UK’s biggest warship suffers propeller shaft damage off south coast after setting sail for US

[penfold]

Wonder how and where you draw the prop shaft on an ACC

In drydock; the prop shafts are in sections and they come apart, otherwise as Bouba suggests the drydock would need extended by ~50%.

 

[SaltIre]

Wonder how and where you draw the prop shaft on an ACC

A man of your artistic talents should manage to find somewhere for a piece of paper and a pencil.

 

[Kukri]

Not ironic, lucky; if she hadn't run aground she'd probably be on the bottom with them, a dozen or so Hurricanes would not have held off 90 bombers.

There are DDs which could be made fit for the carriers but that isn't a priority for MoD(a mistake IMO); KGV in Southampton, Inchgreen in Greenock, No5 dock at Cammell Laird will all fit the hull, but may need changes to accommodate the sponsons etc. There is the big dock in H&W, but IIRC the RN haven't liked sending things to Belfast since an RFA refit went a bit wrong. The industrial strategy still has holes in, Rosyth is not and should never have been considered viable for emergency docking, Between tides and sniffing either the bottom or dock walls it's too hard to get the carriers in and out.

A very good post. Thank you.

I agree that the dry dock situation is not what it should be for these ships. In the days when there was a real Navy, rather than the Ruritanian outfit, run on a shoe string, that we seem to have now, this would have been the very first thing to be considered.

Part of the problem is that no company owning merchant ships will consider dry docking in Europe, with its iffy weather and high labour costs, for anything other than an emergency.

Scheduled dry dockings are done in the Arabian Gulf and in East Asia.

This means that keeping a European ship repair yard running with regular staffing is impossible; all the drydocks you and I have listed have a skeleton staff and bring in contractors as required. This isn’t a recipe for efficiency.

The RN really ought to pick one, better, two, of the docks on your list and come to the sort of arrangement that it used to make with commercial shiprepairers. Not rocket science; the precedents will be on file. £X for modifications and £Y annually for priority access, storage of pre-positioned spares, etc.

Wonder where the spare prop for the QEs is?

(There is a spare prop…?)?

 

[PhillM]

Does England not have a dry dock big enough?

Ruhr harbour, pull up on the sands and you’ve got a few hours to sort out your shaft

 

[SaltIre]

Article from 2019:
Dry docking the Royal Navy’s aircraft carriers – what are the options? | Navy Lookout

 

[penfold]

Wonder where the spare prop for the QEs is?

(There is a spare prop…?)?

There will be spare blades but whether there are spare hubs IDK. KGV makes the most sense as Portsmouth is the home port and will have both civil and RN technical and admin staff there already providing support, commuting to Southampton is not exactly a major imposition. ABP use it for bulk cargo at the moment, but it's not exactly a major revenue earner.

 

[Bouba]

The problem with dry docking an aircraft carrier are the sponsons

 

[Kukri]

There will be spare blades but whether there are spare hubs IDK. KGV makes the most sense as Portsmouth is the home port and will have both civil and RN technical and admin staff there already providing support, commuting to Southampton is not exactly a major imposition. ABP use it for bulk cargo at the moment, but it's not exactly a major revenue earner.

I agree. Returning the KGV / No.7 dock at Southampton to its designed function is the obvious choice. It might pick up some passing trade from boxboats and cruise ships as well, given the dimensions. We used to do quite well at this in HUD (Hongkong United Dockyards - the merged Taikoo and Whampoa Dockyards).

Incidentally Taikoo Dockyard was built with an RN contribution to the cost of construction on condition that it could dry dock the largest ships in the RN. But that was when Victoria was on the throne…

 

[st599]

At least if they go to Rosyth, there's a branch of CA Parson's next door. Not the original Heaton works, but probably still got a big Lathe and a balancing rig.

 

[Bouba]

At least if they go to Rosyth, there's a branch of CA Parson's next door. Not the original Heaton works, but probably still got a big Lathe and a balancing rig.

C&A....wouldn’t Army & Navy be more appropriate ?

 

[st599]

C&A....wouldn’t Army & Navy be more appropriate ?

The Heaton works still has the world's largest pressure vessel for checking large spinning things are running true. Could have been useful in the manufacturing process.

Surprised that POW is listed with that SHP. Swan Hunter's Mauretania (powered by Parsons) had more than that 100 years ago.

 

[penfold]

The Heaton works still has the world's largest pressure vessel for checking large spinning things are running true. Could have been useful in the manufacturing process.

Surprised that POW is listed with that SHP. Swan Hunter's Mauretania (powered by Parsons) had more than that 100 years ago.

CVF has 80MW on two shafts. Wiki says Mauretania was 51MW on 4 shafts, raised to 67MW in the 20s. I'd be curious what the risk assessment for having only two shafts was like; up until HMS Invincible in the 70s all RN carriers had been 4 shafts and Ark Royal at least spent quite a while running on 3 due to marine casualties.

 

[Kukri]

There used to be a naval architect’s rule of thumb that one should not put more than 30,000 shp on a shaft. I don’t remember the reason for this but I do remember the late Marshall Meek of Blue Funnel Line, designer of most of the OCL fleet, quoting it.

 

[Bajansailor]

In the 70's the old Ark Royal visited us here in Barbados, and they had an 'open day' for visitors.
I think that she was too big (or too much draught) to come into the Bridgetown harbour, so she was at anchor out in Carlisle bay.
We went out on a launch to have a look around the accessible spaces to visitors - and I remember picking up a catalogue about her which they were dishing out to everybody, and being very impressed by the quoted power being 156,000 hp.
How many shafts would she had had?

 

[penfold]

The Ark was 4 shafts.

There used to be a naval architect’s rule of thumb that one should not put more than 30,000 shp on a shaft. I don’t remember the reason for this but I do remember the late Marshall Meek of Blue Funnel Line, designer of most of the OCL fleet, quoting it.

I suspect it was the cost of the gear sets rather than any real difficulty doing it; the bigger liners were exceeding that by the end of the 20s. Machinery layout considerations probably discouraged putting more power into single shafts, plus the props start getting very big, heavy and harder to cast.

 

[harry potter]

'Hit something on the bottom'. Please, please don't tell me they tried to go over the submarine barrier rather than go through the forts. Too late to get AIS track on Marine Traffic - can anyone help?

 

[Kukri]

If the ship:
a) struck an uncharted object near the RN’s home port
b) struck a charted danger
c) operated propulsion improperly
d) put to sea when not in all respects ready and prepared to do so
e) suffered from a design, a construction or a maintenance fault,

the embarrassment factor for the Ruritanian Navy is not going to be small.

 

[RivalRedwing]

Today the front page of the Torygraph is reporting from 'naval sources' that it may have been a lack of grease on the shaft that caused the failure ... believable?? possible??

 

[Biggles Wader]

To spoil a ship for a ha'porth of (stockholm) tar.
Would never have happened in my day

 

[dankilb]

Today the front page of the Torygraph is reporting from 'naval sources' that it may have been a lack of grease on the shaft that caused the failure ... believable?? possible??

Or they didn’t burp it? Do McDonald’s still do plastic straws?!