Yaba Posted March 3, 2003 Share Posted March 3, 2003 Hi there, A little off topic but does anyone have an opinion as to why the Russians (and pretty much everyone else eventually) went with Diesel and the Yankees went with Gas? I know that Diesel is more energy efficient and less flamible but there has to be some reason why the americans used and still use gas powered tanks to this day. Hell, even the Canadians (and I am one) converted their tanks to diesel after watching a few brew up after taking hits. Cheers, 0 Quote Link to comment Share on other sites More sharing options...
White Phosphorus Posted March 3, 2003 Share Posted March 3, 2003 Russians still use gas in a lot of their vehicles too. BTR-60s are gas powered. 0 Quote Link to comment Share on other sites More sharing options...
flamingknives Posted March 3, 2003 Share Posted March 3, 2003 Diesel engines also produce more torque at low speeds that a petrol engine, which is a big plus if you're trying to move large heavy objects about (trucks, tanks, tractors, trains). Not sure that everyone went over to diesel though - last I looked, the M1 has a gas turbine that runs on JP-4 (?), the Chieften had some kind of multi-fuel monster that could burn anything and got about 5 gallons per mile. The T80U also uses a gas turbine, although Challenger 2 and the Merkava 4 both use diesel. So, the choices these days seem to be: diesel, multi-fuel or gas turbine 0 Quote Link to comment Share on other sites More sharing options...
MikeyD Posted March 3, 2003 Share Posted March 3, 2003 Gas provides more bang for the buck (top-end power). In a world (1930s) where laughably low-power engines were in most civilian vehicles every little bit helped. Also there's engine availability. The Combat Car predecessor to Sherman initially got that high octane radial aircraft engine simply because That was just about the only engine that could produce enough horsepower to propel the vehicle! There's also logistics. If everything else on wheels is running on gas it's hard to maintain your one diesel powered asset in the supply chain. Once you start down the path of either diesel or gas it's a world of hurt switching. The Russians and I think the Japanese both decided on diesels quite early in the process. As a matter of fact, I believe it was the technology from a WWII Japanese air-cooled v-engined tank diesel that eventually got the U.S. to design one for the M48/M60 series! 0 Quote Link to comment Share on other sites More sharing options...
offtaskagain Posted March 4, 2003 Share Posted March 4, 2003 The M1 uses JP-4 (IIRC) which is basically diesel. 0 Quote Link to comment Share on other sites More sharing options...
Incoming9000 Posted March 4, 2003 Share Posted March 4, 2003 The Germans used gasoline fueled tanks because they had more horsepower and moved faster, something crucial for a blitzkrieg type of war, this ended up being a problem due to the high gas consuption specially in the latter stage of the war. For example the King Tiger had a 850 liter fuel tank that only gave him a maximum average range of 100Km with a 12 cylinder 24 liter 600hp engine. The Diesel engines were more eficient but not as powerfull, making them good a choice for a more long lasting conflict. Modern Gas Turbines have replaced the old piston/gasoline system because they have tremendous power, but, are very complex a hard to maintain. During Desert Storm M1s had to stop every 3 hours for maintenance and refuel while the Diesel powered M60s could go on for a hole day. There is a very inetense debate about the pros and cons of Gas turbines in AFVs and some say that with the new developments in Diesel Power, Gas engines are not worth it! The majority of modern MTBs use Diesel engines exept the US M1 and the Russian T80. Leopard 2-----Diesel-1500hp (ger) Leclerc-------Diesel-1500hp (fr) Ariete--------Diesel-1300hp (ita) Challenger 2--Diesel-1200hp (uk) T80UD---------Diesel-1250hp (rus) T80U-----------Gas---1250hp (rus) T90-----------Diesel-1000hp (rus) M1-------------Gas---1500hp (us) M60A3---------Diesel-750hp (us) [ March 03, 2003, 06:50 PM: Message edited by: Incoming9000 ] 0 Quote Link to comment Share on other sites More sharing options...
-E Posted March 4, 2003 Share Posted March 4, 2003 Originally posted by panzerwerfer42: The M1 uses JP-4 (IIRC) which is basically diesel. More like kerosene... interesting JP-4 facts: 1. JP-4 will wear out flints like no tomorrow in a zippo. 2. JP-4 tastes real bad if ingested and the taste will linger all day long. 3. JP-4 burns the afterburner section when it comes out after ingestion! 4. It's not wise to syphon JP-4 from a B-52's surge tank because of #2 & 3 above, even if you're a young dumb troop who's been handed a hose by someone who outranks you by 4 paygrades. 0 Quote Link to comment Share on other sites More sharing options...
JonS Posted March 4, 2003 Share Posted March 4, 2003 LOL It sucks to be low-rank ... 0 Quote Link to comment Share on other sites More sharing options...
Schoerner Posted March 4, 2003 Share Posted March 4, 2003 If i'm informed correctly, there were (are?) gas-engines needed to start the diesels at extreme cold. 0 Quote Link to comment Share on other sites More sharing options...
Guest Mike Posted March 4, 2003 Share Posted March 4, 2003 I don't think it's a matter of extreme cold - although they'd be useful there. Rather large diesels with high compression are a bit tough for battery powered electric starter motors to turn over!! So they use a small engine to generate the required power. The principle is common enough in all sorts of machinery from Jumbo-jets to earth-moving equipment where there's a large engine to be started - be it turbine or diesel or anythign else. 0 Quote Link to comment Share on other sites More sharing options...
tar Posted March 4, 2003 Share Posted March 4, 2003 I don't think it's a matter of extreme cold - although they'd be useful there. Well, extreme cold is a problem for diesel engines. (I used to have one in New England ). The problem is inherent in the way diesel engines work. They have no spark plugs, but instead rely on the engine compression to heat the air up to the ignition temperature of the diesel fuel. If the air starts out cold enough, then the temperature rise from the compression doesn't get the air inside the engine up to the ignition temperature of the fuel, and the engine will therefore not run. Point of Information. Compression ratios on gasoline engines are typically in the 8:1 to 9:1 range (sometimes a bit higher with higher octane fuel, but generally not above 10:1 or 12:1 at the outside). Diesel compression ratios are easily in the 20s. IIRC my VW diesel had a 23:1 compression ratio. 0 Quote Link to comment Share on other sites More sharing options...
White Phosphorus Posted March 4, 2003 Share Posted March 4, 2003 Well diesels have glow plugs in them to make starting easy, although on cold mornings the battery has to do some work, but it's not a big problem. The real problem is that Diesel oil is too heavy, and has a nasty tendency to congeal in cold weather. You've got to put more j-4 in it as the temperature goes down. 0 Quote Link to comment Share on other sites More sharing options...
LightningWar Posted March 4, 2003 Share Posted March 4, 2003 JP-4 is more like jet fuel or Kerosene. But doesnt the military use JP-8? LW 0 Quote Link to comment Share on other sites More sharing options...
Wisbech_lad Posted March 4, 2003 Share Posted March 4, 2003 The British army, to get around the logistics thing, is developing a diesal powered motor bike... 0 Quote Link to comment Share on other sites More sharing options...
gredeker Posted March 4, 2003 Share Posted March 4, 2003 Some Sherms were diesel powered (I want to say Caterpillar and GM 6-71 diesels). However, in a flash of foresight, someone actually thought to send all (or at least nearly all) vehicles of a particular type to a single theater to simplify the supply chain. Thus, all the diesel Shermans were given to the Marines in the Pacific, where the supply chain was already in place for diesel due to all the landing craft. The Ford V-8s went to the Army in the NW ETO, the Chrysler multibank models went to Italy, other versions were earmarked for Brits or Soviets, etc. I seem to recall reading that the M1 Abrams has a multi-fuel turbine, but that it usually burns diesel to simplify the supply chain - can anyone confirm? 0 Quote Link to comment Share on other sites More sharing options...
SgtMuhammed Posted March 4, 2003 Share Posted March 4, 2003 Unless it runs on MOGAS (regular unleaded) U.S. Army vehicles run on JP8 (which is slightly more refined diesel). The Turbine in the M1 can run on any flamible liquid, for that matter so can some army trucks, but they get the best milage with proper fuel. The M1 does not have to stop for maintainance every three hours. The are actually one of the most reliable tanks in the world. All armored vehicles require a lot of maintainance compared to their lighter bretheren but most of that is of a preventive nature rather than to correct actual breakdowns. 0 Quote Link to comment Share on other sites More sharing options...
Jorm Posted March 4, 2003 Share Posted March 4, 2003 I have the missfortune of being a fuels chemist who works for the dept of defence. just a few points and probably questions of those who use the stuff JP8 = Jet Propellant 8, it is EXACTLY the same crude oil distillation cut as jetfuel, and is in fact jet fuel with a few military additives ( lubricity improver, fuel system icing inhibitor, biocide, static disipator and a few other region specific ones) Most armies seem to be moving to a Single battlefield fuel concept, is the US army using JP8 in all its land vehicles ? Some poeple seem to have the missconception that gas turbines are powered by gas fuel, ie LPG etc. They *can* use gas but no current military land combat vehicle uses compressed gas fuel. anyways,i thought post combat analysis of wwii tank combat revealed that AFV vulnerability to fire was predominatly due to propellant fires and anot the vehicle fuel source. If fuel fires were the main cuase then the US military would probably sue the higher flash point JP5 fuel (US navy jet fuel, which has a flash point of 60C, rather than 38 C for Jp8). anyways, interesting thread and i alwasy love reading posts from those of you who were/are military people , espacially tankers be well Paul 0 Quote Link to comment Share on other sites More sharing options...
aka_tom_w Posted March 4, 2003 Share Posted March 4, 2003 interesting thread PLEASE tell me more with SPECFIC details thanks for all the VERY informative posts! -tom w 0 Quote Link to comment Share on other sites More sharing options...
Schoerner Posted March 4, 2003 Share Posted March 4, 2003 Originally posted by White Phosphorus: Well diesels have glow plugs in them to make starting easy, although on cold mornings the battery has to do some work, but it's not a big problem. The real problem is that Diesel oil is too heavy, and has a nasty tendency to congeal in cold weather. You've got to put more j-4 in it as the temperature goes down. Well, the battery loses energy quite drastically with falling temperature, while the engine would need even more energy to become started. I'm remembering that even the 1970s diesel cars had problems in winter. My grandfather told me, that in his unit the diesel engines were almost useless at strong russian cold (-20 to -45 degree) and it needed a long time to get them running. And thinking about all the necessary logistics for the additives depending on temperature makes me understand that gas was preferred due to the problems with cold. Nevertheless assumptions only. Anyone with knowledge why the German highest command decided for gas and the Soviets for diesel? 0 Quote Link to comment Share on other sites More sharing options...
CavalryMan Posted March 4, 2003 Share Posted March 4, 2003 In relation to Soviet and Axis vehicles was the primary design decision based on available technology? The Soviets had Diesel power unit technology in abundance but relativly poor petrol technology/production. This also applied to the technologies required for refining the fuel. Just my guess 0 Quote Link to comment Share on other sites More sharing options...
flamingknives Posted March 4, 2003 Share Posted March 4, 2003 Modern Gas Turbines have replaced the old piston/gasoline system because they have tremendous power, but, are very complex a hard to maintain. It would be difficult to be more wrong. Gas turbines are the simplest heat engines currently on the face of the planet. In addition, as the only motion involved with their operation is rotary, they are not subject to the massive acceleration loads found in a reciprocating piston engine. Just in case some people don't know (I always get caught out when I assume everyone does know) Gas Turbine = Jet engine In applications such as the M1, rather than producing thrust out the back, there is an extra stage or few of turbine blades that translate thrust into rotary power. Gas turbines provide a great deal of power ofr their weight and size but are very thirsty. 0 Quote Link to comment Share on other sites More sharing options...
apex Posted March 4, 2003 Share Posted March 4, 2003 One thing you also have to consider is the refining process, which creates from crude oil a rather fixed ratio of gas to diesel. IIRC for the US army, gas was used because the Navy used most of the Diesel fuel. That today is less of an issue, most tanks these days can burn both fuels and jet fuel on top of that. apex 0 Quote Link to comment Share on other sites More sharing options...
MikeyD Posted March 4, 2003 Share Posted March 4, 2003 Don't be too fond of the M1's turbine engine. The Pentagon has wanted to replace that gas hog for years with a modern diesel (like in the Leopard 2), but unfortunately the turbine manufacturer was loacated in the district of a certain right-wing former Senate president. And we all know how pork gets Doled out in congress. 0 Quote Link to comment Share on other sites More sharing options...
sgtabell Posted March 4, 2003 Share Posted March 4, 2003 Here it is from a couple points.... Diesel turned to jelly in extreme cold temps. Diesel is a cheaper fuel, as the distillation process requires less time and energy. Lower operating temperatures, less stress on lower quality metals which are used. No spark plugs, when you compress diesel fast, it explodes, and thus keeps running the engine. (Thus the term "cranking it over" like I have had to do on older tractors). I do wonder if part of the reason that Americans made them to be gas engines was due to the refitting of car plants, with our technology and tools being aligned that way. SgtAbell 0 Quote Link to comment Share on other sites More sharing options...
Incoming9000 Posted March 4, 2003 Share Posted March 4, 2003 Originally posted by flamingknives: </font><blockquote>quote:</font><hr /> Modern Gas Turbines have replaced the old piston/gasoline system because they have tremendous power, but, are very complex a hard to maintain. It would be difficult to be more wrong. Gas turbines are the simplest heat engines currently on the face of the planet. (...) </font> 0 Quote Link to comment Share on other sites More sharing options...
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