The Orange & the Green

1970 Allis-Chalmers 220M Military

In 1970, the United States Air Force announced it’s first operationally ready Bare Base squadron, the 336th Tactical Fighter Squadron. Part of the 4th Fighter Wing, which dated back to the beginning of World War II, the 336th became the first rapidly-deployable Bare Base outfits in the Air Force. And, no, a “Bare Base” was not a clothing-optional Air Force Base.

The Bare Base program planned to set up 1,000 to 1,400 locations around the world in friendly countries, or countries that wanted USA protection but maybe without a permanent American base. The bases would be roughly constructed by having a runway, taxiways and parking areas prebuilt near a source of water. In case of need, a specially trained and equipped Air Force squadron could deploy and be ready for forward air combat within 72 hours. Pre-packaged portable structures and equipment would be airlifted in C-130 Hercules transport aircraft and set up at the Bare Base site. When operations were concluded, the unit would pack up and fly everything home in the C-130s.

This tractor belongs to John Pelton, though he prefers to think of it as part of a Pelton family collection. With the exception of a missing tie down bracket on the front (where the orange sign is now) the Pelton’s 220M is as it was delivered to the Air Force in June of 1970. Today, it’s only showing about 360 hours, so it didn’t have many deployments. There are some pictures of the 220Ms in books (copyrights prevent us from showing you) and it appears the Pelton’s tractor was paired with the compacter (apparently now long gone). What little history John knows specific to his tractor suggests it was sold surplus in the early 1990s in Florida. The history books state MacDill Air Force Base, near Tampa, Florida, is where several of the rapid-deployment squadrons were trained, so that make sense. It’s been through several hands but was spotted by John Pelton’s father in 2012 and the pair pursued and finally acquired it in 2014 for the extensive Pelton family collection of A-C tractors.

In 1970, a tactical air squadron comprised 1,680 personnel and the Bare Base Package included 400 collapsible structures with accompanying furniture and equipment, generators, water purification equipment, mobile kitchens, repair and refueling equipment for 24 F4D-31 “Phantom II” fighter-bombers. The Bare Base program soon evolved into BEAR, Basic Expeditionary Airfield Resources, and is ongoing. BEAR still relies on having rough airfields set up in friendly countries and has been utilized in several conflicts, going back to the first Gulf War.

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Part of the package was a “family” of construction equipment that is flown in to set up the structures and assets needed for an air unit to operate. Going back to 1970, the parameters for this equipment was that it be low cost, transportable by C-130 or Chinook Helicopter, have a working life of five years if deployed twice per year and ten years if stored. Further, the equipment was to have commonality of parts as much as possible and worldwide availability of parts and service. These requirements dictated most everything in a family come from one manufacturer.

An Air Force Request

Some time prior to 1970, Allis-Chalmers was tapped on the shoulder for a variety of equipment for a Bare Base equipment family. That package eventually included 11 Allis-Chalmers Model 645-M3 loaders with 2.5 yard buckets, five fork-tine attachments, two backhoe attachments and two self powered snow blower attachments. Also included were four Allis-Chalmers HD-11EP crawlers with dozer blades, winches and A-frame hoists, plus two 12.3 yard elevating tow-behind scrapers. The package also had four Allis-Chalmers M100M2 graders with scarifiers and nine Oshkosh Model P-2301 four-wheel drive 5-yard dump trucks. Finally, there were two Allis-Chalmers 220M tractors (alternatively dubbed “M-220”), designed to operate a soil mixer and a compactor. The engines in all the A-C equipment were the same 3500 series, 426ci turbo diesels.

At the working end, we can see the very unique drawbar setup used for the compactor. Presumably the same setup was used for the mixer, though this is not known for certain. High and to the right are the hydraulic hookups, which are other items unique to this tractor. A pair of more standard hydraulic remotes can also be seen. It has a PTO but you can see the housing for the 3-point lift is empty. The compactor weighed 11,600 pounds ready to transport, but would be loaded with locally obtained ballast, such as water, when being used.

A Different Animal

Built in the “Landhandler” series, the standard 220 was touted as a do-it-all farm tractor. The 220 was one of the A-C’s most powerful tractors when it debuted in 1969, replacing the similar D21. The powertrain had been upgraded in the process and the sheet metal revised to fit the new, more angular, A-C look. Powered by a 426ci, direct injected turbo diesel, the ag 220 was rated at 136 PTO horses in the Nebraska tractor test. The ag 220s, which marketing dubbed the “Two-Twenty” (spelled out gives it so much more class, don’t you think?), were available in several configurations, including with a driving front axle, duals and, late in production, a cab. It’s seen in a row-crop style setup or with the chaff guards common to a wheatland type tractor.

The operator’s station was more bare bones than an ag tractor. Part of that was to save weight, since everything had to be flown in. It also minimized complexity at a remote location.

The 220 M featured here is a different animal. It was built with a specialty drawbar, presumably to fit the compactor and/or mixer mentioned above. We found little specific information on that equipment. It had a completely unique hydraulic system that we presume to be used with the compacter or soil mixer. The tractors used a 24-volt electrical system and had an unusual array of work lights (versus a standard 220). In the rear, the tractor mounts the same wheels and tires as used with the 645 Loaders. The instrument package is minimized and the unit does not have a tachometer. It has tie down rings in various place that are not found on standard 220s. On top of that, it’s painted a military green.

The D3500 engine was one of Allis-Chalmers’ home runs. The first iteration debuted for 1963 in the ag world as the NA D3400, which appeared in the D21 tractor. It was a clean-sheet-of-paper design and the general architecture was shared with several other A-C engines that appeared in the same timeframe. It was a seven main bearing, direct injected, sleeved engine. The D3400 delivered enough of a reliability track record to go turbo in 1965, delivering 127 ponies over the NA 103. By the time the 220 came around, the Nebraska PTO rating was up to 135 ponies (around 160 hp on the flywheel). Evolving into the 3500 Mark II in the ‘70s, the engine was significantly beefed up internally and, with an intercooler, had flywheel ratings up to 220 horses at 2400 rpm. The D3500 saw use in trucks, combines and was a very popular generator powerplant. A particular D3500-powered 60KW generator set was very popular in military circles.

Though it isn’t known for sure, by matching dates it would appear this unit was in the first Base Base equipment family produced. As such, it may have been assigned to the 336th Tactical Fighter Squadron. As far as can be determined, this was the only such order made to Allis-Chalmers. As mentioned above, the Bare Base system kept going, but it did so without Allis-Chalmers equipment.

SPECIFICATION

1970 Allis-Chalmers 220M
Engine: 6-cyl. direct injected turbo diesel, A-C D3500
Displacement: 426 ci
Bore & Stroke: 4.25 x 5.00 in.
PTO Power: 135 hp @ 2200 rpm
Flywheel Power: 161 hp @ 2400 rpm
Rated Torque: 417 lbs-ft @ 1700 rpm
Compression Ratio: 16.0:1
Transmission: 8-speed (4×2)
Weight: 11,380 lbs.
Wheelbase: 100
LxWxH: 331.5 x 95.5 X 89.5 in.
Fuel Capacity: 51 gal.
Tires: Front- 11.00-15
Rear- 17.5-25
Drawbar Pull: 15,710 lbs. (220 ag rating)

SOURCE

Unofficial Allis

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Author

Jim Allen

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