Constructing the perfect vehicle

The South African economy may have been on a rollercoaster ride over the past few years, but that doesn’t mean operators in the construction segment need to treat their vehicles in the same way, writes VIC OLIVER

Construction vehicles have to work hard and need to be inspected regularly, well maintained, correctly loaded and driven by well-trained drivers. This is the only way to ensure a high vehicle productivity rate and low operating cost in this harsh environment.

Construction vehicles are used in dusty, tough conditions and undertake short trips. It is, therefore, of utmost importance that they are inspected and serviced at regular intervals in accordance with the truck manufacturers’ recommended maintenance schedules.

Driving these vehicles requires a specific set of skills, so drivers need to be well trained. For example, they should be skilled at manoeuvring their vehicles safely in the limited space often found on construction sites, and should be able to ensure that they don’t get struck in mud on wet sites, or overturn on sites where the ground is unstable.                                                                                                                

Drivers should also be trained to operate all the ancillary equipment that is fitted to their vehicles.

It is unfortunate that many of the construction vehicles that frequent our roads around the towns and cities are overloaded – especially the vehicles transporting sand and stone – and are contributing to the deterioration of the country’s road infrastructure.

While overloading on the main national long-distance routes is policed, little action seems to be taken against the overloaded vehicles that use the roads around the towns and cities.

A good example illustrating this problem is a 6×4 truck chassis fitted with the standard ten-cubic-metre capacity, end-tipping body – its maximum legal rating, when operating on any public road, is 25 700 kg. (This is also described as the V rating and is displayed on the vehicle data plate.)

To establish the estimated legal payload of a vehicle with a V rating of 25 700 kg, the tare mass of the truck chassis and the end-tipping body must be subtracted from the V rating.

Therefore V = 25 700 kg, minus estimated truck chassis tare mass = 8 600 kg, minus estimated body tare mass = 2 600 kg, gives us an estimated legal payload of 14 500 kg.

However, if the operator of the end tipper described above does not take into account the density of the material being loaded into the vehicle, he could load ten cubic meters of wet river sand with an estimated density of 2 000 kg per cubic metre, which would result in the vehicle being overloaded by 5 500 kg!

Note that the above calculation does not take into account the mass distribution of the vehicle, tyre size, manufacturer’s maximum axle capacity, or gross vehicle rating. Therefore the actual legal rating could be less, depending on the specification of the truck.

Loose material falling off the back of construction vehicles and damaging other vehicles using the road is another problem that drivers and owners of these vehicles need to address. Drivers should also ensure that their vehicles are always clean and correctly loaded before they enter a public road.

Despite the tough economic times that the South African economy has experienced over the last couple of years, the sale of new and used construction vehicles has remained strong thanks to the ongoing demand for new houses, shopping centres, roads, electricity installations and water supply.

A well-maintained, professionally driven and correctly loaded construction vehicle will give the owner many years of trouble-free operation at minimal operating cost.