Capital Equipment News February 2015

COMMENT

MANAGING TARE MASS in trucking

T here are many factors that contribute to the cost impact as a result of truck weight limit changes. Across the nation the practice of road trans- portation brings with it a variety of situations which have arisen as a result of overloading of vehicles. Generally it is a deterioration of the roads infrasructure and more specifical- ly an increase in the operating costs and the accident rate on the road. Therefore the practical maximum gross ve- hicle weight is the optimum level at which a given vehicle can operate in a given set of truck limits. This month we focus on the im- portance of keeping the tare weight of the vehicle down to an economic limit in order to maximise the payload. The tare weight is defined as the weight of the truck and trailer when it is carrying no freight as opposed to payload which is the weight of the freight carried on the truck. When specifying new trucks, fleet operators should consider the lightest weight com- ponents that will suit the application and where appropriate, buy a lighter weight ver- sion of standard truck models.

Not only will the reduction in weight of the vehicle by using lighter weight alternative materials such as metal alloys and com- posite materials, reduce fuel consumptions but will contribute a great deal to reducing greenhouse gas emissions. American truck manufacturers tend to offer lightweight tractor models, which are up to 1000 kg lighter than comparable European models, giving the fleet operator a distinct payload advantage. Let’s look at some of the savings that fleet users can expect by specifying correctly when purchasing new vehicles. First of all the application will determine the technical specification of the truck and thereafter the material composition of each component should be evaluated to establish that the weight-saving properties are inherent in the choice of component. Many truck manufacturers offer a choice of lightweight components specifically to meet the demands of customers wishing to maintain a lighter tare weight. These are not normally standard items and do come at a price premium but the long term financial gains outweigh the initial expenditure.

Some of the areas where lightweight com- ponents have proven benefits in reducing tare weight are; • Using alloy wheels with 11R 22.5 tyres in place of 315x80. Aluminium clutch and transmission housings. • Centrifuse brake drums saving up to 100kg • Aluminium axle hubs with weight savings up to 80kg • Aluminium fuel tanks and brackets. In this instance fit tanks with sufficient fuel for only one duty cycle otherwise carrying excess fuel adds to the weight factor. In some applications engine brakes provide adequate stopping power so the fitting of intarders may be an overkill and add to the tare weight of the vehicle. Cab designs also play a big part in weight re- duction as by using an aluminium skin over a steel reinforced frame will give the vehicle an advantage in weight saving. Economies of scale and environmental contributions are the main essence of maintaining a low tare weight in vehicle selection.

Pierre Sanson

CAPITAL EQUIPMENT NEWS FEBRUARY 2015 2