The Sisu A-45 is a light off-road lorry that Suomen Autoteollisuus built from 1970 to 1982. A two-axle, all-wheel-drive development of the KB-45, it was shaped by the requirements of the Finnish Defence Forces and is remembered by the nickname Proto.
Sisu A-45 at a glance
| Maker | Suomen Autoteollisuus (SAT), Hämeenlinna; some built at Karis |
|---|---|
| Production | 1970–1982 |
| Predecessor | Sisu KB-45 |
| Payload | 4,150 kg |
| Engine | six-cylinder direct-injection diesel; 103 kW naturally aspirated, 110 kW turbocharged |
| Torque | 393 Nm and 468 Nm |
| Gearbox | five speeds forward, one reverse, two-step reduction gear |
| Drive | all wheels, differential locks, planetary hub reduction |
| Fuel | 210 litres |
| Winch | 6.5 tonnes, 60 m cable, usable at front or rear |
| Ground clearance | 340 mm |
| Versions | A-45, AH-45 with Nemo hydraulics, A-45-CI with Valmet engine |
History of the Sisu A-45
From the KB-45
The A-45 was a direct development of the KB-45, which had been designed together with the Finnish Defence Forces for jaeger battalions. The first KB-45 prototypes went to the army in August 1965, and 83 were eventually delivered, two of them as fire engines. The most important change in the A-45 was in the axles: the British Kirkstall units of the KB-45 gave way to Sisu’s own axles with planetary hub reduction. From the same nickname tradition came the name Proto, short for the Finnish word prototyyppi, or prototype.
Production in Hämeenlinna
The A-45 was presented in 1970. After SAT merged with Vanaja in 1969, production of Sisu military vehicles moved from Karis to the former Vanaja works in Hämeenlinna. Occasional shortages of capacity there meant that some A-45s were still assembled at Karis. In Finnish service the type was gradually replaced by the Sisu A2045, which was presented in 2008. The state railway, VR, also used an A-45, equipped as a recovery vehicle.
Engineering
The engine is a six-cylinder in-line diesel with direct injection. The naturally aspirated version produces 103 kW and 393 Nm, while the turbocharged version reaches 110 kW and 468 Nm. The Finnish Wikipedia names the Leyland EO.401 as the direct-injection engine, turbocharged in the AH-45, and the Valmet 611CA in the A-45-CI. The main gearbox has five synchronised forward speeds and one reverse, backed by a two-step reduction gear. Both axles are driven and have differential locks and planetary hub reduction; the front axle can be engaged pneumatically while driving. Suspension uses leaf springs with shock absorbers at the front, the service brakes are air-operated, and the handbrake works by releasing the air pressure.
Cab and equipment
The cab is made of steel and glass fibre and its top is detachable. All windows are safety glass, and the side windows and windscreen can be opened. There are seats for the driver and two passengers, the driver’s seat is adjustable and the instrument panel includes a rev counter. The platform has a steel frame and a floor of plastic-impregnated wood, with access from the rear and a detachable steel canopy. Steering is hydraulically assisted, the tyres are single 14.5–20 inches, fuel capacity is 210 litres and the 24-volt electrical system uses an 840-watt generator and two 145 Ah batteries. A towing bracket is fitted at the rear, and a 6.5-tonne reconnaissance winch with 60 metres of cable can be used at either end of the vehicle.
Design and features
- Built for the army: the A-45 was developed from a vehicle designed to Finnish Defence Forces requirements for jaeger battalions.
- Sisu axles: the change from Kirkstall to Sisu’s own planetary hub reduction axles was the main difference from the KB-45.
- Standard winch: a 6.5-tonne winch with a 60-metre cable could pull from the front or the rear.
- AH-45 hydraulics: the Nemo system drove the axles of a trailer, raising the maximum trailer weight to 8,000 kg for one axle and 12,000 kg for two.
Sisu A-45 versions
- A-45: the standard lorry, with 4,150 kg payload and a maximum trailer weight of 4,000 kg on the road.
- AH-45: a version with the Nemo hydraulic system for trailers with hydraulically driven axles.
- A-45-CI: a version with the Valmet 611CA engine instead of the Leyland unit.
The A-45 followed the earlier KB-45 and was replaced in Finnish service by the A2045. Other Finnish lorries are in the Sisu M-series article and the Sisu S-series article; the whole marque is in our Sisu collection.
Video: sisu A 45 offroad
Video by YouTube on YouTube.
Sources
- Sisu A-45, English Wikipedia: development, technical data, characteristics, variations
- Sisu A-45, Finnish Wikipedia: KB-45 background, engines, production, users
