Alternative History Armoured Fighting Vehicles Part 3

[MarcH]

@MarcH You had been looking for months already for an explanation regarding the weird history of the Vickers 75mm HV, and luckily this book contains some info about that.

What is worth knowing is that based on experience with Grants and Shermans, the British had decided to study a Cromwell rearmament with the 75mm M3 or a medium velocity gun capable of shooting US 75mm ammunition for commonality. This is what led Vickers to offer what would become the OQF Mk V. At this point many officers and in particular director of artillery E.M.C Clarke wanted a gun with greater velocity to punch through heavier armor. Vickers was unofficially approached by Sir Robert Micklem (former managing director at Vickers and now in the war office/ministries) to develop a more powerful gun which would combine the HE performance of the 75 with higher hole punching capability to hopefully replace both the 6pdr and the medium velocity 75mm, to fit in the Cromwell.
While medium velocity 75mm ammo was to come entirely from the USA, the HV 75 could use American projectiles but the British would design a new HE projectile and modify US APCBC so they could manufacture HV 75mm rounds in Britain. As such, the choice of caliber most likely was not really for commonality since the ammo would be built locally anyway, but rather because Vickers was already familiar with 75mm projectiles as it had developped the medium velocity 75 first (the mounting was however delayed quite a lot). Initially only 2400 fps muzzle velocity was expected, but then this was 2750 fps in a new gun, 150 fps greater than the US 76 due to the ability to handle greater pressures, and twice the bursting charge weight. Penetration was slightly better. As such it seemed to be a great gun.

Eventually, as you know the story of "the 75 can't fit" would happen because the 75 HV lacked a semi-automatic mechanism and adding it would make it too big, so a new turret and mounting would be designed. At this point the idea of using the US 76mm M1 resurfaced (it had been considered in December 42, but at the time a new turret was not intended and since it did not fit in Cromwell it was not accepted). However, the 76 would have introduced many ergonomic and turret design difficulties that the British did not like (longer rounds so harder to load, poor compatibility with the BESA, sight and crew layout, unbalanced mounting mounted further forward which led to a King Tiger-style narrow front turret, gun can't be removed from the front, worse frontal arc protection).

However, this now led the British to compare the 75 HV with the 17pdr. It was found that the 75 HV had a more sensible and stronger tied jaw breech while the 17pdr had an open jaw breech (google, you will see what they look like). The stronger tied jaw breech meant that even accounting for the difference in raw power, the 75 HV's breech was a more compact and efficient design. Thanks to improved production capacity, the British assessed that they could now design an optimized tank version of the 17pdr which would use this style of breech and relocated mouting lugs for the recoil buffers to fit any optimized tank mounting. Although I can't confirm it, it appears this would inspire the versions of the 17pdr developped for the Sherman Firefly and Centurion. If necessary, the case of the 75 HV would be used to obtain shorter rounds.

In the meantime, it was finally chosen to adapt the 75 HV to use 17pdr projectiles because manufacturing would be simplified and it could immediately use 17pdr APCR/APDS when these rounds would become available. So there it is.

Thankyou for that.
I have often thought that the HV 75mm was offered based on official prodding rather than being a Vickers enterprise and that settles it. The whole process does seem a bit backwards though. Wanting to design a British version of the US 75mm does make sense from a logistical point of view as does the desire for increased performance of that gun. That the decision would be made to keep the HV gun a 75mm design that could use US projectiles but Britain will build its own separate ones anyway seems like madness. That they eventually "got it right" by switching to 3" calibre and the 17pdr projectiles highlights the waste that likely went into the 75mm HV gun. The 17pdr and its related ammo were well underway when the HV 75mm gun started and while I could understand if the British were simply sticking with US projectiles in a new case going for new/modified 75mm Projectiles...

Well that answers one of my biggest conjectures. I had often thought that the 75mm HV was an attempt by the British to influence the US in some way, perhaps create a "universal" Sherman or something. Instead it seems it was a combination of bureaucracy, inertia and stupidity.

 

[Bougnas]

Thankyou for that.
I have often thought that the HV 75mm was offered based on official prodding rather than being a Vickers enterprise and that settles it. The whole process does seem a bit backwards though. Wanting to design a British version of the US 75mm does make sense from a logistical point of view as does the desire for increased performance of that gun. That the decision would be made to keep the HV gun a 75mm design that could use US projectiles but Britain will build its own separate ones anyway seems like madness. That they eventually "got it right" by switching to 3" calibre and the 17pdr projectiles highlights the waste that likely went into the 75mm HV gun. The 17pdr and its related ammo were well underway when the HV 75mm gun started and while I could understand if the British were simply sticking with US projectiles in a new case going for new/modified 75mm Projectiles...

Well that answers one of my biggest conjectures. I had often thought that the 75mm HV was an attempt by the British to influence the US in some way, perhaps create a "universal" Sherman or something. Instead it seems it was a combination of bureaucracy, inertia and stupidity.

Yes, though the book probably misses some meetings which might further explain why 75mm built in the UK was deemed ok at the time. Regardless, the change in caliber did not actually delay the gun in anyway, and in fact the new turret and mounting didn't really do it either. Rather the main delays came from manufacturing difficulties for the changeover to weldings and castings (1 month), and more importantly a flu epidemic at Leylands for 2 months, a lack of draughtsmen (only 7 allocated by the govt rather than the 30 needed), and a change in the suspension which would now use 18" tracks and increased ground clearance.

It didn't help that by this point the biggest bottleneck for the British tank program was labor with aircraft production having pretty much all the priority (to the point where there were regular rumors of Meteor production lines about to be vampirized for Merlins or at least deprived of the tools and parts coming from the Air Ministry). Another issue was US policy, as the refusal of models other than M4A2s by the Soviets meant that the US was suddenly overproducing Shermans compared to its national requirements. The variable of adjustment was the British tank program with the British regularly reducing targets both to reduce the number of Centaurs (and tanks in general), reallocate production to railway stock and other stuff needed to absorb the additional US tanks, and use the limited labor available. They also were already kinda preparing for peacetime production.
What the British did not yet realize at the time was that the Americans had badly underestimated wastage through mechanical wear and combat losses and therefore actually had insufficient reserves of Shermans (they had reduced production rates). This was only really realized as Overlord was ongoing and let teh US to divert Shermans to their own forces instead of the British. This shortage in part explained the difficulties in converting more Shermans to Fireflies for British and US use as reserves were insufficient. But in the end the Western Allies accidentally conspired in ending the war with low surplus, which was efficient at the time but probably problematic for the postwar period as it limited surplus that could easily be sent to Western Europe for military rebuilding.

 

[MarcH]

Yes, though the book probably misses some meetings which might further explain why 75mm built in the UK was deemed ok at the time. Regardless, the change in caliber did not actually delay the gun in anyway, and in fact the new turret and mounting didn't really do it either. Rather the main delays came from manufacturing difficulties for the changeover to weldings and castings (1 month), and more importantly a flu epidemic at Leylands for 2 months, a lack of draughtsmen (only 7 allocated by the govt rather than the 30 needed), and a change in the suspension which would now use 18" tracks and increased ground clearance.

It didn't help that by this point the biggest bottleneck for the British tank program was labor with aircraft production having pretty much all the priority (to the point where there were regular rumors of Meteor production lines about to be vampirized for Merlins or at least deprived of the tools and parts coming from the Air Ministry). Another issue was US policy, as the refusal of models other than M4A2s by the Soviets meant that the US was suddenly overproducing Shermans compared to its national requirements. The variable of adjustment was the British tank program with the British regularly reducing targets both to reduce the number of Centaurs (and tanks in general), reallocate production to railway stock and other stuff needed to absorb the additional US tanks, and use the limited labor available. They also were already kinda preparing for peacetime production.
What the British did not yet realize at the time was that the Americans had badly underestimated wastage through mechanical wear and combat losses and therefore actually had insufficient reserves of Shermans (they had reduced production rates). This was only really realized as Overlord was ongoing and let teh US to divert Shermans to their own forces instead of the British. This shortage in part explained the difficulties in converting more Shermans to Fireflies for British and US use as reserves were insufficient. But in the end the Western Allies accidentally conspired in ending the war with low surplus, which was efficient at the time but probably problematic for the postwar period as it limited surplus that could easily be sent to Western Europe for military rebuilding.

My guess (or at least hope) would be that it wasn't one decision but multiple. Start with building a UK version of the US 75mm then comes the decision to see if the gun can be improved then improvements to the shell are considered as well. That to me would be the most logical explanation, it was not one decision but a series of creeping decisions leading to a whole new weapon system. That does make the whole situation easier to understand as if the decision was to go for a completely clean slate 75mm gun someone surely must have pointed out that the UK is already producing or about to produce two types of 3" AT gun rounds in the modified 3" 20cwt rounds and the 17 pounder. This would probably be even more likely when Vickers submitted their proposal and it used 3" 20cwt cases which already have their own production up and running for the RN submarines that used that gun as well as some UK use. Add to that the fact it had an AT round as well and I cant see someone not at least thinking about it.
I have also seen performance data about the US M61 projectile being fired from the 75mm HV. This would, IMHO, support the notion of a gradual moving of the goalposts rather than a clean sheet design. From memory the US M61 was fired at 2500ft/s which does suggest quite a lot of wasted potential. The 77mm HV fired the 17pdr shells at 2600ft/s despite them being heavier and the modified British 75mm shells being capable of 2750ft/s all points to the standard US shell not being suitable for extracting full performance from the gun. That this realisation would result in the decision to modify the shells to get better performance is logical given the starting point being a British gun that can fire standard US 75mm ammo.
Interestingly the M61 firing data would result in only a couple of millimetres of additional penetration over the performance of the 3" 20cwt AT round. I am not sure if this would have had any impact or even have been noticed at the time but with the benefit of 80 years of hindsight it becomes apparent.

 

[Bougnas]

I have also seen performance data about the US M61 projectile being fired from the 75mm HV. This would, IMHO, support the notion of a gradual moving of the goalposts rather than a clean sheet design. From memory the US M61 was fired at 2500ft/s which does suggest quite a lot of wasted potential. The 77mm HV fired the 17pdr shells at 2600ft/s despite them being heavier and the modified British 75mm shells being capable of 2750ft/s all points to the standard US shell not being suitable for extracting full performance from the gun. That this realisation would result in the decision to modify the shells to get better performance is logical given the starting point being a British gun that can fire standard US 75mm ammo.
Interestingly the M61 firing data would result in only a couple of millimetres of additional penetration over the performance of the 3" 20cwt AT round. I am not sure if this would have had any impact or even have been noticed at the time but with the benefit of 80 years of hindsight it becomes apparent.

The lower 2500 fps figure might not be linked to the round but rather the gun if it was shot at lower pressure than what the final 75/77 HV handled. Dunno about the last bit, the 17pdr projectile had identical performance at close range to the 75 projectile but became slightly better at longer range.

 

[MarcH]

The lower 2500 fps figure might not be linked to the round but rather the gun if it was shot at lower pressure than what the final 75/77 HV handled. Dunno about the last bit, the 17pdr projectile had identical performance at close range to the 75 projectile but became slightly better at longer range.

I am fairly certain it was loaded to lower pressure, the issue would be why.
The 17pdr and 77mm HV are a good case study in this. The 17pdr APC round was reasonably accurate out to 1000 yards however the 77mm HV firing the same projectile achieved superior accuracy. The difference was not massive but noticeable enough in testing. What was more noticeable was the accuracy difference in the APDS shot, the 17pdr was only considered accurate out to 500 yards firing APDS whereas the 77mm HV had no such issues. The often cited separation issues for the APDS round makes little sense as both the 17pdr and he 77mm HV both had the same muzzle break. The only really notable difference was the 300ft/s or so of muzzle velocity between the two rounds. It does seem as though the lower muzzle velocity of the 77mm HV resulted in a more accurate gun overall when using the issued ammunition in WW2.
From memory as well the RN had stability issues with projectiles when they tried to design more aerodynamic shells for the big guns. This is being remembered from a LONG time ago so could be way off or completely wrong so take with a pinch of salt. From memory the centre of gravity shift caused by streamlining the shells caused them to wobble in the barrel and this was more pronounced at higher velocities. Again this is probably being badly remembered from long ago but I am fairly confident on the general accuracy of their being a relation between shell shape design and velocity causing instability.
Is it then that the M61 projectile was not loaded to the maximum possible pressure for no real reason or was it that the projectile had been and it introduced poor accuracy and that it was then down loaded? This is pure speculation on my part I admit but I think it could have some grain of truth to it perhaps.
We already know their was a desire to increase velocity for better AP performance. It would seem strange if the firing data used reduced propellant loads resulting in lower pressure.
As for the 3" 20cwt having similar performance. The round was a 12.5 pound projectile fired at 2600ft/s so essentially a HVAP round. That the M61 is slightly better at 1000 yards is not too bad.

OK Quick edit. I have just double checked and the expected performance of the M61 round was actually 2600-2650 ft/s which negates some of my point. That being said that still raises a couple of questions.

1. Why did the British want to go to the trouble of developing a new projectile for only 100ft/s of additional performance?
2. That still suggests some performance being left on the table, what was going on?

Perhaps the penetration figures of the M61 round suggest an answer? The British figuring that with a better designed shell they could get better performance?

 

[Bougnas]

Is it then that the M61 projectile was not loaded to the maximum possible pressure for no real reason or was it that the projectile had been and it introduced poor accuracy and that it was then down loaded? This is pure speculation on my part I admit but I think it could have some grain of truth to it perhaps.
We already know their was a desire to increase velocity for better AP performance. It would seem strange if the firing data used reduced propellant loads resulting in lower pressure.
As for the 3" 20cwt having similar performance. The round was a 12.5 pound projectile fired at 2600ft/s so essentially a HVAP round. That the M61 is slightly better at 1000 yards is not too bad.

OK Quick edit. I have just double checked and the expected performance of the M61 round was actually 2600-2650 ft/s which negates some of my point. That being said that still raises a couple of questions.

1. Why did the British want to go to the trouble of developing a new projectile for only 100ft/s of additional performance?
2. That still suggests some performance being left on the table, what was going on?

Perhaps the penetration figures of the M61 round suggest an answer? The British figuring that with a better designed shell they could get better performance?

I don't think there is anything more to see in lower loadings than just early tests while refining the gun and checking its capabilities. The US tested M62 (similar to M61, but 3") up to 2850-3000 fps (hot powder in 76 M1 and more fully-filled charge on 3" M7) but don't mention any stability/accuracy issues, so I don't think this was much of a factor behind British manufacture of 75 ammo. They do at best refere to APBCBC shot which would imply they also developped a solid shot version of the round (logical, US ammo faced severe break-up and fuzing problems due to the poor implementation of its APHECBC design). They also mention the damage on US ammo during transatlantic shipping, and finally maybe they just wanted to secure a good supply of projectiles for perfect assembly on 3" 20 cwt cases.

Note that some sources refer to 2650 fps velocity on the 75 HV and 2600 fps on the 76 M1. This corresponds to quarter worn guns, rather than new guns where the values are respectively 2750 and 2650 fps (the 76 wears somewhat more slowly due to straight cases allowing a straighter chamber-bore interface which wears more evenly and due to lower pressure. Improved British powder improved 75 HV's wear pattern later on).

I can't answer your two questions. The extra performance was solely linked to the gun. The projectile mods are solely related to the adaptation to British manufacture, with improved performance being a bonus. But aside from the possible move to solid shot (unless it's a typo), it doesn't appear that the British were particularly interested in maximizing performance per se.

An unfortunate consequence of the move to 17pdr projectiles is that contrary to the requirement to give a high capacity lower velocity HE shell to any 17pdr derivative, this was not done until much later so the true dual purpose capacity of the 77 and the 17pdr was not achieved until late 1944 (and for A30 Challenger, too late to ensure compatibility with this round), and really early 45.

---

Having finished Knight's book on Comet, the development story of this tank remains relatively uneventful after production started like most late-44 WW2 tanks.

Only unfortunate losses from an AH perspective was that neither the restowed turret with the basket cut in most of the loader's area and ammo restowed to provide much more space and accelerate loading, nor the high reverse speed gearbox (10 miles per hour reverse) were adopted owing to 1945 cuts. 2500 vehicles were once on order, but only 1186 were finally built.

The book also references the well-known proposal to incorporate a single sloped plate for the front hull instead of a vertical visor plate and sloped glacis. This was proposed as early as April 44, but somewhat late and while Centurion was modified, Comet wasn't as the hull Besa was still deemed essential. Crews wanted the sloped plate, but the lack of tanks and AT guns and the sheer quantity of infantry with Panzerfausts in 1945 meant that the environment was quite conducive to the use of the hull MG. The compromise of thickening the visor plate to 102mm (somehow without access to the MG still?) after a meeting in February 45 was not implemented either, and slapping a thin sloped plate like the so-called A34* was not useful as just welding an equivalent weight of plate to the visor plate and glacis plate was more ballistically sound.

The book does make another reference to the ring spring suspension I talked about for Challenger. This further confirms the remarkable load-carrying and spring rate values of this type of spring, and its inherent dampening qualities. An external Christie suspension with 6 wheels per side ala A36, with ring springs instead of coil springs, would probably have been the ultimate implementation of the concept postwar.

 

[Ramontxo]

So I have just found this little gem

The Strange Propeller Car Of WWI: The Story Behind Sizaire-Berwick's Armored Car - SlashGear

The story behind Sizaire-Berwick's Armored Car is a strange one. This propellor car was made to help in World War I, but it had several design flaws.

www.slashgear.com

 

[Jim Smitty]

So I have just found this little gem

The Strange Propeller Car Of WWI: The Story Behind Sizaire-Berwick's Armored Car - SlashGear

The story behind Sizaire-Berwick's Armored Car is a strange one. This propellor car was made to help in World War I, but it had several design flaws.

www.slashgear.com

View attachment 861543

Was this a hold my beer moment?

 

[Virginia Liberal]

Was this a hold my beer moment?

Is that Florida in the background? Lol

 

[Bougnas]

And at last I have finished the book on Covenanter (only Tetrarch left as far as gun tanks go in P.M. Knight's series). As far as AH goes there are a few interesting bits at the start but not much after that since combat capability got pretty much frozen during production:

- not only Crusader (through Crusader II), but also Covenanter were recommended with 50mm frontal armor basis. The first pilot Covenanter was even loaded up for 60mm frontal basis, requiring 7 cwt of ballast. However the basis remained at 40mm for production (except the mantlet which was 50mm starting from late Covvie I) because the suspension was at its limit. This last argument was a bit questionable in hindsight as Covenanter eventually grew to a much greater weight than that required to install this armor, getting reinforced axle arms in consequence. The Crusader had an inherently high weight limit thanks to the extra wheel station per side, but Covvie had some growth potential if required.
Brigadier Vyvyan Pope from the Tank Board recommended as early as June 1940 that Cruiser tanks carry 60mm of armor with 80mm as a longer term target. With little attention being given to Covenanter and Crusader to maximize production, it wasn't until A24/27 that this was done.

- We now know what is behind the A21 tank designation: an upscaled infantry tank version of the Covenanter with 22-29" wide tracks, a Matilda II turret, a Meadows or Vauxhall engine, A20 suspension units and 75mm of armor basis at 25 tons and 10 hp/ton. It was preferred to downscale A20 into Vauxhall's A22.

Covenanter otherwise shares much the same leading causes of problems as Crusader. The stringent weight limits (able to cross a Class 18 Bridge, 16 tons for Covvie and 18 tons for Crusader) combined with ambitious armor requirements led to an excessively compact vehicle with little initial growth potential. This was combined with the absolute lack of a required overhaul life which meant that ease of maintenance, simplicity and durability weren't emphasized. As a result, Covvie had external air filters like Crusader, and the small engine bay led to a complicated (and compromised once the Wilson transmission was cancelled) cooling system, while Crusader suffered from the redesigned water pump and fan drive required for the lower engine bay relative to Cruiser Mk IV.

However, the full (Leyland, Covenanter III) and interim (LMS, Covenanter II) cooling modifications which were suitable for Middle Eastern operations were actually ready quite early on. The problem was that the 1940-late 42 policy of getting the maximum quantity at all costs delayed the introduction of Covenanter III in production and the overhaul of Covenanter Is into Covenanter II (due to a shortage of thin armor plate), when both could have been introduced in mid 1941 (instead of late 42 for Covvie II). Another problem was that the task of making truly decent air filters for Covenanter III was initially given to the rookies at LMS rather than the specialists at Vokes, which made the III unsuitable for ME operations for a while. Had Vokes been called in from the start or had the Covvie II been implemented early at the cost of full production, the Covenanter could have been deployed to the Middle East as early as 1942 as desired.

It is worth noting that the desire to send Covvie (once suitable) to the ME was because it was more durable and reliable than Crusader, especially in the first 1000 miles. Crusader had earned a bad reputation after the operation of the same name, as its low overhaul life of 1200 miles meant that entire units were lost to breakdowns after travelling hundreds of miles to get to battle, fight and then retreat. Covvie otherwise had the same problems as Crusader, that is insufficient armor and armament.

The book also gives more context for the 1940-42 period. The War Office had very poorly anticipated the needs of mobile warfare in WW2, thinking rail transport would be sufficient and that the front would be static enough to withdraw entire tank units for overhaul like in WW1. This is why a high overhaul life wasn't emphasized. Moreover, it failed to anticipate the sheer number of tanks that would be operated, and thus the sheer amount of skilled personel needed to operate and maintain these vehicles (the prewar plan up to 1941 was for well under 2000 tanks in all, against a real production of thousands of tanks in 1941 and 42). This was compounded by complicated vehicles which required a high level of skill to operate, not ideal for rookie draftees. Overall, the British production and maintenance systems as well as the army were very badly overloaded for the first 3 years of war. The emphasis on only tactical qualities of tanks didn't help, like the desire for MG turrets so that Armored Divisions made of tanks only could fight multiple targets at once. You thus had the weird situation where Crusader was lengthened compared to Covvie solely to mount the radiators at the rear to mount a MG turret that ended up being useless, instead of using the enlarged hull compartement to install the air filters internally.​

 

[CaptainCalvert]

And at last I have finished the book on Covenanter (only Tetrarch left as far as gun tanks go in P.M. Knight's series). As far as AH goes there are a few interesting bits at the start but not much after that since combat capability got pretty much frozen during production:

- not only Crusader (through Crusader II), but also Covenanter were recommended with 50mm frontal armor basis. The first pilot Covenanter was even loaded up for 60mm frontal basis, requiring 7 cwt of ballast. However the basis remained at 40mm for production (except the mantlet which was 50mm starting from late Covvie I) because the suspension was at its limit. This last argument was a bit questionable in hindsight as Covenanter eventually grew to a much greater weight than that required to install this armor, getting reinforced axle arms in consequence. The Crusader had an inherently high weight limit thanks to the extra wheel station per side, but Covvie had some growth potential if required.
Brigadier Vyvyan Pope from the Tank Board recommended as early as June 1940 that Cruiser tanks carry 60mm of armor with 80mm as a longer term target. With little attention being given to Covenanter and Crusader to maximize production, it wasn't until A24/27 that this was done.

- We now know what is behind the A21 tank designation: an upscaled infantry tank version of the Covenanter with 22-29" wide tracks, a Matilda II turret, a Meadows or Vauxhall engine, A20 suspension units and 75mm of armor basis at 25 tons and 10 hp/ton. It was preferred to downscale A20 into Vauxhall's A22.

Covenanter otherwise shares much the same leading causes of problems as Crusader. The stringent weight limits (able to cross a Class 18 Bridge, 16 tons for Covvie and 18 tons for Crusader) combined with ambitious armor requirements led to an excessively compact vehicle with little initial growth potential. This was combined with the absolute lack of a required overhaul life which meant that ease of maintenance, simplicity and durability weren't emphasized. As a result, Covvie had external air filters like Crusader, and the small engine bay led to a complicated (and compromised once the Wilson transmission was cancelled) cooling system, while Crusader suffered from the redesigned water pump and fan drive required for the lower engine bay relative to Cruiser Mk IV.

However, the full (Leyland, Covenanter III) and interim (LMS, Covenanter II) cooling modifications which were suitable for Middle Eastern operations were actually ready quite early on. The problem was that the 1940-late 42 policy of getting the maximum quantity at all costs delayed the introduction of Covenanter III in production and the overhaul of Covenanter Is into Covenanter II (due to a shortage of thin armor plate), when both could have been introduced in mid 1941 (instead of late 42 for Covvie II). Another problem was that the task of making truly decent air filters for Covenanter III was initially given to the rookies at LMS rather than the specialists at Vokes, which made the III unsuitable for ME operations for a while. Had Vokes been called in from the start or had the Covvie II been implemented early at the cost of full production, the Covenanter could have been deployed to the Middle East as early as 1942 as desired.

It is worth noting that the desire to send Covvie (once suitable) to the ME was because it was more durable and reliable than Crusader, especially in the first 1000 miles. Crusader had earned a bad reputation after the operation of the same name, as its low overhaul life of 1200 miles meant that entire units were lost to breakdowns after travelling hundreds of miles to get to battle, fight and then retreat. Covvie otherwise had the same problems as Crusader, that is insufficient armor and armament.

The book also gives more context for the 1940-42 period. The War Office had very poorly anticipated the needs of mobile warfare in WW2, thinking rail transport would be sufficient and that the front would be static enough to withdraw entire tank units for overhaul like in WW1. This is why a high overhaul life wasn't emphasized. Moreover, it failed to anticipate the sheer number of tanks that would be operated, and thus the sheer amount of skilled personel needed to operate and maintain these vehicles (the prewar plan up to 1941 was for well under 2000 tanks in all, against a real production of thousands of tanks in 1941 and 42). This was compounded by complicated vehicles which required a high level of skill to operate, not ideal for rookie draftees. Overall, the British production and maintenance systems as well as the army were very badly overloaded for the first 3 years of war. The emphasis on only tactical qualities of tanks didn't help, like the desire for MG turrets so that Armored Divisions made of tanks only could fight multiple targets at once. You thus had the weird situation where Crusader was lengthened compared to Covvie solely to mount the radiators at the rear to mount a MG turret that ended up being useless, instead of using the enlarged hull compartement to install the air filters internally.​

I know the extra MG turrets had a logic behind them but it was still a mistake to persist with them. And what you've just written only adds to that view.

 

[MarcH]

I know the extra MG turrets had a logic behind them but it was still a mistake to persist with them. And what you've just written only adds to that view.

There does seem to be a lot of bureaucratic inertia in British tank development early to mid war. I think a lot of this can be put down to the frantic need for any tank now rather than stopping to think about what they are building. Had Britain stopped to actually think things through as happened later on in the war with tanks like the Cromwell (turret ring excepted), Comet and Centurion then Britain could have produced a very good tank. The issue is no-one did stop and think as until lend lease really kicked in Britain was in a mad scramble.

 

[Claymore]

Romfell V2.0 Armoured Car Update: (@Petike)

It has been a little while since my last update, but I have not been sitting idle. There have been a couple of troublesome problems that have taken time to resolve but I think we are well on the way now. 'What problems?' I hear you say. Well...

First off, I needed to select and make the decals I would be using - and thanks to Petike for providing the necessary ground forces insignia for the vehicles in his TL and instructions for the relative size. So far so good. Petike also liked the idea of Romanic numerals to identify the specific vehicle - OK. Unfortunately, I had not used enough acrylic varnish when making the decals and when I tried to apply them the colour washed out and, as the final insult, they fell apart! Time to make some more but, of course, I had run out of inkjet decal paper... Needed to order more from Amazon!

Second issue. The model tyres are completely smooth/slick which seems more than a little odd for a vehicle that was supposed to have some off-road capability - although several photos of the original Romfell AC seem to show distinctly smooth treads. Nevertheless, given that the Romfell V2.0 has wider tyres, the lack of treads seemed even more of an issue - what could be done? Trying to etch on something was, IMHO, fraught with possibilities of total disaster and so was not an option. What I settled on was to make a tread decal - oh much easier said than done, I can assure you!! And, as mentioned above, I had run out of decal paper... Several designs and attemps later, I think I have something workable.

Third problemette. What paint to use? I settled on Revell Bronze Green silk acrylic as the closest match to Petike's drawing. The silk finish was good for applying the decals and the oil paint pin washes and looked very reminisant of the Deep Bronze Green finish in use by Britain at the time. It was also at this stage that I realised the positioning of the decals would need to change slightly as the Romanic numbers looked lost sitting in a panel by themselves. The end result (see below) was OK but perhaps a little too dark for Petike's drawing.

In the end I have decided to go back to a matt finish which lightens up everything a bit and will allow me to better add a little light weathering. Still have some touch ups to do and said weathering. I have also sent off for a couple of realistic Austro-Hungarian crew members as I just wasn't happy with what I could cobble together from my spares boxes.

 

[BlackDragon98]

Is it just me, or does the Romfell look like the bastard child of the BA-6 and the SdKfz. 231 6 rad?

 

[Bougnas]

I know the extra MG turrets had a logic behind them but it was still a mistake to persist with them. And what you've just written only adds to that view.

Yes, the book shows that the exact reason was for a tank to engage more than one target at a time when fewer tanks were expected to be available per unit. So for the War Office, Heavy Cruisers with MG turrets were more powerful.

On 1st May of 1939, the Director of Mechanization Alexander Davidson had talked to the Director of Staff Duties (Carr) to advocate A15 (Crusader), and in fact in a different form than the one we actually got. His justification was that with a 30mm armor basis, MG turrets were harder to traverse due to greater inertiaand represented a greater weight penalty than at 14mm basis. They also necessitated a 16" taller tank to clear the turrets when the gun was fully depressed.

Quote from Davidson:
"The acceptance of the A10 arrangement on a modified A13 Mk III (Covvie) would make for a lighter tank than one with two separate auxiliary turrets. What you stand to lose is only a few degrees of arc not covered by an auxiliary machinegun while the saving may be two or three tons, mostly bulletproof plate which is very difficult to obtain in the quantities now required".
At the time Davidson did not tell Carr that A15 was already in development, probably because the DSD and War Office wouldn't have accepted a tank with a machinegun in a static compartment. He also argued that this would reduce the crew from 6 to 5 and simplify the tank, and allow the mounting of heavier armament (6 pounder).

He added: " Now that Cruiser Tanks are operating in such considerable numbers, could not the requirement of taking on more than one target be met by mutual protection from other Cruiser tanks in the same formation?"

Davidson's initiative with A15, even if it kept an auxiliary turret in the end allowed the British to kill the A14 and A16 Mediums/Heavy Cruisers which were heavier and thus required more armor plate and would take longer to produce. It says a lot that the 21 tons of the A16 and the 28 tons of the A14 (20.2-24 tons for the A14E2 with a transversely mounted RY8 engine and auxiliary turrets on the turret instead of the hull!) were justified to simply mount auxiliary turrets rather than a bigger gun or thicker armor than 30mm.

Although Davidson ideally wanted a standardization on this A10'ed A13 Mk III/A15 (also called A13 Mk IV by Davidson), he retained Covenanter both because the War Office was still wedded to the Light/Heavy Cruiser mix but more importantly because Covenanter's development had started earlier and it was expected to enter service sooner than A15. He also recommended 40mm all around on A15 instead of the 40mm front and 30mm sides of the real Crusader I, at the cost of an extra ton and a top speed of 28 instead of 31 mph. This was likely rejected to meet the 18 ton weight limit. Note that at this point A15 was proposed with both the Meadows DAV with rear radiators and the Liberty engine. Nuffield could not develop both configurations at the same time, and the Liberty was chosen because it was lighter than the DAV and could thus fully meet the 18 ton target.

There does seem to be a lot of bureaucratic inertia in British tank development early to mid war. I think a lot of this can be put down to the frantic need for any tank now rather than stopping to think about what they are building. Had Britain stopped to actually think things through as happened later on in the war with tanks like the Cromwell (turret ring excepted), Comet and Centurion then Britain could have produced a very good tank. The issue is no-one did stop and think as until lend lease really kicked in Britain was in a mad scramble.

Exactly. The core changes happened towards August 1942 when tanks were now required to have a 3000 mile overhaul life, bringing reliability on par with American tanks (and ahead of German tanks which had a 1200 mile overhaul life for the HL120-powered vehicles and sometimes poorer reliability on later vehicles). The anti-invasion Nuts and May scheme to produce as many tanks as possible was also finally relaxed, which was helped by the fact the Americans could now cover a large portion (in fact a majority) of British needs. By this point production of British tanks was there as an insurance for emergencies (which turned out to be right), for postwar needs and for niche improvements over what the Americans could offer (hole punchers and heavily armored tanks notably). Covenanter was actually quite close to meeting teh 3000 mile target.

Another thing the book mentions is that Armored Divisions were also finally reworked to a sensible scheme in August 1942, with one armored brigade replaced by an infantry brigade and the proportion of artillery being increased. This finally understood the fact that armored formations could not operate alone, adressing an issue that could have been fixed 2 years prior if the October 1940 reorganization had been adopted.

Covvie was also quite unlucky as it could have been used more in new roles. There was a plan to convert a lot of them to Observation Post, Command and Bridgelayer variants, but most were cancelled to instead use Shermans for the OP role to absorb excess American production and because the Bridgelayer program was a clusterfuck with constant changes in the number of Covvie and Valentine B/Ls planned. Also, in late 1942 a few Covenanter III Command Tanks were actually landed in North Africa but were super unlucky as they were damaged by a German air attack, and were replaced by Crusaders which were not very liked in the role.

 

[Petike]

Romfell V2.0 Armoured Car Update: (@Petike)

It has been a little while since my last update, but I have not been sitting idle. There have been a couple of troublesome problems that have taken time to resolve but I think we are well on the way now. 'What problems?' I hear you say. Well...

First off, I needed to select and make the decals I would be using - and thanks to Petike for providing the necessary ground forces insignia for the vehicles in his TL and instructions for the relative size. So far so good. Petike also liked the idea of Romanic numerals to identify the specific vehicle - OK. Unfortunately, I had not used enough acrylic varnish when making the decals and when I tried to apply them the colour washed out and, as the final insult, they fell apart! Time to make some more but, of course, I had run out of inkjet decal paper... Needed to order more from Amazon!

Running out of crafting / model-making supplies is something I can certainly sympathize with. It's happened to me as well.

Second issue. The model tyres are completely smooth/slick which seems more than a little odd for a vehicle that was supposed to have some off-road capability - although several photos of the original Romfell AC seem to show distinctly smooth treads. Nevertheless, given that the Romfell V2.0 has wider tyres, the lack of treads seemed even more of an issue - what could be done? Trying to etch on something was, IMHO, fraught with possibilities of total disaster and so was not an option. What I settled on was to make a tread decal - oh much easier said than done, I can assure you!! And, as mentioned above, I had run out of decal paper... Several designs and attemps later, I think I have something workable.

I like the tyres as they are now. I think the decal works well and gives them more off an off-road feel, without any need for more physical modification. It's honestly pretty much how I imagined it, especially given the darker colour of the tyres in my design. So, perfectly fine be me.

Third problemette. What paint to use? I settled on Revel Bronze Green silk acrylic as the closest match to Petike's drawing. The silk finish was good for applying the decals and the oil paint pin washes and looked very reminisant of the Deep Bronze Green finish in use by Britain at the time. It was also at this stage that I realised the positioning of the decals would need to change slightly as the Romanic numbers looked lost sitting in a panel by themselves. The end result (see below) was OK but perhaps a little too dark for Petike's drawing.

View attachment 862146

In the end I have decided to go back to a matt finish which lightens up everything a bit and will allow me to better add a little light weathering. Still have some touch ups to do and said weathering.

I'm actually really pleased with how the colour turned out. The original colour in my illustrated design was only ever more of a guideline, a darker green to darker spruce green, and this fits perfectly. I also like that the slight sheen and the weathering you'll apply in a few places will enhance the more realistic look of the surface. Well done.

I've even had time to figure out a backstory for that one cute turret decal with the playing card. While it's not a card suit that would be the most common over here in the early 20th century and the interwar years, card suits like that were available and played by some. They might actually be a bit more readily available and a bit more popular in the ATL, in addition to more domestic card suit styles, given the different socio-economic developments already prior to WWI. I can easily imagine that the commander of "Hačur III" of many years was something of a fan of those "more foreign" card suits and liked to use them for some French-style card games, and this was eventually reflected by the Ace of Spades his crew painted on the turret of their unit's car. So there, even if there was no previous explanation for that playing card on the turret, you now have one. I consider it canon.

I have also sent off for a couple of realistic Austro-Hungarian crew members as I just wasn't happy with what I could cobble together from my spares boxes.

As long as they'll fit the model kit's scale, i.e. won't look too gigantic next to the car, it's all fine. About the only detail you'll likely need to modify is repaint their uniforms to a different colour hue and apply a tiny amount of paint on their collar lapels, to hint at the different rank insingia colours of the infantry and armoured crews.

View attachment 862147

View attachment 862148

View attachment 862149

Without exaggeration, a genuinely awesome model.

Besides being a wonderful physical representation of something from my timeline, I'm sure it'll also look good among any ATL interwar era models you might already have in your collection. Might even draw some eyes... "Huh, now what sort of armoured car is that ?! Haven't seen one like that before among alternate history models..."

 

[Claymore]

Running out of crafting / model-making supplies is something I can certainly sympathize with. It's happened to me as well.


I like the tyres as they are now. I think the decal works well and gives them more off an off-road feel, without any need for more physical modification. It's honestly pretty much how I imagined it, especially given the darker colour of the tyres in my design. So, perfectly fine be me.


I'm actually really pleased with how the colour turned out. The original colour in my illustrated design was only ever more of a guideline, a darker green to darker spruce green, and this fits perfectly. I also like that the slight sheen and the weathering you'll apply in a few places will enhance the more realistic look of the surface. Well done.

Thank you! 👍

I've even had time to figure out a backstory for that one cute turret decal with the playing card. While it's not a card suit that would be the most common over here in the early 20th century and the interwar years, card suits like that were available and played by some. They might actually be a bit more readily available and a bit more popular in the ATL, in addition to more domestic card suit styles, given the different socio-economic developments already prior to WWI. I can easily imagine that the commander of "Hačur III" of many years was something of a fan of those "more foreign" card suits and liked to use them for some French-style card games, and this was eventually reflected by the Ace of Spades his crew painted on the turret of their unit's car. So there, even if there was no previous explanation for that playing card on the turret, you now have one. I consider it canon.

I wanted something that would distinguish between the two different types of vehicle and, as I was using a common hull, the decals would therefore need to fit on the turret sides. What I had in mind was that the 4-wheeled variants (not built) would sit within a Light Company, the Mg-armed 6-wheeler would be in a Medium Company and the AT-armed 6-wheeler would be in a Heavy Company. As you will see from the attached picture, I used a different insignia for the Mg turret. I used what decals I had available and would fit. I leave it to you to come up with some suitable historic reason why those insignia were used... 😉

As long as they'll fit the model kit's scale, i.e. won't look too gigantic next to the car, it's all fine. About the only detail you'll likely need to modify is repaint their uniforms to a different colour hue and apply a tiny amount of paint on their collar lapels, to hint at the different rank insingia colours of the infantry and armoured crews.

The figures will indeed be in scale (1/35) - acknowledged regarding uniform colours and insignia. 👍

Without exaggeration, a genuinely awesome model.

Besides being a wonderful physical representation of something from my timeline, I'm sure it'll also look good among any ATL interwar era models you might already have in your collection. Might even draw some eyes... "Huh, now what sort of armoured car is that ?! Haven't seen one like that before among alternate history models..."

Thank you once again! 👏

 

[GrahamB]

Romfell V2.0 Armoured Car Update: (@Petike)

(*snip!*)

I say there chaps, that appears to be a lion! Make haste to the Romfell before the bounder ruins your moustaches!

(sorry, couldn't help myself, I'm rather sleep deprived)

Another exceptional model from Claymore! Brilliant work as always.

 

[Claymore]

Well, well… Just looking out my study window and it’s snowing. Wet to be sure but definitely snow!! 😳🌨❄️💦🙄

 

[Claymore]

I say there chaps, that appears to be a lion! Make haste to the Romfell before the bounder ruins your moustaches!

(sorry, couldn't help myself, I'm rather sleep deprived)

Another exceptional model from Claymore! Brilliant work as always.

Hee, hee! Thanks mate, still a bit of work to do on it but getting there.

Looking outside again, I think it’s a night for hunkering down by the fire with a fine glass of the water of life! 🥃👍