It has been confirmed that HMS Queen Elizabeth is currently having rectification and repair work done after a propeller issue was identified in sea trials.
Multiple sources, some on board the vessel, have told the UK Defence Journal that an issue has been identified with the prop shaft, specifically that the part of the frame/bracket holding the prop shaft in place is 12mm out of alignment, causing the prop to be slightly at an angle leading to ‘cavitation, excess noise and drag’.
It’s possible that this may have been caused by debris as earlier in the month as HMS Queen Elizabeth picked up an item of debris around one of her propeller shafts.
The Aircraft Carrier Alliance confirmed at the time that divers had been investigating the debris around one of the propeller shafts:
“The ship is performing well, however an item of debris was caught around one of the propeller shafts. This was subsequently cleared and an investigation has been undertaken.”
HMS Queen Elizabeth visited Invergordon for a planned stop to re-fuel and store the ship however she has been alongside longer than planned. We understand that the opportunity has been taken to undertake some engineering work, but sources close to the programme assure us that “this is very much in hand and, whilst I’m aware of the speculation, we expect this to be routinely undertaken and for sea trials to continue successfully.”
Earlier in the week a crew member told us that “On the 24th of this month we are going back to dry dock as on the props need to completely stripped apart”, he did add however that this was only a rumour and may not be the case.
We reached out to the ACA for comment who responded by suggesting that this isn’t out of the ordinary:
“HMS Queen Elizabeth is making progress through the sea trials programme, designed to test the full spectrum of her vast and complex systems.
We fully anticipate this will identify areas for improvement that will be addressed at sea, during routine port stops or as part of the planned engineering period.”
Sea trials monitor speed, manoeuvrability, power and propulsion as well as undertaking weapons trials and additional tests on her levels of readiness.
Following this initial period, HMS Queen Elizabeth will return to Rosyth for further testing and maintenance before heading back to sea for a second stage which aims to test her Mission Systems. She will transit to her home port of Portsmouth Naval Base to be handed over to the Royal Navy later this year.
It remains to be seen what the true cause of this issue is, however, it doesn’t appear to be a major issue.