A competent team of repair engineers is vital if downtime’s to be kept to an absolute minimum. In the hot, harsh conditions of the Middle East, regular maintenance is vital for dredgers working round the clock on the many prestigious projects.
Currently partnering sister vessels on Dubai's Deira Corniche project, Van Oord's jumbo 23,697m3 trailing suction hopper dredger HAM 318 is no exception and when engineers found the vessel was developing a problem with its thrust bearing in the starboard propulsion gearbox, immediate action was taken.
Van Oord won the Deira Corniche contract at the end of 2003. It consists of three falcon-shaped artificial islands connected by bridges, will have a total surface area of 13km2, extends 8km into the sea and will have consumed 250,000,000m3 of sand and 26,000,000 tonnes of rock by completion in 2009.
On average, five TSHDs are at work on it at any one time and HAM 318's a vital team player – which is why Van Oord had no hesitation in flying out Dutch specialists Machine Support (MS) to analyze the problem.
"The gearbox manufacturer suggested that a possible cause could be alignment between the propulsion shaft and gearbox," MS' Geoffrey de Vlaam told DPC. "While it was not possible to remove the coupling to check shaft alignment, we've a unique combination of measurement methods available to cope with such conditions."
MS measured the shaft alignment with strain gauge technology and checked the shaft's load on its bearings. Laser equipment was also used to check shaft alignment. Measurements were taken while HAM 318 was at work, with the hopper both empty and fully loaded, as well as at rest. Simultaneously, the vessel’s hull deformation and engine room machinery was checked with 3D measurement equipment.
"By comparing the theoretical and measured models using shaft analysis software, we were able to calculate the optimal alignment for the complete propulsion line and position it, solving the problem," Geoffrey concluded.
Follow-up checks have shown all is well and HAM 318 is working at optimal levels, building tomorrow's world.
