Best possible tank for UK Commonwealth, 1940

[tomo pauk]

Using the present state-of-the-art from the late 1930s, could the Brits managed to design produce the best tank in the world for service for 1940? A true MBT? I'm not trying to get Merlin/Meteor, or 17pdr installed for Battle of France, but trying to grasp what the best possible design was feasible for that era.
The tank should be license produced abroad, too, so let's not make it too complicated.

 

[davebender]

The 6 pounder (i.e. 57mm) is probably the best tank main gun Britain could mass produce by 1940. With good AP and HE rounds it would be state of the art during 1940 to 1941. It's essential that Britain give HE round development the same priority as AP rounds. Otherwise your tank will be crippled from the start vs soft targets.

 

[Glider]

Personally its my belief that the main problem was the basic tank. The PzIII originally had a poor gun and thin armour, in a stand up fight the Matilda had most of the advantages. But what the Pz III had in spades was growth potential.
The british started the war with the Matilda and there was nothing wrong with that, where they went wrong was designing the Valanine. They should have designed it with growth potential so as the 6pd came on stream they could have installed it, in the same way the Pz III was easily upgunned from the 37mm to the 50mm L42 and 50mm L60

 

[tomo pauk]

Agreed with above posts; the tank need to be a reliable, mass produced all-rounder if it's to play any role in a major war.

Let's start with size weight. Matilda II was 27 tons, Independent was 33 tons. Something in between, under 30 tons, growing later above 30 tons - much like M4/T-34.
All that bulk need to be propelled by a powerful engine. The Liberty tank engine (340 HP) received plenty of bad press, much to the usage in the desert (due to sand) - perhaps it would been fared better in Europe? The another choice might be the 370 HP V-12 from Independent tank (making it go 20 mph on road). Yet another choice can be the variant of the RR Kestrel, plenty of power there even in 1920s (450 HP).
The armor should be comparable with Matilda II/Sherman/T-34. Silhouette, due to 'all rear' nature of drive, is to be lower than Sherman, more akin to the T-34.
Being an all-rounder, the armament need to be at least 57mm (being from the UK), the turret need to accommodate crew of 3 - so we need a decent turret ring. Without the sponsoons, that is not to be achieved, if the tank is to fit the much-blamed British train gauge. The 57mm will be using the 19th century vintage round, in order to expedite the development production. The new guns (old barrels ammo will be used for pre-series examples, in order to accelerate the testing and training) will allow for a better power, comparable in HE AP performance of the German 'short' 5cm tank gun. We will not develop the 2pdr, nor the 3in howitzer.

I was initially thinking about the 10% increased Valentine, but that wouldn't suffice for all of the capabilities wanted/needed for a proper MBT of 1940

 

[Shortround6]

The weight limits on tanks usually had little to do with combat capabilities, except for power to weight ratios with available engines ( more on that later) and much more to do with transportation and general mobility. Mobility in the sense that if the majority of bridges in the area you want to operate in are only rated for 20 ton vehicles a 22 ton tank is a gamble, a 30 ton tank probably won't make past the the first couple of rivers. What is the capacity of the tactical temporary bridging equipment if the existing bridges are blown? Weight also governs the number of available railway carriages and even the docks (cranes) that can be used for sea movements.

There are reasons that some weight limits were what they were before the shooting started and why some bigger, heavier tanks stayed limited in production.

The Liberty was a bad decision. It had a very troubled reputation as an airplane engine. a good Liberty wasn't a bad engine but a bad Liberty was a disaster. Many of the WW I Liberty's should have been melted down while brand new. Anybody who thought this was a good choice in 1937 must have been looking at the bottom line (cheap).

 

[michaelmaltby]

"... The tank should be license produced abroad, too, so let's not make it too complicated. "



MM

 

[tomo pauk]

The weight limits on tanks usually had little to do with combat capabilities, except for power to weight ratios with available engines ( more on that later) and much more to do with transportation and general mobility. Mobility in the sense that if the majority of bridges in the area you want to operate in are only rated for 20 ton vehicles a 22 ton tank is a gamble, a 30 ton tank probably won't make past the the first couple of rivers. What is the capacity of the tactical temporary bridging equipment if the existing bridges are blown? Weight also governs the number of available railway carriages and even the docks (cranes) that can be used for sea movements.

There are reasons that some weight limits were what they were before the shooting started and why some bigger, heavier tanks stayed limited in production.

The Liberty was a bad decision. It had a very troubled reputation as an airplane engine. a good Liberty wasn't a bad engine but a bad Liberty was a disaster. Many of the WW I Liberty's should have been melted down while brand new. Anybody who thought this was a good choice in 1937 must have been looking at the bottom line (cheap).

Doh, I did not know that Liberty was (without dirt/sand issues taken into account) such a troublesome machine. Still we have the two good choices.

'My' tank would be, ideally, a ton heavier than Matilda II, for 1940. It would be lighter than the Independent, let alone the Churchill (almost 40 tons, specifications laid down in July 1940; the predecessor, A20, specified prior ww2, was to be at 43 tons). Or, as heavy as the Char B1, M3 medium (Lee/Grant).

 

[Shortround6]

Weight comes from the military requirements. Like the desired armor thickness, Steel weighs 40lbs per 1ft X 1ft x 1in piece. Make a tank one foot longer (to house larger engine) and with even a 6ft wide hull (between the tracks) and 5/8ths (16mm) armor top and bottom you have gained 300lbs. what do you want for side armor? 30mm armor is about 47lbs per square ft a four ft high hull will need another 376lbs. about 1/3 of a ton to provide armor for a 1 ft longer engine. tank designers worried more about the size of an engine than than they did the weight.

Bigger turret rings meant longer, wider tanks with all the extra armor. More powerful engines meant longer engine bays. more fuel (or ammo) also meant a bigger hull. Once the requirement for armor went past the protection level needed for 12.7-20mm weapons the extra space (volume) needed for multiple turret tanks like the Independent became prohibitive.

Cross country performance needs a good power to weight ratio. Road speed can be an illusion. what is wanted is the ability to climb hills at a fair pace. Not racing but not crawling. The Churchill was slow on the road but in low gear (walking pace) it could climb hills other tanks could not. Also in soft ground the tank is continuously trying to pull it self UP out of a pair of shallow trenches. this sucks up considerable power.

 

[tomo pauk]

No quarrel with your analysis

Basically, I'm looking at what could be called 'Cromwell tank of 1940'; the Meteor engine is off for obvious reasons, replaced with either Armstrong-Siddeley V-12 or RR Kestrel. A smaller engine, needing a smaller cooling system, can save on weight for the engine compartment. Cromwells at 28 tons were featuring the armor impervious to the 3,7cm fire from frontal arc, even to the Czechoslovakian 4,7cm; the short 5cm of the Pz-IIIs will also have trouble. Since we've saved some weight from the engine compartment, we can add some armor on sides making the tank bulletproof for at least frontal 270 deg, if not all 360, for 1940.

An interesting engine choice could be the AEC engine from Valentine. The 1st versions of that tank was powered by a 130-135 HP engines, a 50% increase over Matilda (later at 160 HP). The engines would offer yet another saving on the engine department weight, so we can have a well armored, decently maneuverable tank, with all-round fighting capabilities. If I'm not mistaking it badly, the AEC engines were off-the-shelf stuff? Of course, this is as far from 'pre-Cromwell' as it gets.

Another possibility: DH Gipsy Twelve, even if it's de-rated to 350 HP.

The gearbox ratio can have the really short 1st gear, so we can climb hills other unfavorable terrain. No worries about multiple turrets, those are not at my liking

 

[stona]

Panzer IV .........I'll get me coat.
Steve

 

[tomo pauk]

Play with us, Steve
Pz-IV was a good tank, a 'Britanized' version would've served the UK Commonwealth froces well.

 

[PJay]

The Valentine could take a 6 pdr. Valentine tank - Wikipedia, the free encyclopedia

Personally its my belief that the main problem was the basic tank. The PzIII originally had a poor gun and thin armour, in a stand up fight the Matilda had most of the advantages. But what the Pz III had in spades was growth potential.
The british started the war with the Matilda and there was nothing wrong with that, where they went wrong was designing the Valanine. They should have designed it with growth potential so as the 6pd came on stream they could have installed it, in the same way the Pz III was easily upgunned from the 37mm to the 50mm L42 and 50mm L60

 

[pbfoot]

Which Brit tanks had welded armour

 

[Shortround6]

The Crusader and Valentine tanks with 6pdr guns had two man crews which lowered the rate of fire and distracted the tank commander from his job of commanding the tank.

 

[Readie]

I think some fresh thinking was needed for a modern British tank.
Things like.
Interchangeability of ammo with artillery
Common parts
etc.
This would have a field advantage in battle zones.
There is an argument for the disposable mass produced tank, crudely made like the Russian T34 or a state of the art tank like the German Tiger.
Which way would you have gone?
John

 

[tomo pauk]

The interchangeability of ammo with Royal artillery could be achieved with a version of 'our' tank featuring a 25pdr, either like it was done for Shermans (105mm howitzer in turret) or as in StuH-42 (Pz-III hull with 10,5cm howitzer with limited traverse). Should be great to take out the ATGs, MG nests etc. Even to make a mess of the medium/light armor, provided it hits (the 25pdr was used as an AT gun).
The usage of an existing engine in the tank's offsprings should make for better maintainability.
A tank gun version of the 3in AAA should be introduced in 1941/42, so the tank can compete with long-barrel wielding Pz-III, StuGs and -IV.

I'm not a favorite of a 60-70 ton tanks for the ww2.
The 28 ton tank should be practically ATG-proof (not for the 8,8 ) in 1940. It should grow to 30 tons in 1941 (so the 5cm ATG should have problems to make a kill), 32 tons in 42. The UK would have access for the mass produced M4s from late 1942, so they maybe should venture for the 45-50 ton tank to be deployed in early 1944 (17pdr, Meteor tank, sloped armor to defeat Tiger's Panther's guns at 500-1500 yds, and 'medium length' 7,5cms from 200-500 yds - depending on direction of the attack). They also have their own equivalents of late M4s/T-34-85s.

 

[Shortround6]

The British had a problem with ammo inter-changeability for tanks in WW II. The 25pdr used separate load ammunition. Projectile loaded and then case I believe. AP rounds were crimped together for faster rate of fire.

These are hand loaded guns and the loader usually didn't have room to stand fully upright. Granted the 25pdr doesn't use the cartridge case of the 88 but the projectiles were the same diameter and weight.

The low muzzle velocity makes long range hits difficult (and by long range we are still way under 1000 yds or meters). A rough rule of thumb for "practical point blank range" the max range from the gun muzzle that the shell will neither rise above or fall below a tank sized target (depending on the size of the tank, of course) is the muzzle velocity + 10%. Longer ranges require enough elevation that is is possible to over shoot at close range. Point blank range for the 25pdr is a bit under 600meters while the 2 pdr in about 870meters.
the 25pdrs use as an AT gun was desperation.

 

[tomo pauk]

I guess someone would see the light and crimp the HE shells with cases, once the 'crimped' AP shots are used some time. The loader would have easier work than the loader in M4/105 or StuH-42 (depending on what configuration is chosen).
The 25pdr were (not) viable for AT work as the 105mm howitzers were (not) - rather hard to hit a moving target, but a hit was able to make a mess, depending on the part where it landed. With 57mm, and later 3in installed, the AT capabilities seem fulfilled, so the 25pdr in the AT role would be the exceptions.

 

[yulzari]

The simplest item to pin down is the gun. The 6 pounder (57mm) was a period item and could have been introduced before the war. Design began in 1938 even if production was delayed until 1941. It had a usable HE round and ammunition development kept it a viable anti armour gun until the end of the war (some Regiments kept 6pdr tanks as anti armour protection when the rest were changed to 75mm.) Thus we can settle on just one gun type and refit some later to take US 75mm ammunition (like the WW1 French 75mm).

Now we need an engine, gearbox, hull, suspension and tracks. These need to be within industry capability of 1938 and able to be developed. It need not be more than 20 tonnes rough ground speed is more important than flat road speed.

My candidate would be the Valentine in all these areas. Ideally with a bulkier 3 man turret to release the commander from loader duty. This will also improve reliability and ease crew fatigue with an extra man to assist maintenance, stand guard etc.

Easily built and later up engined versions can carry more armour, welded armour and benefit from track material and design upgrades. Not a star performer but able to be built in bulk so you will have numbers of effective tanks able to kill armour, to support infantry with HE and knock out anti tank guns with HE.

Effectively this is a Sherman production concept but available from 1939 and we have proven development potential from the actual Valentine.

It also needs to be matched with a 'modern' tank transporter to give theatre commanders the option of transferring their armour from battlefield to battlefield at relative speed and without wearing out limited life components. This can be used to recover damaged tanks to further multiply their effectiveness.

This is no sexy 17 pounder 600bhp designer tank for the few but an industrial plodder tank for the masses.

Once this is in mass production then you can set the design teams to make the next generation tanks for introduction in 1944.

 

[parsifal]

The Brits started with a faulty concept on Tank roles....the so-called infantry Tanks and Cruiser tank concepts. What they needed was a blend of both.

The other glaring weakness in Brit tanks were the inadequate engine development, and to a lesser extent the poor armament carried (the two pounder). these things all conspired to make Brit Tank designs second rate compared to those of germany, or even france.

Best tank of 1940-41 was the matilda II despite all these shortcomings. But it lacked a number of things, and could not easily be updated.