7th January 2020
Berthon Spain Maintenance Logs – Bow & Stern Thruster Repairs

Bow and stern thrusters are something that Berthon Spain are continually working on and are now often key to the manoeuvrability of some modern yachts. Although the old sea dogs would tell us never to be reliant on our thrusters that’s often easier said than done with twin rudders and variable draft keels. From my experience the amount of speed you need to manoeuvre effectively in even a moderate wind with two rudders is a daunting prospect and a little electronic or hydraulic assistance is usually welcome.

Berthon Spain are currently working on two yachts in the yards with side power thrusters. The drop-down thrusters are very cleverly designed but we often find that the annual checks and maintenance have been forgotten, leading to problems arising.

To avoid having to carry out an unscheduled mid-season haul out to replace a leg, it is important that your bow and or stern thrusters are checked over whenever your yacht is out of the water for yard repairs on a yearly basis. Most of this is common sense. You can easily see if a part is wearing excessively or if something is leaking.

We can usually tell if something is going wrong with a thruster just by listening to it carefully when it is operated. Grinding noises tell you that something is not right and if parts are wearing excessively, failure is almost certainly just around the corner. Never carry out these tests when the yacht is out of the water as the thrusters cannot handle the lack of friction. They should always be done when the yacht is floating.

Commonly, it will simply be something stuck around the thruster blades and in the tunnel causing issues, but if you continue to operate the thruster, this will quickly lead to damage. This is obviously something you can check yourself with a mask and snorkel; just make sure it is switched off with nobody operating it. This is far easier with smaller electric units than it is with the bigger hydraulic ones.

The couplings between the motor and the thruster leg are sometimes prone to failure due to the extreme loads they are put under. This again is a very simple check and if replacements are needed, it can all be done very quickly whilst the yacht is in the water.

Our skilled Mechanical Engineering Team have a wealth of experience in the maintenance and repair of all types of bow and stern thrusters. They are quick to identify and deal with issues before they turn into something more dramatic.

Please do get in touch with us at Berthon Spain if you want us to carry out a quick inspection of your thrusters this winter, to give you piece of mind for the next season. We would be delighted to help.

Managing Director – andrew.fairbrass@berthonspain.com
Office Tel: +34 971 415 441
https://www.berthonspain.com/