For any application, it is important to get the right balance of strength, lightness, ride comfort and reliability. Sometimes, steel suspension answers the need as well as air suspension.

For example, many operators prefer the combination of steel parabolic springs on the front axle and air at the rear. Scania vehicles designed for highway use that have steel suspension give a good ride. It is a simple two-spring assembly, assisted by an anti-roll bar and shock absorbers. Ride quality approaches that associated with air, but of course versatility (such as load handling) has to be sacrificed.

The same two-spring parabolic design is used for construction vehicles where operating conditions permit – which these days is virtually to the limit of arduous conditions. When it comes to extremes, a multileaf design with 9 tonnes design capacity can be specified.

For the rear suspension, there are four main options. There is a parabolic springs with a design capacity up to 13 tonnes, or 21 tonnes with a balance bogie. If you need more strength, there are multileaf springs for bogies rated at 26 and 30 tonnes.