1936-1941: your best RA (tanks/artillery)

[Shortround6]

starting here.
"On Land
The Matilda was replaced by the Valentine. A tank with essentially the same gun, armour, speed, and size of the Matilda. Why didn't someone say, what can we do with all these old WW1 13pdd or even 18pd guns we have in our warehouses, why not see how they work in a tank. Its more or less what the US did with the 75mm gun used in the Lee/Grant and Sherman. I believe that there was a High Velocity version of the 18pd gun using a 13pd shell developed for AA fire in WW1 which had a higher MV than the 75mm L40. That would have been worth a look."

There were nowhere near the numbers of these guns in the warehouses that some people think.
The barrels might be usable but the mounts (elevation and traverse) are useless and the guns need new recoil systems. These old guns have a 3-4 foot recoil on the carriage.
basically all you get is a tube and breech mechanism. Then you have to jump through hoops to fit it into a vehicle.
In the end you get a gun with rather poor armor penetration.
the 18pdr/13pdr wasn't much better than the 75MM L40, it fired a lighter shell. Stick in a heavier AP shot and the velocity drops.

There was no real reason the 2pdr and 6pdr couldn't have had HE ammo from day one. The real restriction on British tank gun ranges (especially for HE support and machine gun fire) was the dubious fire on the move tactic which required the free elevation mount controlled by the gunners shoulder which made precise elevation changes needed for long range fire and repeat shots nearly impossible.

 

[swampyankee]

A G Williams published an essay on a better choice for the RAC's tank gun: a version of the 6 lb (57 mm) gun (see AN ALTERNATIVE 1930s BRITISH TANK GUN)

For the RA, I'd get all the gun carriages modernized for towing by trucks at high speed -- at least 70 km/hr -- and get the appropriate trucks to tow them and supply ammunition. Next, get some long-range coastal artillery in place, perhaps railroad guns using 9.2 and 13.5 inch guns that were in storage. For air defense, get the RA and RAF to integrate fighters and air defense artillery. Get more anti-tank guns and start looking at an A/T weapon more viable than anti-tank rifles.

 

[tomo pauk]

British can install the 3pdr Vickers and 12 or 13 pdr guns in their late-1930s tanks, and not trying to re-invent the weheel with 2pdr and 6pdr. Granted, the whole 'fire on the move' idea is to be axed 1st, so the turret can grow even without the increase of turret ring.

 

[Shortround6]

The 3pdr gun dated to black powder days (and did the old 6pdr used in WW I tanks) although modern (post 1900) ammunition used smokeless powder ballistics were not improved much. The WW I 12pdr and 13pdr guns were NOT even approaching HIgh Velocity. The 13pdr fired a 12.5lb projectile at 1675fps. The US 75mm field gun (French 75mm decedent) fired a 14.7lb HE shell (or 14.96lb AP shell) at 1955fps (2000fps for the AP). The 13pdr HE shell (like many British HE shells)

carried a smaller than usual HE payload (9 oz 4dr/262 grams) compared to the American 75HE which held 1.5lbs of TNT or 1.36lbs of Amatol. There was never an AP projectile for the !3pdr and there was never a chemical or smoke projectile. Yes one could be built, but it was it's small capacity that saw production dropped during WW I and the 18pdr taking over just about all duties except accompanying the calvary. the 13 pdr was expected to keep up the cavalry moving at the gallop using a 6 horse team.

Impressive in it's way but not really the criteria for selecting a tank cannon.


There were under 500 13pdrs built, production stopped early in WW I, production was never resumed, ever. The converted AA guns came out of that under 500 guns.
The fact that a small number of guns were brought out of store and mounted in some pillboxes in the dark days after Dunkirk in no way changes the fact that the gun was obsolete during WW I and in no way was a starting point for a gun that would leapfrog the UK into the forefront of AFV design.

 

[WARSPITER]

The 2lber was produced from 1936 and was quite a capable AT gun at the ranges of the time against the armour of the time.

The Valentine tank was a private venture which was designed by Vickers-Armstrongs using proven components from earlier vehicles.
It was less maintenance intensive than the Matilda and was very reliable over great distances.

Fitting guns of much larger caliber was a real problem in the thirties due to recoil and physical size. making a hull with a large enough
turret ring meant increasing everything. Production lines to handle such a vehicle were not that easy to come by. A good example is
the Tiger A. The only company with facilities to produce it was Henschel as they made locomotives. Every time more locomotives
were needed Henschels Tiger production suffered.

The armour and gun for the Matilda and the Valentine were as good as or better than possible opponents in the late thirties.

The weakness of British AT guns was definitely the lack of high explosive ammunition. This was in part due to anti tank gun development
being seperate to artillery gun development so ammunition was developed for the type of gun. A strange situation.

The 6lber was also developed in the late thirties but the carriage development was slowed by events. After Dunkirk anything was better
than nothing and for each 6lber built 5 or 6 2lbers could be produced.

 

[yulzari]

It might be tempting to make more of the 3.7" QF Mountain Howitzer used in the A 9/10 etc. but a look at it's performance shows it to have a very low velocity and limited HE capacity. But enough to merit it's use as towed/mule mountain artillery throughout the war. However the gun needed proper artillery users to accommodate the slow speed and arching trajectory. Not a quick shot from a just topped tank. OK for smoke which only has to somewhere round about the intended objective. This is reinforced when one looks at it replacement. The 95mmQF Howitzer which had roughly twice the velocity and nearly twice the HE weight. Even then it was mostly used in the indirect fire role. Most notably by the Royal Marine's Cavaliers amongst others.

It makes it easier to understand the period doctrine to use the 3.7 in the gun tank support role with smoke ammunition. A task within it's capability. As a towed/mule mountain artillery piece it worked well in most theatres where it's light weight and small size allowed it to be placed where other artillery could not go.

78- MM CALIBRE CARTRIDGES

 

[tomo pauk]

The 3pdr gun dated to black powder days (and did the old 6pdr used in WW I tanks) although modern (post 1900) ammunition used smokeless powder ballistics were not improved much.

785 m/s for a 3 lb projectile - excellent for the era.

There was never an AP projectile for the !3pdr and there was never a chemical or smoke projectile.

Do we need a working nuclear reactor to have the AP, chemical or smoke projectile for a 3lb Vickers?

The WW I 12pdr and 13pdr guns were NOT even approaching HIgh Velocity. The 13pdr fired a 12.5lb projectile at 1675fps. The US 75mm field gun (French 75mm decedent) fired a 14.7lb HE shell (or 14.96lb AP shell) at 1955fps (2000fps for the AP).
...
Yes one could be built, but it was it's small capacity that saw production dropped during WW I and the 18pdr taking over just about all duties except accompanying the calvary. the 13 pdr was expected to keep up the cavalry moving at the gallop using a 6 horse team.
Impressive in it's way but not really the criteria for selecting a tank cannon.
There were under 500 13pdrs built, production stopped early in WW I, production was never resumed, ever. The converted AA guns came out of that under 500 guns.
The fact that a small number of guns were brought out of store and mounted in some pillboxes in the dark days after Dunkirk in no way changes the fact that the gun was obsolete during WW I and in no way was a starting point for a gun that would leapfrog the UK into the forefront of AFV design.

This ww1 12pdr cannon is certainly above the 2000 fps league, let alone the 1700 fps league: link

The 13pdr HE shell (like many British HE shells) carried a smaller than usual HE payload (9 oz 4dr/262 grams) compared to the American 75HE which held 1.5lbs of TNT or 1.36lbs of Amatol.

British don't need to match Americans here.
What they need is a good gun, be it as AT or tank gun, that is much better than what they fielded in these roles, and pronto.

 

[Shortround6]

It might be tempting to make more of the 3.7" QF Mountain Howitzer used in the A 9/10 etc. but a look at it's performance shows it to have a very low velocity and limited HE capacity

The A 9/10 used a different gun and ammo than the 3.7" QF Mountain Howitzer. the 3.7" QF Mountain Howitzer fired a shell almost twice as heavy as the tank gun. It also fired it somewhat faster, 798fps (using charge 4) vs about 600/620fps for the tank weapon. The tank weapon never had a towed version.

There seems to be quite a bit of confusion as the 3.7in weapon used in the early cruisers, but it seems that the 3.7in mountain howitzer was never used in an armored vehicle (at least a factory one). The later 95mm weapon was supposed to use the 3.7in mountain gun ammunition but it got "improved".

 

[Shortround6]

785 m/s for a 3 lb projectile - excellent for the era.

which 3pdr was that?
the one in the Vickers tank of the 20s was good for 533m/s or 563m/s.
The Naval 3pdr was a rather large and heavy gun. Only about 100lbs lighter than the 6pdr anti-tank gun. If you are going to stick a 99in long 650lb gun (barrel and breechblock) in a tank it better do more than this 3pdr.

Do we need a working nuclear reactor to have the AP, chemical or smoke projectile for a 3lb Vickers?

Sorry for the missprint, I meant 13pdr but yes, you need a nuclear reactor, or at least some way of making chemical or smoke round much, much more effective. 75mm was considered the smallest practical smoke/chemical round as anything smaller simply didn't carry enough payload. British 13pdr shell was certainly suspect in this regard. British loved ot make shells out of crappy steel which meant several things, easier and cheaper to make so supply is easy, but you need a lot more for them for the same target effect. Crappy steel means thicker shell walls to stand up to the firing stress so less room for payload. the 13pdr firing He would have been useful, just not as useful as the shell weight and caliber suggest.

Since a general rule of thumb for armor penetration is that it goes up with the square of the speed (everything else being equal) so 17 X 17 = 289 while 20 X 20 = 400 so the 1700fps gun has 72% of the penetration of the 2000fps gun, except the 2000fps gun is using a heavier projectile. for given caliber and impact velocity penetration is directly proportional to shell weight. So yes you do need something extra tricky to get the 13pdr up to the standards of the day.

This ww1 12pdr cannon is certainly above the 2000 fps league, let alone the 1700 fps league: link

http://www.navweaps.com/Weapons/WNBR_3-40_mk1.php

The problem isn't getting a 12-15pdr cannon (75-76mm) cannon with good performance, it is getting one that fits in a tank, or at least a tank of the time. While some may shrug off the idea of a few hundred extra pounds of weight in a 15-25ton tank the fact is that the heavier gun creates a Domino effect. You need a larger turret, which has to be balanced to rotate properly. Using old naval or coast defence guns was done but it was hardly ideal. The gun in the American M-10 tank destroyer was an old (pre WW I) coast defence gun. The 76mm gun in the Sherman fired the same projectiles using a much smaller cartridge case (new propellants) out of a much lighter barrel (new steel alloys and manufacturing techniques)

British don't need to match Americans here.
What they need is a good gun, be it as AT or tank gun, that is much better than what they fielded in these roles, and pronto.

If you are just looking for some sort of HE capability (equal to a hand grenade?) , the 2pdr could have been supplied with HE ammunition from day one. The failure was not the weapon but doctrine. The 2pdr HE ammunition that was supplied later in the war held about 63-65 grams of HE. While certainly not great it beats the heck out of german 37mm ammo which held about 25 grams of HE. German 50mm HE ammo held about 165 grams.

British alos cheaped out on the AP ammo.
see : http://www.wwiiequipment.com/index....er-anti-tank-gun&catid=40:anti-tank&Itemid=58

the APCBC shot, first made in 1943 had a penetration at 1000 yds equal to what the early shot (pre war) did at 500yds. At 500 yds it was nearly equal to the old shot at 100yds.
The British had been making APCBC shot for naval guns since before WW I, it didn't require anything new in either materials or knowledge.

Build the 6pdr earlier, the plans had been completed in 1938. Same thing, make HE ammo from day one, make APCBC shot from day one.
There was a 6pdr coast defence gun that used a different cartridge case. It's most famous use was at Valetta Malta, 35/36 July 1941.
A 6pdr AA gun had a shell with an 8 oz (225 grams?) of filler.

Both guns were limited in range by the shoulder controlled elevation making follow up shots difficult, not by the accuracy of the guns or ammo.

 

[WARSPITER]

HE ammo was available for the 2lber early on and was issued to artillery units for defence from infantry attack. Tank units didn't really want
this ammo as they preferred to have more storage of AP shot.

The difference between the 2lber and 6lber is significant and the 6lber was ready to go in 1940 but lacked a carriage until 1941. There was
no real point in going for a 47mm gun as it wasn't a big step up from the 2lber at 40mm and was nowhere near as capable as the 6lber at
57mm.

The problem of tank size has also been noted twice now and cannot be underestimated. A stable mobile platform for a large gun requires
weight. Mid to late 30's British tanks just weren't that big due to transport size limits imposed on designers.

 

[Admiral Beez]

starting here.
There was no real reason the 2pdr and 6pdr couldn't have had HE ammo from day one.

A 2pdr (40mm) HE shell was designed but the explosive charge was deemed to small. There was a 40mm HE mortar shell, but perhaps the HV of tank guns requires a thicker shell wall and thus reduced HE charge.

It would have been interesting if the Canadian-built Valentines had been armed instead with US-origin 37mm guns, like Britain's US-origin Grant tanks, as the 37mm had a HE shell. And, for those close encounters in the Far East against Banzai charges, the 37mm also had the M2 canister shot. 37 mm gun M3 - Wikipedia

Expedite production the Valentines, order some 37mm guns and a mix of AP, HE and canister and ship Colonel Worthington, the CAC and the first 50 tanks to Vancouver to arrive at Malaya before November 1941. But we need to start the tank production a few months sooner..... sigh, if only.

 

[tomo pauk]

which 3pdr was that?
the one in the Vickers tank of the 20s was good for 533m/s or 563m/s.
The Naval 3pdr was a rather large and heavy gun. Only about 100lbs lighter than the 6pdr anti-tank gun. If you are going to stick a 99in long 650lb gun (barrel and breechblock) in a tank it better do more than this 3pdr.

We don't have the 6pdr gun, unlike the Naval 3 pdr . So I'd stick a better gun than it was either mid-speed 3pdr or the 2pdr on a tank and call it a day. The 2pdr does not offer anythin even over the interwar, mid-speed 3pdr found on British tanks.

Sorry for the missprint, I meant 13pdr but yes, you need a nuclear reactor, or at least some way of making chemical or smoke round much, much more effective. 75mm was considered the smallest practical smoke/chemical round as anything smaller simply didn't carry enough payload. British 13pdr shell was certainly suspect in this regard. British loved ot make shells out of crappy steel which meant several things, easier and cheaper to make so supply is easy, but you need a lot more for them for the same target effect. Crappy steel means thicker shell walls to stand up to the firing stress so less room for payload. the 13pdr firing He would have been useful, just not as useful as the shell weight and caliber suggest.

The 12 or 13 pdr HE shell made from crappy steel still beat the cr@p out of the 2pdr, 3pdr or 6pdr shell made from crappy steel. The 12 pdr smoke or chemical shell is again much better than 6 pdr one.

Since a general rule of thumb for armor penetration is that it goes up with the square of the speed (everything else being equal) so 17 X 17 = 289 while 20 X 20 = 400 so the 1700fps gun has 72% of the penetration of the 2000fps gun, except the 2000fps gun is using a heavier projectile. for given caliber and impact velocity penetration is directly proportional to shell weight. So yes you do need something extra tricky to get the 13pdr up to the standards of the day.

You will note that I've suggested he 12lb 12cwt gun, it fired at ~2230 fps, or 200-400 fps better than the US M3 75mm found on Shermans or Lees.

Britain 12-pdr [3"/40 (7.62 cm)] 12cwt QF Marks I, II and V - NavWeaps
The problem isn't getting a 12-15pdr cannon (75-76mm) cannon with good performance, it is getting one that fits in a tank, or at least a tank of the time. While some may shrug off the idea of a few hundred extra pounds of weight in a 15-25ton tank the fact is that the heavier gun creates a Domino effect. You need a larger turret, which has to be balanced to rotate properly. Using old naval or coast defence guns was done but it was hardly ideal. The gun in the American M-10 tank destroyer was an old (pre WW I) coast defence gun. The 76mm gun in the Sherman fired the same projectiles using a much smaller cartridge case (new propellants) out of a much lighter barrel (new steel alloys and manufacturing techniques)

The 12 lb 12cwt was a much smaller gun than the AA gun the 3in 20 cwt was - a similar situation as with US 75 and 76 mm guns. I don't recall my suggestion for installing the 3in 20cwt on tanks.

If you are just looking for some sort of HE capability (equal to a hand grenade?) , the 2pdr could have been supplied with HE ammunition from day one. The failure was not the weapon but doctrine. The 2pdr HE ammunition that was supplied later in the war held about 63-65 grams of HE. While certainly not great it beats the heck out of german 37mm ammo which held about 25 grams of HE. German 50mm HE ammo held about 165 grams.
British alos cheaped out on the AP ammo.
see : http://www.wwiiequipment.com/index....er-anti-tank-gun&catid=40:anti-tank&Itemid=58
the APCBC shot, first made in 1943 had a penetration at 1000 yds equal to what the early shot (pre war) did at 500yds. At 500 yds it was nearly equal to the old shot at 100yds.
The British had been making APCBC shot for naval guns since before WW I, it didn't require anything new in either materials or knowledge.

I'm not looking just for 'some sort' of HE capability, but rather finding a way for overall increase in British tank and AT gun lethality against any likely targets, on budget and on time. Reinventing the wheel (= design & producing of 2 and 6 pdr) goes against these goals.

Build the 6pdr earlier, the plans had been completed in 1938. Same thing, make HE ammo from day one, make APCBC shot from day one.
There was a 6pdr coast defence gun that used a different cartridge case. It's most famous use was at Valetta Malta, 35/36 July 1941.
A 6pdr AA gun had a shell with an 8 oz (225 grams?) of filler.
Both guns were limited in range by the shoulder controlled elevation making follow up shots difficult, not by the accuracy of the guns or ammo.

We don't exactly know when ww2 will start. For example, Munich talks ending up without the Czechs being thrown under a bus probably means war in 1938, hence the all new and shiny 6 pdr is too late.

 

[Admiral Beez]

The problem of tank size has also been noted twice now and cannot be underestimated. A stable mobile platform for a large gun requires
weight. Mid to late 30's British tanks just weren't that big due to transport size limits imposed on designers.

Had road transporters been readily available so many options are opened up. For starters, build the tank around three men in the turret. Conduct ergonomic and operational efficiency studies. on wooden mock-ups.

 

[tomo pauk]

...
The problem of tank size has also been noted twice now and cannot be underestimated. A stable mobile platform for a large gun requires
weight. Mid to late 30's British tanks just weren't that big due to transport size limits imposed on designers.

The myth of railroad-imposed limits on British tank's size is long past it's exipiry date. The Vickers Medium Mk.II of mid-1920s was produced in several hundreds, and it was as wide and as tall as the Pz-IV. There was one or more reasons why many British tanks conceived in 1930s were both narrower than needed and under-gunned, however transport requirements were not among the reasons.

 

[Shortround6]

We don't have the 6pdr gun, unlike the Naval 3 pdr . So I'd stick a better gun than it was either mid-speed 3pdr or the 2pdr on a tank and call it a day. The 2pdr does not offer anythin even over the interwar, mid-speed 3pdr found on British tanks.

The 2pdr beats the crap out of the "interwar, mid-speed 3pdr" used in the British Vickers Medium MK I & II.
The 3pdr Mk 1 L/31.4 weighed 217lbs and fired it's 3lb shot at 1750fps for a penetration of 25mm at 30 degrees at 500yds.
The 3pdr MK 2 L/40.5 weighed 25,75lbs and fired it's 3lb shot at 1850fps for a penetration of 27mm at 30 degrees at 500yds.

The much despised 2pdr fired a 2.375lb shot at 2600fps in the early loadings for a penetration of 46mm at 30 degrees at 500yds.
The German 37mm fired a 1.5lb shell at 2500fps for penetration of 36mm at 30 degrees at 550yrds.
The British 2pdr got a HV shot, also weighing 2.375lbs at 2800fps that boosted the penetration to 51mm at 30 degrees at 500yds.
The German 50mm L42 gun is credited with a 2.06kg ( 4,54lb) shell at 685 mps (2250fps?) for a penetration of 46mm at 30 degrees at 550 yds.

The American 37mm fired a 1.92lb shot at 2600fps (or 2900fps depending on source?) for penetration of 36mm at 0 degrees at 500yds. to around 48mm at 30 degrees at 500yds dependingon source. There was also an APCBC shot at 1.92lbs and 2900fps that could manange 61mm at 30 degrees at 500yds.
Please note that in US service ALL APC projectiles were actually APCBC, Since the US never fielded an actual APC shot or shell they left of the BC (Ballistic Cap)

When the British 2pdr gets the APCBC shot the weight goes to 2.69lbs and the velocity drops to 2650fps and the Penetration goes to 54mm at 30 degrees at 500yds. the more streamline projectile increases the penetration at 1000yrds by almost 15% and just gets even further ahead the HV shot the more the range opens up.

The 12 or 13 pdr HE shell made from crappy steel still beat the cr@p out of the 2pdr, 3pdr or 6pdr shell made from crappy steel. The 12 pdr smoke or chemical shell is again much better than 6 pdr one.

A 6pdr shell is near useless as a smoke or chemical shell ( but so was a German 50mm) However the British 13pdr horse artillery projectile was not very good. as listed in previous posts, The 6pdr coast defence gun had a projectile with about 8 oz of explosive, the 13pdr carried around 9 oz (262g)of explosive.
The German 50mm tank and anti-tank cannon had HE shells with 165grams (5.8 oz) of HE and we do not hear much about how useless they were.
The American 37mm used 1.5 oz (42.5g) of HE while a 40mm Bofors shell held 65 grams.

You will note that I've suggested he 12lb 12cwt gun, it fired at ~2230 fps, or 200-400 fps better than the US M3 75mm found on Shermans or Lees.

Unfortunately this is an illusion. The 12lb 12 cwt gun did indeed achieve that velocity but did it with a 12.5 lb shell, The 75mm guns on the Shermans and Lees used a 14.7lb HE shell and a 14.92lb APC shell. Try firing a shell about 20% heavier out of the 12lb 12 cwt and I think you will find that the velocity will drop off quite a bit.

The short stumpy British shell is much more likely to lose velocity quicker.

I'm not looking just for 'some sort' of HE capability, but rather finding a way for overall increase in British tank and AT gun lethality against any likely targets, on budget and on time. Reinventing the wheel (= design & producing of 2 and 6 pdr) goes against these goals.

Trouble is keeping the existing wheels you are keeping ones that out of round or approaching octagon in shape. You need a 3in or 75mm gun as a minimum for a smoke or chemical shell, anything smaller doesn't carry enough payload, and it should be a good 3in/75mm and not a short shell with thick walls.
Trying to use a gun from 1894 doesn't save any time (they need to make new barrels in any case not to mention new recoil systems). AS been mentioned by others there is a limit as to how big a gun you can stuff in a 15-20 tank and have it work properly, like not crack the turret ring or bounce the tank around too much under recoil. Some tanks and vehicles were decidedly over gunned.


try from 1:30 on. No prewar British tank would have been that bad unless you strapped a 25pdr on top of a Bren carrier but the principle applies. Heavy recoil slows follow up shots. Small turrets also limit the size of ammo that can be used.

Early Valentine? Want to try loading a 75mm gun that way?

The problem was doctrine, not hardware.
Why was the effective range of a 7.9mm British Besa gun about 800yds while a German 7.9mm turret machinegun was 1200 meters or more using the same ammo?
1. the Germans used a geared handwheel for elevation.
2. the Germans placed triangles of known sizes in mils in the sight for range estimation.
3. the Germans used a range drum on the sight. Estimate range and turn the drum to the estimated range and it offset the aiming mark in th esight to needed point to get the ammo to hit the target while holding the aiming mark on the target. British gunner got crosshairs and had to hold the aiming mark (the actual intersection point) at the estimated distance above the target to get a hit, while controlling the elevation with his shoulder. If the German gunner hit low his commander could order "up 100" or "up 200" and the gunner could make the adjustment on the range drum. British commander might yell 'UP 100" but all the poor gunner could do was try to guess at how much higher to put the cross hairs above the target.

Now apply this it the main gun. High velocity helps get hits, especially with crude sighting systems. You may estimate a crude point blank range (round will never go above the target or below it using an aiming point in the middle of the target ) as the muzzle velocity + 10%. but once you start needed to elevate the gun for longer ranges the put the cross hairs over the target method of fire control becomes increasingly ineffective.

We don't exactly know when ww2 will start. For example, Munich talks ending up without the Czechs being thrown under a bus probably means war in 1938, hence the all new and shiny 6 pdr is too late.

The 6pdr is too late but then the Germans have no tanks with 50mm guns, in fact probably less than 25 tanks with 37mm guns. no tanks with more than 15mm of armor, Germans have no 50mm AT guns.
MK IVs with the short 75 are support element and are primarily smoke and HE throwers with a very secondary anti-armor role.

The British wasted a lot of time and effort on the initial 3.7in smoke gun and the 3in howitzer in the close support tanks. Both of which were exceedingly short ranged and neither of which really carried the smoke or HE payload of even a mediocre 75mm field gun. A bit less time designing guns used in small numbers and a bit more time developing good ammo that could be used in large numbers of guns might have paid dividends.

 

[WARSPITER]

The myth of railroad-imposed limits on British tank's size is long past it's exipiry date. The Vickers Medium Mk.II of mid-1920s was produced in several hundreds, and it was as wide and as tall as the Pz-IV. There was one or more reasons why many British tanks conceived in 1930s were both narrower than needed and under-gunned, however transport requirements were not among the reasons.

The British loading gauge was less than that used in continental Europe due to the British system being so much older so the rail limit is not a myth. The Matilda II was
narrower than the Panzer IV but not that much. The main difference is that it was heavier by several tons. The MKII was under half the weight of the Matilda II as well.
It is true that there were other design constraints such as bridge weight limits and the requirement for the fighting compartment of the tank to be between the tracks / suspension to keep height down.

These constraints applied until 1943.

The other major problem for the tank force was the budget. Priority went to home defence which meant the RAF and RN received the bulk of available funding.
All of these factors had a bearing on design and adoption.

 

[swampyankee]

The other reason for the tighter British rail loading gauge is that British property laws— at least partly due to those nasty middle-class liberal upstarts — was that British property rights were much stronger than in the Continental monarchies.

 

[WARSPITER]

Also, most of the original system was built by private owners so there were various sizes according to what the owner/s thought best.

 

[tomo pauk]

The British loading gauge was less than that used in continental Europe due to the British system being so much older so the rail limit is not a myth. The Matilda II was
narrower than the Panzer IV but not that much. The main difference is that it was heavier by several tons. The MKII was under half the weight of the Matilda II as well.
It is true that there were other design constraints such as bridge weight limits and the requirement for the fighting compartment of the tank to be between the tracks / suspension to keep height down.

Medium Tank Mk.II was not transported by continental railways, but by British railway(s). Seems like nobody said to the designers of the tank to keep the height down, either.
No tank with a rotating turret, of any country ever, had the fighting compartment that was only as high as the 'returning' tracks before.

These constraints applied until 1943.
The other major problem for the tank force was the budget. Priority went to home defence which meant the RAF and RN received the bulk of available funding.
All of these factors had a bearing on design and adoption.

British have designed 10 (ten) separate types between 1935 and 1940 - 3 types of light tanks (V, VI, VII), 4 types of cruisers (II, III, V, VI) and 3 infantry tank types (Matilda I and II, Valentine). That's double the number of types Germans designed in the same time (NbFz, Pz-I to IV).

 

[WARSPITER]

The railway constraint was because of British railways and the need to transport tanks from the factories in the home country - not across Europe.

The fighting compartment refers to the area the crew uses which includes the turret but in the British design did not "flow over" the tops of the tracks
as in have sponsoons as the T34 and Panther. This kept the hull height down.

The British may have had many designs but again most were not able to be refined due to budget constraints.