The Tandem Hitch replaces the front bumper of a military jeep with a rounded steel bar and an A-frame ending in a lunette that mates with a jeep pintle hook. When originally released to the field in December 1943, the Tandem Hitch was intended as a means to lock two Willys MB / Ford GPW jeeps together in tandem, hence the name. In that configuration, two jeeps had the towing capacity of a 2 1/2-ton truck, able to tow 105mm artillery, planes on concrete or hard-surface taxiways, or similar loads. In some cases, jeeps were even hooked in sets of three. Even tasks that a single jeep can normally handle, when the ground is uneven or wet an extra jeep may be needed. When hooked in tandem, the jeeps had to be driven very carefully; many accidents occurred. Tandem operation was considered an emergency expedient, not for regular use.
While never widely used, the Tandem Hitch was in service until the 1960s. Some jeeps were substituted for a larger prime mover, but more commonly the Tandem Hitch was used as a tow bar to move a single jeep. The Tandem Hitch continued in use with the post-war M38 and M38A1 jeeps. It is often seen today on restored jeeps to make it easy to tow to the jeep to events.
Tandem Hitch installed on Willys MB/Ford GPW, secured for travel.
Tandem Hitch for World War II and Early M-Series Jeeps
An M4 Sherman tank, reinforced with sandbags, leads a column through a village in Europe, circa 1945. Jeeps following the tank are equipped with the Tandem Hitch tow bar.
During World War II, the Tandem Hitch was allotted as a kit to certain Field Artillery, Anti-Aircraft, Airborne and other units. Air Service Command distributed kits to all Army Air Forces squadrons: two each except heavy and troop-carrier which were allotted three each.
After installation, the Tandem Hitch becomes a permanent part of the jeep, replacing the original bumper. It is bolted on without cutting or otherwise changing the original parts of the receiving jeep. When not in use, the hitch is folded back and up against the radiator grill where it is securely fastened to a bracket by a strap.
Operating a Jeep with the Tandem Hitch
Tandem Hitch Caution Plate, part of the installation kit.
A jeep with a Tandem Hitch is no different than a jeep with the stock bumper, until two or more jeeps are hooked together. But two jeeps together don't act like they do separately; drivers have to learn to operate them in tandem. Besides learning all the tricks of maneuvering and other special skills, both drivers must strictly observe the speed restrictions on the caution plate which comes in the kit, to be mounted on the dash. The caution plate warns the driver not to exceed 30mph in tandem over level ground and not over 10mph downhill.
When the Tandem Hitch was tested, two tandem-hitched jeeps towing a 105mm howitzer down a 10 percent grade were speeded up to about 20mph. The first thing the driver of the lead vehicle knew, his jeep was swerving wildly from side to side and suddenly flipped over into a ditch. The towed howitzer went into a slideslip, turned butt over wheels and upset the second jeep. Based on that experience and further tests, the caution plate limits and driver training are considered mandatory.
Because the loads that will be towed with the tandem set-up put extra strain on jeep's pintle hook, a reinforcement plate is supplied. No jeep should be used for tandem towing operations until the plate is installed.
The original U.S. Army release that describes the Tandem Hitch includes these helpful hints:
A couple of tips: in applying the brakes, apply the brakes of the second jeep first to keep the load from compressing the middle jeep. Also, the turning radius of tandem and towed load is about 37 feet.
The drawbar of the Tandem Hitch may be used in reverse direction for pushing stalled or mired jeeps, where the second jeep provides the push to the first one. A hitch-equipped jeep can also be towed by means of the drawbar, with care in choosing the towing vehicle. For example, the jeep cannot be towed behind the 2 1/2-ton truck because the height of the 2 1/2-ton's pintle will allow the jeep to run under it.
Tandem Hitch Installation Kit
A pair of WWII jeeps, connected by the Tandem Hitch.
The Tandem Hitch was distributed as a kit, available to units authorized to get it by their T/O&E. It was obtained by requisition under the name Hitch, Tandem for 1/4-ton 4x4 Truck, part number WO-A-8500. Organizational Maintenance, or higher echelon, was expected to perform the installation. The kit distribution was managed by Tool and Equipment Distribution Unit, St. Louis Ordnance Depot, St. Louis, MO. or the Air Service Command for Army Air Forces. It was reported on a Forum that the NOS kit included Installation Instructions with Willys Part Number A-9193 dated 29 May 1944.
The kit distributed during World War II includes all parts -- down to nuts, bolts and washers -- needed to convert one MB/GPW jeep. In addition to the tow bar and frame components (WO-A-7927-A), there are the grill bracket assembly (strap, footman loops, and mounting point, Wood Block A-8105), pintle hook reinforcement plate (WO-A-7811-C), and the caution plate for the instrument panel (WO-A-7811-D). Installation instructions are packed with the parts.
Installation takes less than an hour, including these steps:
Remove the stock bumper (the Tandem Hitch includes a special bumper)
Place the tow bar and frame bracket assembly of the Tandem Hitch in position over the frame bumper gussets and install, using the nuts and bolts that held the old bumper
Attach the radiator bracket to the jeep's grill
Attach the pintle hook reinforcing plate
Mount the caution plate on the instrument panel
Tandem Hitch for Post-War Jeeps
The Tandem Hitch was originally designed for the World War II jeeps, the Willys MB and Ford GPW. However, it will fit, without modification, the first two post-war jeeps, the M38 and M38A1. The document TB ORD 621 (2 Dec 1955) describes the kit and installation procedures for all of these jeeps. In 1955, the Federal Stock Number was 8-H-1826, and FSN 2540-735-8343.
The installation is slightly more complicated on the M38 and M38A1 jeeps since the bumper is retained. The installation instructions provide for M38 or M38A1 vehicles with and without lifting hooks installed.
Material on this page adapted from Army Motors, Vol. 5 No. 5, August 1944 and reprinted in the publication Army Motors, Vol. 1, issue #3, January 1977, and other sources.