ERIKS knows how important setting sail on time is to any ship as fines from Ports can be massive. ERIKS assisted the RMAS Salmaid set sail on time by finding the issue and solving it all within the tight dealine set to them.
The Royal Maritime Auxiliary Service vessel RMAS Salmaid was due to depart for Newcastle from Grimsby when the motor/generator supplying the ships main winch began to fail. Excessive vibration and noise was coming from the unit, which consists of a 124Kw DC generator, a 124Kw A.C Drive motor and 24/13.5Kw DC Generator. Without this system being operational, a large buoy could not be lowered and raised from the sea, making the vessel unfit to carry out its service without immediate repairs.
An order to overhaul the unit was sent from the Ministry of Defence through to EMS Plymouth, who then took advantage of the UK wide network of ERIKS branches and contacted the Grimsby division. That same day, a team of engineers arrived at the nearby East Royal Docks and found the 124Kw DC generator unit to be emitting bearing noise along with movement in the coupling element. They then set to work replacing the bearings and coupling rubbers in-situ, but once the split flange had been removed, it became obvious that the damage was worse than previously thought.
As a result, they had to remove the complete A.C. rotor core pack and the detachment of the drive end-coupling unit with the D.C. generator still attached to the A.C. Drive. The end shield also had to be removed in order to access and replace the drive end bearing assembly, a process that required a 25ft hydraulic ram to pull free the inner race and revealed extensive shaft wear.
Due to the extent of the tapering on the shaft, the complete generator set had to be removed for repairs and testing at the nearby EMS workshop. However, with a combined weight of 5 tons, a hole had to be cut in of the side of the vessel and a mobile crane set up on the dockside to lift the large components out through the bulkhead.
Once the generator unit arrived at EMS, the A.C / D.C unit was completely dismantled and the wear damage assessed and measured. The results showed that the armature-bearing seat needed to be machined and sleeved back to size. Over the weekend, the fan coupling and keyway were machined along with the worn bearing grease plate. The Commutators on both armatures were also skimmed and new roller bearings sourced and fitted to the shaft before the unit was reassembled ready for testing.
Within a few days the complete generator set had been run tested for one hour and favourable vibration levels and spike energy levels recorded. The single D.C Generator was then split from the unit ready for dispatch to the ship and both items were returned and re-fitted to their bed the following day. To check that the final assembly was done precisely, running tests were carried out on-board, with vibration and spike energy levels re-taken and checked against previous readings obtained from the no-load test in the workshop.
Once the repair was considered satisfactory, ERIKS staff returned to the vessel and cleared the site from loose welding debris and repainted the bulkhead, ensuring that the generator repair was completed well within the tight deadline set.
Such tasks are coordinated by ERIKS’ Marine Division that specialises in providing vessels of all sizes with guaranteed repairs at their intended destination, rather than having to make unscheduled voyage deviations or incurring excessive layover periods. The services available include mechanical engineering, electrical work in addition to a worldwide product supply network. Take a look at our website to see what else we are capable of in the Marine Industry