High Speed Tractor: A Visual History of the U.S. Army's Tracked Artillery Prime Movers

When it comes to tracked vehicles, most of the glory goes to tanks, armored personnel carriers, infantry fighting vehicles, and self-propelled guns with a few nods to recovery vehicles. But few reference works, and even fewer kits, honor the unsung "heroes" of tracked vehicles: the unarmored gun tractors and prime movers that lugged just about everything else.

Some vehicles, like the M4 18-ton High Speed Tractor, gained popularity back in the 1950s when Revell put out a model of the 155mm M2 "Long Tom" gun with the tractor and a crew of figures, and this neat looking vehicle first became known to modelers. Later Aurora put out a model of the postwar M8A1 with all kinds of moving parts and a choice of either the tractor alone, the tractor with an M2 155mm gun, or an M115 8" howitzer in 1/48 scale. Nitto of Japan later essentially copied this vehicle in 1/35 scale and those molds continue to migrate to the present day. Other companies, such as Monogram and Lindberg, provided copies in 1/48 scale of the diminutive Cletrac M2 7-ton tractor with their B-24 and Snark kits respectively. But no references existed for any of these models.

Ampersand has now continued its great series of focused books looking at US vehicles with one covering the five primary series of high-speed tractors and prime movers that were placed in production between 1940 and 1956. All of these vehicles had relatively long lives by military standards and as such are both important and of interest to modelers. Written by David Doyle, contributing author from Military Vehicles Magazine, and Pat Stansell of Ampersand, the book follows the past format of presenting new, large, clear photos of the vehicles, based on both contemporary sources and restored vehicles.

A short history of the vehicles under their ordnance G numbers is provided at the front of the book. This gives a thumbnail description of the developmental history of the vehicle and its background, as well as production runs and variants. Photos of some of the prototypes are also included.

The section on G-096, the M2 7-Ton High Speed Tractor, covers the Cletrac vehicle which was found wanting by the Army Ground Forces, but was the perfect airfield servicing and towing vehicle for the USAAC (and later the USAAF and USAF) due to its dependability, power, tractive force and a powerful two-cylinder air compressor mounted at the rear of the chassis. Over 8,500 were built and these served into the 1960s with the USAF as a prime mover and airfield "hack." The book dedicates 21 pages to this vehicle, and any aircraft modeler who wants to do theirs up right should take a look at the book to see what it really entails. (It always struck me as silly for some aircraft modelers to spend dozens of hours detailing wheel wells and then stick a seven part Cletrac on the same base with no added details!)

The section on G-150, the M4 18-Ton High Speed Tractor, covers the Allis-Chalmers built gun tractor which the US Army used in two variants. Type A carried a rectangular chest at the rear of the hull for 90mm AA or 3 inch antitank gun ammunition, and Type B had a bulged chest with an open top which could be fitted with variable plates for carrying either 155mm, 8", or 240mm ammunition and propellant, and was fitted with a small crane and hoist to handle that. The book provides 25 pages of coverage of both variants, and gives plenty of detail coverage to them.

The section on G-162, the M5 13-Ton High Speed Tractor family, covers one of the lesser known but still widely used prime movers used by US Army Field Artillery – it was the prime mover for the 155mm M114 towed howitzer late into the 1950s. Built by IHC, the vehicle used a suspension based on that of the M3/M5 light tanks but modified to provide more suitable performance when towing heavy loads. The book allocates 26 pages of coverage to all four major versions of this tractor – M5, M5A1, M5A2 and M5A3.

The section on G-184, the M6 38-Ton High Speed Tractor, covers another lesser known but still highly important vehicles used during WWII. Designed again by Allis-Chalmers, the M6 looked like an M4 HST on steroids with a longer wheelbase and wider hull, and was designed to tow either the barrel and carriage sections of either the 240mm howitzer or 8" guns, as well as other sectional weapons. While it appeared to use parts from the M4 medium tank series, it did not and this book puts any allegations to that effect to rest. While over 1200 were built, it still is among the most elusive of American HSTs to discover, and happily the book provides some 24 pages of detailed coverage (including following the 1,235th and last one being built.)

The last section of the book covers the G-262 M8 High Speed Tractor family. Built during the 1950s using the common M24/M41 light tank parts then being used on all sorts of Army vehicles and prototypes, the M8 was originally planned to combine the functions and replace the first four series of vehicles. Later, the M8A1 with swing-out platform for a generator set was accepted for service with the M51 75mm "Skysweeperer" radar directed antiaircraft gun. But when that system was scrapped in favor of the Nike-Ajax missile system, the systems were either allocated out to other units or rebuilt as prime movers. Over 480 were built, and the book does present some of the uses for them, mostly as prime movers and cargo transports in Alaska. This covers the last 12 pages of the book.

Overall this is a great reference, and for example, the section on the M4 provides more information of use to modelers than the FM for the vehicle does, and that alone costs more than three times the price of this handy little volume.

Thanks to Gene Bagnoli for the review copy.