A belt/mag fed version of the French 25mm AT gun could have been quite interesting.
Sir John Valentine Carden survives.
- Thread starter allanpcameron
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Or...POM POM POM POM POM POM POM POM
The 2 pounder was already in production and with a 14 round linked belt - there would be no need for a dedicated loader so it could have a 3 man crew (Commander, Gunner, Driver) in a 2 man turret.
the Vickers 25x189 round was very potent for it's size with a MV of around 3,000ft/s. Both HE and AP ammunition was available IIRC. In 1939 not a bad choice for an Armoured car of light tank IMVHO.
It's unlikely it would be used in any but semi automatic mode so a 5 round mag will do just fine and be easier to handle in the cramped turret though to honest single shot would work almost as well.
better use an existing proven lightweight semi-auto design then ... COW gun from 1918
5 round clip, 1.5 lb HE shell (AP option) , 200lb all up weight for gun barrel and mounting
(smaller and lighter than the Vickers S 40mm semi auto or the 2lb QF single shot)
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It wouldn't have to be the 2pdr Anti Tank gun fitted into a Mk VI. I was thinking something like the C.O.W gun.
COW 37 mm gun - Wikipedia
en.wikipedia.org
Vickers 40 mm Class S gun - Wikipedia
View attachment 587976
1 December 1937. 15:00hrs. Newcastle-upon-Tyne. England.
allanpcameron
Donor
1 December 1937. 15:00hrs. Newcastle-upon-Tyne. England.
The A10E1 and A10E2 were back at Elswick Works after testing at Farnborough. The A10E1 was the welded version powered by the AEC engine. This tank turned out to be a good ton heavier than the A9. Without a hull mounted machine gun, and therefore one less crewman and the associated weight of the gun and its ammunition, the extra armour on the A10E1 didn’t completely overwhelm the AEC engine’s power, but it came close. The tank was between five and ten miles per hour slower than its A9 stablemate on the road, but not that much discernibly slower on the cross-country parts of the trials. The tests noted that the fuel capacity was limited and recommended an increase in fuel tank volume.
What had been interesting for the Vickers team was the reaction to the welded armour. When the A10E1 was examined it was noted that the angles that the armour was mounted, especially on the front hull made it extra effective. The absence of rivets or bolts was also noted, it was judged that this meant the crew would have better protection, since the rivets wouldn’t be knocked out by a strike against the armour. The question came back to overall cost per tank, and whether the welding workforce would be big enough to produce the tanks in a timely manner. It had also been noted that the armour thickness of about an inch (30mm) wouldn’t protect it from the 2-pdr gun, and therefore conceivably from any enemy anti-tank gun at 500 yards. The sloped armour helped, but the thickness of the armour would have to be considered, for all tanks under consideration. It raised questions about wisdom of the half an inch (14mm) armour thickness on the A9 and the planned A13.
The A10E2 differed from the A10E1 by being longer and having a raised engine deck to contain the Rolls-Royce Eagle aero-engine. With the bigger engine and more traditional riveting, the whole tank was 15 tons, two tons heavier than the A9 and one ton more than A10E1. However, the engine was producing 400hp, which moved the tank at a faster speed than the A9, reaching over 30mph in some trials. It came at a cost however. Despite improvements to the tracks, they weren’t up to the kind of punishment that the greater mass and higher speed put on them. The suspension coped with the increased weight, but there wasn’t too much room for growth. During the test the tank was weighted to take the tonnage if it was to be given the same level of protection as the A11 infantry tank, over 2 inches (60mm) of armour. While the engine would be capable of keeping the speed up to about 25mph on the road, the suspension and the tracks would have to be improved, the suspension wouldn’t be far from its limit under that weight.
The large engine had been adapted to take the normal petrol that was used by the army, but had lost some power in the process. It proved to be thirsty, and while extra fuel storage had been added as part of the lengthening of the hull, it wasn’t satisfactory enough in terms of the tank’s road radius. The higher power of the engine also meant that extra effort had to be made with the cooling system. This had been noted for reference with the Liberty engine powering the A13.
With the much the same turret as the A9 and A10E1 there was little to separate it from the others regarding its fighting prowess, though the absence of a hull mounted machine gun was noted. The A10 was expected to work more with the infantry and so the extra machine-gun might be considered useful. One of the things that Sir John Carden had done with this particular turret, designed to fulfil the role of Close Support, was to add geared elevation apparatus, rather than the shoulder balanced system for the 2-pdr. He had also fixed the the co-axial machine-gun to the movement of the main gun. This simplified the process for the gunner, who only had to control one set of movement for traverse and elevation rather than two separate systems for each weapon. The report on this had noted it as being an innovation worth further examination.
The A10E2 hadn’t been ordered by the War Office, it was being seen by them basically a Vickers commercial proposition. The fact that the larger engine could shift a heavier tank was noted, after all the Liberty engine was designated for the A13 for the same reason. Certainly, the information gained from the test would be passed to Vulcan Foundry for their work on the A12. At this point however, the plan to order 60 A10s based on the A10E1 model was affirmed, asking Vickers to begin planning to put this tank into production, but adding the stipulation that a hull mounted machine-gun be added. Vickers noted that the extra weight would overtax the engine, slowing the tank substantially, as well as delay production while the front hull was redesigned. They also noted that the A13 design did not include a hull mounted gun, so perhaps it wasn’t essential. The War Office said they would consider these arguments, but perhaps a redesign, similar to the A9 front hull might be expedited, before the order was confirmed.
When advised that Sir John Carden was currently working on a using the A10E2 as a basis for an alternative design for the A12 specification, the War Office accepted the offer of looking at the design, but at this point would not commit to it. Therefore, they did not assign a specific A (tank) classification to it, but would look on it as an alternative A12. Vickers stated that they hoped to have a mock up of the design by spring and a mild steel prototype by the end of the year. The fact that Vulcan Foundry’s A12 design was proposing using a diesel engine to power it was noted, and Vickers was asked, if it were to produce an alternative, to consider using the same type of engine.
The A10E1 and A10E2 were back at Elswick Works after testing at Farnborough. The A10E1 was the welded version powered by the AEC engine. This tank turned out to be a good ton heavier than the A9. Without a hull mounted machine gun, and therefore one less crewman and the associated weight of the gun and its ammunition, the extra armour on the A10E1 didn’t completely overwhelm the AEC engine’s power, but it came close. The tank was between five and ten miles per hour slower than its A9 stablemate on the road, but not that much discernibly slower on the cross-country parts of the trials. The tests noted that the fuel capacity was limited and recommended an increase in fuel tank volume.
What had been interesting for the Vickers team was the reaction to the welded armour. When the A10E1 was examined it was noted that the angles that the armour was mounted, especially on the front hull made it extra effective. The absence of rivets or bolts was also noted, it was judged that this meant the crew would have better protection, since the rivets wouldn’t be knocked out by a strike against the armour. The question came back to overall cost per tank, and whether the welding workforce would be big enough to produce the tanks in a timely manner. It had also been noted that the armour thickness of about an inch (30mm) wouldn’t protect it from the 2-pdr gun, and therefore conceivably from any enemy anti-tank gun at 500 yards. The sloped armour helped, but the thickness of the armour would have to be considered, for all tanks under consideration. It raised questions about wisdom of the half an inch (14mm) armour thickness on the A9 and the planned A13.
The A10E2 differed from the A10E1 by being longer and having a raised engine deck to contain the Rolls-Royce Eagle aero-engine. With the bigger engine and more traditional riveting, the whole tank was 15 tons, two tons heavier than the A9 and one ton more than A10E1. However, the engine was producing 400hp, which moved the tank at a faster speed than the A9, reaching over 30mph in some trials. It came at a cost however. Despite improvements to the tracks, they weren’t up to the kind of punishment that the greater mass and higher speed put on them. The suspension coped with the increased weight, but there wasn’t too much room for growth. During the test the tank was weighted to take the tonnage if it was to be given the same level of protection as the A11 infantry tank, over 2 inches (60mm) of armour. While the engine would be capable of keeping the speed up to about 25mph on the road, the suspension and the tracks would have to be improved, the suspension wouldn’t be far from its limit under that weight.
The large engine had been adapted to take the normal petrol that was used by the army, but had lost some power in the process. It proved to be thirsty, and while extra fuel storage had been added as part of the lengthening of the hull, it wasn’t satisfactory enough in terms of the tank’s road radius. The higher power of the engine also meant that extra effort had to be made with the cooling system. This had been noted for reference with the Liberty engine powering the A13.
With the much the same turret as the A9 and A10E1 there was little to separate it from the others regarding its fighting prowess, though the absence of a hull mounted machine gun was noted. The A10 was expected to work more with the infantry and so the extra machine-gun might be considered useful. One of the things that Sir John Carden had done with this particular turret, designed to fulfil the role of Close Support, was to add geared elevation apparatus, rather than the shoulder balanced system for the 2-pdr. He had also fixed the the co-axial machine-gun to the movement of the main gun. This simplified the process for the gunner, who only had to control one set of movement for traverse and elevation rather than two separate systems for each weapon. The report on this had noted it as being an innovation worth further examination.
The A10E2 hadn’t been ordered by the War Office, it was being seen by them basically a Vickers commercial proposition. The fact that the larger engine could shift a heavier tank was noted, after all the Liberty engine was designated for the A13 for the same reason. Certainly, the information gained from the test would be passed to Vulcan Foundry for their work on the A12. At this point however, the plan to order 60 A10s based on the A10E1 model was affirmed, asking Vickers to begin planning to put this tank into production, but adding the stipulation that a hull mounted machine-gun be added. Vickers noted that the extra weight would overtax the engine, slowing the tank substantially, as well as delay production while the front hull was redesigned. They also noted that the A13 design did not include a hull mounted gun, so perhaps it wasn’t essential. The War Office said they would consider these arguments, but perhaps a redesign, similar to the A9 front hull might be expedited, before the order was confirmed.
When advised that Sir John Carden was currently working on a using the A10E2 as a basis for an alternative design for the A12 specification, the War Office accepted the offer of looking at the design, but at this point would not commit to it. Therefore, they did not assign a specific A (tank) classification to it, but would look on it as an alternative A12. Vickers stated that they hoped to have a mock up of the design by spring and a mild steel prototype by the end of the year. The fact that Vulcan Foundry’s A12 design was proposing using a diesel engine to power it was noted, and Vickers was asked, if it were to produce an alternative, to consider using the same type of engine.
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Another good update.
I'm half surprised they went with the welded tank given the less powerful engine. That said the radius of action was concerning, I was half expecting an A10E3 model be asked for (welded with aero engine) to test.
Keep up the good work and keep the updates coming please.
I'm half surprised they went with the welded tank given the less powerful engine. That said the radius of action was concerning, I was half expecting an A10E3 model be asked for (welded with aero engine) to test.
Keep up the good work and keep the updates coming please.
20 January 1938 11:00hrs. Farnborough. England.
allanpcameron
Donor
20 January 1938 15:00hrs. Farnborough. England.
Leo Anderson shivered and kicked the wheel of the tank, which just added a sore toe to his tale of misery. His boss, Walter Christie had designed this new tank, the M1938, and since the Limeys had bought the last one, he’d been certain they’d buy this one too. So certain in fact, that he’d invited the French over too.
The big show had got off to a bad start the day before. Anderson had been harassed all the time by his boss who wanted this done and that done pronto. In all the hullabaloo Anderson hadn’t checked everything, and sure enough after a few miles driving through the MEE range the thing seized up. The oil in the gearbox should have been changed after the sea voyage, so as driver, Anderson had had to spend the freezing cold night in the middle of nowhere with the tank. Meanwhile Christie hared around the place trying to find an engineering firm who could supply replacement gears. Being the home of testing British tanks, miracle of miracles, sure enough he succeeded. Having spent the morning fixing the tank, they’d knocked the limeys’ socks off clocking 64.3mph on a flying quarter mile.
When an official looking car turned up, Christie thought the Frenchies had arrived, but it was a couple of State Department goons from the Embassy. They had taken Christie aside and were giving him a verbal going over. If there was one thing that Walter Christie couldn’t deal with well, it was getting a public dressing down from a couple of cheap suits. All hell broke loose. The limeys of course seemed terribly amused, though as oily as all get out when the Embassy car drove off.
The sales pitch had obviously died a death, it seems the Embassy goons had made it clear to Christie that it was illegal for an American citizen to export war materials. The limeys had come over all sympathetic, but Anderson could see they weren’t too impressed anyway. After all the M1938 didn’t have any kind of weapons, Christie didn’t believe in all them “high in the sky turrets.” Some limey called Martel, who seemed like a big cheese in the gang, was impressed enough with the speed coming from the Curtiss D12 aero engine. You should have seen his face when informed it was rated at 670bhp at 2600rpm, his imitation of a big bass was a sight to behold. That was one of the few highlights of a very cold and unhappy couple of days.
An offer to store the M1938 was made by the Farnborough team, while Christie organised shipping back to the States. Anderson was worried that he’s be left behind to guard the thing from British meddling, but thankfully he could ship home with Christie. Once the shipping across the pond was sorted, the limeys would deliver the tank to Southampton, then it’d be back to business as usual.
Leo Anderson shivered and kicked the wheel of the tank, which just added a sore toe to his tale of misery. His boss, Walter Christie had designed this new tank, the M1938, and since the Limeys had bought the last one, he’d been certain they’d buy this one too. So certain in fact, that he’d invited the French over too.
The big show had got off to a bad start the day before. Anderson had been harassed all the time by his boss who wanted this done and that done pronto. In all the hullabaloo Anderson hadn’t checked everything, and sure enough after a few miles driving through the MEE range the thing seized up. The oil in the gearbox should have been changed after the sea voyage, so as driver, Anderson had had to spend the freezing cold night in the middle of nowhere with the tank. Meanwhile Christie hared around the place trying to find an engineering firm who could supply replacement gears. Being the home of testing British tanks, miracle of miracles, sure enough he succeeded. Having spent the morning fixing the tank, they’d knocked the limeys’ socks off clocking 64.3mph on a flying quarter mile.
When an official looking car turned up, Christie thought the Frenchies had arrived, but it was a couple of State Department goons from the Embassy. They had taken Christie aside and were giving him a verbal going over. If there was one thing that Walter Christie couldn’t deal with well, it was getting a public dressing down from a couple of cheap suits. All hell broke loose. The limeys of course seemed terribly amused, though as oily as all get out when the Embassy car drove off.
The sales pitch had obviously died a death, it seems the Embassy goons had made it clear to Christie that it was illegal for an American citizen to export war materials. The limeys had come over all sympathetic, but Anderson could see they weren’t too impressed anyway. After all the M1938 didn’t have any kind of weapons, Christie didn’t believe in all them “high in the sky turrets.” Some limey called Martel, who seemed like a big cheese in the gang, was impressed enough with the speed coming from the Curtiss D12 aero engine. You should have seen his face when informed it was rated at 670bhp at 2600rpm, his imitation of a big bass was a sight to behold. That was one of the few highlights of a very cold and unhappy couple of days.
An offer to store the M1938 was made by the Farnborough team, while Christie organised shipping back to the States. Anderson was worried that he’s be left behind to guard the thing from British meddling, but thankfully he could ship home with Christie. Once the shipping across the pond was sorted, the limeys would deliver the tank to Southampton, then it’d be back to business as usual.
allanpcameron
Donor
The photo in Mechanised Force is different, but obviously the same vehicle as that picture which came from a Russian site which I found through image search for M1938 Christie tank. Fletcher says about it:
Was it? The 1935 neutrality act was saying that it was prohibited to sell “arms, ammunition, and implements of war” from the United States to foreign nations at war and arms manufacturers in the United States had to apply for an export license. Britain or for that matter France are not belligerents at the moment.
I assume that "A10 infantry tank" is a typo for "A11"?
Some interesting stuff here - the pieces are starting to come together and the aero-engine is showing what needs to be done, but it looks like Sir John and Vickers are hitting the limits of the basic A9/10 design. Now to come up with something just that little bit bigger...
Are Vickers committing to producing welded tanks in quantity, or will the production A10s still be rivetted? And should I be worried that it's 1938 and the War Office is still ordering tanks in penny packets?
Loved the Christie picture. That chassis looks fun, futuristic and completely impractical (look at the size of the driver and work out how small it is).
Still, with the Vickers cruisers shaking their suspensions apart at 25-30mph, You can understand why Martel wants Christie for his fast tanks.
Mark1878
Donor
No it is the A10 cruiser this was known in TTL as a heavy cruiser. The latest version is improved over TTL https://en.wikipedia.org/wiki/Cruiser_Mk_II
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