By Don Loughlin,Loughlidon@aol.com 360-318-1134
Revised 22-Jul-2000

This paper is a rebuttal to a 1998 U.S. Army Strategic Studies Institute (SSI), Army War College, report: "The Case for Army XXI 'Medium Weight' Aero-Motorized Divisions: A Pathway to the Army of 2020" (1), insofar as it deals with "Armored Fighting Vehicle Options."

A. Foreword.

The SSI report is associated with the "GEN Shinseki initiative", the Army's Chief of Staff (CSA) since 21 June 1999. The initiative is Shinseki's move to transform the Army's strategic deployment capabilities by creating lightweight Brigades capable of rapid airlift. (2, 3) Many of the things said, or left unsaid, about these Brigades are puzzling.

For example, the CSA never mentioned the very clear need for more or improved sea- and airlift capability. Then he dropped a figurative bombshell announcing a potential plan to buy an all-wheeled vehicle fleet that allegedly will save 50%-70% of vehicle weight. (2) His attempted later qualifier that it would be done "...as soon as technology permits..." did not quell the uproar. (3) The fact that he offered no evidence or sources to support the supposed weight saving of wheeled combat vehicles makes his decision all the more mystifying. In searching for the rationale for the "wheels" initiative, a colleague told this writer about the SSI report, which is the subject of this rebuttal. If the SSI paper is the best that can be said for replacing light armored tracked vehicles with armored cars (shorter than "wheeled armored vehicles"), then the argument is very weak, indeed.

A point about the SSI report is that it was published over a year before GEN Shinseki took office. Thus, at some level in the hierarchy, the push for armored cars predates the Shinseki régime. What is harder to understand is just why the push exists; and the SSI report doesn't explain it. The SSI report states some worthy goals in its Foreword (See Appendix). However the report itself claims that:

1. The Army's force structure suffers because the force has a "barbell posture", a mixture of very light and ultra-heavy combat formations. That is an exaggeration insofar as it relates to hardware, specifically combat vehicles.

2. "...strategic responsiveness coupled with enhanced theater agility and combat power..." will be improved by creating "...medium weight combat units... ...equipped with light armored vehicles..." (p. iii) The context makes it clear that "light armored vehicles" means wheeled light armored vehicles, and that the "strategic responsiveness" can supposedly be accomplished by just buying wheeled light armored vehicles (anybody's?) without ever describing the physical or operational characteristics of these same armored cars.

3. Furthermore, the report appears to postulate a current light armored vehicle population of zero. It completely ignores, as if they didn't exist, the family of approximately 13,000 M113-series tracked light armored vehicles already in the operational fleet, all capable of C-130 transport. The M113 family has later versions as well, but the point here is to highlight vehicles already in the Army's fleet that, for some unstated reason, the authors of the SSI report have chosen to discount at 100%.

This is what the SSI report says, or omits:

A. The "barbell organization".

"The authors contend that today's Army is essentially a "barbell" shaped organization: very light or very heavy forces with very little in the form of "middleweight" units.."(p. 1, and similar statements on at least five other pages: iii, 3,4,7, and 16.) Elsewhere in the report, in much the same vein, it makes this claim: "The Army has been generally configured into either very heavy armored and mechanized units armed with large numbers of heavy fully tracked vehicles or very light infantry-type units that are primarily foot mobile." (p. 4)

As to armored combat vehicles, the "barbell" description is both exaggerated and misleading. In addition to foot-mobile infantry, and in addition to the "heavy fully tracked vehicles" (M1 Tanks, and presumably M2 and M3 Bradley Fighting Vehicles); the Army already has a fleet of M113-series tracked, light armored vehicles fully capable of C-130 airlift. The authors are correct in that the Army is organized roughly along "barbell" lines, but it is not equipped that way.

Since the authors believe in a "medium weight force" comprised of armored cars to rectify the alleged barbell organization, how can it be that such vaguely described vehicles, of unknown performance, are any more of a strategic deployment improvement than M113-series vehicles, of known weight, size, cross-country mobility, and armor protection, and that the Army already owns? Why aren't M113s the medium weight force? Is it that the M113s lack "staying power" in a fight? Then the report should state the staying power of the undefined armored cars. The authors say nothing of the weapons, armor protection, speed, fuel consumption, cost (acquisition or life cycle), personnel carrying capacity, or whatever of the unspecific armored cars they espouse. For example, once upon a time, the large rear exit ramp/door of tracked APCs was considered to be a significant asset for both relatively safe and rapid exit of troops and rapid loading of cargo. Is that consideration no longer valid? Or do the armored cars espoused have such rear exit doors? Do the SSI authors even know, one way or another?

B. Why not even a mention of the M113?

What is astounding is that nowhere in the SSI report is the M113-series vehicles ever mentioned. The M113-series fleet has an existing production and logistic support base, and every M113 is fully capable of C-130 aircraft transport - and airdrop as well. There are about 13,000 M113s of all variants in the operational inventory, with another 6,000 stored in depots in varying condition. Approximately 3-4 thousand M113s in the operational inventory are the M113A3s that participated successfully in Operation Desert Storm. Omitting even mention of the Army's large fleet of existing light armored vehicles is mind-boggling.

C. "Advanced Technology" applies equally to tracked vehicles.

The potential for advanced technologies to improve wheeled vehicle performance is mentioned in several places: Targeting sensors on page 7, engine and power train on pages 10 and 11, armor and passive protection on pages 10 and 11, and improved weaponry on pages 11 and 12. The fallacy of the report is that these same technologies offer just as much capability improvement to tracked vehicles as to wheeled.

D. Three statements in the report are absurd.

Absurdity No. 1: "There are available in the world today a wide variety of wheeled light and medium weight armored vehicles in the 5-25 ton weight class." (P. 9, and there is a reference to a Jane's publication.) A true but absurd statement - the absurdity being that there are a wide variety of tracked and wheeled vehicles under 25 tons.

Absurdity No. 2: "Many of the models of wheeled armored vehicles in production already have command and medical versions available." (P. 12) True! There are also the same command and medical versions available in M113s.

Absurdity No. 3: "Finally, light-medium armored vehicles can be designed to be inherently amphibious, ..." (P. 12) Inherently amphibious! The absurdity in the statement is that all the Army's current tracked, light armored vehicles are amphibious, and have been since at least the M59 APC of the '50s; as is the entire M113 fleet.

E. False claims re: Wheels vs. Tracks.

Decades of studies, testing and experience have indicated the superiority of tracks over wheels for combat vehicles, except for the lightest and most road bound.

"Tracks versus Wheels" by Paul Hornback, U.S. Army Armor magazine, March 1998 (PDF format)

http://147.238.100.101/dtdd/armormag/ma98/2wheels98.pdf

Current "... operations in Bosnia have demonstrated the inherent weaknesses of wheeled vehicles with regard to mobility and protection..." (4) Since the importance of strategic mobility is finally emphasized within the Army, especially for airlift, compactness for aircraft loading is important. Do wheeled vehicles have an advantage there? Certainly not: "...Tracked vehicles, by design, are inherently more compact than wheeled vehicles. The primary reasons for a tracked vehicle's compactness are reduced suspension clearance, wheel turning clearance, and the absence of multiple transfer cases and drive shafts that are integral to the design of multiwheeled vehicles." (4)

Armored cars are inefficient with respect to weight and size, as compared to tracked armored vehicles. For example, the armored M113A3 is only a thousand pounds heavier than an unarmored FMTV 5-ton truck.

Up until the last paragraph on page 9 of the SSI report (carried over to page 10), the report has been mainly errors of omission, misstatements, circumlocutions, and statements of the obvious. However, the last paragraph on page 9 is much worse because it makes false claims and cites another Army report as the source of the claims. Following is the paragraph, verbatim:

"Studies by the Army Corps of Engineers indicate that the all terrain mobility 'break-point' between wheeled and tracked armored vehicles is around 20 tons. That is to say, wheeled vehicles have similar cross-country mobility attributes as track laying vehicles below the weight of 20-tons. Even heavier wheeled vehicles will have superior mobility on road surfaces. Further there have been some interesting innovations in wheeled armored vehicle designs, which suggest that the break point may move upward. 14 " In the following two paragraphs I dispute statements made in this last SSI paragraph:

1. The reader of the SSI report would logically believe that the Reference "14" cited (a Corps of Engineers report, my Reference 5 in this paper) at the end of the paragraph contains the supporting data to validate the claims of wheeled vehicle mobility, especially the claims of "interesting innovations". But SSI Reference 14 says no such thing. It is simply a Corps traction study comparing three different kinds of vehicles [M113A1, LAV-25, and a Heavy Expanded Mobility Tactical Truck (HEMTT)], investigating loss of traction associated with soil type and rainfall amounts. What were the Conclusions? There were four, but only the last has any relevance:

"d. The traction loss is more appreciable for the wheeled vehicles than for the tracked vehicle."

2. Also note this statement in the first sentence of the second paragraph above: "...the Army Corps of Engineers indicate that the all terrain mobility 'break-point' between wheeled and tracked armored vehicles is around 20 tons." I have no idea whether the Corps ever really reported that, but there was certainly no such statement in the Corps report. However, most wheels vs tracks studies that I have seen report that wheels are usually better below about 10 tons, and between 10 and 20 tons the tradeoff is mission- and terrain-dependent. Above 20 tons "...a tracked configuration is the optimal solution for tactical, high-mobility roles..." (4)

Do we plan to go to war? Or perhaps the Army plans for the for the prototype Brigade to become "...the Service's first combat arms unit designed for peacekeeping operations." (6) Ground Pressure. Regarding all-terrain mobility: there is a governing figure of merit, or parameter - not mentioned by the authors - for such comparisons. That parameter is ground pressure. Its effect is well known to all who have ever tried getting through heavy snow without snowshoes or skis. Wheeled-vehicle ground pressure [roughly 40.0 PSI for the LAV-III, just 8.63 PSI for the M113A3] can be reduced to some extent by tire deflation (or by the use of enormous tires), but there are practical limits, and for vulnerability reasons neither method is very attractive on the battlefield. The authors admit that "...in some types of very adverse terrain [wheeled armored vehicles] have cross country mobility that is inferior to tracked systems." (p. 9). The truth is, in most types of moderately adverse terrain, wheels are inherently inferior. This isn't some soft value judgment, it's a matter of the laws of physics and soil mechanics. It's why serious bulldozers aren't wheeled. It's why tracks were invented in the first place.

A specific comparison of wheels vs tracks was the mid-'70s Army program called the XM800 Armored Reconnaissance Scout Vehicle Program (ARSV); later cancelled. What is relevant here is that both a wheeled and a tracked vehicle were designed to the same specification by competing contractors, then built and exhaustively tested by the Army. Neither vehicle weighed more than 19,000 lb (less than 10-tons, please note!), and the tracked vehicle had lower height and less ground pressure than the wheeled vehicle. (7) Once cancelled, the program lost the notice of most people, but author Christopher Foss did say on page 175: "At the time of writing the best vehicle had yet to be announced, but it did appear that the tracked FMC ARSV was superior to the Lockheed wheeled ARSV."

We are not yet done with misleading citations. Here is the citation of Ref. 14 on page 22 of the SSI report:

"14. See Dennis W. Moore, The Influence of Soil Surface Conditions On The Traction of Wheeled and Tracked Military Vehicles, U.S. Army Corps of Engineers, Report GL-89-6, 1989. During the 1980s, major advances in off-road wheel technology occurred with the deployment of radial/run flat tires and central tire inflation systems."

Once again, the reader is likely to believe that the sentence added to the citation (During the 1980s, ... tire inflation systems.) refers to affirmative statements of wheeled vehicle technology advances made in the Corps report. Not so. The closest thing said in the Corps report is a recommendation (beginning on p. 41) for further testing to include varying tire pressures and tire sizes for wheeled vehicles. There were no conclusions drawn either way, since there was no testing of radial/run flat tires or central tire inflation systems!

F. Conclusion.

The SSI report's treatment of "Armored Fighting Vehicle Options" is clearly an attempt to justify procurement of wheeled armored vehicles, but it provides no meaningful data or rationale to support the pitch. The report correctly states that the Army needs light armored vehicles for rapid strategic mobility, and then concludes that, since light armored vehicles are (by the authors' definition) wheeled, the Army must buy some, perhaps anyone's. It is the conclusion that light armored vehicles must be wheeled, and only wheeled, that is not just wrong, but bizarrely wrong. It ignores the real capabilities and financial investment in the Army's existing fleet of M113 variants, all tracked light armored vehicles capable of C-130 airlift. Whatever its merits as to organization and doctrine, the document's approach to combat vehicles is seriously flawed, as evidenced by its own distortions and omissions. If there is any real justification for a wheeled armored vehicle procurement program, the authors have not presented it here.

G. Disclaimer.

The author is an engineer retired from two companies formerly in the defense industry. Both companies have, to his knowledge, withdrawn from the defense business. He is a financially disinterested party since his limited retirement income is safely sequestered from the fallout of any DoD decisions.

H. Acknowledgement.

The author wishes to acknowledge the assistance and contribution to this paper made by COL David A. Appling, U.S. Army (Ret.)

I. References:

1. John Gordon IV and Peter A. Wilson, "The Case for Army XXI 'Medium Weight' Aero-Motorized Divisions: A Pathway to the Army of 2020", Strategic Studies Institute, U.S. Army War College, 27 May 1998. A copy should be available on the web at:

PDF form:

http://carlisle-www.army.mil/usassi/ssipubs/pubs98/aeromotr/aeromotr.pdf

Regular web-page HTML form:

http://www.geocities.com/equipmentshop/wheeledarmoredcarlie.htm

2. GEN Shinseki's Address to the Eisenhower Luncheon, AUSA Annual Meeting, Oct. 12, 1999, First Para. On p. 4. Army Home Page, US Army News Release, "What Senior Leaders Are Saying."

3. Army Link News, "Chief of Staff expands on Army Vision," Army News Service, Jan. 31, 2000, p. 1.

4. Paul Hornbeck, "The Wheel Versus Track Dilemma," ARMOR, March-April 1998, p. 33.

5. Dennis W. Moore, The Influence of Soil Surface Conditions On The Traction of Wheeled and Tracked Military Vehicles, U.S. Army Corps of Engineers, Report GL-89-6, 1989. DTIC No. AD-A208 253.

6. John G. Roos, Editorial: "Headlong Charge: As US Army Leaders Rush To Recast Force, ...", AFJI, January 2000.

7. Christopher F. Foss, , "XM800 Armoured Reconnaissance Scout Vehicle," Jane's World Armoured Fighting Vehicles, p. 175. St. Martin's Press, NY. 1977.

L. Appendix:

FOREWORD to Reference 1, SSI report. [Pages iii and iv.] Since the end of the Civil War nearly a decade ago, there have been repeated calls for the U.S. Army to make major changes to accommodate to a transformed geo-strategic environment. Specifically, advocates of major change believe the Army should become strategically agile while maintaining a high in-theater combat and mobility capability. For example, much of the design work associated with the Army After Next (AAN) exercise series has focused on the development of a next generation of combat forces which have very high strategic/theater mobility and dramatically enhanced combat power. Unfortunately, some of the concepts associated with the AAN are true "leap-ahead" technologies that even in the most favorable budgetary circumstances and development schedules will not likely be available during the 2020 timeframe. At present, the Army appears to have settled on the selective modernization of its current force structure that is a mixture of very light and ultra-heavy combat formations; a "barbell posture." This approach provides an inadequate strategy for dealing with near-term political military challenges and acting as a transition to a true next generation Army.

The purpose of this monograph, therefore, is to stimulate a debate within the Army as to whether there is a credible transition strategy to modify a portion of its force structure to gain some AAN-like attributes---enhanced strategic responsiveness coupled with enhanced theater agility and combat power. The authors believe there is a mix of extant and near-term combat systems and technologies that will allow the Army to create a number of "aero-motorized" divisions within likely budgetary constraints by the end of the next decade. These medium weight combat units would exploit the large investment the Air Force is making to modernize its strategic and theater airlift fleets during the first decade of the 21st century. The authors believe that forces equipped with light armored vehicles, next generation combat aviation, and enhanced indirect fire support will provide the Army with a strategic "fist." Aero-motorized forces can be used either as part of a leading edge of a large and inherently slower to deploy expeditionary force or as a central combat component of future lesser contingencies including operations other than war. Finally, the aero-motorized will allow the Army to develop thoroughly the doctrine and concept of land forces operations that have the strategic agility of current light forces and approach the combat power of current heavy forces---major features of a desired next generation Army.

The Strategic Studies Institute strongly encourages readers to participate in a continuing discussion on the future of American land power and the challenges it holds for the U.S. Army.

LARRY M. WORTZEL
Colonel, U.S. Army
Director, Strategic Studies Institute
The End