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Features

Specialist Off Road Vehicles:

Aktiv Snow-Trac

Although we don't get that much snow in this country we thought you would be interested to see and read about a specialist over snow vehicle from Sweden. Perhaps some readers will have seen one of these whilst on a skiing holiday, since they are a common site on the piste . They have also been employed by the Scottish Hydro Board for over head power cable work in the Highlands and are used on several Highland estates for maintenance and hunting purposes.

The machine is very simple in its design and is based on a steel box section chassis with aluminium panels and body work and a timber boarded floor for the cabin. Power is provided by a 1200cc flat-four air cooled VolksWagen petrol engine powering the tracks through a conventional four speed gearbox with reverse. There isn't a high and low range, just a set of low gears, providing the vehicle with a top speed of 24 kmh, with an optional high speed version of 30 kmh. What is interesting about this vehicle is the steering. No levers to pull for left and right, but a steering wheel ! The way this works is as ingenious as it is simple. In effect there is a brake on each half shaft after leaving the differential unit. Thus by stopping the right half shaft from turning power goes to the left which creates a left turn and vice versa. The connection between the steering wheel and half-shaft is via a "variator" belt, a tough rubber belt of the same thinking as the Daf Variomatic system, with two discs which it runs through on either side, tensioning and releasing as required by the direction the wheel is turned. Drive is transfered from the half shafts inboard via a substantial duplex chain to two drive sprockets at the front of the vehicle which in turn drive the steel bands on the inside of the rubber tracks making the tracks turn. Tracks are constructed from conveyor belt rubber and can be shortened by cutting a section out and the steel cleats re-fastening. Suspension is via 16 pneumatic tyres running inside the tracks, shock absorbers and leaf springs, the tyres also assist with track tensioning. In the cabin there is a conventional set of clutch, brake and accelerator pedals, steering wheel, gear lever and handbrake, as well as the dashboard controls, interior light, hour meter and two opening side windows.

The cabin space is designed for the driver who sits at the rear of the engine and gearbox assembly, with the personnel being seated on bench seats down either side of the vehicle. Entry and exit is via a single door at the rear of the vehicle, and the complete roof area opens and folds back.

Whilst conceived as a civilian vehicle the Snow-Trac was adopted by the British Royal Marine Commandos for operations in Norway on NATO's Northern Flank and an example of the variant they used can be found at the REME Museum at Arborfield, Berkshire, England.

The over snow vehicle Snow-Trac was invented by Lars Larsson an engineer who worked for Vasteras Maskiner in Morgongava, Sweden a company that manufactured farming equipment. Like many great concepts the beginnings of the Snow-Trac stemmed from necessity. Every winter Lars would visit his home village of Oviken and his cabin in the mountains. Since it was difficult to travel there he began to develop his "snowcat" and in 1955 he registered a patent for his creation. Vasteras Maskiner, later renamed Aktiv, purchased the right to manufacture the Snow-Trac and between 1957 and 1981, 2265 machines were produced. Of that total made nearly 75% were exported and it is believed that most of these are still in use today.

Technical Description
 
 

Snow-Trac Data Links:

www.klovsjo.com/snowtrac

www.karl-hotel.se/snoweng.htm

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