jfb@ihlpm.att.com (Joseph F Baugher) (09/14/90)
From: jfb@ihlpm.att.com (Joseph F Baugher) There has been much talk recently in sci.military about the M1 Abrams tank. Here's a few facts which I dug up which I thought might be of interest. Enjoy! M1 and M1A1 Abrams Engine: One 1500 hp Avco Lycoming AGT-1500 gas turbine of 1500 hp. Torsion bar suspension with rotary shock absorbers. Drive sprocket at rear, idler sprocket at front. Crew: Four (commander, driver, loader, gunner) Driver sits in forward area of main hull. Performance: Maximum road range: 300 miles. Maximum speed: 45 mi/hr. Can climb 60-percent grade. Can crawl over 4-foot obstacle. Height of turret roof: 7.8 feet. Acceleration: 0-20 mph in six seconds. Weight: Combat weight: 120,000 pounds (60 tons) Armament: Main gun: One 105-mm M68E1 gun (M1) One 120-mm M256 smooth bore gun (M1A1) Can be elevated at much as 20 degrees or depressed as much as 9 degrees Can fire depleted uranium or HEAT rounds. Stabilized in both elevation and transit. Secondary armament: One 7.62 mm machine gun mounted coaxially to the right of the main gun One 7.62 mm machine gun at loader's position on the left side on top of main turret. One 12.7 mm machine gun at commander's position on top of main turret. I think that this gun can be fired remotely from inside the turret, aimed by an optical periscope system, but I'm not sure. Smoke dischargers on either side of main turret. Armor: Most details appear to be classified. The armor seems to be similar to Chobham armor developed in UK and used on the Challenger and Leopard 2 tanks. This provides enhanced protection against antitank missiles. Crew compartment is separated from the fuel tanks by armored bulkheads. Sliding armor doors and spall-protected boxes help to protect the crew from on-board main ammunition explosions. Top of suspension protected by armored skirts. Some of the TV news footage from Saudi Arabia shows M1s with what appears to be applique armor strapped to the sides of the main turret. Weapons systems: Commander is provided with six periscopes, plus a magnifying sight for the 12.7mm machine gun. Gunner has an optical sighting system which can produce scenes of variable magnification during day or night. This sighting system is stabilized in elevation, making it possible to do accurate aiming while the tank is moving. Turret is equipped with Hughes laser (Nd-YAG) rangefinder Gun is equipped with a bend sensor, and there is a wind sensor on top of the main turret. All of these sensors input data into the full-solution digital main computer. The gunner puts the graticules of his sighting system on the target that he wants to destroy, and the computer calculates the amount of sighting offset that must be applied to the main gun in order to achieve a direct hit. Remarks: The M256 gun of the M1A1 was designed by the German Rheinmetall corporation. Engine can be completely removed and replaced in one hour. The turbine engine suffered a lot of teething troubles during development and early deployment. It is claimed that these problems have been resolved and that the MTBF of the M1 engine is much superior to that of conventional Diesel tank engines. There were some initial problems with dust ingestion into the turbine engine. I wonder how the M1 will handle sand? Loader's position appears to be safe for fast loading in a high mobility environment. Standard equipment includes a radiological warning device, chemical agent detector kit, a collective NBC protection unit, and personnel heaters. The turbine engine has a conspicuous infrared signature. Assuming that everything on board is working, the M1 should be able to defeat any Iraqi tank that is foolish enough to challenge it in battle. [mod.note: I'm reminded of an anecdote related by George Forty in his book, _M4 Sherman_. He got it from an American correspondent, Frank Woolner, who said that many captured German tankers used the same joke. "Von off our tanks iss better than ten off yours," they'd say; and just when their captors started to get angry, they'd add, "but you always haff eleven !" - Bill ] Up to a thousand M1 Abrams tanks may ultimately be transferred to the Persian Gulf. What happens in battle if your computer goes down? Is there a manual backup or are you dead meat? Sources: Jane's Main Battle Tanks, Christopher Foss Modern Tanks and Fighting Vehicles, Ray Bonds. Joe Baugher ************************************* AT&T Bell Laboratories * "Good against remotes is one * 200 Park Plaza * thing. Good against the living * Naperville, Illinois 60566-7050 * is something else." * (708) 713 4548 ************************************* ihlpm!jfb jfb200@cbnewsd.att.com Who, me? Speak for AT&T? Surely you jest!
consp21@bingvaxu.cc.binghamton.edu (Ken Hoover) (09/18/90)
From: consp21@bingvaxu.cc.binghamton.edu (Ken Hoover) In article <1990Sep14.042819.1844@cbnews.att.com> jfb@ihlpm.att.com (Joseph F Baugher) writes: >M1 and M1A1 Abrams > Performance: > Maximum road range: 300 miles. > Maximum speed: 45 mi/hr. It is noted in Tom Clancy's _Red Storm Rising_ that the governor limiting the tank to that 45 mph speed is one of the first things removed by the tank crews when they get assigned to a tank; producing a new top speed of about 60 mph (!). Can anyone verify this? > Armor: > Most details appear to be classified. The armor seems to be > similar to Chobham armor developed in UK... Is this the armor that is made up of alternating layers and gaps of metal to break up the plasma from an exploting HEAT round or fragment an incoming solid-core round? > Some of the TV news footage from Saudi Arabia shows M1s with > what appears to be applique armor strapped to the sides of > the main turret. Reactive armor? I heard that Isreal (and the USSR) are ahead of us on this one. Might it be being deployed now on US armor? - Ken Hoover -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Ken Hoover - Research Programmer | "In the East there is a great tree- consp21@bingvaxu.cc.binghamton.edu | structure that men call 'Corporate Disclaimer : I claim dis... | Headquarters'..." dat is yours. | - The Tao of Programming - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
coshima@s.psych.uiuc.edu (Craig Oshima) (09/24/90)
From: coshima@s.psych.uiuc.edu (Craig Oshima) In article <1990Sep18.024642.21045@cbnews.att.com> consp21@bingvaxu.cc.binghamton.edu (Ken Hoover) writes: >From: consp21@bingvaxu.cc.binghamton.edu (Ken Hoover) > >In article <1990Sep14.042819.1844@cbnews.att.com> jfb@ihlpm.att.com (Joseph F Baugher) writes: >>M1 and M1A1 Abrams >> Armor: >> Most details appear to be classified. The armor seems to be >> similar to Chobham armor developed in UK... > > Is this the armor that is made up of alternating layers and gaps of >metal to break up the plasma from an exploting HEAT round or fragment >an incoming solid-core round? > The following was excerpted from the game manual of "M1 Tank Platoon" by MicroProse (an authoritative source I realize, by it might be of interest to some: "Chobham & Other Composites: Composite armor has a hard steel outer face, like normal armor. But below that are succesive layers of metals and ceramics. On the latest M1A1s, the first interior layer is depleted uranium, a substance about 2.5 times denser than steel. Below this are successive layers of steel and ceramic. The ceramics resist heat better, while the steel absorbs kinetic energy better. The overall effect is armor that resists kin- etic energy at least as well as conventional steel, and which absorbs the hot gas jets of HEAT ammo so well that most of these weapons are useless. The final inner layer is undoubtedly a special metal or plastic that resists spalling much like the ballistic cloth "wallpaper". "The exact makeup of Chobham armor is probably more complex than simple layering. The ceramics may be locked within steel honeycombs, or vice versa. The layers may overlap or wrap around each other in complex patterns..." There's more, but not related to Chobham armor in particular. I don't know how accurate that is, or if it's quite what you were looking for, but I hope it was of interest. Craig. P.S. MicroProse did a great job with that game. I love it.
xvm@mentor.cc.purdue.edu (Joe Lucas) (09/24/90)
From: xvm@mentor.cc.purdue.edu (Joe Lucas) In article <1990Sep18.024642.21045@cbnews.att.com> consp21@bingvaxu.cc.binghamton.edu (Ken Hoover) writes: > >In article <1990Sep14.042819.1844@cbnews.att.com> jfb@ihlpm.att.com (Joseph F Baugher) writes: >>M1 and M1A1 Abrams >> Performance: >> Maximum road range: 300 miles. >> Maximum speed: 45 mi/hr. > > It is noted in Tom Clancy's _Red Storm Rising_ that the governor >limiting the tank to that 45 mph speed is one of the first things >removed by the tank crews when they get assigned to a tank; producing >a new top speed of about 60 mph (!). Can anyone verify this? This is my first posting so if I mess up I'm sorry. Anyways I had the pleasure of talking with an Abrams driver who had been stationed in Germany. He had some very interesting things to say. The first and most interesting was the top speed of the M1. He stated that the top speed was 85 MPH on level ground and the fastest he had been in a tank trap (with all those hills and valleys to really test the suspension) was 65 MPH. It's kind of hard to imagine this 60 ton best moving this fast but I imagine the gas turbine engine puts out a lot of power. The second item was the loudness of the turbine. He told of how in a simulated attack against a Canadian unit the M1's roared through the front lines while the Candians enjoyed their breakfast. Lesson - Evidently the gas turine is very quiet (well at least compared to the other engines that inhabit a battlefield). The Canadians never heard then coming until the M1's were passing through the rear. The third item we discussed was 'What to do when the brakes go out?' His replay? 'Don't hit a chicken.' The United States government has to foot the bill for damaged civilian property while on maneauvers. He said it was better to go through a house (as long as you didn't hurt anyone) than to kill a chicken. If a house gets taken out the Uncle Sam only has to pay to replace the house itself. In the case of the chicken, the original chicken has to be replaced plus the cost of the loss productivity because the eggs it would have laid in its lifetime cannot mature to lay their eggs. The United States ends up paying fo quite a few generations of chickens. Comments and replys are welcome. If I'm wrong on any of these let me know ------------------------------------------------------------------------ Would anyone else be stupid enough to claim these thoughts as their own? A .sig is in the works . . . Another message from xvm@mentor.cc.purdue.edu Joseph Lucas - Computer Science
bxr307@csc.anu.oz.au (09/24/90)
From: bxr307@csc.anu.oz.au In article <1990Sep18.024642.21045@cbnews.att.com>, consp21@bingvaxu.cc.binghamton.edu (Ken Hoover) writes: > > > From: consp21@bingvaxu.cc.binghamton.edu (Ken Hoover) > > In article <1990Sep14.042819.1844@cbnews.att.com> jfb@ihlpm.att.com (Joseph F Baugher) writes: >> Armor: >> Most details appear to be classified. The armor seems to be >> similar to Chobham armor developed in UK... > > Is this the armor that is made up of alternating layers and gaps of > metal to break up the plasma from an exploting HEAT round or fragment > an incoming solid-core round? The best similie that can be given for Chobham armour is that it is an Aluminium composite structure backed by a ceramic armour. It is designed to work like the steel panels of your car when struck by an AP style round. In other words it crushes and collapses, slowing the round so that it is unable to penetrate. The Aluminium structure also disipates the energy of a HEAT round more efficiently than normal mono-construction hardened steel armour. The ceramic armour backing is designed to prevent any final chance of either AP or HEAT from gaining entry to the vehicle. The ceramic also has the advantage of having a much higher melting point than any metal with the result it is nearly impossible for the stream from a HEAT round from being able to melt its way through. >> Some of the TV news footage from Saudi Arabia shows M1s with >> what appears to be applique armor strapped to the sides of >> the main turret. > > Reactive armor? I heard that Isreal (and the USSR) are ahead of us > on this one. Might it be being deployed now on US armor? What I think the original poster is referring to is not reactive armour but rather plates of Depleted Uranium which have been attached externally to the armour of the turret front. I believe the correct designation for such a vehicle, so equipped is M1e2. However I could be wrong (not being really sure how to decypher the very weird nomencluture (?sp) that the US Army uses). What was interesting about some TV news reports from the Gulf, and which I am surprised has not been mentioned here yet is the sudden appearance of what I believe were M60 tanks fitted with what was obviously reactive armour packages all over the hull and turrret. As the narration failed to identify who actually owned these vehicles, however it was implied they were US, makes me wonder how prevelant this modification is, and who actually owns the vehicles. If they were Saudi and not US, where did the Saudi's buy the armour refit from? I suspect from Israel through intermedaries. Which adds an interesting twist to the matter. I'm also interested in the sudden deafening silence from the media about the Saudi's ownership of a number of Chinese Manufactured IRBM's. The media has been trumpeting about how dangerous it is that the Iraqi's have such things, and they were also commenting upon how destablising was the Saudi purchase two years ago, but now nothing. Interesting isn't it? Brian Ross
ab3o+@andrew.cmu.edu (Allan Bourdius) (09/24/90)
From: Allan Bourdius <ab3o+@andrew.cmu.edu> I have a friend who's a TC with the 1st Bde, 3rd ArmDiv in Frankfurt and he's told me that the M1A1 can push 80+ road and 50+ cross-country without the governor (unofficially). The M1A1's armor is supposedly Chobham modified with an extra layer of depleted uranium added. I think they also probably have lots of Kevlar on them too. All USMC and USA tracked and wheeled armored vehicles have provisions for mounting reactive armor. RA was an American idea anyway. Just remember that RA is only effective against shaped charges, HESH and mabye HEAT rounds. Kinetic energy rounds (APDS and APFSDS) would go through RA like, to quote James Bond, "a blowtorch through butter." The depleted uranium was probably added to the M1A1 for protection against KE rounds. I've heard that the M1A1's armor has been tested against every known antitank weapon and the armor has yet to be breached with less than three rounds in the exact same place. MIDN 3/C Bourdius CMUNROTCU
anthony@batserver.cs.uq.oz.au (Anthony Lee) (09/27/90)
From: anthony@batserver.cs.uq.oz.au (Anthony Lee)
bxr307@csc.anu.oz.au writes:
: What was interesting about some TV news reports from the Gulf, and
:which I am surprised has not been mentioned here yet is the sudden appearance
:of what I believe were M60 tanks fitted with what was obviously reactive armour
:packages all over the hull and turrret. As the narration failed to identify
Are you sure they are reactive armour ? Since both of us are from Australia
then we must be looking at the same TV pictures. I remember seeing
reactive armour on Israel's M60s several years ago (it must have been the
invasion of Lebanon). The reactive armour on the Israel's M60s were box
shaped. The armour plate on the US M60s were thinner plates.
:who actually owned these vehicles, however it was implied they were US, makes
:me wonder how prevelant this modification is, and who actually owns the
:vehicles. If they were Saudi and not US, where did the Saudi's buy the armour
:refit from? I suspect from Israel through intermedaries. Which adds an
:interesting twist to the matter.
I thought the commander on the turret looks Western so must have been
a US tank.
--
Anthony Lee (Michaelangelo teenage mutant ninja turtle) (Time Lord Doctor)
ACSnet: anthony@batserver.cs.uq.oz TEL:+(61)-7-371-2651
Internet: anthony@batserver.cs.uq.oz.au +(61)-7-377-4139 (w)
SNAIL: Dept Comp. Science, University of Qld, St Lucia, Qld 4072, Australia