Coupling weak spots

Important info

Engine Maintenance


Generally, if you’ve maintained components to running hours, you’d expect them to be able to spring back into use with no issue.

But that’s not always a sensible expectation.

A while back, we overhauled a couple of Twindisc gearboxes as part of a project on a beautiful 20ft yacht, built back in 1967.

The engines had been out of use for some time, but the gearboxes had been maintained to running hours, so the owners were only expecting the gearboxes to need a quick check over before they were reused.

It turned out not to be as simple as that.

During our inspection, we found two issues that had absolutely nothing to do with wear or use, but everything to do with the environment the yacht has been left in.

One of the biggest issues was these warning signs of weak spots on the coupling:

Coupling weak spots

What’s clear from this picture is that it was a matter of ‘when’ not ‘if’ these teeth would snap if they were left alone.

It’s difficult to predict exactly when that would have happened, and equally difficult to predict where the yacht owner would have been at the time, with every chance that they would have been out at sea and unable to drive any power to the propellers.

Here’s my point:

Just because an engine, gearbox, or other mechanical equipment has not been running, it doesn’t mean it hasn’t degraded, and regular checks are absolutely VITAL if you don’t want to end up a creek without a paddle (or a propeller).

Make sure your critical equipment is thoroughly inspected before being reused, so you are not left exposed.

With our experienced diesel engineers and support from the propulsion specialists at Bartech Propulsion, we are even better equipped to help with every aspect of your vessel’s power and propulsion equipment.

If you have any concerns or upcoming maintenance, let us know and we’ll be happy to help.

Signup to receive our newsletter

Simply enter your details below to be kept up to date

  • This field is for validation purposes and should be left unchanged.

Engineer Resource Vol. 2 is now out for FREE download. Get your copy now!

A collection of articles to help you improve engine reliability, performance and safety specifically for engineers, brought to you by Bartech Marine. Simply enter your email below to get instant access.

  • This field is for validation purposes and should be left unchanged.

By completing this form you are agreeing to our privacy policy.

free engineer resource guide