Thruster Exchange Project

Oil and Gas Project - SMS Thruster

In the sheltered waters of Loch Kishorn, we partnered with Subsea Global Solutions to undergo a thruster exchange project on one of the worlds largest semi-submersible drilling rigs.

The Job Scope

A thruster exchange project of this stature required the combined experience of qualified divers and an engineering company with an enviable reputation in thruster repair.

During the Scottish winter months, the SMS team were situated in the north-west Highlands where the rig underwent essential repairs to remove a thruster that had failed. The 60,700-tonne semi-submersible drilling rig which has a draft of over 23 metres needed a deep water location to anchor to carry out the refit. The project required our team of skilled engineers to strip, examine and overhaul the unit.

Thruster Removal and Installation

As expected at this time of year in the Scottish Highlands, the weather conditions played their part in delaying our progress throughout the project. However, when we received the go-ahead, our team were transferred to the rig to begin work on the overhaul.

The initial removal process included fitting and connecting the strand jacks before we released the mounting studs and removed the thruster unit. Therefore, our team drained the water from the moonpool where the strand jacks were to be assembled and secured them into position. We connected the hydraulic hoses, which allowed for the jacks to be tensioned onto the thruster unit.

With minimal fuss, the removal process was almost complete. The thruster was lowered using the strand jacks with help from the crane. This left the divers to release the strand jack anchors to complete the unit removal. The transfer vessel arrived and was tied up at the rig as the lift commenced. Finally, the unit was slung aboard the vessel, and the removal was complete.

Images of the thruster removal process below.  

The team quickly turned their attention to the replacement thruster. We manoeuvred and secured the unit into position after the water was pumped out of the threaded holes. Our team fitted the floating drive shaft into position before we tested the thruster and carried out the set to work.

Images of the replacement thruster installation below. 

Our Experience

Through our partnership with Subsea Global Solutions, we have the specific knowledge and engineering expertise to ensure that all thruster repair work is carried out to OEM standard. With a reputation for service excellence, SGS is experienced in working with clients across the globe in what is a vitally important sector.

Together we have worked with multiple oil and gas operators to successfully execute on the exchange and repair of their critical marine assets.

For more information on how we can help, get in touch with our team.


Contact our specialised team today to find out more about any of the services we offer.