De Beers recently turned to ALE to replace two engines on its Debmar Pacific mining vessel, in use at its offshore diamond operations in Namibia.
Since 2002, diamond mining operations in Namibia have taken place in larger volume offshore than onshore, as gemstones washed into the Atlantic Ocean over millions of years are dredged and processed. It’s an expanding market, generating over a 100 Mct/y, according to ALE.
When, as part of routine maintenance operations the Debmar Pacific mining vessel required removal and replacement of two engines, De Beers turned to ALE to ensure a swift and efficient job, the company said.
The company said: “As time in port at Cape Town was limited to just a few weeks, several other similar procedures were taking place at the same time, meaning this work had to take place under strict space limitations.”
Prior to the lift operation, ALE installed two custom-designed gantries on either side of the vessel parallel with the floor of its engine rooms. These gantries were enlarged at the client’s request, in order to provide better access to the engines, ALE said.
Each engine was then jacked-up to a height of around 1 m, using four 60 t jacks. A medium skid track measuring 25 m was then laid, from a position underneath the engine to the custom-designed gantry at the vessel’s exterior.
Each 38 t GE engine was then skidded the length of this track, where it was uplifted using a 400 t crawler crane and set down in a nearby storage area, ALE said. This procedure was completed in reverse in order to install both 80 t Wartsilla engines.
The company said: “ALE needed to liaise with several onsite authorities and contractors during the project, in particular during the construction of both access gantries. Having executed a large number of vessel upgrade procedures in the past, ALE was well-placed to advise on the lift procedure that would deliver the best value whilst upholding the highest standards of safety.”
The Debmar Pacific was built in 1977 and converted into a mining vessel during 1997. It will return to active service mining gemstones 24 hours a day, 365 days per year, once all maintenance operations on it are completed.