Championing Responsible National Security Policy

The Army's M1 Tank: Has It Lived Up To Expectations?


The Project On Government Procurement has tracked the progress of the M1 tank since our founding in 1980. Because our observations on M1 tank performance have often been called, inaccurate, incomplete or out-of-date, we have released new Army M1 data to the public as it has become available. Since the M1 program may be coming to an end, this report is intended to be a useful summary of M1 performance claims and data. We have included U.S. Army and DoD statements made throughout the history of the program and compared them to data available then and now. We have included a detailed description of our source material, and how we calculated the statistics used in the report. Furthermore, in this updated version, we have included the rebuttal of General Dynamics, as it was sent to the Editor of the Detroit News. The rebuttal addresses an article based largely on this report. You will find our response to General Dynamics' claims at the end of the report.

M1 Overview

Events in Europe may seem to make the issue of tank procurement anachronistic. Nevertheless, the Army is moving ahead not only with the new, more expensive and more complicated A2 version of te M1, but also with an entirely new "armored family of vehicles." In addition, the U.S. Army is aggressively promoting sales of the M1 to our allies, including Britain and Sweden. So not only are we buying more new tanks in an era of budget cuts, we are buying more of a tank which has never met its basic requirements -- and is by far the most expensive tank in the world, according to published figures. For example, it costs far more than the German Leopard II, a tank which was built to the same original performance requirement. (See chart A) Recent data also shows that the M1 continues to fail most of its basic requirements. Despite full knowledge of the M1's shortcomings, the Army has aggressively promoted it, and questioned the honesty and motives of its critics.

"Sir, I appreciate this opportunity to respond. The Army has been very much concerned at the unprecedented media attack on the M1 tank that has occurred in recent months. We would characterize much of that attack as being based on incorrect information, innuendo, selective reporting from test reports that are out of date with no balancing of information." -- General Maloney, tstifying before the House Armed Services Committee in 1982 (hearings on HR 5968)

The data presented here was gathered primarily from U.S. Army sources, and the congressional record. Some information was also taken from established trade journals. Additional information and clarification was requested of the Army in January of this year, but as yet there has been no response. This information was originally to include a briefing on M1 tank performance, as well as current U.S. Army positions on the M1 and tank warfare. The information we gatehred shows some significant improvements, dramatic in the case of drivetrain reliability. Nevertheless, on the whole the M1 still appears ro fall short of many of its basic requirements.

The M1 is the most expensive tank in the world, its $4.3 million price tag nearly doubling the $2.4 million cost of the German Leopard II. Furthermore, its cost may continue to rise as quantities purchased drop, and expensive options are added. It should be emphasized that the German price of $2.4 million per tank, is achieved at a production rate of only 70 tanks a year.1 The M1's price has risen dramatically since quantities purchased fell from over 500 a year, to less than 250. It is conceivable that the Leopard II, if produced in such large quantities, its price would be even lower.

The M1's high price does not guarantee top performance. There are several competitive tanks in production today that are produced at much less cost (see chart A). Again, the M1A1 was built to meet the same basic requirements as the Leopard II, but costs more, and uses 90% more fuel when driven at a constant speed (In combat, it is likely that the M1 and M1A1 would consume much more.). And the Leopard II carries more ammunition. (See chart A) A common element among cheaper, more fuel efficient foreign tanks is that they are equipped with reliable, inexpensive diesel engines, tarther than the costly, temperamental turbine engine of the M1 tank. Indeed, the M1 may be the only military land vehicle ever equipped with a turbine engine.

Chart A

This chart list a comparison of tanks, fuels, range, guns and other features.

M1 Reliability Requirements

"Test results show that the M1 meets or exceed most reliability, availability, maintainability requirements established. It exceeds the combat mission reliability requirement by 10%, the system reliability requirements by 15%, and the maintenance ratio by 6%" -- Maj. Gen Durad D. Ball, testimony before the House Armed Services Committee, hearings on HR 2287, 1984

The M1 has in fact consistently failed five of its six Reliability, Availability, Maintainability and Durability (RAM-D) requirements, according to the last operational test, and actual use data collected in 1988 (See Chart B and C).

Many of the M1's reliability failures can be traced to its turbine engine. Every other tank in the world is equipped with a reliable, inexpensive diesel or gasoline engine. Turbines are complex, temperamental and expensive. Yet the Army has been less than forthcoming in justifying the necessity of the turbine, particularly in light of its cost and fuel consumption.

Is A Turbine Necessary?

"Obviously speed and agility are as much a means of survival as is armor protection. ... The ACT 1500 [turbine] engine used in the M1 provides that power." -- Lt. Col. Michael D. Jackson, "Auxiliary Power Unit for the M1 Tank", Army Research, Development & Acquisition Magazine, May-June 1984, p. 26.

In this statement, the Army suggests that a turbine engine is necessary to achieve the speed and agility of the M1. The German Leopard II is just as fast as the M1, because it has a 1500 horsepower diesel engine, the same horsepower as the M1's. (See Chart C) And though mobility is important, it is not all-important. Jane's Armour and Artillery 1988 states:

"Israeli experience in the 1967 campaign proved that mobility was no substitute for armour protection..." (p. 40).

Is A Turbine Reliable and Cost-Effective?

"There are two categories of satisfaction with the [turbine] engine, Mr. Chairman. One is, does it meet the operational needs of the tank, and it meets those very well. The tank performs very well with that engine. Its failure rate is less than our experience with our older diesel engine tanks." -- Maj. Gen. Durad D. Ball, 1993 hearing before the House Armed Services Committee

On the contrary, Army actual use figures show that the turbine-powered M1 requires unscheduled maintenance over five times as often as the diesel M60 tank.2 Furthermore, the M1 and M1A1 tanks cost three to four times as much to maintain as does the diesel-engined M60.3 (See Chart C)

One should take note of the low maintenance figures in Chart B. Reliability, Availability, Maintainability and Durability (RAM-D) requirements. These seem to meet or nearly meet the RAM-D requirements. However, if one goes to Chart C, "Actual Use Data," one can see that this low level of maintenance has a serious effect on the number of tanks available for use. In other words, the less time (maintenance hours) you spend maintaining your tanks, the less tanks there are to use on any given day.

Reference the last two columns in Chart C. As long as the numbers in the MH/H (maintenance hours per operating hours) figures are high, so are the availiability (Avlb) figures. When the MH/H figures go down to 1.0 for the M1 and .7 for the M1A1 in the 3/88 period, only 81% of the M1's and 79% of the M1A1's are available. A high rate of availability (95% is the Army's frequent claim) is implicit in the maintenance ratio (MH/H) figure. Therefore, these low maintenance ratio figures should not be used when evaluating the M1's reliability and maintainability.

The turbine engine also manifests its delicate nature by requiring extra care when operating in less than ideal conditions. The M1's operator's manual specifically warns that falling leaves and/or snow can be sucked into the air intake during normal operations. Both can require organizational maintenance. And if the tank crew attempts to clear snow and ice from the intake system, they may damage it.4

Chart B

This chart goes through some of the Army requirements vs. actual use in the M1 vs. M1A1 tanks.

Is A Turbine Fuel-Efficient?

"[I]f you had a diesel engine with the horsepower that you have with the turbine engine and the weight that you have, it would be about a 15-percent increase in fuel consumption by the turbine engine over the comparable diesel." -- 1982 testimony before the House Armed Services Committee: General Rogers

Again, the German Leopard II is just as heavy, (121,000 lb. for the Leopard II and 120,000 for the M1) and just as powerful as the M1 (1,500 horsepower for each), yet the M1 consumes 83% more fuel than the Leopard II when driven at a constant speed (1.71 gal/mile for the M1 vs. only .93 gal/mile for the Leopard II). (See Charts B and C)

The amount of fuel consumption in an armored division is of paramount importance. The Army's field manual FM 100-5 observes:

"Today, it is estimated that one armored division equipped with M1 tanks will consume over 600,000 gallons of fuel per day, more than twice the consumption of Patton's entire army." (and they ran out of gas!) (p. 60, chapter 4) (an M1 armored division has 348 tanks)

Chart C

This chart goes through the actual use of various different tank comparisons.

The Army has often contended that the bottom line in fuel consumption is the tank's capability of operating for a whole day without refueling. While this is important, it is also vital that sufficient fuel be available to accomodate daily refueling. As stated earlier, an M1 division is expected to consume roughly 600,000 gallons of fuel per day. To get this to the front requires a large supply train. And a tank battalion can only move as fast as its supply moves.

As a result of the M1's lack of fuel efficiency, the Army has had to increase the number of trucks that follow it. As of 1981, the army had to add the following equipment to each M1 tank battalion:

  • 6 five-ton trucks

  • 6 tank pump units

  • 1 semi-tractor with 5,000 fallon fuel trailer

  • 6 tank pump units

  • 6 1.5 ton cargo trailers

With the introduction of the M1A1, the fuel situation has worsened. The Army has had to add another four 10-ton, 2,500 gallon fuel carriers, according to Maj. Mazzia of the Army's Ft. Knox Armor School. This totals 128 support vehicles assigned to each battalion of 58 M1A1 tanks. While the M1 may be able to move quickly across terrain, it must always wait for these vehicles to catch up. Nonethelss, in the past, Army officials have seemed unconcerned about the M1's fuel consumption:

"We don't even think about the fuel consumption as a [tank crewman]. We don't care." -- Sgt. Kinney, hearings before the House Armed Services Committee, 1982.

Indeed, instead of combating the fuel consumption problem, the Army is making it worse: In an effort to standardize the fuel used by all Army vehicles, the Army will no longer use diesel to fuel the M1. Instead, a type of aviation fuel, which runs less efficiently in the M1, will be used by all Army vehicles.5 General Patton emphasized the folly of disregarding tank fuel consumption in his famous statement:

"My men can eat their belts, but my tanks gotta have gas."

The Three Basics of Tank Warfare

While reliability and fuel consumption are the M1's most dramatic features, the M1 has deficiencies in all of the three criteria by which a tank is judged: Mobility, Protection, and Firepower. Furthermore, there are a variety of state-of-the-art tanks available at much lower prices. (See Chart C)


"A 1500-horsepower engine supplies the Abrams with double the power of its diesel-powered predecessor, the M60. Coupled with an improved suspension system, its agility is unsurpassed by any tank in the world today." -- Written testimony of Lt. Gen. Louis C. Wagner, Jr., in hearings on HR 1872, 1985.

The M1's power to weight ratio and agility are matched by the M1's more fuel efficient diesel contemporaries (23.9 horsepower/ton for the M1A1 vs. 24.7 horsepower/ton for the Leopard II. See Chart A) And while the M1 has a very powerful engine, and an advanced suspension, it is handicapped by its track (tread) system. The M1 is the only series of tanks in the world that has permanently bonded (non-removable) rubber track pads. While this saves over a ton in weight, it makes the M1 very difficult to maneuver in mud, snow or ice, according to Army test results.6 On most other tanks, including the German Leopard II, the rubber pads are removable. This allows snow grousers to be substituted for greater traction. In addition, it means that the rubber pads can be replaced when they wear out. When the M1's pads wear out, the entire track shoe (section of track) must be replaced. In every M1 Quarterly Operation and Support Cost Study Report reviewed by the Project, more money was spent on track shoe assemblies than on any other part. (See appendices B and C)

In addition, the M1's suspension and track system suffers from a propensity for throwing the track off the tank. In particular, the armor that covers the top of the track system has a habit of trapping mud, snow and sand around the drive sprocket (the wheel which actually moves the track), which causes it to throw the track off the tank. Despite the Army's insistence that this problem has been solved, it was recently cited in a British Army review of the M1 tank.7 That article cites:

  • Poor suspension when compared to the excellent system on the Challenger (British main battle tank)

  • Short track life

  • Rear skirting plate allows mud to build up around sprocket, thus encouraging a thrown track


"The future battlefield will be thick with antitank weapons. Therefore, the Abrams is protected by advanced armor. This, plus its low silhouette and agility, increses its survivability on the battlefield." -- Written testimony of Lt. Gen. Louis Wagner, House of Representatives 1985, see previous quote.

Again, while the M1 has very advanced armor protection, and a low profile, so do other modern tanks. The M1 is unique, however, in suffering from an enormous heat signature. The heat signature (ability of the tank to be seen with infrared devices) of the M1 comes from the hot exhaust of its turbine engine. While the Soviets have reduced their tanks' thermal signature by roughly 24% in recent models8, we have increased our heat signatures dramatically by adopting the turbine engine for the M1. The M1's exhaust is so hot that it can burn the paint off a car should it follow the tank too closely. The operator's manual repeatedly warns that the exhaust if "very hot and can burn personnel."9 This means that the M1 is not only easily spotted, but is also positively identifiable at extremely long ranges with infared equipment - being the only tank in the world with such a heat signature.


"[The M1's] stabilized sighting system ensures that speed is combined with accurate firepower. Tankers are able to routinely hit 5-foot targets over a mile away while moving rapidly cross-country. This kind of shoot-on-the-move capability is made possible by design features of the fire control and improved suspension systems. ...the gunner need only squeeze the trigger to hit the target." -- Lt. Gen. Louis C. Wagner, congressional testimony, 1985.

All of the above capabilities are standard on most modern tanks. Furthermore, with the exception of the suspension system, all these features have been back-fitted to our M60 tanks. And the M1A1 carries less ammunition than any other tank listed in this report (See Chart A). In addition, the M1's thermal sight is often cited as a serious deficiency, as it was in the aforementioned British review of the M1A1 in U.S. Army Armor Magazine.10

Furthermore, to accomplish its mission, a tank needs more armament than just a good main gun system.

The tank's purpose is to bring machine-guns to bear on the enemy's unprotected rear, using speed and surprise. -- General George S. Patton

A tank's role is to break through enemy troop concentrations, and thereby lead assaults on their rear. While the main cannon is crucial to destroying enemy tanks blocking the initial breakthrough, the tank must then direct its attacks to infantry, and more-lightly-armored vehicles and equipment. For this it needs machine-guns.

The Army's last operational test of the M1 tank showed that the M1's machineguns were still limited in effectiveness.11 This has been acknowledged in test reports, including OT III. The Army has admitted it has problems with the M1's machineguns, but has allowed them to go unattended. The Army believes that machineguns are largely unimportant, as is illustrated by this Army response to criticism of the M1's machine-gun effectiveness:

"The main gun gives the tank its punch. A lesson from the Yom Kippur was illustrates this. ... The Israelis quickly relearned the message of combined arms operations... The key to success was combined arms operations, not the machine gun." -- U.S. Army information paper, "Criticisms of the M1", 4/25/1981.

Since the Yom Kippur war the Israelis have, among other things, made provisions for added heavier machineguns to their tanks, especially when operating in urban situations. Furthermore, both hatch-mounted machineguns are swivel-mounted, for easy operation by the crew.

The importance of tank support of infantry in urban areas was highlighted during the recent Panama invasion. The March-April issue of Armor magazine, an official U.S. Army publication, commented on this specifically. An article on M551A1 light tank performance in Panama states:12

Sheridans (M551A1's) were absolutely critical to fighting in built-up areas by providing direct fire support to infantry, as well as surgical fires capable of penetrating reinforce concrete buildings.

In built-up areas, the M2 .50 caliber machine gun on a flexible mount is superior to the weapons station found on M60- or M1-series tanks. Yes the [tank commander] is exposed, but it is easier for him to acquire targets and bring the .50 caliber to bear on those targets.

Satisfied with the performance of their .50 caliber machinegun, M551A1 crewmen also wanted another machinegun for the loader:

The M3A1 submachinegun is useless as a weapon for the loader. The loader needs a pintle-mounted machinegun (or an M16 [rifle] at minimum).

So according to recent combat experience in Panama, at least two pintle-mounted machineguns are needed to effectively support infantry from a tank. At present, the M1 has one pintle-mounted machinegun, and the aforementioned deficient .50 caliber commander's automated machinegun weapons station. It should be noted that with the installation of the commander's periscope on the new M1A2, the field of view/fire of the loader's machinegun will be significantly restricted.

Other Important Capabilities

"The problem is that neither the M1 nor the M60 or indeed neither any tank, has sufficient ground pressure to drive a [bulldozer] blade into even marginally hard ground. They are not bulldozers, they are tanks, whether you are talking about the M1 or the M60's. So if you are going to dig in a tank, you need to have some kind of equipment." -- Frank Carlucci, in hearings before the House Armed Services Committee, 1982.

It was discovered early on that the M1's drivetrain is too weak to push a bulldozer blade. This is important because most other tanks, including our older M60, and the Israeli Merkava, can and are often equipped with such blades to clear obstacles and dig in themselves and other tanks for defensive firing positions. While the above quote suggests that the Army has no dozer blade capability for the M60, or other tanks, the following statement from Jane's Armour and Artillery, 1988, details the M60's ability to be fitted with the M9 dozer blade kit (p. 119):

"This was developed as a depot retrofit package and is used to give already fielded M60's bulldozing capabilities similar to those of the M728 Combat Engineer Tractor ... which is used for clearing obstacles and preparing [tank] fire positions."

The ability to clear obstacles was another important capability cited in Armor magazine's analysis of armored operations in Panama:

M551A1's were used to drive over or eliminate enemy roadblocks that were constructed of cars, trucks, buses, concertina wire, and rubble.

While the M1 is likely capable of performing these light obstacle clearing duties, heavier ones that previously could be easily cleared with a tank-mounted dozer blade, may present problems for the M1.

The full story of the M1 Abrams tank cannot be told in a memo such as this. We have enclosed some documents, listed below. but have many more in our files. Please contact us if you have questions, or would like to see further documentation.

Further Documentation Available Through the Project:

  • The most recent U.S. Army Operation and Support Cost Studies for the M60, M1 and M1A1 tanks.

  • The most recent U.S. Army Logistic Management Analysis Summaries for the M60, M1 and M1A1 tanks.

  • Chapters from Jane's Armour and Artillery 1988 describing the M1, M1A1, M60, Leopard II and Merkava tanks.

  • M1 Operational Test Report III, and Independent Evaluation

  • Project On Government Procurement bibliography of Army quotes, footnoted with rebuttals

Notes on Charts

Chart A: Tank Capacities and Performance

This chart list a comparison of tanks, fuels, range, guns and other features.

The data in this chart is meant to reflect the official claims of performance and price by the countries involved. Much of this information comes from Jane's Armour and Artillery 1989. Jane's is a widely accepted source if such information. As is noted, other information was gathered from Israeli Defense Forces Journal, and the Pentagon's Procurement Programs (P-1) report to Congress. Further information regarding the Leopard II tank was obtained from the West German Liaison Office in Washington D.C., and from Kraus Maffei, tha manufacturer of the Leopard II's engine.

Calculated figures, including "mileage', and 'power', are direct calculations from the original figures. Mileage is arrived at by dividing the stated range by the stated fuel tankage. Tank "range" is generally taken to mean the distance a tank will travel on level roads at a constant speed of roughly 25 miles-per-hour. Power is simply the tank's stated weight divided by the power of the engine measured in horsepower. Weight, has been translated from metric to english tons (2,000 pounds = ton). Similarly, other weights have been converted from metric to english. Factors of conversion were taken from the Random House Dictionary of English Language, Second Edition.

We would like to emphasize that the range and mileage figures are generally taken to mean the distance a tank will travel on a level road, at a constant 25 mph. Actual combat involves much stopping and starting, and idle time with the engine running. (The M1 can only run on batteries for a very limited time, and has no auxillary power unit, which means the weapons systems cannot be kept ready without the engine running. Even if there were an aziliary power source, the main engine would have to on most of the time, since starting it up requires an elaborate, time-consuming procedure. The crew would not want to be surprised with the engine off.) The M1 in particular consumes roughly 15 gallons per hour at idle. Chart C, "Actual Use Data", provides a more realistic view of fuel consumption.

Chart B: U.S. Army RAM-D Requirements

This chart goes through some of the Army requirements vs. actual use in the M1 vs. M1A1 tanks.

The data in this chart comes from three sources within the U.S. Army: Operational Test III of the M1 tank, the Logistic Management Anaylsis Summaries for the M1 and M1A1 tanks, and the Quarterly Operation and Support Cost Study Reports for the M1 and M1A1 tanks. The latest copies available are enclosed. Army Reliability, Availability, Maintainability and Durability (RAM-D) requirements were taken from the written testimony of Maj. General Durad D. Ball, submitted to the House Armed Services Committee for hearings on HR 2287 [HR 2969], 1984, p. 1625.

Developing actual use data to determine whether or not these standards have actually been met was not a simple task. Since the Army has used a variety of values for M1 tank reliability, we are forced to try to compare those most similar in meaning. The Army's original Reliability, Availability, Maintainability and Durability (RAM-D) factors were stated in "Combat Mission" and "System" mean-miles-between-failure (MMBF). These are both values for the entire tank. What we have in our possission is a variety of figures which describes the components that make up the tank. They include mean-miles-between: "operational mission failure" (OMF), "essential maintenance actions" (EMA), and "unscheduled maintenance actions" (UMA), for each tank subsystem. By combining the values of all the subsystems, we can get total tank values for MMBOMF, MMBEMA and MMBUMA, respectively.

What is primarily in question is the definition of a "Combat Mission Failure" and a "System Failure". Once this is established, one need merely divide the number of miles traveled by that number, to get a mean-miles-failures value. Army test reports are very clear about what they consider generic "failures". In paragraph, page 119 of M1E1 OT II, the Army says:

The results should be comparable to the demonstrated mean miles between unscheduled maintenance actions (MMBUMA) reliability levels for the M1 tank.

This is perfectly manageable since MMBUMA in on of the values we have in hand. So this is the value I have used for "System MMBF" as defined on p. 124 of M1E1 OT II. However, combat mission failures are derived in a more complicated way: The Army breaks down the tank into subsystems relevant to the tank's mission. These subsystems are given "combat mission reliability factors" corresponding to their importance to the tank's mission. These values are multiplied by the number of actual failures. This is the Army's Combat Mission MMBF. (See p. 124, sec.2(U) para.

We cannot use this definition because the subsystems listed in our data are different than the ones grded by "combat mission reliability factor". For instance our data includes "gun mount recoil" in "turret hydraulics", rather than placing it in a separate category. For this reason, I have used an arguably more lenient standard for failures to be included in this category. The figures listed in the chart as "actual combat mission mean miles between failure" use the Army's "Mean-Miles-Between-Operational-Mission-Failures". Instead of including and grading failures which degrade the tank's performance, this value includes only failures that meet the following strict requirement found on page C-3 of the Army's 31 October 1988 Logistic Management Analysis Summary for the M1A1 Abrams Combat Tank:

An unscheduled maintenance incident where the mission was aborted due to the loss of its mission essential function (i.e., movement or power source). (Used to establish MMBOMF.)

In other words, the Army approximates actual mean miles between combat mission failures by recording failures which merely hamper the tank, and grade them so that they theoretically add up to the number of times the tank is actually unable to perform its mission. Our definition records precisely the actual failures which make it totally unable to perform its mission.

Bear in mind that our definitions and data are real world values, which indicate the actual performance of the tank. The Army's values are developed from the highly-controversial "scoring conferences" which disqualify any error attributable to crew or maintenance error, or which can be fixed later on in development. Remeber, however, that the data we have involves well trained crews and maintenance personnel of active Army units, not people unusually fresh to the M1 system. And it involves production tanks which represent the actual performance of the M1 system, which in some sense, the scoring conference was seeking to simulare (they didn't want the tank maligned by problems that would eventually be fixed). It should also be noted that, as in Army test figures, the actual use figures we use disqualify any maintenance action that can be accomplished in less than 30 min. by the operator or crew using equipment and parts available on the tank.

Chart C: Actual Use Data

This chart goes through the actual use of various different tank comparisons.

Chart Citations

1. This is a 1990 price which comes from DoD's 1/9/1989 version of Procurement Programs (P-1), which is a budget information package distributed to Congress.

2. This figure was submitted for the record and is included in the record of House Armed Services Committee hearings on H.R. 596 [H.R. 6030], p. 371.

3. 85 rounds is a maximum. According to Jane's Armour and Artillery 1988, 62 is the normal load. Also a squad of ten infantrymen can be substituted for 45 main gun rounds.

4. Associated Press, May 3, 1989

5. All data on the Mk3 comes from IDF Journal, issue #17, summer, 1989, "Israel Unveils Its Homemade Tank".

6. This figure was supplied by MTU of West Germany, the manufacturer of the Leopard II's diesel engine.

7. This price was given by the German Procurement Liaison Office, in Washington D.C.. The $2.4 million figure was given for the latest Leopard II's produced.

8. While this maintenance ratio nearly meets the required maximum of 1.25 man-hours per operating hour, it does so at a sacrafice of tank availability. "Availability" is the average number of tanks available for combat each day during a reporting period. The tank sample on which the 1.4 mh/oh rate is based had an availability rate of only 88%, far below the 95% figure the Army claims as standard.

9. Again, meeting this requirement meant sacrificing availability. This tank sample achieved only 82% availability. See previous quote.

10. See M1 Operational Test III. In this case the unadjusted figures were 15% likelihood of going 4000 miles without a major powertrain overhaul. These are the last operational test figures the Army ever released (1981). The adjusted figure, which the Army put forward at the time, was still only 22% (as opposed to the 50% requirement). If you have any questions regarding these "adjustment" please ask us for information on "scoring conferences".

11. While we have no numerical data on this, Maj. D.I. Viccars, Cdr. Sqn. 3d RTR, complains of "short barrel life" in his article, "A British Tank Squadron Tries the M1A1", Armor magazine, U.S. Army Publications, September-October 1989.

12. While this is an impressive figure, notice the effect this lack of maintenance has on availability. 81% is not nearly as good as the 95% often claimed by the Pentagon.

13. See previous note.


Appendix A: Letter to U.S. Army Chief of Public Affairs Requesting Briefing

Appendix B: "Reporter's Notebook" section of July 2, 1990 Defense Week noting Army's lack of response to our inquiries

Appendix C: "Michigan-Built Tank a Bad Deal for Army, Report Says," Detroit News, July 16, 1990

Appendix D: Letter to Detroit News Editor from Donald Gilleland, Director of Communications, General Dynamics Land Systems Division

Appendix E: Letter from Project on Government Procurement to Donald Gilleland, General Dynamics Land Systems Division


1. Figures provided by the Federal Germany Liaison Office, Washington D.C..

2. See the Army's Logistic Management Analysis Summaries, for the M60 and M1 tanks. Latest periods available are 10/85 - 4/86 for the M60, and 1/88 - 6/88 for the M1.

3. See the Army's Operation and Support Cost Study, Field Usage Summaries for M1, M1A1, and M60 for 1985 through 1988.

4. U.S. Army manual Technical Manual, Operator's Manual, Operation Under Usual and Unusual Conditions: Tank, Combat, Full-Tracked, 120-MM, M1A1, TM 9-2350-264-10-2, p.2-398.

5. See David Evans, "Tanks Running on Poor Ideas and Bad Planning," Chicago Tribune, September 1, 1989.

6. See p. 21 of U.S. Army Report IER-OT-058: Independent Evaluation of the M1 Main Battle Tank.

7. Maj. D.I. Viccars, Cdr. Sqn., 3d RTR, "A British Tank Squadron Tries the M1A1", Armor Magazine, U.S. Army Publication, September-October 1989, p. 16.

8. See Stephan P. Rosa and Sgt. 1st Class Thomas Lindley, "Tank Thermal Signatures: The Other Variable in the Gunnery Equation", Armor Magazine, September-October 1989, p. 31.

9. U.S. Army M1A1 Operator's Manual, Op. Cit., p. 2-408.

10. Maj. D.I. Viccars, Op. Cit.

11. See p. iv of U.S. Army report IE-OT-058: Independent Evaluation of the M1 Main Battle Tank.

12. This is not intended to be an argument for procuring M551A1 over the M1. The M551A1 is a light tank and is not designed to have the capabilities of a main battle tank. Nonetheless, it was the only Army tank available for Panama, and performed infantry support missions that the M1 could be called upon to perform in other situations.