United States General Accounting Office

GAO Report to Congressional Requesters

April 1996 M1 TANKS

Status of Proposed

Overhaul Program

G O A

years

1921 - 1996

GAO/NSIAD-96-100

GAO United States

General Accounting Office

Washington, D.C. 20548

National Security and

International Affairs Division

B-271121 

April 10, 1996

The Honorable Floyd D. Spence

Chairman

The Honorable Ronald V. Dellums

Ranking Minority Member

Committee on National Security

House of Representatives

The Honorable Glen Browder

House of Representatives

House Report 104-131 to the National Defense Authorization Act for Fiscal

Year 1996 expressed concerns about the absence of a procurement

program to modernize the M1 tank fleet beyond the upgrade of existing

tanks and to address new tank threats that are appearing. The report

requested that we determine whether the (1) current readiness level of the

M1 tank is adequate to meet its war-fighting requirements, (2) operating

condition of the tanks at the National Training Center (NTC) is adequate to

meet training requirements, and (3) change in repair parts funding has

adversely affected unit maintenance. In discussions with members of your

staff, we were also asked to report on the status of the Army’s proposed

M1 tank overhaul program, which is referred to as the Abrams Integrated

Management XXI (AIM XXI) program.

Background The Army started fielding the M1 Abrams tank (the Army’s main battle

tank) in the early 1980s. Table 1 shows as of October 1995, there were

about 7,600 M1s (in various configurations) in active and reserve Army

and Marine Corps units and war reserve and prepositioned storage sites.

Since the initial fielding, the M1 has undergone several modernization and

enhancement upgrades.

Page 1 GAO/NSIAD-96-100 M1 Tanks
B-271121 

Table 1: Number of M1 Tanks by

Configuration as of October 1995 Configuration Number Description

M1/IPM1 3,141 The IPM1 is the improved version of the basic

M1. The IPM1 has an extended turret, increased

capacity shock absorbers, and added armor.

M1A1 4,351 The M1A1 has a larger gun (120mm) than the

M1; nuclear, biological, and chemical

overpressure system; and additional armor

protection.

M1A2 87a The M1A2, an enhanced version of the M1A1,

has depleted uranium armor, digital electronics,

an improved commander’s weapons station, a

positioning navigation system, a commander’s

independent thermal viewer, an intervehicular

information system, a radio interface unit, and a

commander’s integrated display.

Total 7,579

aWhen fielding is completed in about 2004, the M1A2 fleet will consist of 1,079 tanks, which is

sufficient to equip all the early deploying contingency forces (force package 1) and some of the

forward deployed forces (force package 2).

The M1 tank was not designed with a depot overhaul maintenance

strategy.1

 The maintenance strategy envisioned that maintenance would be

performed at the organizational, direct support, and general support

levels. Tank items that could not be repaired at those maintenance levels

would be sent to the depot for repair. It was never planned for the entire

tank to be completely overhauled, unless the tank was involved in an

accident, suffered battle damage, or experienced some other catastrophic

failure.

How much maintenance would be performed and where it would be

performed was influenced by the Department of Defense’s decision to

change repair parts funding. Beginning in 1992, Army units had to use their

operation and maintenance funds to buy repair parts and major

components. Prior to this, units did not pay for major components, such as

engines or transmissions. These items were “free issue” to units and there

was little incentive to repair them. It was easier and cheaper to order a

new engine or transmission from the supply system. Concerns have been

raised that under the new system, commanders might defer maintenance

to conserve unit operation and maintenance funds.

1

If a tank has a depot overhaul maintenance strategy, it is shipped to the depot where it is completely

disassembled. The disassembled items are inspected and repaired or replaced. The tank is then

reassembled and considered to be in like-new condition.

Page 2 GAO/NSIAD-96-100 M1 Tanks
B-271121 

Results in Brief As of March 31, 1995, over 94 percent of the active and reserve Army units

reported that their M1 tanks were ready to perform the majority of the

assigned wartime missions; about 56 percent of the units reported that

their M1 tanks were ready to perform all of their assigned wartime

missions.

Because of the high operating tempo of the training tanks, the M1 tanks at

NTC are experiencing more maintenance problems than tanks in active

Army units. However, in spite of the maintenance problems, NTC has

fielded the required number of tanks to meet all of its training

requirements. On average, the NTC M1 fleet maintained an operational

readiness rate of about 82 percent for the 8-month period that ended

December 1995.

Commanders at three Army divisions that have 834 M1 tanks told us that

the change in repair parts funding had not caused them to alter their

maintenance approach. The commanders cited some instances in which

they had experienced repair parts shortages. However, they emphasized

that lack of funds to buy the parts was not the reason for the shortages.

The parts were generally not available in the supply system.

Notwithstanding, some Army officials have proposed a M1 overhaul

program, at a cost of $559,000 a tank, because they were concerned that

latent deficiencies that do not show up during routine readiness

inspections could show up during wartime and affect the tanks’

performance. Other Army officials, however, are resistant to the overhaul

program because of concerns that the program would take funds away

from the ongoing M1A2 upgrade program. The Army does not maintain

data that shows the extent, if any, of the latent deficiencies, nor does the

Army have a predictive readiness system that would show what would

happen to operational readiness if there were no depot overhaul program.

At the time we completed our review, the Army had not made a decision

concerning the proposed overhaul program.

Reported Readiness

of the M1 Tank Fleet

Is High

We used the Status of Resources and Training System (SORTS) report to

assess the readiness of M1 tanks. SORTS uses C-rating designations to

denote degrees of readiness: C-1 is the highest readiness rating and C-5 is

the lowest.

Our analysis of the SORTS data as of March 1995 showed that over

94 percent of the units with M1 tanks reported that their tanks were C-3

Page 3 GAO/NSIAD-96-100 M1 Tanks
B-271121 

(can accomplish the majority of the assigned wartime missions) or higher

and that about 56 percent of the units reported that their tanks were C-1

(can accomplish all of the assigned wartime missions). Table 2 shows the

distribution of C-ratings.

Table 2: Readiness Ratings as of

March 1995

C-rating

Number of M1

tank units

Cumulative

percent

C-1 39 55.7

C-2 25 90.9

C-3 2 94.3

C-4 3 98.6

C-5 or lower 1 100.0

Total 70

Discussions with officials at three Army divisions that have 834 M1 tanks

confirmed that they were not experiencing any major readiness-related

maintenance or supply problems with their tanks. The officials were

confident that they could deploy as required and carry out their assigned

missions.

The M1 tanks at NTC and the M1 tanks that were in prepositioned storage

were also reported to be in a high state of readiness (as shown in table 3).

Table 3: Reported Readiness Rates of

M1 Tanks at NTC and in Prepositioned

Storage (as of October 1995) Prepositioned storage

location:

Number

of tanks

Operational

readiness rate

(percent) Comments

2 348 99 Equates to C-1

readiness rate

3 123 100 Equates to C-1

readiness rate

4 116 81 Equates to C-2

readiness rate

5 116 96 Equates to C-1

readiness rate

NTC 109a 82b Equates to C-2

readiness rate

aThe number of tanks at NTC ranged from 89 to 122 during the 8-month period ending

December 1995.

bThe operational readiness rates of the NTC are an 8-month average as of December 1995.

Page 4 GAO/NSIAD-96-100 M1 Tanks
B-271121 

Training Not

Adversely Affected by

Operating Condition

of M1 Tanks at NTC

NTC is authorized 122 M1 tanks (2 battalions) for training. These tanks are

operated at a higher tempo than tanks in a typical tactical unit. For

example, each tank averages about 2,300 miles a year, compared with the

Army-wide average of about 630 miles a year. The NTC M1 tank fleet

averages about 8,400 miles, compared with the Army-wide average of

about 3,500 miles.

As a result of the high operating tempo, the NTC M1 tanks have

experienced many more maintenance problems than the tanks in the

tactical units. However, according to NTC officials, the tanks have not

missed any training days due to the maintenance problems. The officials

said that they are always able to provide the training unit with the required

number of tanks because only one of the two tank battalions is being used

at a time2

. Another factor that has enabled NTC to meet its training

requirements is that its tanks are cycled through the Anniston Army Depot

under the Army’s inspection and repair only as needed (IRON) program.

Under the IRON program, the tanks are inspected and those components

and systems that do not meet the minimum operating characteristics are

repaired or replaced.3

 For example, if an engine does not meet its 

1,350 horsepower characteristic, repairs are performed. Anniston officials

told us that the NTC tanks generally need a lot of work when they arrive.

They said, however, that the tanks’ condition is about what could be

expected considering the tanks’ high usage rate.

NTC officials and officials from a unit that was training at NTC at the time of

our visit said that the condition of the tanks and the maintenance

problems had not detracted from the realism of the training. Unit officials

also said that the condition of the NTC tanks may not be as good as the

condition of the tanks at their home station, but this added to the training

realism because, in a wartime situation, tanks will have maintenance

problems and personnel need to know how to deal with them.

2

The training unit is issued 58 M1 tanks. While these tanks are being used for training, the remaining

tanks are being readied for the next training rotation.

3

The average cost of the program is $196,000 a tank, and the program is expected to be completed in

fiscal year 1996.

Page 5 GAO/NSIAD-96-100 M1 Tanks
B-271121 

Change in Repair

Parts Funding Has

Not Adversely

Affected Unit

Maintenance

Some Army officials have expressed concern that the change in repair

parts funding could lead unit commanders to delay maintenance because

they may not have the funds to buy the needed repair parts. In prior

reports,4

 we stated that this is generally not the case. With few exceptions,

the lack of funds to buy repair parts has not been a problem. In fact, we

have reported that units often transfer funds intended for repair parts and

maintenance to other operation and maintenance purposes.

None of the officials we spoke with at three Army divisions cited the lack

of operation and maintenance funds to buy repair parts as a problem. The

commanders said that the shortages they experienced were not caused by

a lack of repair parts funds, but rather by a lack of repair parts in the

supply system.

During our visits to the three divisions and NTC, we compiled a list of

repair parts that were in short supply at the units and determined their

supply position at the wholesale level inventory control points. The results

of our analysis are shown in table 4.

Table 4: Wholesale Inventory Level for

Repair Parts in Short Supply at the

Unit Level On hand

Wholesale inventory level

Repair part Serviceable Unserviceable Back ordered

Rear engine module 8 653 75

Hydraulic motor 0 118 104

Front engine module 45 740 50

Exhaust seala 0 0 1,116

aThe exhaust seal is not a reparable item. Therefore, there are no unserviceable items on hand.

The problems being experienced with the M1 tank’s rear engine module is

illustrative of the type of problems the Army faces with the other parts

shortages. As of December 7, 1995, there were only eight serviceable M1

tank rear engine modules in the supply system, and all eight modules were

4

Depot Maintenance: Some Funds Intended for Maintenance Are Used for Other Purposes

(GAO/NSIAD-95-124, July 6, 1995).

Army Training: One-Third of 1993 and 1994 Budgeted Funds Were Used for Other Purposes

(GAO/NSIAD-95-71, Apr. 7, 1995).

Army Inventory: Reparable Exchange Items at Divisions Can Be Reduced (GAO/NSIAD-95-36, Dec. 28,

1994).

Army Inventory: Opportunities Exist for Additional Reductions to Retail Level Inventories

(GAO/NSIAD-94-129, June 6, 1994).

Page 6 GAO/NSIAD-96-100 M1 Tanks
B-271121 

in prepositioned war reserve. At the same time, there were backorders for

75 modules, of which 53 were high priority backorders.

According to Army officials, there are sufficient engine rear modules in the

supply system, but most of the modules are unserviceable because of a

shortage of repair parts to fix the modules. The officials attribute the

shortage of repair parts to (1) insufficient demand forecasting due to

Bosnia operations, (2) implementation of an engine service life extension

program before the needed repair parts were in the system, (3) worsening

condition of returns from the field (the returned items require extensive

repairs), and (4) a reduced number of qualified part suppliers in the

industrial base.

Cost and Benefits of

Army’s Proposed M1

Tank Overhaul

Program Are

Uncertain

Some Army officials in the maintenance community believe that an M1A1

overhaul program is needed because of the fleet’s age and because there is

no new tank production planned. The officials acknowledge that reported

readiness rates are high. However, they are concerned that there may be

latent deficiencies in the tanks that are not detected during readiness

inspections and that these deficiencies could affect the tanks’ operational

capabilities during a conflict.

To address the potential latent deficiencies, the officials proposed a joint

proof of principle test program with General Dynamics (the M1

manufacturer) to essentially overhaul the M1A1 tanks. The proposed joint

effort is referred to as the AIM XXI program, and the officials believe that it

would produce a better-than-original M1A1 tank that would enhance

training, be more reliable, and have sustained go-to-war capability.

Additionally, the officials believe that the program would reduce the tank’s

life-cycle operating and support costs.

Under the AIM XXI proof of principle test, the Army would bring 17 M1A1

tanks to the Anniston Army Depot and completely rebuild and update

them with the latest modifications. The estimated cost of this effort is

$559,000 per tank, about $9.5 million total. The Army Materiel Systems

Analysis Activity (AMSAA) would compare certain operational

characteristics, for a 9-month period,5

 of the AIM XXI tanks with IRON tanks

and with tanks that had not received any depot level maintenance. On the

basis of evaluation of the test data, the Army would decide whether to

5

The operational characteristics would include maintenance actions per mile, operating cost per mile,

availability, and reliability.

Page 7 GAO/NSIAD-96-100 M1 Tanks
B-271121 

expand the AIM XXI program. Appendix I shows the scope of work under

these two programs.

AIM XXI program officials estimate that over a 20-year life cycle, the

program for the 17 tanks would result in operating and support cost

savings of about $28.8 million, compared with the IRON program. However,

if the investment cost differential is considered, the overall savings for 20

years is reduced to about $24.4 million, about $1.2 million a year.

AMSAA officials who have responsibility for validating the estimated savings

told us that they could not project cost savings for an AIM XXI program

beyond the proof of principle because any projected savings would not be

data driven. They said that they believe the AIM XXI program would result in

some operating and support savings, but they were unsure how much. The

officials also said that they would be in a better position to estimate the

savings after the proof of principle test was completed and the operational

characteristics of the AIM XXI, IRON, and nondepot maintenance tanks are

compared and evaluated.

AMSAA and depot officials also told us that the savings calculations were

based on certain assumptions on tank mileage and repair and maintenance

costs that may not be representative of the M1 tank fleet. AMSAA officials

said that the mileage (1,500) used to compute the annual operating and

support cost was not typical of the usage in an operating unit, which

averages about 630 miles a year. Consequently, the estimated savings

between AIM XXI and IRON tanks would be much less and this, in turn, would

reduce the life-cycle savings. Depot officials also told us that the direct

IRON program costs had been reduced to $196,000 a tank for fiscal year

1996, compared with the $266,000 used in the analysis. This reduction

would reduce the investment cost for the 17 IRON tanks to about

$3.9 million.

AIM XXI program officials told us that one of the difficulties they are facing

is that there is no empirical data that shows there are latent deficiencies in

the tanks as a result of not having a depot overhaul program. Additionally,

the Army does not have a predictive readiness system to demonstrate that

if the tanks are not overhauled, the tanks will not be able to maintain a

high rate of operational readiness.

The officials also told us that if the test data proved what they expected

and that if the AIM XXI program was approved, they would like to begin

Page 8 GAO/NSIAD-96-100 M1 Tanks
B-271121 

inducting an average of 66 M1A1 tanks into the depot beginning in fiscal

year 1998 and continue the program for 20 years.

The concern raised by Army officials and unit commanders about the AIM

XXI program centered on the impact the program could have on the M1A2

modernization effort. The officials said that in today’s budget environment

the funds for the AIM XXI program would probably come from some

existing program as it was unlikely that the Army would receive additional

budget authority for the program. They said that while it would be nice to

have overhauled M1A1 tanks, they would much rather have M1A2 tanks.

Therefore, if the AIM XXI program would result in M1A2 fielding delays, they

would opt for the M1A2 tanks.

Anniston officials said that because General Dynamics is involved in both

the AIM XXI and M1A2 programs and both programs could be performed in

the same facilities, the M1A2 unit cost should be reduced. However, they

were not able to estimate the extent of the cost reduction.6

Anniston officials also told us that in the absence of the AIM XXI program or

some other heavy armor work, the depot could lose as much as 50 percent

of its heavy armor repair capability and the lost capability would be

difficult to replace in a surge situation. They said that when the IRON

program is completed in fiscal year 1996, the depot’s workload will consist

primarily of component repair.

The officials also said that, in their opinion, the AIM XXI program would not

only increase the availability, reliability, and fightability of the M1 tank

fleet but also protect industrial base core capabilities that would be

needed in time of conflict.

Scope and

Methodology

To determine the readiness of the M1 tank fleet, we reviewed data from

the Army’s readiness reporting system along with readiness reports from

three Army divisions and the NTC, which we visited during our review. We

also interviewed brigade and battalion officials at the three divisions and

officials at NTC to obtain their views on the operating condition of their M1

tanks and the tanks’ ability to perform assigned missions.

6

Under the AIM XXI proposal, Anniston would perform about 70 percent of the overhaul effort 

(2,700 hours per tank), and General Dynamics Land Systems would perform about 30 percent of the

overhaul (1,300 hours per tank). Under the M1A2 program, Anniston performs about 33 percent of the

work (1,560 hours per tank), and General Dynamics Land Systems performs about 68 percent of the

work (3,200 hours per tank).

Page 9 GAO/NSIAD-96-100 M1 Tanks
B-271121 

At NTC, we focused on the maintenance of the tank fleet and on training

realism. We also obtained the views of contractor personnel who maintain

the M1A1 tank fleet.

To determine whether the change in repair parts funding had affected the

units’ ability to maintain the M1 tank, we interviewed Army division

officials at the three divisions. We also identified parts that were in short

supply and that were (in the opinion of division officials) affecting the

divisions’ maintenance capabilities. We then obtained the supply position

of these items at the wholesale level and discussed the reasons for the

shortages with wholesale level supply management officials.

We interviewed Army and contractor officials and reviewed

documentation relating to the proposed AIM XXI overhaul program for the

M1 tank fleet. We obtained the officials’ views on the need for such a

program, along with their proposals to test and implement the overhaul

effort. We also reviewed the effect of the proposed overhaul program on

future tank repair workload at the maintenance depot by examining depot

workload statistics and forecasts and obtaining the views of depot

officials.

Our review was conducted at the

• Office of the Project Manager, Abrams Tank System, and the Army

Tank-Automotive and Armaments Command, Warren, Michigan;

• Army Materiel Command, Alexandria, Virginia;

• Office of the Deputy Chief of Staff for Logistics, Pentagon, Washington,

D.C.;

• National Training Center, Fort Irwin, California;

• Anniston Army Depot, Anniston, Alabama;

• 1st Infantry Division (Mechanized), Fort Riley, Kansas;

• 1st Cavalry Division and the 2nd Armored Division, Fort Hood, Texas; and

• Army Materiel Systems Analysis Activity, Aberdeen Proving Grounds,

Maryland.

The Department orally commented that it fully concurred with our draft

report. We conducted our review from August 1995 to February 1996 in

accordance with generally accepted government auditing standards.

Page 10 GAO/NSIAD-96-100 M1 Tanks
B-271121 

We are sending copies of this report to the Secretaries of Defense and the

Army; the Director of the Office of Management and Budget; and the

Chairmen of the House Committee on Government Reform and Oversight,

Senate Committee on Governmental Affairs, House and Senate

Committees on Appropriations and Senate Committee on Armed Services.

Please contact me on (202) 512-5140 if you have any questions concerning

this report. Major contributors to this report are listed in appendix II.

Mark E. Gebicke

Director, Military Operations

 and Capabilities Issues

Page 11 GAO/NSIAD-96-100 M1 Tanks
Appendix I 

Scope of Work for Abrams Integrated

Management XXI Program as Compared

With Inspect and Repair Only as Needed

Program

SUBASSEMBLY AIM XXI IRON

AGT-1500 turbine engine —Complete disassembly and

100-percent inspection

—New high-pressure turbine blade

assembly

—New high-pressure nozzle

—Improved double bellows recuperator

(laser welded plate pairs)

—New power shaft ring seal

—New critical position bearings

—New critical position seal

—Limited disassembly

—Limited inspection

—Minor repair

—Components replaced as indicated by

failure

X1100-3B transmission —Complete disassembly and

100-percent inspection

—New style steering pistons (aluminum)

—New governor

—New pump and motor cups

—New output shaft

—New internal wiring harness

—Inspect/replace hanging ring

—Non-destructive test of

pistons/housings

—Complete dynamometer testing

—Limited disassembly 

—Limited inspection

—Minor repair

—Components replaced as indicated by

failure

—Dynamometer tested to abbreviated

acceptance testing procedure

Suspension/track —100-percent disassembly, clean, and

inspect

—Replacement of mandatory

replacement parts

—Replacement of compensating idler

arm bearings

—Compensating idler, roadwheel arm,

and shock absorbers removed and

inspected

—Replaced only the degree of

disassembly 

—Replaced only if inspection requires

Optical fire control —100-percent disassembly, clean, and

finish

—Replacement of mandatory

replacement parts

—100-percent inspection of solder joints,

connectors, and electronic components

—Disassemble only to degree necessary

to correct deficiency

—Replaced only to degree of

disassembly

—Visual inspection to degree of

disassembly

Electro-hydraulic pneumatics —100-percent disassembly of slip ring

—Replacement of mandatory

replacement parts

—100-percent inspection of contact

rings, solder joints, wipers, brushes, and

connectors

—Complete cleaning, inspection, and

repacking of internal bearings

—Disassemble only to degree necessary

to correct deficiency

—Replaced only to degree of

disassembly

—Visual inspections to degree of

disassembly

Thermal components —100-percent vendor reclamation —Repaired to direct support/general

support level

Electronics —100-percent disassembly, clean, and

inspect

—Replacement of mandatory

replacement parts

—100-percent inspection of solder joints,

connectors, and wiring harnesses

—Disassemble only to degree necessary

to correct deficiency

—Replaced only to degree of

disassembly

—Visual inspections to degree of

disassembly

Page 12 GAO/NSIAD-96-100 M1 Tanks
Appendix II 

Major Contributors to This Report

National Security and

International Affairs

Division, Washington,

D.C.

Sharon A. Cekala

Robert J. Lane

Kansas City Regional

Office

James S. Moores

Darryl S. Meador

(703114) Page 13 GAO/NSIAD-96-100 M1 Tanks
Ordering Information

The first copy of each GAO report and testimony is free.

Additional copies are $2 each. Orders should be sent to the

following address, accompanied by a check or money order

made out to the Superintendent of Documents, when

necessary. VISA and MasterCard credit cards are accepted, also.

Orders for 100 or more copies to be mailed to a single address

are discounted 25 percent.

Orders by mail:

U.S. General Accounting Office

P.O. Box 6015

Gaithersburg, MD 20884-6015

or visit:

Room 1100

700 4th St. NW (corner of 4th and G Sts. NW)

U.S. General Accounting Office

Washington, DC

Orders may also be placed by calling (202) 512-6000 

or by using fax number (301) 258-4066, or TDD (301) 413-0006.

Each day, GAO issues a list of newly available reports and

testimony. To receive facsimile copies of the daily list or any

list from the past 30 days, please call (202) 512-6000 using a

touchtone phone. A recorded menu will provide information on

how to obtain these lists.

For information on how to access GAO reports on the INTERNET,

send an e-mail message with "info" in the body to:

info@www.gao.gov

PRINTED ON RECYCLED PAPER
United States

General Accounting Office

Washington, D.C. 20548-0001

Official Business

Penalty for Private Use $300

Address Correction Requested

Bulk Rate

Postage & Fees Paid

GAO

Permit No. G100