Engine overhaul for Subsea 7 OSV

The 98m, 4,905gt ship had been working in the Irish Sea area and was in Barrow-in-Furness for 18 days of scheduled maintenance. Rockwater 1 is powered by a diesel-electric propulsion system consisting of five 1,700kW Brons-MAN ASL25/30 diesel engines that each drive a 2,125kVA NEBB WAB 630 generator. These produce power for two 1,800kW azimuth thrusters and three 790kW tunnel thrusters. The service required the Royston engineers to completely dismantle three engines and overhaul their cylinder heads and liners, pistons and con rods, cam shafts, bearings, vibration dampers and injectors and two turbochargers.

A nine-man team worked onboard day and night while six engineers at the Royston workshop in Newcastle undertook the machining of components. This included servicing 27 cylinder heads and liners, fuel injectors and the complete overhaul of two turbochargers. The Royston team will overhaul the two remaining engines during the ship’s next maintenance interval.