The Forge of Weyland

Very much it's too early for the 17pdr, but I would think that when it goes go into development, the designers think to themselves:

"Hang on, we've already got a tank gun in this calibre, with AP, HE and Smoke already in production. Why don't we bore out this gun tube a tad and see what happens?"
 

Driftless

Donor
It's probably going to substantially change the 17 pdr as well. Who wants to bet that the 17pdr 76L50 morphs into the 20pdr 84L45 to make use of the existing shells?

Well, its a bit early for a 17pdr!
These two posts basically set the scene as far as Vickers is concerned for the next couple of years, but things are going to change from their current expectations. But they already have a good 3pdr and hopefully the new 18pdr, which are two of the best tank guns around in 1936. Of course, right now they haven't actually put a tank around them, but they are working on that :D
Oh yeah, to be sure, it's too soon for a quick path to the 17pdr, but having an early and logical, plausible path to a much more potent weapon would change minds on the battlefield. Even a practice battlefield on Salisbury Plain, or wherever tests and maneuvers would be run. Different capabilities put into devious and creative minds will likely contribute to a differing development track.
 
This picture is of a German SPG conversion of the Vickers Mk VI. This shows that a reasonable size support weapon was possible using the Vickers MkVI as a base vehicle

View attachment 606572
The picture below shows a MkVI converted to a prime mover/load carrier by the Germans and gives a further indication of the possibilities of development open to Carden.

View attachment 606574
This third German version is a dedicated ammunition carrier. View attachment 606577
So a complete light armoured family is practical. It may be a bit on the light side but is based on current production.
some of the neccesary conversions could done using older marks of the light tank that are now basically obsolete.
An early family of vehicles such as this?
 
Yeah i was intrigued by the 18 pounder when i was doing some tank research especially for infantry tanks and early war . Hell 18 pounder would be fine for most of the war wich is very rare even if its a rebored thing for that role . U might look into 25 pounder variants for a successor tank maybe to get the logisitics abit simpler then ?

And u didnt think of straight up doing the 6 pounder early instead and its HE round was a thing actually so you could atleast design the turrets for the a9/10-s to maybe take the gun as a mark 2 design maybe ? I mean eventually u can just switch guns and design the tank like that while throwing money and resources into 6 pounder ? It would also help with the rebored 6 pounder for ur infantry tank aswell maybe ?
 
The reason for not putting a 6pdr into a tank is that its barely 1936, and that's way too soon to be able to justify it. The 3pdr just finishing development is actually better than anything n Europe (they haven't realised what the Russians are doing). However Vickers are being just a little cunning here. There is little difference as far as turret design goes between the 6/18 pdr and the full-power 6pdr. So they will have a turret design that can easily take a much better hole-puncher when the time comes. If they can persuade the Army to have a common turret size on Cruiser and Infantry tanks (it's cheaper, don't ye know!) they are sorted for the next generation of guns. It will come to be needed at some point - if then they just have to say 'no worries, its just a few minor changes', they are sitting pretty for new tank and gun orders, anyone else has to design a new tank.
 
I meant design the turret so it can be upgraded into 6 pounder eventually ? Maybe ton or two weightier but gives a upgrade path to it maybe ? Like we were discussing upgrading the light tanks firepower before this post for the italian opponents. The idea would be that mark 2 of the current designs could be a 6 pounder variant.

And push resources into 6 pounders after u finish the 2 pounder and are doing the 3 pounder redesign. And as u mentioned the idea of 6 pounder and its variant being the goal for like in 1940 doesnt seem a super bad idea if ur following from u idea of a rebored 6 pounder anyway ?
 
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The tankette problem
19th January 1936, Mechanisation Committee, War Office



The committee hadn't originally intended to meet so early in the year, but the issues over Italy in Africa had meant an urgent response for the idea of getting armour reinforcements to Egypt had pushed things forward. They also had a report from Vickers about the ongoing design of future tanks to consider.

The most urgent issue was Egypt. As the tank men had pointed out before, while there were tanks available in the UK that could be redeployed, that was all there was - the Army wasn't well equipped. What made that problem worse was that many of the tanks were old, and while maintaining them in the UK, and making them available for training and exercises was one thing, sending them out to the desert and keeping them going there - with very little in the way of maintenance facilities - was a nightmare that would likely result in inoperable and immobile tanks scattered all over Western Egypt rather than a fast, deadly mobile force.

While that wasn't what the senior officers wanted to hear, the tank men were quite adamant about the problem. Certainly they could send them out as a deterrent, but it would be a paper force, and it would also severely limit training in the Home command. Their preference was one of the Vickers suggestions for modifying their light tanks. From a support point of view, this was much easier to handle. They already had support available, and they were familiar with operating them in various parts of the world. The light tanks available were far less worn out than their mediums, and Vickers were already building more for an existing order.

After considerable discussion, the committee decided on a course of action. Vickers would modify some of the Army's existing light tanks, and some of the new ones under construction, to take the COW gun. They'd looked at the issue of the space in the turret the new gun would need, and while not ideal it was felt to be adequate. This would have the advantage of being a fast modification. Vickers had also said that if they got the order now, they could build either a version of their Mk VI with a turret modified to take either the current 3pdr or the new 2pdr guns, or build some of their 6-ton tank with the same armament choices.

The armament decision came down, after some argument, on the existing 3pdr. This was available immediately, and the men were familiar with it. It would be better to use the first production run of the 2pdr to supply the infantry, who lacked any real defence against even light tanks. The Army had never ordered the 6-ton tank, but it had sold well abroad, and Vickers had noted in their report that issues raised initially by the Army had been solved or proven to be not critical. They could build 24 of these this year, again assuming a quick decision on the order. On paper, the tank men admitted this would be a better tank for the role envisaged, although it would mean supporting a different tank. Vickers had one available that they could use for familiarisation and training, which would help matters. Given the time constraints, they recommended to ask for immediate funding for 24 of these tanks, as well as money to do the conversions to the COW gun.

While no-one felt that this would actually solve the Italian problem, at least the failure of the diplomatic moves after the revelations before Christmas had made some sort of military reinforcement more acceptable to the Treasury. Fortunately it did seem that the difficulty of actually conquering Ethiopia - something the Foreign Office had assumed would be simple, a different view to that taken by some of the Army people who'd actually seen the country - meant that it was unlikely anything would threaten Egypt in the immediate future, and the French had made some noises about providing help, or at least making sure the Italians had to keep an eye on their own Western frontier. Still, getting some extra funding from the Treasury was never to be ignored. There was also the issue of improving the frontier defences, as well as infantry and air force reinforcements, but these were questions for a different meeting. What the tank men did point out - quite firmly- was that this proved the need for a new medium tank to be quite urgent.
 
Hmm compare to OTL how much effort did the Brits make on tanks when the Italians presence threaten Egypt at that time?
I only know the basics on those events.
 
They did respond in OTL by sending out some old light tanks.
But this is where the butterflies start spreading their wings. In OTL, the 1934 exercise showed tanks could be handled, so the threat wasn't seen as so dangerous. This time, the RTC is showing that in fact they are dangerous, so obviously a stronger reaction is indicated, and involves more - and better- tanks
 
"I'm not even sure if [light tanks] are ideal for that, a good heavy armoured car would seem just as suitable, except in very poor terrain."
Sounds vaguely AEC Armoured Car-esque.


Um, are there actual 300-400 hp engines available this early? My best guess would be maybe adapting another aircraft engine if you don't want to rip off Allan with his lion option ?
Rolls-Royce Kestrel aero engine – they looked at it the same time as the Merlin which became the Meteor in our timeline. The Kestrel generated 475 bhp on pool petrol, by comparison the Matilda II's engines generated around 200 bhp combined and the Panzer IV's roughly 300 bhp. The major hurdle is that they cost £2,000 each during the period the thread is set in and even switching from aluminium to steel parts won't reduce that massively.


The Kestrel did about 500 bhp on the speed-trial car conversion (that's un-supercharged), but that's going to be much better petrol than pool. Its not just the lower octane, you'd need to make changes to let it run on it. Some engines were happier with rubbish octane than others...
As I replied to Atrophied the Kestrel produced 475 bhp on pool petrol when Rolls-Royce looked at it alongside the Merlin during WWII. It's expensive but with that sort of performance a 'universal' tank that could avoid the cruiser/infantry split would be possible.
 

Driftless

Donor
Most of the storyline has centered on tracked vehicles so far. Are we to assume that wheeled armor, or even trucks are being designed and made at their historic path?

Or, just be patient weedhopper, all will be revealed at the appropriate time... :biggrin:
 
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It's expensive but with that sort of performance a 'universal' tank that could avoid the cruiser/infantry split would be possible.
You would need to change the dominant thinking of the time to achieve that. Liddel Hart theorised that tanks would be like warships, cruising the landscrape after a breakthrough had occurred. Treasury hated spending more than they thought necessary on tanks, which is why light tanks were preferred in the 1930s OTL. Suddenly they will need to spend more, much more and that would be impossible. The military leaders believed that tanks would be like cavalry horses.
 
Nice to see the Vickers 6-tonner/Mark E might actually see service with the nation of its birth.
I have in on the authority of David Fletcher MBE (praise his moustache!) that it was the superior tank to its contemporaries and the British Army was rather silly in not adopting it.
 
Nice to see the Vickers 6-tonner/Mark E might actually see service with the nation of its birth.
I have in on the authority of David Fletcher MBE (praise his moustache!) that it was the superior tank to its contemporaries and the British Army was rather silly in not adopting it.
 
Oh, it's by no means all about tanks! Just that the PoD was the EAF exercise, so while the results of that will work through into all sorts of areas - some of which might surprise you! - the tank changes are first up. You'll start seeing other effects soon, and then of course the butterflies start interacting with each other!
 
Sounds vaguely AEC Armoured Car-esque.



Rolls-Royce Kestrel aero engine – they looked at it the same time as the Merlin which became the Meteor in our timeline. The Kestrel generated 475 bhp on pool petrol, by comparison the Matilda II's engines generated around 200 bhp combined and the Panzer IV's roughly 300 bhp. The major hurdle is that they cost £2,000 each during the period the thread is set in and even switching from aluminium to steel parts won't reduce that massively.



As I replied to Atrophied the Kestrel produced 475 bhp on pool petrol when Rolls-Royce looked at it alongside the Merlin during WWII. It's expensive but with that sort of performance a 'universal' tank that could avoid the cruiser/infantry split would be possible.
The Kestrel is expensive - apparently RR was selling them for about £2,000. They can reduce this a bit, a tank engine doesn't need the same level of quality components, and they are looking at a production run that's very large by current aero engine standards. I haven't been able to find any costs for the other engines, but one source gave the Liberty as $17,000 dollars after WW1, which would imply a cost of over £3,000, and that was considered OK for a tank.
 
I haven't been able to find any costs for the other engines, but one source gave the Liberty as $17,000 dollars after WW1, which would imply a cost of over £3,000, and that was considered OK for a tank.
Oho? A third less would certainly be nice. IIRC Merritt-Brown had completed development of their eponymous gearbox by the mid-1930s, combine it with the Kestrel and an eventual move to Horstmann suspension and, once the track issues are dealt with, that's the mechanical side of things pretty much taken care of.
 
The Kestrel is expensive - apparently RR was selling them for about £2,000. They can reduce this a bit, a tank engine doesn't need the same level of quality components, and they are looking at a production run that's very large by current aero engine standards. I haven't been able to find any costs for the other engines, but one source gave the Liberty as $17,000 dollars after WW1, which would imply a cost of over £3,000, and that was considered OK for a tank.
That Kestrel price is clearly not a representative number. It appears to all be based on how much Rolls Royce charged Junkers for 10 Kestrels in the early 1930s, which comes out at £2,000 each. I would be amazed if RR, knowing any engine they sold would be torn apart for secrets, actually charged Junkers a fair price. Even if they did, a small one-off order can't be representative of the actual selling price to UK govt.

But as you say finding costs is hard, because accounting rules were (and are) odd, it's never clear exactly what is in any contract, aircraft get cheaper the more you make and the cost of a prototype often gets quoted as the unit cost, even though they are wildly different things.
 
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Driftless

Donor
That Kestrel price is clearly not a representative number. It appears to all be based on how much Rolls Royce charged Junkers for 10 Kestrels in the early 1930s, which comes out at £2,000 each. I would be amazed if RR, knowing any engine they sold would be torn apart for secrets, actually charged Junkers a fair price. Even if they did, a small one-off order can't be representative of the actual selling price to UK govt.

But as you say finding costs is hard, because accounting rules were (and are) odd, it's never clear exactly what is in any contract, aircraft get cheaper the more you make and the cost of a prototype often gets quoted as the unit cost, even though they are wildly different things.
Getting a true Cost of Goods Sold out of (or even inside) any business is a form of alchemy.... It's an endlessly moving target. In many cases, a good solid SWAG is the difference between a companies success and bankruptcy.
 
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