"Christie suspension, Bofors guns and licnesing" Topic

Just a general meandering thought or two…

Reading the Finnish lists in Ostfront, I see that they "can have" 40mm Bofors guns. It says to use the US model for that. I guess the 8th Army would look silly in ths snow with the gunners wearing shorts.
I know this is a Swedish design. Obviously, it is going to be difficult for Britain and the USA to get them from Sweden, not so hard for Finland.
Were there factories in the US and Britain producing them, under license? Were royalties paid to Bofors?

The famous "Christie suspension".
What is it, exactly? Any pictures?
I have read that the Soviets paid for the right to produce tanks with this suspension. Which tanks used it?
Did any American tanks use it?
How scrupulous were the Soviets in paying royalties, if such were owed?

As some may have noticed, I like to get into such questions like this. Like how did prisoner exchanges worked in the Civil War, without recognizing the Confederacy. Like the legal justification for D-Day. Things like that.

In the current climate, *any* answers might tend to result in harsh penalties, so I decline to provide any.

Allen

Like the legal justification for D-Day

Same as the justification for any other invasion, surely? "I have a million soldiers and a load of tanks, and I'm not afraid to use them".

link

Better than nothing; looks like the British version was derived from Polish versions, then modified. US ones look like they were also based on the British versions (although not identical). As for royalties, according to that article, no initially, no. .

Walter Christie was an American tank designer. He sold two prototypes (one of which can be seen at the Aberdeen Ordnance Museum). He sold one to the US and one to the USSR. The US decided to persue a differnt philosophy in tanks. The Reds developed the BT seeries and ultimately the T-34 from the Christie model. They bought the rights when they bought the tank.

Also, the Russians have since tried to claim royalties for the many AK-family of assault rifles. The one big hitch is that the trigger mechanism is a direct copy of the M1-Garand and the gas reciprocation system was copied, also directly, from the German 1944 assault gun.

As a rule, however, the Soviets paid royalties, in rubles to a Moscow account. As the ruble was never fully convertable, you had to go to the USSR to access and spend your royalties. (American humorist Art Buchwald – whose columns were printed as straight news in the Soviet press – amassed a small fortune in Soviet Rubles.)

Having been a fan of Art, I bet he enjoyed the irony, if not the rubles.

The Sweded produced the Bofors for export, with Holland, Poland and other countries as buyers. The Russians got hold of one and used it as the basis for their 37mm AA gun (basis = direct copy, in this case). No royalties were paid.

The Brits were also buyers, with the Army getting it first. When the Royal Navy asked Bofors for a deal, they were told that all production was being taken by the British Army.

When the US wanted the gun, they bought the rights to produce it from Bofors and set up their own production. I'm not sure of the exact business arrangement agreed to.

While I am not sure of the arrangements back in WW II the US now has a policy that if a foreign made product is selected for military use and the product is highly unique and not easily replaced that the foreign company must set-up a factory in the US. This is to prevent the US finding themselves with equipment that they cannot get spare parts for and/or make more of in case a disruption occured at the country of origin.

Everything from foreign designed pistols to helicopters that have been awarded US military procurement contracts have had to build full-up factories here in the US.

The BT series for sure but I think the suspension was the inspiration for the T-34's suspension as well.

Bofors 40mm : link

Christie suspension : link

Hi

In the case of 20mm cannon, the british and french airborne twenties as well as the US 20 were licenced from various subsidieraries owned by Krupp, The madsen, oerlikon, Hispano guns. And the allies payed royaldies all through the war to a swiss bank account owned by the germans.

R

In ita earliest form Christie suspension was convertable, in that the tank could run on the road without tracks around the wheels. Here are some pics

link

link

my favorite:

picture

but ya gotta love these shots:

englishrussia.com/?p=1015

There was a famous example during WW1 where the British tested a number of different MGs for the first Tanks.

Far and away the best was a Danish gun. They tried to buy the rights, but were stymied by some problems with the Turks wanting to buy it too. In the end the British did without, the Turks bought them, and lo and behold German units started turning up with them as well.

And why did we not just COPY the MG34/42 or the Panther? Hell, the panther was just a T-34 Knock-off anyway.

'Kill Germans. Yes indeed. Bomb them flat. Burn their kids alive in their homes. But infringe a PATENT? What sort of barbarian ARE you?'

Pat

Walter Christie was also famously an evil-minded . The books all try different ways of saying this. Irrascible. Famously Irrascible. Touchy. Odd. Eccentrically Touchy.

I often thought the Dawghouse should have a Walter Christie Memorial Wing, next to the Reinhard Heydrich Children's playground.

Pat

"And why did we not just COPY the MG34/42'

We (the US) tried to copy the MG42, but the draftsman who made up the blue prints got a number wrong, so the thing didn't work, so they gave up.

I'm sure the 'not designed here' mentality must have come into it as well.

Why copy the MG42 when you have the Browning .50?

> Why copy the MG42 when you have the Browning .50?

Perhaps you'd like something that you can pick up …

Not only did he design his famous suspension, but J. Walter Christie was also one of the early (perhaps the first?) to be a strong proponent of purposely angling a tank's armour plating to increase its effective thickness.

Had J. Walter not been such an, er, difficult person to deal with, it's likely the US military would have spent more time and energy studying his design ideas, and maybe, just maybe, the US would have entered WWII with better tanks than the M2 Medium Tank. True, the M2 Medium did lead to the M3 Lee which lead to the M4 Sherman, but I can't help thinking we could have been further along than that.

The US Army did build a few different prototypes based (to varying degrees) on Christie concepts. None were accepted into mass production. The T1 Combat Car was a modified Christie T3, as was the M1931 Medium Tank T3, and T3E1. The T3E2 and T3E3 played around with the design. (Maybe 20 total built of all the T3 variants). The Medium Tanks T4 and T4E1 (at least 16 built) and Combat Cars T4, T4E1, and T4E2 strayed further from Christie's original design. Then we get the Combat Cars T2 and T2E1 which went even further afield. After that, the whole Christie layout was dropped and we start to see designs that look like early prototypes of the M3 Stuart Light Tanks.

Meanwhile, the Soviet BT-1 was an almost exact copy of the Christie T3, and as all wargamers know, the T-34 was evolved from the BT series.

Kill… Yes indeed… But infringe a PATENT? What sort of barbarian ARE you?'

Back in 1995 at the July 4th WWII reenactment at Fort Knox I noticed that the German truck they were using had a shiny blue and white oval Ford emblem on each side. It looked odd standing out against the camo paint and so I asked if this was how they looked on actual German trucks during the war. The reply was, "yes, this is an actual truck produced by the Germans during the war. Even with the war going on they honored the license agreement by including the emblem and they kept track of the numbers produced for later payment."

Regarding the Christie bloodline wich lead to the T34. Could the Panther then be a Christie suspension too?

And the allies payed royaldies all through the war to a swiss bank account owned by the germans.

Even with the war going on they honored the license agreement by including the emblem and they kept track of the numbers produced for later payment</q?

Thanks. That is just what I was looking for.

The Christie suspension was basically a series of horizontal springs inside the hull of the tank linked to an arm that could take quite a lot of punishment. The drawback was that they took up a lot of internal space and that the springs or the arms could break off.

The Panther used torsion suspension, basically you mount a steel bar on one side of the vehicle and hook up the wheel at the other end through an arm. The effect is a bit like wringing a towel. The torsion suspension is also very strong, while being mechanically simple.

The interleaved wheels were designed to spread the weight of the tank over a larger surface with more contact points with the ground, resulting in less surface pressure overall.

The Soviets realised that the torsion suspension was much better than the Christie model, but they never adopted it because they feared it would disrupt production. Most post-war Soviet tanks used torsion or other systems.

And why did we not just COPY the MG34/42 or the Panther? Hell, the panther was just a T-34 Knock-off anyway.

There were two tanks designed as an answer to the T34.

One was in essence a german copy of the T34 (sloped armour, christie suspension, 75mm gun) with petrol engine as their logistics weren't set up for diesel etc… simple, effective and fast to produce. Just what the army wanted and had specifically asked for.

The other was the Panther.

The He177 Grief, a four engine, two propellor bomber (I'm not kidding each propellor was driven by two engines) was nicknamed 'the flying panther'. It was not a compliment. It was a reflection on it's habit of catching fire in flight.

Back to the Christie suspension, the T34 was about the heaviest tank it could be applied to. I think (think) the Crusader had a christie suspension.

Mind you, the Germans never really got the hang of the Christie suspension. One model of the PzII had it (the D or E model) and wound up with a woeful cross country performance and was withdrawn and converted to flame tanks.

Many questions can be resolved by looking in books.

Many questions can be resolved by looking in books.

And sometimes you get peculiar answers. I remember one of Stephen Ambrose's more egregious clangers when he referred to "the American-designed T-34". I admit I don't remember which book it was; I've expunged most of Ambrose from my memory.

LT

"And sometimes you get peculiar answers."

Which makes TMP answers better… how?

On this thread so far, there are some accurate answers, and others which are… less informed. How is the poor (and presumably uninformed himself, else he wouldn't be asking) questioner to know which posters are the Stephen Ambroses?

Well, the US did pay Mauser to license the action of the Gew98 and turn it into the '03 Springfield, so occasionally the bills DO get paid. What I've read about the Christie suspension agrees with what others have said – when the Russians bought the model, they bought the rights to copy the suspension along with it.

The AK-47, by the way, is emphatically not a copy of the STG44. In fact, the Germans copied gas reciprocating systems from the Russians, not the other way 'round. Also, we DID copy the MG42 – it's the M60. The funny thing is that when the Germans wanted to copy it for the MG3 in NATO 7.62x51, they had to borrow one from a museum – the original engineering drawings were gone.

Doug

The British also used a derivitive of the Christie suspension in their Cruiser tanks – A13 onwards. Anyone want to swap their Sherman for a Crusader?

Personally I remember one logistics staff meeting right after the Tehran Embassey seizure when the Commanding Officer of Air Force Logistics Command authorized all Iranian AF assets to be considered as USAF property. But the item managers had to keep track of whatever was they used for future improvement in foreign relations – fat chance.

Right around the same time one of my technical equipment specialists for F-111 airframe items had a very large-narrow carton box at his desk. It was a set of covers to seal off where the Panavia Tornado's swing wings cranked back against the fusellage during full sweep. Panavia wanted to know how they work for our F-111's so they sent a sample set.

My equipment expert said they were in every way, especially cost, absolutely superior to what General Dynamics or "GD -we usually said the obscenity when dealing with this contractor" sold us in the first place.

Earl's answer was "NIH equals NWIH," or "Not Invented Here = No Way In Hell."

"Anyone want to swap their Sherman for a Crusader?"

A Crusader, no. A Comet, certainly!

"And sometimes you get peculiar answers."

Which makes TMP answers better… how?

On this thread so far, there are some accurate answers, and others which are… less informed. How is the poor (and presumably uninformed himself, else he wouldn't be asking) questioner to know which posters are the Stephen Ambroses?

I did at least provide a source for my uninformed ramblings. Readers are invited to follow the trail.

In the spirit of your reply, perhaps you'd like to suggest some books?

Christie vs torsion bar susspension:

If I understand it correctly, both Christie suspension and torsion bar suspension are similar in that both are based on metal bars that are bent in the shape of a crank. Picture a metal bar running horizontally across the bottom of the tank from one side to the other, and then out of one side of the tank. Just after exiting the side of the tank the bar takes a right hand turn towards the back of the tank and then after about a foot or so it takes another right hand turn to extend again outwards away from the side of the tank. The wheel is attached to this last part. So the wheel moves up or down by 'turning' this 'crank.'

With Christie suspension the turning of the crank, and this the upwards or downwards motion of the wheel, is resisted by a vertical spring that is attached to the crank near the wheel. With torsion bar suspension the far end of the bar, the end on the side of the tank opposite of the wheel, is fixed so it can't turn. So in order for the crank to turn at the wheel's end the bar has to twist. This twisting, or torsion, acts as the spring.

I think many post war vehicles use a combination of these two methods.

On the Panther the torsion bars at the front took the most punishment, so a worn out tank can bee seen to be tipped downward at the front. Internal fires would weaken the torsion bars, so many burnt Panthers appear to have settled on their suspension ultil the botton of the tank is resting on the ground.

I hope this aint one of the less informed answeres :-)