Sir John Valentine Carden survives.

That is not how I read what you and others have said. Disparaging remarks about needing them, about building them and so on. Why? Are you jealous that Australia dared to think and act for itself?
Dude, you seem to be taking this way to personally. Please calm down, it’s just a discussion about tanks.
 
Just three pages to read this morning, what's wrong guys?
Not going to get involved in the Australian tank debate...What if because Britain doesn't build thousands of (relatively) useless Covenanters then there are more Valiants available to be sent to equip the Australian Armoured Division? The Covenanters were only relatively useless because they couldn't be sent overseas with their cooling problems. One author remarked that having a really unreliable training tank is a useful means to training crews on how to fix things...not sure I wholeheartedly agree.
Specifically:
Whats the difference between TTL's Matilda I and 2? I know the 1 is a far more modern looking tank and has the 2lb pom-pom, I assume the Matilda II is as per OTL? Perhaps that could replace the 1 in the Pom-pom tank role?
The Vulcan Foundry A12, Matilda II is unchanged from OTL. The Vickers designed A11, Matilda I, is as you say improved over OTL. Unlikely that the Vickers pompom will appear in any other tank, I've mentioned that the Director of Artillery Clarke, is deeply opposed to such a thing. The Close Support Matilda II however is likely to be a thing.
A few things to note, given allanpcameron’s recent post. The tanks of the 4th RTR, went to France via Cherbourg probably from Southampton, and would have been craned on and off their transport. This was up until the development of the LCT/LST, much later in the war the only way of shipping tanks overseas.
Not getting into LCT/LST. That'll develop as OTL.
The problem of ARP Air Raid Precautions, at the beginning of the war were legion, and took time to sort out. If you want to see what was the eventually solution, watch the film, Millions Like Us, the scenes of an air raid on a war time factory, were filmed at the Castle Bromwich aircraft shadow factory, which was managed by Vickers at the time of filming. And the worries about machine tools was unfounded, you could blow the roof off and the walls out of a factory, which happened, but it was very hard to damage the machine tools.
Yes, but, worth asking the question in 1939. Especially as Metro-Cammell in OTL was badly damaged which affected the A17 Tetrarch production. I don't want it to affect Valiant production.
As for events in North Africa and the Far East, I think it’s a bit early to speculate, but for what it’s worth here’s my two bobs worth. Benito will get his nose in to the events in France, there were bits of France he wanted to add to Italy. If the British get a bit luckier than they did, they will by the time the Germans intervene be in Tripoli, and the Germans will divert to French North Africa, and take up position on the French Marethi defence line.
RR.
Hmmm, not sure I agree, but we'll see how it goes.
That assumes the German advance up until that point even plays out the same. The addition of 120-odd extra cruiser tanks and 60+ extra infantry tanks, all more reliable and in the latter case much better armed too could easily mean that the whole battle plays out differently.
There is a driver with the extra tanks to bring the 1st Armoured Division to France earlier and a wee bit better prepared. But simply the presence of more/better tanks isn't in itself enough to 'easily mean that the whole battle plays out differently.'
Hm, looking at it, some of the LCTs used Lion petrol engines. I wonder if Carden will ask for a design for a landing tank capable of shifting larger loads than the current ones, in anticipation of the follow-on vehicle to the Valiant.
I would say highly unlikely, we are more likely to see a desire more more Scammell tank transporters first.
At this rate we’ll be on thread 2 before we even get to the battle of France.
Jings, josie, help ma boab!
That is not how I read what you and others have said. Disparaging remarks about needing them, about building them and so on. Why? Are you jealous that Australia dared to think and act for itself?
Not getting involved in the Aussie tank debate, but I have a very high opinion of Australia's contribution to WW2, and hopefully that will come across in this TimeLine.

Again, thanks everyone.
Allan
 
Australia had no tanks, apart from a few light ones. The Sentinel was the be all and end all as far as the Australian Army was concerned. I am unsure why people are so anti-Sentinel. It was a tank with faults but then all tanks had faults and all tanks continue to have faults. Nothing is perfect, not the M3 Stuart, the M3 Lee/Grant, the M4 Sherman. I keep pointing out that the Sentinel was intended to fight the Germans, not the Japanese. The Japanese just were an inconvenience.
I think what people forget is that when the Sentinel project was started there was no mass production of tanks in the USA and the fact that Chrysler (to provide the best example) and US tank production in general would be spamming out M3 Lees and then M4 Sherman's at such a rate along with lend lease etc was not then known and could not be then know.

And the US entry into WW2 was also not known

And this at a time when the Australians who would otherwise have 'happily' relied on British tank production realised that with the fall of France and the North African campaign that the UK source of equipment was going to be flaky for some years to come.

For me as a dabbler in project management, the Sentinel project is an understandable decision made at the time, considering when it was made and had WW2 gone differently those Chullora built AFVs could well have been vital by 1943 and built in much larger numbers.

And what they built was very impressive considering it was from a standing start - I was always interested in the idea of a 25 pounder armed infantry support tank and the AC4 seems to have been that tank

I do feel though that perhaps they could have gone the Valentine route that Canada did and this might have enabled them to better leverage the existing industry and produce a working AFV much earlier (and usefully earlier) but again that is with my hindsight tinted flying google on

Nah for me the Sentinel makes sense

But that armoured bow machine gun - gets me every time - can every one just take a moment to admire it - I am almost 100% convinced it was designed with psychological warfare in mind

Sentinel bow machine gun.jpg
 
It is mentioned by Fletcher in one of his books (Towards a Universal Tank?). It is widely known downunder and in the UK amongst armoured circles. I can dig out the references if you want. The Sentinel III with twin 25Pdr was a real thing and it's trial contributed substantially to the Firefly's development.

Edit: I see someone already has. Well done.
I am very aware of the Sentinel and the subsequent trials with twin 25 pounder (which looks absolutely amazing) and planned installation of a single 25 pounder (with 120 rounds!)

What I was not aware of was the link between those trials and the actual installation of a 17 pounder and the Firefly development

Happy to have been learned.
 
Dude, you seem to be taking this way to personally. Please calm down, it’s just a discussion about tanks.
Mate, I would suggest it is the other people who appear upset by the mere suggestion that someone, somewhere, like Australia would dare to build a tank that wasn't British or American in origin. They are taking it all far too seriously.
 
Mate, I would suggest it is the other people who appear upset by the mere suggestion that someone, somewhere, like Australia would dare to build a tank that wasn't British or American in origin. They are taking it all far too seriously.
Nope. You’re the one who seems far too emotionally involved in this. Others have questioned the decision and there is definitely a debate to be had, but you are the only person who seems to see this as an emotional thing.
Again, it’s a discussion about tanks from a war 80 years ago. Should be easy to be dispassionate about it.
 
Nope. You’re the one who seems far too emotionally involved in this. Others have questioned the decision and there is definitely a debate to be had, but you are the only person who seems to see this as an emotional thing.
Again, it’s a discussion about tanks from a war 80 years ago. Should be easy to be dispassionate about it.
What is your definition of "dispassionate"? I am dispassionate. I have been rebutting the bullshit from the other posters, nothing more. It seems I have upset you. I wonder why? Yes, it was 80 years ago. Yes it was by a small nation at the art's end of the earth. My country.
 
There is a driver with the extra tanks to bring the 1st Armoured Division to France earlier and a wee bit better prepared. But simply the presence of more/better tanks isn't in itself enough to 'easily mean that the whole battle plays out differently.'
Depends on their deployments. It's not impossible that adding and extra RTR will mean the Germans (particularly in the south) run into the Matildas a few days earlier than OTL, which might slow them down and make them more cautious. That is, or course, entirely at your discretion though.

I would say highly unlikely, we are more likely to see a desire more more Scammell tank transporters first.
That will also help, particularly in North Africa, where, no matter how reliable the tracks, they'll eventually wear out of those miles-long runs.

I think what people forget is that when the Sentinel project was started there was no mass production of tanks in the USA and the fact that Chrysler (to provide the best example) and US tank production in general would be spamming out M3 Lees and then M4 Sherman's at such a rate along with lend lease etc was not then known and could not be then know.
Indeed. I've never (as I recall, I'm not going to check back through pages of debate to check) denied that the reasons the Sentinel project was started were entirely logical.

Of course, Sentinel might have been a technical marvel, especially for a nation like Australia, the ability of its crews to operate it is a little more questionable:
 
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Couple of questions.

To the engine people out there. Could Perkins make any improvements to the Lion in terms of power output etc? They're already going to have to make changes to it for mass production so in the process could it be improved?

The 6pdr, does anyone know when it was ready to enter production? As far as I can see OTL it was delayed by either the post Dunkirk invasion and or the fact that no carriage was ready until 41.
If it was ready to enter production in late 39 or early 40 (which would make sense if production was being set up to start mid 40 but Dunkirk delayed it) then in all likelyhood there were pre production models etc around in latish 39 so around now in story TL.
 
During the whole "Sentinel Affair", it was mentioned that Australia would have been better off building Armoured Cars. Putting aside that, I took a look at what ACs were around for British/Commonwealth, and why?

Why did they build so many different types, many of which seem to be rather similar to each other?
 
During the whole "Sentinel Affair", it was mentioned that Australia would have been better off building Armoured Cars. Putting aside that, I took a look at what ACs were around for British/Commonwealth, and why?

Why did they build so many different types, many of which seem to be rather similar to each other?
What they went for was speed of production , a lot are using what ever parts the manufacturer could get hold of easiest and/or adapting an existing chassis. So Indian built designs are different to Canadian built mainly due to what they could source locally. A couple at least are the the same or slightly modified shells fitted to different base chassis ( Guy and Humber armored cars for example. )
 
To the engine people out there. Could Perkins make any improvements to the Lion in terms of power output etc? They're already going to have to make changes to it for mass production so in the process could it be improved?
It already checked many of the boxes for what a powerful engine needed,shaft driven, dual overhead cams for good breathing, and in Aero form, was able to run at high RPM for the Trophy runs.

The easiest way to add more power to an engine is more displacement, bigger cylinders by more stroke or bore diameter, or number of cylinders.

Napier during initial development considered making the Lion a W18, but went with a W12 over crankshaft reliability over vibration.

Balancing the reciprocating bits of an engine was almost more Art than Science at this point, with static balance well understood, but not dynamic, that lead to duds like the Sunbeam Arab.
Balancing was really well understood til the mid 1920s

But the Lion wasn't one of these dud. Napier got things right.

The next way to get more power, was to raise compression, that when designed, the Lion was at 5.8:1, high, given the fuel quality at the time, and then increasing RPMs, that magnifies any weak spots in the design. Regular Lions operated at 2200 rpm

Napier wanted an aluminum monobloc with steel liners, but manufacturing was not up to that in 1918, so each cylinder was welded from 28 pieces.
Cylinders and heads had independent cooling passages, so no coolant going thru the head gaskets.


By the late 1920s, casting technology had moved on the where individual built-up cylinders was necessary, enough accuracy could be done for a entire block to be cast,
and that's why things moved past the Lion, they were cheaper to make , while not leaking

For the racing Naiper Lions for the Schneider Trophy, they were built from Magnesium and reduced stroke for reduced cross-sectional area
ran at 3300 rpm with 10:1 compression, using the new Tetra-ethyl Lead on the best Romanian fuel stock in 1925
898HP 1.06 pounds per horsepower. Naturally Aspirated.
That's the next way to make more power, extra boost at sea level
Supercharging. The Lion VIID
6:1 compression 3600 rpm with 1320 HP These used integral intake manifolds with the heads.
The racing Lion development
WWPD?

So What Would Perkins Do?, given what had been done for limited production models?

These had been real labor intensive engines to build, so that would have to change, using monobloc cylinders
Then the improved heads. At this point, a W18 engine would be reliable, without needing high rpms to make good power


However, if they keep individual jugs, they could revert to aircooled, with WWII improvements in putting more, thinner fins to aid in cooling.
Above is the Continental AVD-1790 V-12
Aircooled Diesel


though an aircooled 'W' engine would look like this
 
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