Improved Early War British Tanks?

[Paul_Sussex]

The problem with so many ideas is the Treasury. Also that any new gun needs to be suitable for use as an AT gun as well as tank mounting. The vz.38 is an AT gun and it should be possible to adapt it to a turret.

As per my original post, I don't see any changes in the outcome to the Battle of France - I think these will be in the North Africa campaign, where I'd hope to see increased use of HE against German and Italian AT guns with fewer tanks lost and (slowly) improving tactics that would feed into later tank designs.

 

[PMN1]

Set up a shadow factory run by a big car manufacturer. Ford is going to make Merlins, Austin are building bombers, Morris are building the Liberty so it seems obvious stop building an antique that will never be great no matter how you tinker with it and set up a Kestrel line. Kestrels for the Miles Master trainer were in very short supply so kill two birds with one stone build Kestrels for Advanced trainers and land Kestrels for tanks.

We just need a name for the land Kestrel as good as Meteor

Petrel?

Meteorite (OTL 2/3 of a Meteor)?

 

[Dorknought]

Mestrel.

The late 20's exercises show the success of the Experimental Mechanised Force. Working with Vickers and their A1E1 Independent Tank the requirement quickly becomes communication, speed and coordination with aircraft, an update of 1918 combined arms mobile warfare. A 27ton tank with a 450hp engine, 3 man turret, good armour and a 6pdr gun becomes the tank of the future. The hull is adapted to carry an 18pdr artillery piece fixed to fire in a limited arc over the rear for artillery units, ditch the gun and it's a supply tank. Both types are fast enough to keep up with the tracked infantry carriers. Exercises in the early 30's with sympathetic judges leads to the formation of 3 Mobile Divisions by the late 30's.

 

[Simon]

Pre-war I think the best engine would have been a Kestrel it was getting too small for air use but was still a modern V12 which detuned could have given maybe up to 500 hp which would have sufficed for all British tanks until the Centurion it might even have fitted in the Churchill and given that tank a dazzling top speed of 18 mph or even downhill as much as 20 mph.

When Rolls-Royce tested it alongside the Merlin converted for tank use the Kestrel generated 475 bhp on pool petrol. You might not get quite that high in actual operation and you have to also run the auxiliary systems and peripherals but I don't think getting on for 400 bhp for driving the vehicle would be unreasonable. To put that in perspective the German Panzer III and Panzer IV look to have had 265 bhp and 296 bhp engines respectively whilst the British Matilda II used two engines giving a combined 190 bhp.

 

[fastmongrel]

When Rolls-Royce tested it alongside the Merlin converted for tank use the Kestrel generated 475 bhp on pool petrol. You might not get quite that high in actual operation and you have to also run the auxiliary systems and peripherals but I don't think getting on for 400 bhp for driving the vehicle would be unreasonable. To put that in perspective the German Panzer III and Panzer IV look to have had 265 bhp and 296 bhp engines respectively whilst the British Matilda II used two engines giving a combined 190 bhp.

Even 400hp is enough for everything short of the Comet

 

[Cryhavoc101]

Rolls Royce Raptor?

 

[fastmongrel]

Rolls Royce Raptor?

Rolls Royce Rex

 

[Derwit]

The big early war issue was numbers more than designs (yes British tanks where a bit rubbish) but where broadly comparable to other nations in 1939/40 and usable into 1941. The big failing was not having anything comparable to the new heavier german tanks (apart from the Churchill which athough a personal favourite isn't the big jump forward Britain needed) in the works mid war.

I have often considered the what might have happened if the powers that be hadn't played around with spec for the A13 so much during its design phase. This apparently caused much delay and many of the myriad issues with the Covenator. A proper development would have noted a number of the flaws that bedevilled this tank in service.

As the Covenator was meant to start production pre war but was significantly delayed, it stands to reason that it should be possible with a small POD to get it into production as planned OTL with less design issues. If nothing else the factory that was waiting to produce the first batch of Covenators gets going in the summer of 1939 this would increase the number of gun armed British tanks in the critical period of 1940.

Indeed If the British had Covenanters that dont break down if you look at then in a funny way and can be driven in a straight line sigh) earlier than they would have a tank compatible to mthe early war Pz3&4's. Assuming they can overcome the engine overheating in warm condition so the Covenator can be used in the desert (sighs louder) then its heavier armour than the Cruisers would be welcome to the crews as they charge the German anti tank guns as their own armament doesn't come this a HE shell! That also requires a more significant POD to really make early war British tanks less rubbish.

 

[Peg Leg Pom]

Good engine, designed with heavy armour in mind, an improved turret for a6 Pounder and later 75 Millimeter and the Hamlet should be a pretty good tank until about mid war, where it's replaced with a Universal Tank with the old Hamet chassis being repurposed for APCs and SPGs.

The regular tank gets the standard 6 pounder while the close support version gets the 75mm version of the same gun.

 

[Derwit]

Rolls Royce Kommando (with Norton making components)

 

[marathag]

The 'hand-fitted Merlins in the UK' story is a myth, long past it's sell date, and despite flag-waving by some American wannabe-journalists. For example, RR tollerannces on Merlin were severe, half of measure of what DB prescribed for their V12 engines. Merlin production in 1940 was in the ballpark of DB 601 and Juom 211 combined, that would not be the case if the Merlins were hand-fitted.

Stanley Hooker's Autobiography "Not much of an Engineer"

From the enginehistory.org article on the Merlin

If parts aren't the same as the drawings, well to me, that means that fitters are involved.
I never said that RR tolerances were poor: they can't be, at those levels of power. They have to be very close

 

[tomo pauk]

Stanley Hooker's Autobiography "Not much of an Engineer"
...
If parts aren't the same as the drawings, well to me, that means that fitters are involved.
I never said that RR tolerances were poor: they can't be, at those levels of power. They have to be very close

Thank you for the excerpts.
Tolerances are specified in order to be achieved in production. Or, no point in specifying tolerances if Bob or Joe will do whatever they are pleased when making engine parts. Fitters were certainly involved, but there was no 'file to fit' procedure - pick up the parts, and install them on engine on production line.
FWIW, this might be of interest: link

 

[Simon]

Even 400hp is enough for everything short of the Comet.

Oh certainly. If they're using 375-400 bhp then chances are they'll start running into issues with the gearbox, with any luck that would push them towards Merritt-Brown that IIRC had developed theirs in the mid-1930s. As for suspension depending on how heavy the tank gets Christie might be good enough although Horstmann would be better.

If the British had a solid tank design at the start of the war then, providing it could be up-gunned with the 6-pounder when it appears, it should be able to see them through until just before D-Day.

 

[Some Bloke]

Mestrel.

The late 20's exercises show the success of the Experimental Mechanised Force. Working with Vickers and their A1E1 Independent Tank the requirement quickly becomes communication, speed and coordination with aircraft, an update of 1918 combined arms mobile warfare. A 27ton tank with a 450hp engine, 3 man turret, good armour and a 6pdr gun becomes the tank of the future. The hull is adapted to carry an 18pdr artillery piece fixed to fire in a limited arc over the rear for artillery units, ditch the gun and it's a supply tank. Both types are fast enough to keep up with the tracked infantry carriers. Exercises in the early 30's with sympathetic judges leads to the formation of 3 Mobile Divisions by the late 30's.

Any thoughts on the engine?

 

[McPherson]

I think a lot of hay could be made by (somehow) improving British experience with welding. The Crusader and Covenanter especially were let down by the weight of riveted construction, since they were planned to be welded in the first place before the factories declared they couldn't meet requirements and switched back to rivets.
An early push for the 6-pounder as standard armament over the "good enough" 2-pounder would also lead so some interesting butterflies.

A shipbuilder could help out there. I seem to recall the British had some who had workers who knew how to weld hull-metal?

Another potential POD is if British tank development had more input from the Dominions. Exercises in Canada and Australia with more room to run around in might change design assumptions. Does anyone know off-hand what the scale of military exercises were like in the 30's? A massed Empire-wide shindig in Manitoba would lead to some interesting cross-pollination of ideas, especially if the Americans were invited.

NIH does not stand for National Institutes of Health

Good point, but given the tight treasury of the era, where's a good alternative? Locations in Scotland for winter conditions could be do-able. Also, with Britains world-wide empire, you'd probably want to test in desert and jungle as well, but that will cost.

(See photos (^^^)

You know they could have done what the Americans did and use radial aircraft engines to power tanks.

The Curtiss Wright engines were junk. The Continental R-975 was "adequate".

About The Covenanter...

 

[tomo pauk]

I'll just toss here the engines, that could power the early war (1939-41-42) British tanks. Each has it's benefits and shortcomings.

- RR Kestrel - it is a mature engine, with a known track record, small and compact enough for tanks of the day. Might be a little pricey, the V12 aero engines were not known for being cheap (although the price will be coming down with mass production and introduction of cheaper if heavier parts where that is possible) . Someone will need to manufacture the tooling that RR can't spare in late 1930s.
- Liberty - if kept at 'normal' HP levels (at 340 HP and under, even 300 will make Matilda II go fast enough) and if cooling system is well tanke care of, it can provide useful service. Just don't push for more HP, the 410 HP version was very problematic.
- Bedford 12 cylinder - it worked well in the 40-ton Churchill, it will work even better in a 25-30 ton tank. It was even a bit smaller than the Matilda's twinned bus engine. Just make sure to have Bedford make it at least 18 months earlier. To the best of my knowledge, the twin 6 was just two commercial engines 'welded together'.
- Twinned AEC petrol engines - use the commercial engines as starting point (= can be cheap & readily available), and twinned engine from Valentine will give 270 HP from the starters.
- Air cooled V12, like De Havilland engines - make sure that forced cooling works and that might work.
- Air cooled radial engines - as above, the cooling fan is mandatory. Possible candidates include A-S Cheetah (keep the superchager), Bristol Mercury, perhaps the Bristol Neptune. These radial engines, even with fans, are much shorter than in-lines and very light, but also taller than in-lines.

 

[Bougnas]

- Twinned AEC petrol engines - use the commercial engines as starting point (= can be cheap & readily available), and twinned engine from Valentine will give 270 HP from the starters.

Were the OTL twin AECs diesels?

- Air cooled radial engines - as above, the cooling fan is mandatory. Possible candidates include A-S Cheetah (keep the superchager), Bristol Mercury, perhaps the Bristol Neptune. These radial engines, even with fans, are much shorter than in-lines and very light, but also taller than in-lines.

Even if radials are taller you can pull a M18 move and turn them 90° down to circumvent that issue if you are willing to accept a more complex transmission.

Re-Churchill: Did it have to be this long because of powerpack size and ergonomics or solely to cross trenches? If the latter can we make it shorter but wider to have something closer to regular medium tanks?

 

[tomo pauk]

Were the OTL twin AECs diesels?

Yes, those installed on Matilda II, either from AEC or Leyland.

Even if radials are taller you can pull a M18 move and turn them 90° down to circumvent that issue if you are willing to accept a more complex transmission.

Yes - either 90 deg, or even 45 deg.
Transimssion might be a bit more complex, but then there is no liquid cooling system to worry about.

Re-Churchill: Did it have to be this long because of powerpack size and ergonomics or solely to cross trenches? If the latter can we make it shorter but wider to have something closer to regular medium tanks?

IMO - the extra length was due to requirement to cross trenches, at least by looking at cutaways & schematics, and reading about the conception of the tank. Yes, the shorter Churchill would've shave some weight without touching the tank internal volume.

 

[fastmongrel]

To the best of my knowledge, the twin 6 was just two commercial engines 'welded together'.

The Twin six was a 22 litre side valve petroleum engine with hydraulic valve lifters and a single crankshaft. Bedford was part of the giant General Motors conglomerate but non of the GM companies made a six cylinder 11 litre side valve that matched half a Twin six. The engine was a fresh design that took little from commercial engines.

It must have been a decent design as once the initial problems every new engine suffers were sorted it pretty much stayed the same as long as Churchill's were built. I don't think there was a MK2 version.

 

[tomo pauk]

The Twin six was a 22 litre side valve petroleum engine with hydraulic valve lifters and a single crankshaft. Bedford was part of the giant General Motors conglomerate but non of the GM companies made a six cylinder 11 litre side valve that matched half a Twin six. The engine was a fresh design that took little from commercial engines.

Thank you.

It must have been a decent design as once the initial problems every new engine suffers were sorted it pretty much stayed the same as long as Churchill's were built. I don't think there was a MK2 version.

Agreed all the way.