines’ easy access single-sided servicing points.

Dependability is underpinned by the engines’ low-stressed low-revving 2600rpm maximum power output. “Reliability is a major concern for every workboat operator, but it is absolutely critical for a floating crane,” said Nick Oxley. “An engine failure during a heavy lifting operation is likely to have expensive consequences, as there is rarely a second floating crane nearby that can be called upon to complete the lift.”

The engines were supplied by Cannock-based Finning (UK), the Perkins distributor for England, Wales and Ireland. Parts and service support are available only through the Perkins distribution network that today numbers 4,000 distributors in 160 countries. Full details of the engines in the current Perkins Marine Power range, including contact details for the distributor network, are available on www.perkins-sabre.com.