Sir John Valentine Carden Survives. Part 2.

[MarcH]

I'm not sure the Ram/Jumbuck will see service in Europe, at least not on mainland Europe. The Dominion tanks while based on the Valliant aren't just Valliant's with a 25 pounder gun in the turret. They use different Engines and suspension along with the ancillary parts that come along with those. That will lead to logistical difficulties in a mainland European campaign. The British will be moving to the Victor as the main tank along with the supporting tanks likely based on the Valiant unless the current versions stay as they are based on other cruisers.

Where I can see the Ram/Jumbuck providing sterling service will be out east. While the current mix of tanks are doing good work, particularly the Matilda II's, they have limitations. The Dominion tanks will be superior to anything else out their either in DUKE service or in Japanese hands. The only arguably better tank will be the Sherman and they will be in limited supply out east so I can't see the DUKE forces getting any. Given it's superiority along with the advantage of simplifying logistics focusing on this "one" tank design then sending it out east would seem like the best option.

What this will mean for the Canadian tankers, well they should get Victors eventually. I can't see the Canadian government wanting to be seen sending their troops into battle in a 2nd rate tank, even a "home grown" tank. The training they are currently doing will need updating for a new tank but the fundamentals will still apply.

 

[trekchu]

I'm not sure the Ram/Jumbuck will see service in Europe, at least not on mainland Europe. The Dominion tanks while based on the Valliant aren't just Valliant's with a 25 pounder gun in the turret. They use different Engines and suspension along with the ancillary parts that come along with those. That will lead to logistical difficulties in a mainland European campaign. The British will be moving to the Victor as the main tank along with the supporting tanks likely based on the Valiant unless the current versions stay as they are based on other cruisers.

Where I can see the Ram/Jumbuck providing sterling service will be out east. While the current mix of tanks are doing good work, particularly the Matilda II's, they have limitations. The Dominion tanks will be superior to anything else out their either in DUKE service or in Japanese hands. The only arguably better tank will be the Sherman and they will be in limited supply out east so I can't see the DUKE forces getting any. Given it's superiority along with the advantage of simplifying logistics focusing on this "one" tank design then sending it out east would seem like the best option.

What this will mean for the Canadian tankers, well they should get Victors eventually. I can't see the Canadian government wanting to be seen sending their troops into battle in a 2nd rate tank, even a "home grown" tank. The training they are currently doing will need updating for a new tank but the fundamentals will still apply.

Or they see service in asia. Those tanks are perfect for there.

 

[Derek Pullem]

I'm not sure the Ram/Jumbuck will see service in Europe, at least not on mainland Europe. The Dominion tanks while based on the Valliant aren't just Valliant's with a 25 pounder gun in the turret. They use different Engines and suspension along with the ancillary parts that come along with those. That will lead to logistical difficulties in a mainland European campaign. The British will be moving to the Victor as the main tank along with the supporting tanks likely based on the Valiant unless the current versions stay as they are based on other cruisers.

Where I can see the Ram/Jumbuck providing sterling service will be out east. While the current mix of tanks are doing good work, particularly the Matilda II's, they have limitations. The Dominion tanks will be superior to anything else out their either in DUKE service or in Japanese hands. The only arguably better tank will be the Sherman and they will be in limited supply out east so I can't see the DUKE forces getting any. Given it's superiority along with the advantage of simplifying logistics focusing on this "one" tank design then sending it out east would seem like the best option.

What this will mean for the Canadian tankers, well they should get Victors eventually. I can't see the Canadian government wanting to be seen sending their troops into battle in a 2nd rate tank, even a "home grown" tank. The training they are currently doing will need updating for a new tank but the fundamentals will still apply.

Most likely this is right. A long barreled version of the jumbuck with a MK 2 25 PDR with 2000 ft/s muzzle velocity and APDS might be competitive in Europe late war just like the Pz IV late models

 

[MattII]

I wonder if the USMC might want a few tanks...

After all, with the Short 25-pounder it will be good for dealing with bunkers.

 

[Cryhavoc101]

I'm not sure the Ram/Jumbuck will see service in Europe, at least not on mainland Europe. The Dominion tanks while based on the Valliant aren't just Valliant's with a 25 pounder gun in the turret. They use different Engines and suspension along with the ancillary parts that come along with those. That will lead to logistical difficulties in a mainland European campaign. The British will be moving to the Victor as the main tank along with the supporting tanks likely based on the Valiant unless the current versions stay as they are based on other cruisers.

Where I can see the Ram/Jumbuck providing sterling service will be out east. While the current mix of tanks are doing good work, particularly the Matilda II's, they have limitations. The Dominion tanks will be superior to anything else out their either in DUKE service or in Japanese hands. The only arguably better tank will be the Sherman and they will be in limited supply out east so I can't see the DUKE forces getting any. Given it's superiority along with the advantage of simplifying logistics focusing on this "one" tank design then sending it out east would seem like the best option.

What this will mean for the Canadian tankers, well they should get Victors eventually. I can't see the Canadian government wanting to be seen sending their troops into battle in a 2nd rate tank, even a "home grown" tank. The training they are currently doing will need updating for a new tank but the fundamentals will still apply.

The British in North Africa had during early use of the M3 Stuart found that it was not a good match for the PZ III, lacked range although had excellent reliability vs other British tanks and relegated it to a recce tank and in many cases use 'Kangaroo' variants without turrets.

So a precedent existed and I expect that in time users of the M3 light tank faced with the same limitations are almost certainly going to use a turretless version for the same task for the same reasons.

The requirement for a armoured troop / assault carrier will still exist ITTL and the British where always looking to find machines or a mechanical answer that would save blood and lives - and so one way or another I cannot see a similar requirement happening and so we might still see 'lesser' commonwealth tank designs 'defrocked' and used as APCs

 

[Merrick]

The requirement for a armoured troop / assault carrier will still exist ITTL and the British where always looking to find machines or a mechanical answer that would save blood and lives - and so one way or another I cannot see a similar requirement happening and so we might still see 'lesser' commonwealth tank designs 'defrocked' and used as APCs

I doubt this will happen to the Ram/Jumbuck TTL. They'll be too valuable as assault guns. Throwing a 25lb HE shell is one of the things a Victor can't do, and if the Armoured Regiments don't want them, you can bet the RA would be interested in an SP 25-pounder.

The tanks I'd expect to see cut down to Kangaroo status would be the M3 Grant/Lee (if available in numbers) and the Churchill. Both have roomy interiors, and once the Victor/Ram/Sherman are available in sufficient numbers, are obsolescent as gun tanks.

 

[MattII]

I doubt this will happen to the Ram/Jumbuck TTL. They'll be too valuable as assault guns. Throwing a 25lb HE shell is one of the things a Victor can't do, and if the Armoured Regiments don't want them, you can bet the RA would be interested in an SP 25-pounder.

The tanks I'd expect to see cut down to Kangaroo status would be the M3 Grant/Lee (if available in numbers) and the Churchill. Both have roomy interiors, and once the Victor/Ram/Sherman are available in sufficient numbers, are obsolescent as gun tanks.

The Victor is planned to mount a 75mm HV gun, so they could almost certainly be converted to take a 25-pounder. Plus there's the question of logistics.

 

[Gryle]

Doing some googling and apparently the short 25 pdr used by the Aussies did not have a "super" charge rating so was limited to 1550 ft/s muzzle velocity for the 20 pdr shot.

25-pr data sheet

Technical characteristics, list of publications and short history

nigelef.tripod.com

Even so - it is allegedly good enough for 60-70mm penetration at 500 yards. Although there were tests that suggested it was likely that they could mission kill a Tiger by wrecking its cooling system with HE shrapnel. Of course the TIger could still fire back ................

That's probably information that has been simplified in the re-telling to the point that it is not really true. The Short 25 pounder can fire with the super charge, it is just that with the light build of the carriage it will push it to its limit and shorten its life. So you are only supposed to fire it in emergencies, not regularly. And with that short a barrel it's going to concuss the gun crew quite badly too, although that's not going to be a concern in a tank.

Having said that the 25 pounder tank gun for the Australian Cruisers is a standard length Mk II barrel. The Short gun hadn't even been made when the tank work was done and the earlier tank gun work was specifically cited as aiding in the speed with which the Short 25 pounder was developed, and that fact is probably why the internet sometimes seems to believe the Australian tank gun is a Short gun. In testing, AP shot fired with super charge from the tank gun will reach around 1900ft/sec. Hypothetically if you were to load super plus increment it'd likely exceed 2000. The muzzle brake might not even be required, as it seems to be for the towed gun, as there was at least one Long 25pdr tested on the tank mounting which with AP shot, super charge, and a supplementary propellant charge hit about 2150ft/sec at the muzzle.

 

[MarcH]

The British in North Africa had during early use of the M3 Stuart found that it was not a good match for the PZ III, lacked range although had excellent reliability vs other British tanks and relegated it to a recce tank and in many cases use 'Kangaroo' variants without turrets.

So a precedent existed and I expect that in time users of the M3 light tank faced with the same limitations are almost certainly going to use a turretless version for the same task for the same reasons.

The requirement for a armoured troop / assault carrier will still exist ITTL and the British where always looking to find machines or a mechanical answer that would save blood and lives - and so one way or another I cannot see a similar requirement happening and so we might still see 'lesser' commonwealth tank designs 'defrocked' and used as APCs

I doubt this will happen to the Ram/Jumbuck TTL. They'll be too valuable as assault guns. Throwing a 25lb HE shell is one of the things a Victor can't do, and if the Armoured Regiments don't want them, you can bet the RA would be interested in an SP 25-pounder.

The tanks I'd expect to see cut down to Kangaroo status would be the M3 Grant/Lee (if available in numbers) and the Churchill. Both have roomy interiors, and once the Victor/Ram/Sherman are available in sufficient numbers, are obsolescent as gun tanks.

IIRC a lot of work is already being done on various "support" tanks as well as a dedicated APC type design. The APC is being worked on by Leslie Little from memory, this should prevent much of the mish mash of converted tanks being used in other roles we see in OTL, at least in Europe.
What happens in other theatres though is anyone's guess.

On the 25pdr, I have to wonder will it appear in a Victor variant? I think a OQF 95mm howitzer might have started development ITTL but I'm not sure. If not then "borrowing" the dominion idea of using a 25pdr could be one route taken. Another option could be an updated/modified 4.5" howitzer, that would pack a real bang.

 

[kelgar04]

I'm not sure the Ram/Jumbuck will see service in Europe, at least not on mainland Europe. The Dominion tanks while based on the Valliant aren't just Valliant's with a 25 pounder gun in the turret. They use different Engines and suspension along with the ancillary parts that come along with those. That will lead to logistical difficulties in a mainland European campaign. The British will be moving to the Victor as the main tank along with the supporting tanks likely based on the Valiant unless the current versions stay as they are based on other cruisers.

Where I can see the Ram/Jumbuck providing sterling service will be out east. While the current mix of tanks are doing good work, particularly the Matilda II's, they have limitations. The Dominion tanks will be superior to anything else out their either in DUKE service or in Japanese hands. The only arguably better tank will be the Sherman and they will be in limited supply out east so I can't see the DUKE forces getting any. Given it's superiority along with the advantage of simplifying logistics focusing on this "one" tank design then sending it out east would seem like the best option.

What this will mean for the Canadian tankers, well they should get Victors eventually. I can't see the Canadian government wanting to be seen sending their troops into battle in a 2nd rate tank, even a "home grown" tank. The training they are currently doing will need updating for a new tank but the fundamentals will still apply.

I think the Ram/Jumpbuck may make a decent SPG in Europe depending on how its used and if the RAR and RHA can get their hands on some for testing and work up I could see a few squadrons being fairly useful in providing support for Victor's/Venoms.

 

[Derek Pullem]

That's probably information that has been simplified in the re-telling to the point that it is not really true. The Short 25 pounder can fire with the super charge, it is just that with the light build of the carriage it will push it to its limit and shorten its life. So you are only supposed to fire it in emergencies, not regularly. And with that short a barrel it's going to concuss the gun crew quite badly too, although that's not going to be a concern in a tank.

Having said that the 25 pounder tank gun for the Australian Cruisers is a standard length Mk II barrel. The Short gun hadn't even been made when the tank work was done and the earlier tank gun work was specifically cited as aiding in the speed with which the Short 25 pounder was developed, and that fact is probably why the internet sometimes seems to believe the Australian tank gun is a Short gun. In testing, AP shot fired with super charge from the tank gun will reach around 1900ft/sec. Hypothetically if you were to load super plus increment it'd likely exceed 2000. The muzzle brake might not even be required, as it seems to be for the towed gun, as there was at least one Long 25pdr tested on the tank mounting which with AP shot, super charge, and a supplementary propellant charge hit about 2150ft/sec at the muzzle.

Okay - would be interested if Allan could clarify. It was my assumption that the shorter 25 pdr mentioned was derived from the short 25 pdr field gun developed by the Australians. However it would seem that actually it was the Sentinel tank gun that was developed into the short 25 pdr!

Question still stands - is the "shorter" 25 pdr in the Ram / Jumbuck limited in its charge the same way as the short 25 pdr field gun was?

EDIT - Sentinel MkIII design book attached for info https://recordsearch.naa.gov.au/Sea...ieve/NAAMedia/ShowImage.aspx?B=382893&T=P&S=3

 

[Gryle]

Oh I wasn't making any statement one way or the other about Allan's work, only the that the limitation stated in the link you posted isn't really a blanket ban, just strongly worded guidance in relation to the carriage. So if the ordnance is tank mounted that really doesn't apply.

 

[ArtosStark]

I think the Ram/Jumpbuck may make a decent SPG in Europe depending on how its used and if the RAR and RHA can get their hands on some for testing and work up I could see a few squadrons being fairly useful in providing support for Victor's/Venoms.

The SPG thing is interesting to consider. In a lot of ways 25 pounder is a bit small for an SPG. It can be used that way and was at times. But the 25 pounder is already a light and mobile platform and in most cases can probably keep up and deploy normally with a tank force. Having it self propelled does mean that at least a few engagements would have support that would not otherwise, but I think it’s actually going to be a relatively small sample. And mounting them all would be an expensive fix.

You probably want to focus first on mounting those guns that are more difficult to keep mobile with your force. That means the heavier artillery (4.5 and 5.5” guns and heavy howitzers) and the heavy AT guns (17 pounders). As well as your less mobile AA (40 mm Bofors, 3.7” AA at the heavy end and possibly 20 mm at the lower). Only when those are able to keep in support of the mobile forces would you likely want to look at field guns and lighter AT/AA since they can generally keep up as is.

Additionally the Rambuck is going to be much heavier armoured than required for a SPG and I doubt it will have the elevation or the sights necessary to perform the indirect fire role. Personally I think it could probably go to Europe just fine and either be used by the Canadians separately or (more likely) be mixed into Tank brigades to give a heavier anti-fortification punch without losing much AT ability. Either that, or it will be mostly a training tank like the OTL Ram was.

 

[Look More Closely Later]

Well if the Americans can pull of a Doolittle Raid, not only will it be a propaganda victory, it will almost certainly prompt the Japanese into doing something incredibly stupid and detrimental.

Timeline is now in May 1942, so the original timeline Doolittle Raid date has come and gone.
It may be with Burma secure and the Burma Road (possibly weather permitting - I'm not sure how badly the monsoon affected the original one Burma Road) still open, Roosevelt is looking at running a raid from Chinese territory, if he can get bombers with the range into China over or around the mountains, which would at least avoid the headache of trying to figure out how to launch bombers off a carrier and putting said carrier potentially at risk deploying it far enough forward to launch a raid.
Or maybe the American (and other Allied) cryptanalysts can figure out something from Imperial Japanese communications which would offer a juicy target for attack from an Allied base still secure in this timeline.

 

[pjmidd]

The SPG thing is interesting to consider. In a lot of ways 25 pounder is a bit small for an SPG. It can be used that way and was at times

Only if you are American . The British OTL dumped the Priest ( aka M7 , 105mm gun) as soon as they could for the Sexton ( 25pdr ) due to the 25pdr fitting British doctrine better ( not very surprising as the 25pdr was optimised for it ),

 

[Some Bloke]

What the the Aussies call enemy tanks?
Swagmen?

Sergeant : Swagman!
Captain: Crikey! Call up the Jumbucks quick or we're all in deep didgeridoo!

 

[ArtosStark]

Only if you are American . The British OTL dumped the Priest ( aka M7 , 105mm gun) as soon as they could for the Sexton ( 25pdr ) due to the 25pdr fitting British doctrine better ( not very surprising as the 25pdr was optimised for it ),

1) I’m very much not American
2) the Priest was replaced by the Sexton largely because it used a nonstandard gun and ammunition, not because there was a preference for lighter self propelled guns.
3) The Priest was armed with the 105mm howitzer, not gun. It was in a similar weight class to the 25 pounder.

 

[MattII]

The SPG thing is interesting to consider. In a lot of ways 25 pounder is a bit small for an SPG. It can be used that way and was at times. But the 25 pounder is already a light and mobile platform and in most cases can probably keep up and deploy normally with a tank force. Having it self propelled does mean that at least a few engagements would have support that would not otherwise, but I think it’s actually going to be a relatively small sample. And mounting them all would be an expensive fix.

You probably want to focus first on mounting those guns that are more difficult to keep mobile with your force. That means the heavier artillery (4.5 and 5.5” guns and heavy howitzers) and the heavy AT guns (17 pounders). As well as your less mobile AA (40 mm Bofors, 3.7” AA at the heavy end and possibly 20 mm at the lower). Only when those are able to keep in support of the mobile forces would you likely want to look at field guns and lighter AT/AA since they can generally keep up as is.

Additionally the Rambuck is going to be much heavier armoured than required for a SPG and I doubt it will have the elevation or the sights necessary to perform the indirect fire role. Personally I think it could probably go to Europe just fine and either be used by the Canadians separately or (more likely) be mixed into Tank brigades to give a heavier anti-fortification punch without losing much AT ability. Either that, or it will be mostly a training tank like the OTL Ram was.

Loading a 25-pounder wore the crew out less, because 25 pounds (the 25-pounder used two-piece ammunition) is physically easier to manage than the 33-34 pounds of 105mm. the 25-pounder is also going to be small enough to mount in place of the 75mm gun on the Victor.

 

[ArtosStark]

Loading a 25-pounder wore the crew out less, because 25 pounds (the 25-pounder used two-piece ammunition) is physically easier to manage than the 33-34 pounds of 105mm.

Very true. Though I am not sure how it relates to what I wrote. I don’t think I advocated for the use of the 105 mm. I advocated for focusing mechanization on heavier artillery. That’s a suggestion I kind of expect some pushback on and am certainly willing to discuss the merits of. But it is not an advocation for the use of the American 105mm.

the 25-pounder is also going to be small enough to mount in place of the 75mm gun on the Victor.

Possibly. But that’s a totally separate issue. I was responding to the suggestion that the Rambuck with its 25 pounder in the turret would make a good SPG.

 

[MattII]

Very true. Though I am not sure how it relates to what I wrote. I don’t think I advocated for the use of the 105 mm. I advocated for focusing mechanization on heavier artillery. That’s a suggestion I kind of expect some pushback on and am certainly willing to discuss the merits of. But it is not an advocation for the use of the American 105mm.

I'm pointing out that a 25-pounder will be easier to manage in a turret than a heavier gun might be.

Possibly. But that’s a totally separate issue. I was responding to the suggestion that the Rambuck with its 25 pounder in the turret would make a good SPG.

Full traverse vs having to turn the vehicle is a big consideration.