Shiprepair & Maintenance: January 2019
Tight schedules and budgets mean that time is a critical factor in almost all repair jobs. This is particularly true for those conducted underwater, where the possibility of water ingress presents an extra logistical challenge.
Belgian underwater repair specialist Hydrex has recently reported the successful completion of an especially time-critical bow thruster removal, undertaken alongside in Italy. The vessel subject to the works was a 300m container ship, chartered under a very strict schedule, which required an overhaul of its bow thruster but did not have the time to enter drydock.
After being notified of the job, Hydrex considered the setup of the vessel’s thruster, the client’s schedule, and potential locations to perform the works, in order to develop what sales officer Steven De Keyzer calls a “custom solution.” This entailed advance work including the removal of the grid and the welding of rigging points to allow the unit to be hoisted.
With divers on site, the blades were removed in turn, whilst the thruster room was prepared for the detachment of the equipment. A tailor-made Hydrex mobdock (mobile drydock) was then utilised around the thruster tunnel to prevent water ingress and allow access for technicians. To move the thruster, the gearbox was secured with hoisting equipment. Following disconnection, the thruster was lifted onto the quayside, and a blind flange was installed to cover the connection point whilst the unit was in the workshop.
De Keyzer states: “The most difficult part in this operation was the timing. The operation was performed on a large container vessel which has a very strict schedule, and for this job there is a specific procedure to be done. In this case the time we had was the absolute minimum needed to remove this thruster.” Hydrex’s project team therefore worked non-stop on a shift pattern, both day and night, resulting in the successful completion of the work.
