HMS Hermes as Sea Control Ship

[uk 75]

The saga of HMS Hermes is well known. But it might have been different if the RN had followed the US example and kept her as an ASW carrier or interim Sea Control Ship.

The US were introducing the S3 Viking on to their attack carriers but were keen to get as many to sea as possible.
HMS Hermes began its conversion to a planned Commando Ship role replacing Albion. SACLANT asked the RN to look at operating S3 Vikings from her in addition to the Seakings.
Retaining the waist catapult would also allow the Hermes to retain Gannet AEW and COD aircraft to provide information for its T42 and County class escorts.
By 1974 Hermes had recommissioned as a combined Commando and ASW ship. 8 S3K Vikings on loan from the US joined the ship and the Gannets from her last fixed wing commission.
The Labour Government ordered Sea Harriers for Hermes and the new Invincibles.
The loan of S3 aircraft came to an end in 1976 when NATO urged the RN to buy them outright. However, the RAF had a surplus of Nimrods withdrawn from Malta and the S3 were reluctantly returned to the States.
The Gannets remained. And when the new Sea Harriers joined the ship they added greatly to her capabilities.

 

[Archibald]

Well, the Americans used an Iwo Jima LPH as a SCS demonstrator, rather than an Essex. So why not ? Plus you have a pretext to keep the catapult on Hermes, and with some Gannet AEW still hanging around, a day of spring 1982... well, you know.

 

[EwenS]

The saga of HMS Hermes is well known. But it might have been different if the RN had followed the US example and kept her as an ASW carrier or interim Sea Control Ship.

The US were introducing the S3 Viking on to their attack carriers but were keen to get as many to sea as possible.
HMS Hermes began its conversion to a planned Commando Ship role replacing Albion. SACLANT asked the RN to look at operating S3 Vikings from her in addition to the Seakings.
Retaining the waist catapult would also allow the Hermes to retain Gannet AEW and COD aircraft to provide information for its T42 and County class escorts.
By 1974 Hermes had recommissioned as a combined Commando and ASW ship. 8 S3K Vikings on loan from the US joined the ship and the Gannets from her last fixed wing commission.
The Labour Government ordered Sea Harriers for Hermes and the new Invincibles.
The loan of S3 aircraft came to an end in 1976 when NATO urged the RN to buy them outright. However, the RAF had a surplus of Nimrods withdrawn from Malta and the S3 were reluctantly returned to the States.
The Gannets remained. And when the new Sea Harriers joined the ship they added greatly to her capabilities.

Hermes had two bow catapults. A waist catapult would have to be fitted far enough aft to avoid the side lift.

 

[uk 75]

EwenS oops comes of my shooting from the hip.
Does that mean I dont get my S3s? sigh

 

[EwenS]

1964-67 Hermes port bow catapult was extended from 151ft to 175ft and not the 199ft of the waist cats in Ark & Eagle. Can’t remember the launch parameters offhand.

 

[uk 75]

If Hermes could launch Bucs and Gannets S3 might be possible.

 

[EwenS]

The 151ft BS4 was capable of launching 50,000lb at 94 knots. The 199ft BS4 was capable of launching 50,000lb at 105knots. So 175ft must be somewhere between. But these are without any additional natural or ship generated wind over the deck.

Lockheed S-3 Viking MTOW 52,539lbs and stall speed was 97 knots.

So it looks like Hermes would need to be able to generate some wind over the deck to operate the S-3 safely or operate it below MTOW. Question then is, how much additional wind would be needed.

Edit:- Gannet AEW3 only weighed 25,000lb. Buccaneer S2 operated from carrier may have only been 45-46,000lb MTOW as opposed to 62,000lb MTOW from a runway. See FAA Museum data

Hawker Siddeley Buccaneer S2B

Fleet Air Arm Museum, Somerset exhibits include Hawker Siddeley Buccaneer S2B

www.fleetairarm.com

 

[bobtdwarf]

The 151ft BS4 was capable of launching 50,000lb at 94 knots. The 199ft BS4 was capable of launching 50,000lb at 105knots. So 175ft must be somewhere between. But these are without any additional natural or ship generated wind over the deck.

Lockheed S-3 Viking MTOW 52,539lbs and stall speed was 97 knots.

So it looks like Hermes would need to be able to generate some wind over the deck to operate the S-3 safely or operate it below MTOW. Question then is, how much additional wind would be needed.

Edit:- Gannet AEW3 only weighed 25,000lb. Buccaneer S2 operated from carrier may have only been 45-46,000lb MTOW as opposed to 62,000lb MTOW from a runway. See FAA Museum data

Hawker Siddeley Buccaneer S2B

Fleet Air Arm Museum, Somerset exhibits include Hawker Siddeley Buccaneer S2B

www.fleetairarm.com

I read that the USN liked to have 5 knots over stall as their launch speed, may have been on here that I read it.

 

[BlackBat242]

And as Hermes had a listed max speed of 28 knots, then it would easily reach 20-24 knots sustained during flight ops... which would, added to ~95 knots catapult end speed, easily suffice for a fully-loaded S-3 Viking's required 97 knots with safety margin for hot day operating conditions.

 

[GK Dundas]

I've got a question as we all know as a usable aircraft for Hermes the Phantom was a non-starter. So my question is would the F/A 18A be capable of flying off her ?

 

[bobtdwarf]

I've got a question as we all know as a usable aircraft for Hermes the Phantom was a non-starter. So my question is would the F/A 18A be capable of flying off her ?

nope.

 

[GK Dundas]

I've got a question as we all know as a usable aircraft for Hermes the Phantom was a non-starter. So my question is would the F/A 18A be capable of flying off her ?

nope.

Didn't really think so

 

[bobtdwarf]

I've got a question as we all know as a usable aircraft for Hermes the Phantom was a non-starter. So my question is would the F/A 18A be capable of flying off her ?

nope.

Didn't really think so

I double checked the Bucc and Hornet stats.. it might be possible at some weights but I have serious doubts about a "stock" Hornet. The Bucc had BLC and they jacked the nose way up in the air

 

[orlovsky]

Could you post the nrs you have for the Hornet?

 

[bobtdwarf]

Could you post the nrs you have for the Hornet?

if that was for me I just used the numbers from wiki for weight

 

[orlovsky]

Ah, ok. It seems the official F/A-18A numbers are still not around, just various guesswork. Fighter with 1 droptank, ~39k lbs, 140-150 kts end speed. Which translates into maybe 35-45 kts wod for Hermes, so in all likelihood not practical.

 

[bobtdwarf]

Ah, ok. It seems the official F/A-18A numbers are still not around, just various guesswork. Fighter with 1 droptank, ~39k lbs, 140-150 kts end speed. Which translates into maybe 35-45 kts wod for Hermes, so in all likelihood not practical.

yeah it would have to be something along the lines of with 20% fuel and the smallest pilot you got and before breakfast kind of deal...

 

[alejandrogrossi]

Sorry to reopen a old and close theard.
But i have question, its crazy i know.
Could HMS Hermes en her final configuration, operate F-35B? ( weights / size)
Thanks

 

[BlackBat242]

F-35B specs:
Empty weight 32,472 lb (14,729 kg); Max takeoff weight 60,000 lb (27,200 kg) class.
length 51.2 ft (15.6 m), wingspan 35 ft (10.7 m), height 14.3 ft (4.36 m).

Hermes specs:
Hangar height 17' 6"; aircraft lifts 54' long x 45' wide (side) and 54' long x 44' wide (aft), 40,000lb capacity (both).
Aft flight deck rated for 45,000lb aircraft impact during arrested landing*.
Bow ramp weight capacity for take-off unknown (max takeoff weight of any Harrier variant 31,000 lb (14,100 kg)).
Flight deck was rated for Sea Vixens (max takeoff weight FAW.2 46,750 lb (21,205 kg)) and Buccaneers (max takeoff weight S.2 62,000 lb (28,123 kg)).

The bow ramp might need a little strengthening, but the aircraft lifts and flight deck are fine.

 

[Scott Kenny]

F-35B specs:
Empty weight 32,472 lb (14,729 kg); Max takeoff weight 60,000 lb (27,200 kg) class.
length 51.2 ft (15.6 m), wingspan 35 ft (10.7 m), height 14.3 ft (4.36 m).

Hermes specs:
Hangar height 17' 6"; aircraft lifts 54' long x 45' wide (side) and 54' long x 44' wide (aft), 40,000lb capacity (both).
Aft flight deck rated for 45,000lb aircraft impact during arrested landing*.
Bow ramp weight capacity for take-off unknown (max takeoff weight of any Harrier variant 31,000 lb (14,100 kg)).
Flight deck was rated for Sea Vixens (max takeoff weight FAW.2 46,750 lb (21,205 kg)) and Buccaneers (max takeoff weight S.2 62,000 lb (28,123 kg)).

The bow ramp might need a little strengthening, but the aircraft lifts and flight deck are fine.

You'd need to arm F-35s on deck, it looks like. Not sure what RN practice was regarding weapons in the hangar deck, so that may not be an issue.

 

[alejandrogrossi]

Thanks to both

 

[Archibald]

F-35B on HMS Hermes... this could bust the time space continuum, as would say Doc Emmett Brown.

 

[SSgtC]

And as Hermes had a listed max speed of 28 knots, then it would easily reach 20-24 knots sustained during flight ops... which would, added to ~95 knots catapult end speed, easily suffice for a fully-loaded S-3 Viking's required 97 knots with safety margin for hot day operating conditions.

I know, I'm responding to a year+ old post, but 20-24 knots during flight operations is exceptionally optimistic. An Essex class, with far more shaft horsepower avaliable to her, and capable of 31 knots at flank speed, would fall all the way down to 19 knots during flight operations. More likely, Hermes would end up in the 15-18 knot range while diverting steam to the cats. If the 151' BS4 can get an S-3 at its catapult MTOW to around 95-96 knots, add in 15 from the ship (worse case), you're looking at an end run speed of 110 knots. The S-3A has a power off stall speed at 45,000 pounds of 102 knots. (The 45,000 pound weight is when armed with 4xMk-46 Torpedos and 60 Sonobouys, though max cat weight is 43,400). So even with the fall in speed, Hermes shouldn't have an issue operating the Viking. Well, beyond the sheer fucking size of the thing. I don't think the FAA could cram all that many in her.

 

[GK Dundas]

I know, I'm responding to a year+ old post, but 20-24 knots during flight operations is exceptionally optimistic. An Essex class, with far more shaft horsepower avaliable to her, and capable of 31 knots at flank speed, would fall all the way down to 19 knots during flight operations. More likely, Hermes would end up in the 15-18 knot range while diverting steam to the cats. If the 151' BS4 can get an S-3 at its catapult MTOW to around 95-96 knots, add in 15 from the ship (worse case), you're looking at an end run speed of 110 knots. The S-3A has a power off stall speed at 45,000 pounds of 102 knots. (The 45,000 pound weight is when armed with 4xMk-46 Torpedos and 60 Sonobouys, though max cat weight is 43,400). So even with the fall in speed, Hermes shouldn't have an issue operating the Viking. Well, beyond the sheer fucking size of the thing. I don't think the FAA could cram all that many in her.

I suppose it's all relative the S-2 was pretty big on both Melbourne and Bonneventure . And took up a fair amount of both flight and hanger deck space too.

 

[SSgtC]

I suppose it's all relative the S-2 was pretty big on both Melbourne and Bonneventure . And took up a fair amount of both flight and hanger deck space too.

Yeah. The S-3 was 29'6" by 49'5" when it it's wings and tail were folded. She was a big girl.

And I misspoke a little earlier. Max catapult weight for the S-3 was 52,539 pounds. It's normal cat weight was 43,449 pounds. So end run speed is probably around 107 knots. Still that does, barely, give you the 5 knot margin to launch in zero wind conditions. And luckily for Hermes, her deck and arresting gear are already good enough to recover the Viking (max trap weight is 37,695 pounds).

 

[GK Dundas]

One of the things the S-3 had was both speed and legs. She had decent radius of action a could really move when prosecuting a contact.

 

[GK Dundas]

I always wonder about the Infamous 40,000 ton carriers that Treasury kept trying to foist on the RN . Would they have made a decent Sea Control Ship ?

 

[Scott Kenny]

I always wonder about the Infamous 40,000 ton carriers that Treasury kept trying to foist on the RN . Would they have made a decent Sea Control Ship ?

Assuming that we're talking 40ktons light (without fuel and boiler feed water), that's practically a Midway-class!

 

[GK Dundas]

I'm not entirely quite sure if the British Treasury were aware of the distinction.
If the RN had been smart about they could gotten the bean counters to compromise on 45,000 tons and then built CVA 01 .
And when Treasury complained about it .
They could turn around and say . " I thought you understood that was 45,000 to light weight displacement?
Oh you thought what ....?
Oh we're so sorry we completely misunderstood .Never happen again , we promise.

 

[Scott Kenny]

I'm not entirely quite sure if the British Treasury were aware of the distinction.
If the RN had been smart about they could gotten the bean counters to compromise on 45,000 tons and then built CVA 01 .
And when Treasury complained about it .
They could turn around and say . " I thought you understood that was 45,000 to light weight displacement?
Oh you thought what ....?
Oh we're so sorry we completely misunderstood .Never happen again , we promise.

Exactly.

 

[H_K]

An Essex class, with far more shaft horsepower avaliable to her, and capable of 31 knots at flank speed, would fall all the way down to 19 knots during flight operations.

What’s your source for this? Was 19 knots for flight ops just a normal catapulting speed with some boilers off? I doubt that was the maximum speed possible with all boilers on.

For reference I’ve seen sources stating a speed drop of 1-2 knots when catapulting on other carriers.

 

[SSgtC]

What’s your source for this? Was 19 knots for flight ops just a normal catapulting speed with some boilers off? I doubt that was the maximum speed possible with all boilers on.

For reference I’ve seen sources stating a speed drop of 1-2 knots when catapulting on other carriers.

Originally, from a few people on other sites. But I was able to speak with a few officers that served on ships of the class, and they confirmed the loss of speed. From what I've was told, because the ships were never envisioned to need to divert that much steam from their boilers, it had a disproportionate impact on their speed during flight operations. The Midway class had the same problem, but they had more spare capacity and only fell to about 23 knots. Newer ships that were designed with steam cats in mind had more steam generating capacity

 

[BlackBat242]

I'm not entirely quite sure if the British Treasury were aware of the distinction.
If the RN had been smart about they could gotten the bean counters to compromise on 45,000 tons and then built CVA 01 .
And when Treasury complained about it .
They could turn around and say . " I thought you understood that was 45,000 to light weight displacement?
Oh you thought what ....?
Oh we're so sorry we completely misunderstood .Never happen again , we promise.

Why, when the Treasury historically placed the limit as "equal displacement to Eagle"... which was 43,060 tons standard (54,100 tons full) after her 1964 modernization?

The RN then designed CVA-01 to a displacement of "50,000 tons" - which, after an additional 2,000 tons of armor and other items were added, ended up as 53,000 tons (47,700 tonnes) "average action condition"; 54,500 tons (49,050 tonnes) standard, and an estimated 63,000 tons (56,700 tonnes) deep load.

Just like you suggested, but nearly 10,000 tons more than you suggested.

 

[Scott Kenny]

Why, when the Treasury historically placed the limit as "equal displacement to Eagle"... which was 43,060 tons standard (54,100 tons full) after her 1964 modernization?

The RN then designed CVA-01 to a displacement of "50,000 tons" - which, after an additional 2,000 tons of armor and other items were added, ended up as 53,000 tons (47,700 tonnes) "average action condition"; 54,500 tons (49,050 tonnes) standard, and an estimated 63,000 tons (56,700 tonnes) deep load.

Just like you suggested, but nearly 10,000 tons more than you suggested.

So RN's version of BuShips was being stupid again? Or was the plan to do two designs with one small and one large, to try to beat into Treasury just how much better a larger carrier is?

 

[BlackBat242]

I'm not sure what you are talking about.

The RN had adamantly refused to even theoretically consider the 30,000 standard tons limit that Treasury was pushing, telling them that Eagle was the absolute minimum size for a useful carrier - and they then designed the largest ship they could get authorized, and even went beyond that using the "take the max displacement of the example ship (Eagle) and use it as the standard displacement of our design" trick to maximize size (and therefore capability).

There never was any "small design" in the process of designing CVA-01.

 

[Scott Kenny]

I'm not sure what you are talking about.

The RN had adamantly refused to even theoretically consider the 30,000 standard tons limit that Treasury was pushing, telling them that Eagle was the absolute minimum size for a useful carrier - and they then designed the largest ship they could get authorized, and even went beyond that using the "take the max displacement of the example ship (Eagle) and use it as the standard displacement of our design" trick to maximize size (and therefore capability).

There never was any "small design" in the process of designing CVA-01.

The problem was that Treasury didn't blink, and said "then you don't get any carriers at all."

 

[GK Dundas]

The problem was that Treasury didn't blink, and said "then you don't get any carriers at all."

Sadly true.
Actually I've been doing a wee bit more digging and I find that the Civil Admiralty Lords were the one's pushing for the the 40,000 ton carrier. The treasury want one that didn't exceed.30,000 tons .
And of the RN wanted the 55-60,000 Ton CVA 01 .

 

[zen]

Civil Lord was clearly trying to square the difference and get No.11 to accept a compromise between their preference and the Admiralty's. But for that to work the Admiralty needed to be able to agree......
Which when faced with a future without OR.346, they shrank back and stoutly refused to contemplate it.
This was before the Soviets displayed their new Anti-ship Missile Systems!

There never was any "small design" in the process of designing CVA-01.

Well....there were studies and the 1960 one ranged down to 42,000tons.
But the main problem is this was being sketched out for a future containing OR.346 aircraft and that shrank airwing down from 32 Buccaneer sized aircraft to 18.
And thus was trying to squeeze 90ft long lifts, 225ft stroke catapults and new recovery systems for these big aircraft into such a ship.

The earlier Medium Fleet Carrier studies of the 50's focused on the 35,000ton ship but this is in a practical sense likely to actually be 45,000tons deep load.
The problem with the other lighter studies is the 30,000ton (or 28,000ton unarmoured) ship lacked a then viable airwing and 30,000ton hybrid Guided Weapon Ship/Carrier, was that DAW had correctly concluded SAMs were not a replacement alternative for DLI and CAP.
Promptly overruled, and everyone started loading more on the Fighter in terms of endurance to sustain a standing CAP and piling more demands on AEW.

 

[GK Dundas]

I suspect that a 40- 45,000 tonne carrier would carry roughly the same number of A/C as an Audacious class . . Not much of an improvement you might think .
Among other things though you'd have a completely new hull , engines and a 440 amp AC electrical system. Newer radars better more ergonomic spaces not just for crew comfort but to maximize efficiency.
Combined with the F4 and and S2 can you imagine what could have been done.

 

[orlovsky]

Originally, from a few people on other sites. But I was able to speak with a few officers that served on ships of the class, and they confirmed the loss of speed. From what I've was told, because the ships were never envisioned to need to divert that much steam from their boilers, it had a disproportionate impact on their speed during flight operations. The Midway class had the same problem, but they had more spare capacity and only fell to about 23 knots. Newer ships that were designed with steam cats in mind had more steam generating capacity

The RN was planning with 25 kts ship speed for Hermes and 28 kts for Eagle when launching phantoms. But it might also depend on the operational tempo?

4th attachment here: https://www.secretprojects.co.uk/th...order-of-battle-1975.20517/page-2#post-420283