Octane, flammability, and tanks

[Stelth]

Like many guys, I have an interest in tanks. I've seen a number of documentaries on the M4 Sherman, and it's often mentioned that the Sherman was dangerous because it used "high octane" gasoline. I don't think the octane rating had anything to do with the danger. Even the fact that it was gasoline powered isn't all that significant, IMO, since most WWII tanks used gasoline engines.

In the earlier models that used radial aircraft engines, high-octane gasoline was required. I'm not sure about the later models with the Ford V-8. This could certainly cause logistical problems, since the trucks and Jeeps could use less-expensive gasoline. Not sure about all the trucks, but IIRC, the Jeeps had a compression ratio of about 6.5 to 1, so they didn't require much in the octane department.

Anyway, my opinion is that the Sherman was dangerous and caught fire easily because of its thin armor and poor design rather than the octane rating of its gasoline.

Does that sound right?

 

[eljefino]

Yup and the enemy figured out how to penetrate the things. Or historical hindsight blamed the fuel, well jeez you need a big gas tank to drag all that stuff around. Or the scrptwriter/ announcer threw in "high octane" like they would say "high speed chase".

I bet they used high test in everything just like they use JP-8 for diesel now. We had plenty of gas, relatively speaking, but rationed it to civilians because we were short on tires.

 

[wallyuwl]

Originally Posted By: Stelth
Anyway, my opinion is that the Sherman was dangerous and caught fire easily because of its thin armor and poor design rather than the octane rating of its gasoline.

Does that sound right?


yes

 

[Scott_Tucker]

Its octane rating doesn't have much to do with its flash point so I would say that's wrong.

 

[sciphi]

If anything, high octane would give the crew an extra split second to get out. Slower flame front, harder to ignite, and all that.

I vote it was poor armor, and a superior German gun that could easily light the tank up.

 

[umungus1122]

The reputation that the Sherman gained for burning when penetrated had nothing to do with gas, but rather the powder contained in it's ammunition. This occurence was not limited to Shermans, as any tank with it's ammo stowed in the turret bins and on the floor could have it's ammo ignited if penetrated. This is the main reason today's Abrams have the ammo stored in a separate compartment at the turret rear with blow out panels, so the burning powder can be vented out and away from the interior if penetrated.

As to the Shermans having thin armor, they had armor comparable to other medium tanks of the period, such as the Panzer IV or T-34.

 

[Shannow]

Originally Posted By: sciphi
If anything, high octane would give the crew an extra split second to get out. Slower flame front, harder to ignite, and all that.


Nope, ease of ignition and flame speed have NOTHING to do with octane.

The WWI ones, sir Harry Ricardo built the engines ran kerosene, which have lower vapour pressures etc. but still not pretty.

But a tracer passing "near" a gasoline spill versus same passing through kerosene makes the kero slightly better.

The military actively trade personnell for materiel, and if it was a deathtrap, it was because it served it's purpose.

Found this (Other but wiki is more condensed) when looking upstuff on Buick Dynaflows transmissions.

http://en.wikipedia.org/wiki/M18_Hellcat

an underarmoured for speed gets renamed tank destroyer and used tactically...at costs.

 

[Bluestream]

As I recall the Sherman had the nickname "The Ronson" from the slogan of the Ronson cigarette lighter company: "lights every time" Thin armor and a small gun made it a less effective tank. It must have been very depressing for the troops to see a Sherman fire at a Panzer and see the shell bounce off the tank.

My Grandfather drove a tank in Africa, and I remember him telling me the first thing they did was remove the rubber seal around the hatch, as it caught fire fast and made it hard to escape. I don't recall if he said he was in a Sherman...

 

[Stelth]

On one of the History Channel shows, a Sherman commander tells a story of a German tank (Tiger?) sticking its gun through a hedgerow right in front of him. The Sherman tank crew fired three rounds at point blank range at the Tiger. None penetrated. The Tiger then fired a round which tore a groove through the top of the Sherman turret from front to back. I don't remember exactly how the story ended, except for the Sherman driver frantically looking for reverse gear. Obviously at least the tank commander survived the encounter, since he was telling the story.

 

[hattaresguy]

The Sherman was a pretty good tank against most German tanks up until the up gunned Panzer 4. But it was certainly a match for the Panzer 3's and did quite well in the desert.

Most of the better German tanks IE the Panther, Tiger, King Tiger etc were allocated to the Eastern front, until the tail end of the war. At which point it didn't matter because their were so few of them. The Panzer 4 was the primary tank of the armed forces and Guderian made a very strong case, but failed to stop all tank development and production and concentrate solely on the Panzer 4. He also tried to kill off those silly assault guns, although most of them were built on obsolete tank chases. Guderian understood all to well that having a lot of tanks that are good enough, is preferable to only a few that are excellent. Having said that the Panther was the best tank fielded during the war by any side.

In general the Germans did so well because of their tactics and vast experience when they came up against our fresh recruits. They had so much experience they could take an inferior force and run our guys raged in the desert, as they had done with the British at the beginning. In Normandy they were mostly overwhelmed by our air power, which had no problem busting tanks. However in certain cases tank aces from the Eastern front did trickle over with Tigers and cause havoc.

German military doctrine of the time generally viewed tank on tank warfare as something only done when they had no other options. The preferred method was to poke around with a combined armor group, ie tanks, half tracks, trucks, etc. Than when they ran up against allied tanks to sit back, wheel up the 88's or whatever artillery was at hand, and blast the living [censored] out of the allied tanks. Than they placed their heavy tanks in front in a V formation and drove like [censored] threw allied lines. It was considered wasteful to lose tanks in armored combat when cheap mobile artillery would do just fine.

This is where the story of the Sherman lighting up came into being. It started with the British who were the first to employ the new at the time Sherman tank. German field artillery would slice right threw them.

We learned how to fight but it took awhile. One must remember that the US came into WW2 very late and only had limited land combat in the desert and as big as Normandy and Italy are for us, in the overall scheme of things they never represented more than 25% combined of the forces the Wehrmacht had available to them. With that most of the units in the west were pretty poor as well, the best units were always on the Eastern front. (IE western units were usually made up of fresh recruits, old men, or tired units recovering from the east and pressed into service.) The Russians really fought and won WW2 in Europe.

 

[Bluestream]

Originally Posted By: hattaresguy


We learned how to fight but it took awhile. One must remember that the US came into WW2 very late and only had limited land combat in the desert and as big as Normandy and Italy are for us, in the overall scheme of things they never represented more than 25% combined of the forces the Wehrmacht had available to them. With that most of the units in the west were pretty poor as well, the best units were always on the Eastern front. (IE western units were usually made up of fresh recruits, old men, or tired units recovering from the east and pressed into service.) The Russians really fought and won WW2 in Europe.


This is very true, as 20 million Russians died in WWII. Not what we were told as I grew up though...(It was the allies who won the war, no mention of the Russian effort).

However, the US (Eisenhower)wanted to get fully involved right away and take the fight to the Germans. The British wanted to attack the "soft under belly of Europe" through Africa and then Italy. These were basically side shows as compared to the Eastern front

 

[Spazdog]

The fuel is a problem. Ask any Japanese pilot. If the fuel lights off, the octane (or cetane) is of little concern. It's on fire. Time to pull the Halon and get out. If the Halon extiguishes it, you can jump back in and fight. That's the beauty of a tank. Lose a track or engine and you're a pillbox. Run out of primary ammo and you're a bunker...

But you are also surrounded by ammunition. The 75mm round was so small that they carried something like 90 rounds.

I've never been more aware of how much I was surrounded by ammo as I was when I trained in an M60A3TTS. In the M1, the ammo is in armored containers, in the M60A3TTS, they are just in aluminum tubes or the ready rack in front of the loader. When you survey the turret of a Patton, there are 105mm rounds everywhere.

With the sophistication of the shaped charge and kinetic energy penetrators today, the type of fuel is the last thing on your mind. When a T-72 is hit with a 105mm FSDS, all the hatches blow open and fire shoots out of them 10m in the air. And that's with diesel on board. Again, you aren't really worried about the grade of fuel.

Originally Posted By: hattaresguy
The Sherman was a pretty good tank against most German tanks up until the up gunned Panzer 4. But it was certainly a match for the Panzer 3's and did quite well in the desert.


Panzer IV had an improved shaped charge round too. I don't think that was developed for the Shermans though. I think they did that to penetrate the tough little T-34s.

 

[hattaresguy]

Originally Posted By: Bluestream
Originally Posted By: hattaresguy


We learned how to fight but it took awhile. One must remember that the US came into WW2 very late and only had limited land combat in the desert and as big as Normandy and Italy are for us, in the overall scheme of things they never represented more than 25% combined of the forces the Wehrmacht had available to them. With that most of the units in the west were pretty poor as well, the best units were always on the Eastern front. (IE western units were usually made up of fresh recruits, old men, or tired units recovering from the east and pressed into service.) The Russians really fought and won WW2 in Europe.


This is very true, as 20 million Russians died in WWII. Not what we were told as I grew up though...(It was the allies who won the war, no mention of the Russian effort).

However, the US (Eisenhower)wanted to get fully involved right away and take the fight to the Germans. The British wanted to attack the "soft under belly of Europe" through Africa and then Italy. These were basically side shows as compared to the Eastern front


Yep the history that's taught in school is quite off.

Africa was always a side show and had no impact on the war. The only countries that really cared about Africa were the Italians and British. Normandy shortened it by maybe a year at most. But either way the Russians were well on their way to Berlin by 1944.

They also only teach of the German war crimes, they make no mention of the allies doing pretty much the same thing.

Shooting prisoners, civilians, etc was done by every army. The Russians and French were probably the most eager in this regard.

 

[hattaresguy]

Originally Posted By: Spazdog


Originally Posted By: hattaresguy
The Sherman was a pretty good tank against most German tanks up until the up gunned Panzer 4. But it was certainly a match for the Panzer 3's and did quite well in the desert.


Panzer IV had an improved shaped charge round too. I don't think that was developed for the Shermans though. I think they did that to penetrate the tough little T-34s.


The T34 caused the Germans a lot of trouble in 1941 when they started to show up. Up to than they were able to use 37mm anti tank guns. With the arrival of the T34 those were obsolete.

This is why in 42/43 you see the fire power of a German armored formation increase dramatically. Everything was up gunned.

The Panzer 2's were on their way out at the beginning of the Russian invasion, but after 1941 the remainder of the 2's and 3's were taken out of service. A lot of the 3's were turned into fixed gun tank killers later in the war. 4's got larger guns and more armor, and larger tanks like the Panther and Tiger 1 were rushed into service. Anti tank guns were also up sized, they started cranking out 88's and a few others.

Most people don't know this but up until oh 1943/44 most German artillery was still horse drawn.

The most mechanized army was ours at the time.

 

[OVERKILL]

Originally Posted By: Bluestream
Originally Posted By: hattaresguy


We learned how to fight but it took awhile. One must remember that the US came into WW2 very late and only had limited land combat in the desert and as big as Normandy and Italy are for us, in the overall scheme of things they never represented more than 25% combined of the forces the Wehrmacht had available to them. With that most of the units in the west were pretty poor as well, the best units were always on the Eastern front. (IE western units were usually made up of fresh recruits, old men, or tired units recovering from the east and pressed into service.) The Russians really fought and won WW2 in Europe.


This is very true, as 20 million Russians died in WWII. Not what we were told as I grew up though...(It was the allies who won the war, no mention of the Russian effort).

However, the US (Eisenhower)wanted to get fully involved right away and take the fight to the Germans. The British wanted to attack the "soft under belly of Europe" through Africa and then Italy. These were basically side shows as compared to the Eastern front


Try 23.4 million Soviets.

The only country that supposedly came close to this was China, though the range given for Chinese fatalities is so broad it is hard to really say just how close (or not) the numbers were.

Considering how few Germans died in comparison, it is rather appalling.

 

[Loobed]

Originally Posted By: Spazdog
...That's the beauty of a tank. Lose a track or engine and you're a pillbox. Run out of primary ammo and you're a bunker...



good movie
http://www.imdb.com/title/tt0094716/

 

[mechtech2]

Originally Posted By: sciphi
If anything, high octane would give the crew an extra split second to get out. Slower flame front, harder to ignite, and all that.

I vote it was poor armor, and a superior German gun that could easily light the tank up.


Right.
The initial burn would have been slower [OK... not enough time to read "War And Peace", but in that direction].

 

[SteveSRT8]

If any of you had ever seen the Americans roaring down the German roads at 80 mph (eighty!) in our M1's you would have been in awe.

The locals would actually jostle to get close in hopes of being tagged so they could get money from the commander. We called them 'speed bumps'!

Imagine the momentum involved. That was about 63 tons.

 

[friendly_jacek]

Originally Posted By: OVERK1LL
Originally Posted By: Bluestream
Originally Posted By: hattaresguy


We learned how to fight but it took awhile. One must remember that the US came into WW2 very late and only had limited land combat in the desert and as big as Normandy and Italy are for us, in the overall scheme of things they never represented more than 25% combined of the forces the Wehrmacht had available to them. With that most of the units in the west were pretty poor as well, the best units were always on the Eastern front. (IE western units were usually made up of fresh recruits, old men, or tired units recovering from the east and pressed into service.) The Russians really fought and won WW2 in Europe.


This is very true, as 20 million Russians died in WWII. Not what we were told as I grew up though...(It was the allies who won the war, no mention of the Russian effort).

However, the US (Eisenhower)wanted to get fully involved right away and take the fight to the Germans. The British wanted to attack the "soft under belly of Europe" through Africa and then Italy. These were basically side shows as compared to the Eastern front


Try 23.4 million Soviets.

The only country that supposedly came close to this was China, though the range given for Chinese fatalities is so broad it is hard to really say just how close (or not) the numbers were.

Considering how few Germans died in comparison, it is rather appalling.


Yes, but human life meant nothing to that monster Stalin. I'm sure you are aware of the true stories of party hardliners manning machine guns just behind the front line, so they would gun down any (poorly armed) regular soviet soldiers trying to retreat.

Soviets were also the first to do large scale prisoner of war and genocide executions. Katyn: http://en.wikipedia.org/wiki/Katyn_massacre

 

[Spazdog]

Originally Posted By: hattaresguy


They also only teach of the German war crimes, they make no mention of the allies doing pretty much the same thing.

Shooting prisoners, civilians, etc was done by every army. The Russians and French were probably the most eager in this regard.


Much is made of Nazi war crimes. But overall, the Imperial Japanese may have actually been more brutal and criminal. They believed themselves to be racially and genetically superior to the Chinese and Koreans.

it's difficult for me personally to say anything positive about the Soviets, but one could argue that they just brought the horrors of the Eastern Front home to Berlin. Also, the Soviet officers were reportedly killing their own men that did not advance fast enough. If they do not care enough about their own troops, why would they care about taking prisoners or leaving civillians alive? If you know the Tokarev behind you is pointed at your head, maybe you do things your conscience doesn't agree with.

The US and Brits weren't exactly angels. War is [heck]. But if you were a Nazi and you decided to surrender, you wanted to surrender to the Brits and/or Americans.