Thiokol Swamp Spryte Model 1301

The Swamp Spryte Model 1301, part of Thiokol's 1300 series, is a small, watertight tracked vehicle built by the Logan, Utah division of the Thiokol Chemical Corporation. It was intended for work such as mosquito control, oil exploration and utility maintenance, and later owners describe it as designed for exploration and search and rescue. The archive's examples date from 1964, and the factory specification sheet is dated October 1966.

Design

The Spryte is about 3.99 m long, 1.97 m wide and 1.60 m high without its cab (2.0 m with it), and weighs roughly 1,450 kg empty. A 101 hp Ford 170 cu in six-cylinder petrol engine drives the tracks through a planetary-controlled steering differential running in oil. The tracks are made of rubber-covered nylon belting with tubular steel grousers, running on 12-inch tyres with trailing-arm, torsion-spring suspension. The vehicle is steered by handles that also work the brakes, and ground pressure is only about 0.78 psi (55 g/cm²) empty.

It seats two as standard and carries about 450 kg of cargo in a 1.88 x 1.78 m load area; the makers note it once carried an 820 kg load with 30 cm of freeboard. It reaches about 56 km/h on land and 7 km/h in the water, climbs 60% slopes on dirt or firm snow and turns in a 3 m radius. A removable aluminium cab with two doors was available.

Surviving examples

Several Swamp Sprytes have appeared for sale in Massachusetts since 2000. One, with only 30 engine hours, was fitted with three radios, a heater, extra lights and a cab; another, built in 1964, was being restored and had been driven at about 48-64 km/h on packed snow and gravel.