Best tank engines of WWII

[J.A.W.]

Does that article you're referring to describe the mechanism for this? In "normal" circumstances one of the features that makes diesel (relatively) safe is that it's so non-volatile that the fuel vapors in the tank saturate to a point below the lower flammability level (which AFAIU is usually considered to be the same as the lower explosive level as well). To reach above the LFL the fuel would either need to be heated quite considerably, or then somehow the explosive charge exploding inside the tank vaporizes fuel and pressurizes the tank to the point a detonation occurs before the tank otherwise bursts?

As an aside, from the perspective of crew survivability I'm not sure this is much of a point against diesel. If a 76+mm shell explodes inside a petrol tank in the crew compartment, if the blast or shrapnel doesn't kill the crew, the explosion spraying and then igniting the petrol from the fuel tank all inside the crew compartment would presumably incinerate the crew.. In both cases it seems the solution is to, well, not put fuel tanks inside the crew compartment.

Trouble is, that combined effect (diesel being considerably more energy dense than gas/petrol) would likely cause a total wreck/fatalities
wherever the fuel tank is located, rather than a 'brew-up' burn - which may allow crew escape from the hatches, & recovery of the vehicle,
speaking of which - a petrol fire burn out is unlikely to damage the heavy armour, but the extra heat from the diesel may ruin its temper.

 

[bf109xxl]

Does that article you're referring to describe the mechanism for this? In "normal" circumstances one of the features that makes diesel (relatively) safe is that it's so non-volatile that the fuel vapors in the tank saturate to a point below the lower flammability level (which AFAIU is usually considered to be the same as the lower explosive level as well). To reach above the LFL the fuel would either need to be heated quite considerably, or then somehow the explosive charge exploding inside the tank vaporizes fuel and pressurizes the tank to the point a detonation occurs before the tank otherwise bursts?

As an aside, from the perspective of crew survivability I'm not sure this is much of a point against diesel. If a 76+mm shell explodes inside a petrol tank in the crew compartment, if the blast or shrapnel doesn't kill the crew, the explosion spraying and then igniting the petrol from the fuel tank all inside the crew compartment would presumably incinerate the crew..

It was just a military report by military engineers - no in-depth investigations of the mechanism of fuel detonation. They just observed combat vehicles destroyed by APHE hit into the petrol tank with no traces of fire within the hull or the turret. Diesel is less volatile, but may be more prone to detonation under very high pressure due to a high quote of molecules with linear structure (just hypothesis, not proved). The charge exploded INSIDE THE FUEL TANK - it was clearly indicated, no shrapnel, etc. My guess is that the shaking and heat from the engine creates enough vapor pressure inside a nearly empty fuel tank. The enhancement depends on the HE amount - the large the caliber the higher the amplification. The 76(75)mm was the smallest caliber whose penetration had an effect.

In both cases it seems the solution is to, well, not put fuel tanks inside the crew compartment.

Yes, of course. But that was the main problem with the clumsy Soviet system: even though they realized the causes of the problems, they did not change anything to prevent a decline in armaments production. The Soviets tended to compensate the lack of quality with quantity (in the vast majority of cases). The reasons were relatively low technological level as well as low mean educational level of the decision-making CPSU leadership.

 

[WARSPITER]

Ford GAA V8.

May 1940 - Henry Ford announces a plan to produce 1000 planes a day. June 1940 saw the first work on a 12 cylinder for the 1000 plane idea.

August 1941 - Ford is asked by the US government to produce whole tanks. The army and Navy had both declined the aircraft idea as the navy
wanted radials and the army already had Allison powered planes.

Development of the engine continued anyway and the new design was basically ready for testing in July 1941. It featured a single piece crankcase
and block which was light and at the same time had good strength. The 32 valve DOHC system gave the engine good power output .

Power requirements for the newer tanks lead to Ford designers cutting four cylinders leaving a V8 of 1100 cubic inches, the largest V8 petrol
engine ever made.

At the time of the preliminary design of the new M4 auto makers were asked to inspect the plans and give their thoughts. Ford designers came up
with a better final drive housing as well as a new method of water cooled dies for armour plate manufacture which replaced the two hour water spray
cooling (to prevent warpage) - the water cooled dies cut the cooling time to eight minutes.

Although Ford had produced M4's and M10's their other commitments plus Fisher and Chryslers capacity meant Ford no longer needed to produce
whole vehicles. Ford was the able to concentrate the resources they had on the GAA engines and the production of armour plate for the M4 series.
Production of the GAA was just under 27,000.

The engine itself produced decent torque and was easy to maintain which soon made it the standard petrol engine for the M4's.

 

[EwenS]

I would hardly say that the Ford GAA engined M4 became the "standard petrol engine" version.

After Ford's production run in 1942/43, production elsewhere restarted in Feb 1944 and ran to June 1945 with just over 10,000 built, of which some 3,000 were the support tank 105mm gunned version.

Meanwhile Wright radial engined M4/M4A1 production rolled through to July 1945, with over 5,000 of tge later versions built 1944/45 (1,600 105mm gunned versions) most of which were for the US Army. Diesel engined M4A2 production mostly for the USSR rolled through from Nov 1943 to May 1945 with over 3,900 built of the later 47 degree hulled versions.

Right through to the end of WW2, US Army units were using a mix of M4/M4A1/M4A3 often in the same units. Only Post war was the US Army able to standardise on the M4A3 powered by the Ford engine.

 

[Shortround6]

By Feb 1953 the Continental and Ford engines were the only ones listed in the M4 tanks (with 3 different guns). No numbers in service of any of the types listed.

 

[WARSPITER]

I didn't say when they became standard though, just soon. The diesel version was of course the standard diesel but the GAA
became the standard petrol version.

Others in smaller numbers became the non standard ones.

 

[EwenS]

The original 1,690 Ford 1942/43 built M4A3s were retained in the US for training purposes. Some were remanufactured in 1944/45 and issued to units in Europe late war. The first of the later versions didn't show up on the battlefield until Aug 1944, and then as replacements due to tank losses in Normandy.

The US Army standardised its front line units on the radial engined M4/M4A1 with the 75mm gun from 1942 until after Normandy.

Numbers of the Chrysler petrol engined M4A4 and diesel engined M4A2 were used in the USA for training. While new M4A4 production stopped in Sept 1943, those tanks still in the USA were remanufactured and supplied to Britain in 1944 under Lend Lease (Over 1,600 M4A4 Sherman V received that year). The recall of these vehicles began in mid-1943 e.g. 100 of 232 held by 7th Armd Div were noted as in transit back to the Detroit Tank Arsenal at the end of June 1943. Ultimately, 250 of that version, IIRC, went to the French in 1943, with almost all the rest ending up in British hands between 1942 & 1945.

Any 76mm or 105mm M4 variants listed in Feb 1943 would be prototypes. The first production 76mm gunned versions were produced in Jan 1944 (M4A1), March (M4A3) & May (M4A2) with 105mm gunned M4 versions in Feb 1944 (M4) and May (M4A3).

 

[Shortround6]

Sorry gentlemen, typo and fail to proof read strikes again.
Correct date is Feb 1953.

As far as diesels go very few vehicles in the Army and Air force were diesel powered at this time. The M36B2 is one of the few that I can find, most or all of the Diesel powered M4 chassis had disappeared.

 

[EwenS]

Sorry gentlemen, typo and fail to proof read strikes again.
Correct date is Feb 1953.

As far as diesels go very few vehicles in the Army and Air force were diesel powered at this time. The M36B2 is one of the few that I can find, most or all of the Diesel powered M4 chassis had disappeared.

Makes more sense.

In Sept 1945 there were some 837 diesel powered M4A2(76) left in the US undelivered to the USSR before Lend Lease ended. About 300 were sold to Canada in 1946. The remainder were stripped of suspension components, turrets etc. These components were used to bring earlier production M4A3(75)W up to the latest M4A3(76)HVSS standard in the late 1940s/early 1950s.

 

[special ed]

A bit of trivia - The Chrysler tank plant New Orleans is now the Michoud space facility building boosters.

 

[Elvis]

6-71 (2)

 

[PStickney]

The original early models of the T-34 had 2x fuel tanks (out of either 4 or 6 tanks total) in the crew compartment - this may have contributed to the vulnerability/fire problem. In the later models the 2x crew compartment fuel tanks were either moved to the engine compartment, or removed from the tank entirely.

One problem with diesel fuel, at least in colder climates, is that it can be problematic as far as starting and fuel 'gelling' - ie the fuel becomes too thick to flow well enough to reach the engine reliably. The Soviet Army figured out ways of dealing with the gelling problem - in the T-34 it was primarily through cutting the fuel in the engine feed tank (under normal circumstances the engine was always fed from the RH forward engine compartment tank) with a mixture of petrol and diesel, and/or running the engine periodically to keep the engine compartment fuel tanks warm. (The previous is from my translation from an original T-34 manual, so if I am off a bit on the details I apologize).

The British/Commonwealth used diesel engines in the Valentine tank (except some of the early-production) until the end of production. I think they also received most of the diesel powered M3A3 Lee/Grant and M4A2 Sherman tanks. As far as I have read they did not seem to have any particular problems with them in Europe. If anyone has any information about diesel engine related problems in the ETO I would be interested.

The USMC also used some diesel powered M4A2 Sherman tanks (I am not sure what models of the M3 Lee), as they did not have the problem of access to diesel fuel that the Army had (many of the landing craft and ship's boats used diesel engines) or gelling in the warm climates they fought in.

The Soviets received the lion's share of the Canadian made diesel powered Valentines and - aside from the small gun - quite liked them. I am not sure what models of the M3 Lee the Soviets received, but I know the diesel powered M4A2 was the majority of the Shermans they received.

Incidentally, the gelling problem is still a problem today, though not as much as in WWII for military applications (primarily due to having learned from past experience, but also helped by modern additives).

Uhm, most U.S. Tank Destroyers - M10s, and most M36s had Diesels. So did most of the Engineer's Construction Equipment, and a fair number of the Heavy Line-Haul trucks (The backbone of Logistics. Getting fuel in the U.S. Army wasn't much of an issue.
A big drawback to Diesels in Armored Vehicles was weight. A Ford GAA or a Meteor weighed in at around 500 KG. The Twin GM 6-71s on an M4A2 massed about 2300 kg.
It wasn't until the late 1950s that the Power-to-Weight of a Diesel got to the point where they made sense.

 

[J.A.W.]

Uhm, most U.S. Tank Destroyers - M10s, and most M36s had Diesels. So did most of the Engineer's Construction Equipment, and a fair number of the Heavy Line-Haul trucks (The backbone of Logistics. Getting fuel in the U.S. Army wasn't much of an issue.
A big drawback to Diesels in Armored Vehicles was weight. A Ford GAA or a Meteor weighed in at around 500 KG. The Twin GM 6-71s on an M4A2 massed about 2300 kg.
It wasn't until the late 1950s that the Power-to-Weight of a Diesel got to the point where they made sense.

Maybe a bit earlier, check out the USN's Nasty Class fast patrol boats, a Norge-boat powered by Napier mills, so much for N.I.H!

Homepage of PTF-Nasty Class Boats

 

[PStickney]

Maybe a bit earlier, check out the USN's Nasty Class fast patrol boats, a Norge-boat powered by Napier mills, so much for N.I.H!

Homepage of PTF-Nasty Class Boats

Uhm, First, Boats Don't Count. Second, the Nastys were late '50s, Early 60s. Some showed up in the Gulf of Tonkin for Market Time.
Third - the German S-Boots (E-Boats if you read War Comics) were Diesel powered.

 

[PStickney]

Sorry gentlemen, typo and fail to proof read strikes again.
Correct date is Feb 1953.

As far as diesels go very few vehicles in the Army and Air force were diesel powered at this time. The M36B2 is one of the few that I can find, most or all of the Diesel powered M4 chassis had disappeared.

All M10 Tank Destroyers. Almost all of the Earthmoving Equipment used by the Engineers, The larger linehaul truck tractors, and most of the Tank Transporters.
Oddly enough, the LVTs (Landing Vehicle, Tracked) were gasoline fueled.

 

[Elvis]

Maybe a bit earlier, check out the USN's Nasty Class fast patrol boats, a Norge-boat powered by Napier mills, so much for N.I.H!

Homepage of PTF-Nasty Class Boats

Napier Deltic engines.
That's one weird lay-out when you first see a cross-section of that engine.
...and yes, you're not imagining it, there's a crankshaft in each corner!

...animation of engine in action...

File:Napier Deltic Animation.gif - Wikimedia Commons

commons.wikimedia.org

 

[Elvis]

...skip...

 

[J.A.W.]

Uhm, First, Boats Don't Count. Second, the Nastys were late '50s, Early 60s. Some showed up in the Gulf of Tonkin for Market Time.
Third - the German S-Boots (E-Boats if you read War Comics) were Diesel powered.

Did you check the site, weight was an important factor, speed in a planing hull particularly.
& the German diesels in a surrender E-boat were replaced by the Napier for trials, as it happens.

GM Detroit 2-strokes pumping/roosting & thunderous/ominously.


View: https://www.youtube.com/watch?v=wqntIr2cKk4

 

[z42]

A big drawback to Diesels in Armored Vehicles was weight. A Ford GAA or a Meteor weighed in at around 500 KG. The Twin GM 6-71s on an M4A2 massed about 2300 kg.
It wasn't until the late 1950s that the Power-to-Weight of a Diesel got to the point where they made sense.

It was possible to do better than the twin 6-71. The Soviet V-2 diesel that powered most of their tanks had a weight of about 750 kg and made 500 hp in the T-34, versions used in heavy tanks made 600 hp.

IIUIC the V-2 was originally developed from a Hispano-Suiza engine designed for airships, which explains weight-saving features like an aluminum crankcase which is perhaps an unnecessary luxury in a tank engine.

 

[bf109xxl]

IIUIC the V-2 was originally developed from a Hispano-Suiza engine designed for airships, which explains weight-saving features like an aluminum crankcase which is perhaps an unnecessary luxury in a tank engine.

Can you support this with references to documents? The story of the B-2 began in the early 1930s (1931-1932). BMW VIa (as M-17) may have certain connection to the B-2 development, but very indirectly. Aluminum was used for different reasons, e.g. ease of casting complex parts, better cooling, etc.