A series of assumptions: a Britwank on a budget?

[Riain]

To be honest, I'm not sure there's a realistic reason for the UK to introduce a HEAT round in your timeframe - HESH is used as a gucci HE round more than an armour penetrator (certainly against other tanks) and I'm not sure HEAT is any better as a HE substitute. The L11 on the Chieftain has a series of very good APDS-T and APFDS rounds to take on T-whatevers, HESH is for BMPs and BRDMs and realistically it's more than good enough for that. If anything you'd maybe want a better HE round to take on infantry in cover, but until the L11 is found wanting against targets of that sort (which is going to be the 1990s and the Gulf War at the earliest unless 3rd Shock Army rolls) and by then the British Army is already looking at CR2 and L30 - now that's a gun that could be so much better if the UK government could occasionally put their hand in their pockets for anything other than the absolute bare minimum of R&D (top attack HE/Frag and working to improve APFSDS beyond the initial round, for example).

Thanks, that's pretty much what I suspected. I'm a big fan of Rule of Cool gadgets but in a TL sense when you start getting all the coolest, fanciest stuff you leave Earth and enter the realm of Star Wars, or CoD:IW at the very least, which is great but you then can't come back and curbstomp Argentina and Iraq with your space age superweapons.

 

[Bougnas]

To be honest, I'm not sure there's a realistic reason for the UK to introduce a HEAT round in your timeframe - HESH is used as a gucci HE round more than an armour penetrator (certainly against other tanks) and I'm not sure HEAT is any better as a HE substitute. The L11 on the Chieftain has a series of very good APDS-T and APFDS rounds to take on T-whatevers, HESH is for BMPs and BRDMs and realistically it's more than good enough for that. If anything you'd maybe want a better HE round to take on infantry in cover.

Gucci HE round indeed: Twice the cost of regular HE.
HESH is a weird niche ammo that doesn't really satisfy any job: it's poorer than HEAT as an anti-armor weapon, and between the different studies I've seen either is slightly superior in the anti-personnel job or outright info (worse fragmentation effect). It's worse againt infantry and more expensive than HE, the latter being no worse against lightly armored vehicles. The theoretical anti-armor advantage of HESH relative to HE is not available in practice against even legacy Soviet tanks, but I guess we can forgive (and blame) NATO because vintage Western tanks didn't have spall or anti-radiation liners.

HESH is claimed to be somewhat better than HE against concrete, barbed wire and apparently sandbags but the first two are rather moot points since fortifications have been obsolete since the late 1940s and the British aren't supposed to go on the offensive anyway. HE likely performs well enough against sandbags. Even the advantage against buildings is dubious because either HESH makes a clean hole that only kills people behind it while HE destroys the whole room, or the former doesn't work at all (1m walls in Eastern European structures for ex).

Now, it doesn't seem that NATO was too concerned about HE use as only France and Switzerland used such ammo in guns above 90mm caliber. Maybe they were concerned about armor only. But in that case, why use HESH and not HEAT which is better for the AT role even if less capable than APDS? If infantry bothers you, why not use HE that will do just as well for cheaper in 99% of cases? Again, the fact that Britain is the only country that bothered to keep HESH (and IIRC actually has obsolete stocks since a few decades) while everyone that used it switched to HEAT must mean something. Maybe the truth is that Britain has just kept silly attitudes because nobody bothers to challenge the institution. Even when it would have been cheap to switch in the 1960s or even 1950s.

The worst thing about all this story is how either the actual army/procurement guys in the 1960s or current british armor enthusiasts brag about how 120mm HESH took out a 150mm plate at 60° or how they chose 120mm to use bigger HESH rounds (which is weird to say when the primary round is APDS but whatever) when a puny 90mm does the same without being a monstrous weapon with two-piece ammo and with actually greater accuracy. The only worse case of attachment to a niche questionnable round is the French Obus G which at least remains a good HEAT round for the era, even though it killed French APDS R&D.

And yet a Chieftain/Challenger often had to waste nearly half of its already bloated ammo racks on this.

The joint trials and reports were there. Britain did not listen.

 

[Riain]

Gucci HE round indeed: Twice the cost of regular HE.
HESH is a weird niche ammo that doesn't really satisfy any job: it's poorer than HEAT as an anti-armor weapon, and between the different studies I've seen either is slightly superior in the anti-personnel job or outright info (worse fragmentation effect). It's worse againt infantry and more expensive than HE, the latter being no worse against lightly armored vehicles. The theoretical anti-armor advantage of HESH relative to HE is not available in practice against even legacy Soviet tanks, but I guess we can forgive (and blame) NATO because vintage Western tanks didn't have spall or anti-radiation liners.

HESH is claimed to be somewhat better than HE against concrete, barbed wire and apparently sandbags but the first two are rather moot points since fortifications have been obsolete since the late 1940s and the British aren't supposed to go on the offensive anyway. HE likely performs well enough against sandbags. Even the advantage against buildings is dubious because either HESH makes a clean hole that only kills people behind it while HE destroys the whole room, or the former doesn't work at all (1m walls in Eastern European structures for ex).

Now, it doesn't seem that NATO was too concerned about HE use as only France and Switzerland used such ammo in guns above 90mm caliber. Maybe they were concerned about armor only. But in that case, why use HESH and not HEAT which is better for the AT role even if less capable than APDS? If infantry bothers you, why not use HE that will do just as well for cheaper in 99% of cases? Again, the fact that Britain is the only country that bothered to keep HESH (and IIRC actually has obsolete stocks since a few decades) while everyone that used it switched to HEAT must mean something. Maybe the truth is that Britain has just kept silly attitudes because nobody bothers to challenge the institution. Even when it would have been cheap to switch in the 1960s or even 1950s.

The worst thing about all this story is how either the actual army/procurement guys in the 1960s or current british armor enthusiasts brag about how 120mm HESH took out a 150mm plate at 60° or how they chose 120mm to use bigger HESH rounds (which is weird to say when the primary round is APDS but whatever) when a puny 90mm does the same without being a monstrous weapon with two-piece ammo and with actually greater accuracy. The only worse case of attachment to a niche questionnable round is the French Obus G which at least remains a good HEAT round for the era, even though it killed French APDS R&D.

And yet a Chieftain/Challenger often had to waste nearly half of its already bloated ammo racks on this.

The joint trials and reports were there. Britain did not listen.

By comparing HESH against both HE and HEAT and finding it wanting seems to indicate that it's a reasonable multi-purpose round, a jack of all trades with KE rounds being the master of 1 when that is needed.

What do you suggest as an alternative to HESH? How is British security enhanced overall by going in that direction, especially if higher performance in one area comes at the expense of performance in other areas? How much will this cost (including the opportunity cost of the change) and does this equate to value for taxpayer money?

As I said above, I love the cool gadgets, but in the real world switching from HESH to HEAT/HE comes with all sorts of costs and baggage and is it worth it in terms of British security?

 

[Cryhavoc101]

Gucci HE round indeed: Twice the cost of regular HE.
HESH is a weird niche ammo that doesn't really satisfy any job: it's poorer than HEAT as an anti-armor weapon, and between the different studies I've seen either is slightly superior in the anti-personnel job or outright info (worse fragmentation effect). It's worse againt infantry and more expensive than HE, the latter being no worse against lightly armored vehicles. The theoretical anti-armor advantage of HESH relative to HE is not available in practice against even legacy Soviet tanks, but I guess we can forgive (and blame) NATO because vintage Western tanks didn't have spall or anti-radiation liners.

HESH is claimed to be somewhat better than HE against concrete, barbed wire and apparently sandbags but the first two are rather moot points since fortifications have been obsolete since the late 1940s and the British aren't supposed to go on the offensive anyway. HE likely performs well enough against sandbags. Even the advantage against buildings is dubious because either HESH makes a clean hole that only kills people behind it while HE destroys the whole room, or the former doesn't work at all (1m walls in Eastern European structures for ex).

Now, it doesn't seem that NATO was too concerned about HE use as only France and Switzerland used such ammo in guns above 90mm caliber. Maybe they were concerned about armor only. But in that case, why use HESH and not HEAT which is better for the AT role even if less capable than APDS? If infantry bothers you, why not use HE that will do just as well for cheaper in 99% of cases? Again, the fact that Britain is the only country that bothered to keep HESH (and IIRC actually has obsolete stocks since a few decades) while everyone that used it switched to HEAT must mean something. Maybe the truth is that Britain has just kept silly attitudes because nobody bothers to challenge the institution. Even when it would have been cheap to switch in the 1960s or even 1950s.

The worst thing about all this story is how either the actual army/procurement guys in the 1960s or current british armor enthusiasts brag about how 120mm HESH took out a 150mm plate at 60° or how they chose 120mm to use bigger HESH rounds (which is weird to say when the primary round is APDS but whatever) when a puny 90mm does the same without being a monstrous weapon with two-piece ammo and with actually greater accuracy. The only worse case of attachment to a niche questionnable round is the French Obus G which at least remains a good HEAT round for the era, even though it killed French APDS R&D.

And yet a Chieftain/Challenger often had to waste nearly half of its already bloated ammo racks on this.

The joint trials and reports were there. Britain did not listen.

I do not know the answer - they had plenty of opportunity to adopt heat rounds - but didn't

I suspect part of it is US made Kit and the US used HEAT so everyone using US made kit used US made ammo and 'system' so used HEAT!

I note they also used HEP in the M68 (L7 copy) although I do not know if that was the case beyond 66 when they introduced a HEAT round?

As for accuracy the L11 on a challenger 1 holds the record

There was a thread on ARRSE with blokes quibbling about the range etc when the actual gunner piped up.

5100+ meters - first round hit

Note again a first round HESH hit through the top of the turret on the "reversing T62" for the 2nd target @ 1500 meters he mentions - perhaps this was how they intended to use it?

HESH verse long range static (or in the below example slow moving) targets where the round hits the top of the turret?

"There seems to be some confusion about what happened and what shot etc. the range was just over 5100m. we had finished moving forward and had gone firm. i was scanning the horizon when picked up what i thought to be T62's across the valley. we had been shooting at whatever targets presented. i lased the target and was surprised by the range that came back, we started talking about having a go at the target amongst ourselves and The Colonel ok'ed the shot. it was a normal fin round, and after lasing again i fine laid the elipse onto the target and fired. it was central hit just below the turret, as to whether the target was manned, i don't know.
however the shot i was really proud of is mentioned by Mad Pierre by mistake,which was a T62 mover reversing up and out of a hull down position at about 1500m, and was hit with a HESH first round through the top of the turret, again fine laid without autolay, never did like it much. hope this helps. i was always a lucky gunner"

I also recall reading the same account from the loader of the same tank who mentions that the gun was fired at such an extreme elevation that the recoiling breech clipped his knee (it having never been fired at such an angle before) and the TC was all heart "Screaming at him to stop rolling around feeling sorry for himself and reload the £$%^ing gun"

Maybe the best idea here is for Challenger 1 to adopt the Rheinmetall Rh-120 L44 gun in the early 80s and for the subsequent 'Vickers made' Challenger II to adopt the L55 gun and ammunition commonality with the rest of the main NATO forces.

Extra point if it both use the same power pack as the Leo II

 

[Not James Stockdale]

It’s important to remember that the Chieftain came around in an era where the performance of HEAT rounds against armor could exceed that of any armor piercing (APDS and APDSFS) rounds. After World War II, it was much simpler to determine correct standoff detonation distances for explosively formed penetrators than it was to improve the performance of armor piercing rounds by switching to long rod penetrators. This was a large part of the reason why the US almost entirely abandoned development of conventional tank guns in favor of gun/missile launchers. It took extensive research into penetrator design and materials science throughout the 1960s and 1970s to reestablish the primacy of the APFSDS round with the smoothbore guns in the 1980s.

The reason why very few countries use dedicated high-explosive rounds in their tank guns is because a high-explosive anti-tank round already comes with a very large explosion, so they can just wrap a fragmentation belt around that. On top of the poor performance of HESH against most targets on the battlefield, the British were already in a position where they were not going to encounter the kinds of targets that HESH is particularly good against. It’s not like the BAOR was planning to assault the Maginot Line anytime soon.

 

[Cryhavoc101]

It’s important to remember that the Chieftain came around in an era where the performance of HEAT rounds against armor could exceed that of any armor piercing (APDS and APDSFS) rounds. After World War II, it was much simpler to determine correct standoff detonation distances for explosively formed penetrators than it was to improve the performance of armor piercing rounds by switching to long rod penetrators. This was a large part of the reason why the US almost entirely abandoned development of conventional tank guns in favor of gun/missile launchers. It took extensive research into penetrator design and materials science throughout the 1960s and 1970s to reestablish the primacy of the APFSDS round with the smoothbore guns in the 1980s.

The reason why very few countries use dedicated high-explosive rounds in their tank guns is because a high-explosive anti-tank round already comes with a very large explosion, so they can just wrap a fragmentation belt around that. On top of the poor performance of HESH against most targets on the battlefield, the British were already in a position where they were not going to encounter the kinds of targets that HESH is particularly good against. It’s not like the BAOR was planning to assault the Maginot Line anytime soon.

And yet they have persisted with HESH through 3 different gun systems over what nearly 60 years?

They must have seen something in it to make it worthwhile keeping for so long!

 

[Riain]

On top of the poor performance of HESH against most targets on the battlefield, the British were already in a position where they were not going to encounter the kinds of targets that HESH is particularly good against. It’s not like the BAOR was planning to assault the Maginot Line anytime soon.

I do not know the answer - they had plenty of opportunity to adopt heat rounds - but didn't

I suspect part of it is US made Kit and the US used HEAT so everyone using US made kit used US made ammo and 'system' so used HEAT!

I note they also used HEP in the M68 (L7 copy) although I do not know if that was the case beyond 66 when they introduced a HEAT round?

TBH I'm not really buying the whole 'HESH is shit' line. If HESH was so bad and so important than Britain would replace it with something better between 1965 and 1990.

My guess is that HESH served Britain's needs well enough that it wasn't worth the effort and cost of changing it when there were other things to do; like the DU KE round that was issued at 12 per tank in 1991 PGW to take on the T72M.

EDIT: Just to clarify, it isn't a simple matter to swap ammo types. Britain would have a 30 day (or whatever) war stock of HESH laid in and modest annual production would cover practice use and 'shelf life expired' replacement every year. If Britain decided to go to HEAT they'd have to undertake a huge initial production run to lay in substantial stocks of HEAT ammo to build up a reasonable war stock and cover the conversion training and large follow on order to phase out HESH at the same rate and Armoured Corps personnel are inducted so they don't have to train new gunners on HEAT, HESH and KE.

 

[Adm_Von_Abrams]

HESH is claimed to be somewhat better than HE against concrete, barbed wire and apparently sandbags but the first two are rather moot points since fortifications have been obsolete since the late 1940s and the British aren't supposed to go on the offensive anyway. HE likely performs well enough against sandbags. Even the advantage against buildings is dubious because either HESH makes a clean hole that only kills people behind it while HE destroys the whole room, or the former doesn't work at all (1m walls in Eastern European structures for ex).

Actually having that clean hole through the building is one advantage for the HESH. You don't want to destroy every building you see, that just makes things harder for your own soldier to secure and if I recall correctly, the British Army doctrine want to minimalize structural damage when those soldier comes and clear the room. HE would risk structural weakness and risking the lives of those soldier even further when they go clear said building.

If you really want to demolish something, they could always call for artillery bombardment or air support.

 

[NOMISYRRUC]

I think the re-lining refits are for the 'firebox' bricks (or whatever) and the boiler cleanings are for the soot and crap that comes from burning heavy fuel oil in a 'firebox'. On 8 June 1982 while in the war zone HMS Hermes withdrew for a day to have her boilers cleaned, which I imagine to be cleaning off all the soot and crap from the water tubes in the actual steam plant.

In TTL CVA-01 & 02 won't have a 'firebox' burning heavy fuel oil to boil water to turn a turbine to drive the ship. It will have 6 Olympus Marine GTs burning marine diesel, these will actually drive the ship and the heat from the GT exhaust will pass through a much smaller heat exchanger to make steam for the catapults and other stuff. There will be no 'firebox' where heavy fuel oil is burnt to make heat, the heat will be made inside the GTs which will be swapped out when need be, and while the Olympus is known to be a 'smoker' I imagine this is a fraction of the crap buildup of heavy fuel oil and in any case this cleaning was done in a single day in wartime conditions in 1982.

Points taken. This arrangement may have another advantage. AIUI "firing" steam catapults (if firing is the correct word) can significantly reduce the amount of steam that's available to drive the ship. The TTL CVA.01 doesn't have this problem.

 

[ArtosStark]

In TTL CVA-01 & 02 won't have a 'firebox' burning heavy fuel oil to boil water to turn a turbine to drive the ship. It will have 6 Olympus Marine GTs burning marine diesel, these will actually drive the ship and the heat from the GT exhaust will pass through a much smaller heat exchanger to make steam for the catapults and other stuff. There will be no 'firebox' where heavy fuel oil is burnt to make heat, the heat will be made inside the GTs which will be swapped out when need be, and while the Olympus is known to be a 'smoker' I imagine this is a fraction of the crap buildup of heavy fuel oil and in any case this cleaning was done in a single day in wartime conditions in 1982.

Hmm. How much steam would you need for the catapults? And what kind of temperature would you expect from the flue gases. Heat Capture is a great way to use waste energy but you do need a fair amount to create reliable steam. I am not sure if you would be able to dispense with boilers entirely. Especially as you may need steam when the turbines are not running at full heat. Seems more like the use of flue gases would be used to improve the efficiency of a small boiler system specifically for the catapults. Just my suspicion, I don't know the variables well enough to do the math.

 

[NOMISYRRUC]

I can vaguely remember Eric Laithwaite demonstrating a linear induction motor in 1974 during that year's Royal Institution Christmas Lectures and the the British Hovertrain project that was cancelled in 1973 used linear induction motors.

Therefore, could Britain have developed an EAMLS between the cancellation of the OTL CVA.01 and the building of the TTL CVA.01?

Some asides...

1. When I looked the Christmas Lectures up on the internet to find the dates, I discovered that Carl Sagan did the 1976 lectures (which I remember) and that the 1973 and 1975 lectures were presented by David Attenborough and Heinz Wolf respectively, which I don't remember.
2. According to the Wikipaedia article on Eric Laithwaite he was involved in the creation of the Magnetic River a maglev device that was demonstrated in the "Q's Laboratory" scene in the James Bond film The Spy Who Loved Me.

Would the development of EAMLS catapult's be feasible in this time period? That is roughly 1965-75?

And if it was feasible, was it plausible? That is did the UK have enough scientists and the money to do it? IOTL the UK was developing linear induction motors for civilian purposes as part of the Hovertrain project so some of the work on that might help the MoD develop an EAML catapult.

 

[Bougnas]

@Cryhavoc101 @Bougnas @Mike D given this TL is about the stories of how and why pieces of kit entered service in the political and budget constraints of the time how would you propose all of this technical stuff enter service? We know that the Chieftain was conceived as a 40 ton Centurion with the 120mm gun derived from the Conqueror, so the Horstmann suspension was fair enough in 1956 and 1959 I suppose. We also know that RR designed a 24 litre V8 engine for the 40 ton Centurion but the 1957 NATO policy on multi-fuel engines meant this was dropped and a new engine developed, the much loved Leyland L60, so it's pretty easy to decide not to develop the L60 which transforms the Cheiftain.

But what about all the other stuff? I understand some was looked at in studies and others were even developed for trials, but when all factors were included especially value for money, how do you get them introduced in the face of Defence Reviews, currency devaluation, oil shocks, minority governments, detente and all the other stuff?

Is there a basis for having Vickers participate more and earlier in AFV development for the British Army postwar? You need someone who can put his foot down to challenge institutional habits.

 

[Cryhavoc101]

TBH I'm not really buying the whole 'HESH is shit' line. If HESH was so bad and so important than Britain would replace it with something better between 1965 and 1990.

My guess is that HESH served Britain's needs well enough that it wasn't worth the effort and cost of changing it when there were other things to do; like the DU KE round that was issued at 12 per tank in 1991 PGW to take on the T72M.

EDIT: Just to clarify, it isn't a simple matter to swap ammo types. Britain would have a 30 day (or whatever) war stock of HESH laid in and modest annual production would cover practice use and 'shelf life expired' replacement every year. If Britain decided to go to HEAT they'd have to undertake a huge initial production run to lay in substantial stocks of HEAT ammo to build up a reasonable war stock and cover the conversion training and large follow on order to phase out HESH at the same rate and Armoured Corps personnel are inducted so they don't have to train new gunners on HEAT, HESH and KE.

I was trawling through the world wide web basically looking for 'why HESH?' but found very little and there was no angst about it on ARRSE that I could find - which generally means there is nothing wrong with it.

I watched several videos where they were shooting the stuff out in Iraq to use up ammo reaching end of life and in one the Rupert went on about how great a round it is - I do not know if he was spouting the party line or what?

But it does seem to be the general refrain - 'HESH is great'

So I am not convinced thus far that HESH is a bad choice and the British Army do seem to rate it despite the rest of the internet telling them that they are wrong!

Okay back to the wider question

As part of my searching through the interwebs using my black belt in google-fu and I read one thing where a former officer in the Army during the 80s spoke about how they were asked to develop the army's requirements for the Chieftain replacement (Challenger II IOTL) as Challenger I had at that time been a bit of a disappointment and they basically told the army 'Buy/build Leo II' but if building a domestic design 'use the same gun as our allies' and of course were subsequently ignored.

So what I would suggest is something along the lines of having ITTL a Vickers led designed Torsion bar/RR V8 'Chad' Chieftain instead of the Leyland led Horstman/L60 Chieftain entering service a few years earlier and being a far more successful tank leads to the SHIR 2 being developed for the Iranians slightly earlier with 1200 units being made (a later or no Iranian revolution?) and the British army are able to leverage this design for TTLs Challenger I making 900 odd by the end of the 80s - Based on the Shir 2 (Lion) the British call this 'Black Prince' with a Vickers derived turret arrangement and sighting system but otherwise similar to the Challenger 1 of OTL

The Shir 2 gains quite a reputation during several boarder conflicts with Iraq during the 80s and Kuwait also buys a number of these tanks to supplement their Chieftain Fleet and these orders are followed by several other middle eastern nations (Jordan and Oman for example) - with a total of 2300 units made of all marks

This tank using the L11A5 gun of the later Chieftain is intended to supplement the existing fleet of tanks and not then replace it.

The Iran Iraq wars flair up throughout the 80s and the Iraqi invasion of Kuwait and Saudi Arabia in 1990/91 sees multiple examples of Lion /Black Prince in the service of the armies of Iran, Kuwait, Oman and the British Army verses Iraqi T55/T62 and T72s with the Lion /Black Prince almost always prevailing in the majority of engagements.

With the fall of the Berlin wall and the reduction of the BAOR and downsizing of the British army all Chieftain tanks are withdrawn from service by 1994 with the final unit based in Berlin ending service as that garrison is finally withdrawn.

In the Mid 80s the decision is made to align the future British tanks with that of the rest of NATO and build the Leopard II an under licence version of the then latest Leo II using the longer Rhm 120mm Smoothbore L55 gun and this tank goes into production (despite the wailing of the Daily Moral panic) during the late 90s and 420 entering service during the early 2000s as effectively Leo2A6's

Subsequent events see the Black Prince (Challenger I) completely withdrawn from service during the noughties as the British army radically downsizes and many of these are sold off to armies around the world

At time of writing the British army maintains about 250 modernised Leo IIs in 4 Regiments (Battalions for those of you who are hard of Commonwealth) - most of them to an A7 standard with 55 of them with 'street fighter' urban warfare modifications for use in the Iraq occupation force and a number of support tanks using the same hull with the remaining tanks kept in a pool of un modernised tanks.

 

[Bougnas]

The Dark Ages of Tanks mentions Britain considering purchasing some French SS-10 trials back in 1950-51, but internal pressures killed that idea. Would it be any useful at this stage to even just trial this small missile at a time when Malkara was just about to enter service, assuming that the British never really saw the former in action before? Could this show, like to the Americans with the Dart, that the more compact French formula was the way to go instead of the bulky and expensive Malkara? Would the SS-10's shaped charge technology bring anything new to the table back in 1951?

I believe that the Aussies actually considered making a smaller Malkara at some point, maybe this could be the basis for an Anglo-Aussie follow-on that is smaller and uses a shaped-charge warhead before the Swingfire and Orange William programs start?

 

[Riain]

Hmm. How much steam would you need for the catapults? And what kind of temperature would you expect from the flue gases. Heat Capture is a great way to use waste energy but you do need a fair amount to create reliable steam. I am not sure if you would be able to dispense with boilers entirely. Especially as you may need steam when the turbines are not running at full heat. Seems more like the use of flue gases would be used to improve the efficiency of a small boiler system specifically for the catapults. Just my suspicion, I don't know the variables well enough to do the math.

Would the development of EAMLS catapult's be feasible in this time period? That is roughly 1965-75?

And if it was feasible, was it plausible? That is did the UK have enough scientists and the money to do it? IOTL the UK was developing linear induction motors for civilian purposes as part of the Hovertrain project so some of the work on that might help the MoD develop an EAML catapult.

The temperature of a GT exhaust is about 600 degrees Celsius and with ~40 fixed wing aircraft the catapults need to fire ~50 times a day between them. Aircraft launching requires wind over deck for safety so I imagine that all 6 GTs would be online when launching aircraft and the ship steaming a high-ish speed so there would be plenty of heat available to create steam for catapults.

EMALS is barely feasible now, it sure as hell won't be feasible in 1971, but there is no need because generating steam with GTs isn't much of an engineering challenge.

 

[Riain]

Funny, the TL ended 3 weeks and 11 pages ago but is still generating discussion.

 

[McPherson]

Funny, the TL ended 3 weeks and 11 pages ago but is still generating discussion.

It is a good timeline with dozens of loose and dangling issues to discuss.

 

[Riain]

It is a good timeline with dozens of loose and dangling issues to discuss.

I find the topic endlessly fascinating, particularly how many of the most damaging decisions were essentially a coin toss that could have easily gone the other way and be fully justified.

 

[Mister Mister]

A question Riain: Why didn't you use VC10 for Nimrod? It's larger and longer-ranged than 111. Also, more in need of state-propping IMHO.
Otherwise, a great TL.

 

[Riain]

A question Riain: Why didn't you use VC10 for Nimrod? It's larger and longer-ranged than 111. Also, more in need of state-propping IMHO.
Otherwise, a great TL.

Thanks, I enjoyed learning about these stories. The Trident and VC10 were some of the bigger surprises of the exercise, both cut down by stupid state owned airlines despite being on development paths that could have lead to much greater success than OTL.

I thought the VC10 Super 200, which was the only version in production from 1965/66 at 213 seats was too big for the job, being bigger than the 707 and DC8 ITTL. ITTL this size advantage over all other airliners for 4 years meant that it was able to sell over 100 units in contrast to the 22 shorter Super VC10 of OTL so was in much less need of state help.

ITTL the Trident had much more power from 3 Medways and had much more scope to carry more fuel to increase range for a bespoke version for the MR/ASW role.