Almost half of the cost of growing, harvesting and delivering cut timber to the mill is spent on transport. It's no surprise, therefore, to find that forestry companies place an enormous emphasis on maximising efficiencies of the transport component of their value chains.

The PBS vehicle operated by Super Group transports timber to Mondi's Merebank mill.

And when you look closer at the cost drivers in transport, the emphasis quickly narrows down to payload and fuel.

As Mondi's transport specialist Des Armstrong points out: "There's not much you can do about your lead distance to the mill or the fuel price, but you can do a lot to maximise payload and reduce fuel consumption."

One of the most exciting heavy transport projects running in South Africa at the moment is Performance Based Standards (PBS). The traditional approach to heavy transport is that prescriptive legislation sets mass and dimensional limitations on vehicles. The vast majority of heavy vehicles on the road are bound by this approach, which limits Gross Combination Mass (GCM) to 56 tonnes.

In contrast, the PBS approach is to evaluate vehicles against a defined set of standards to ensure road safety and infrastructure protection, thereby making it possible to increase the payload without increasing the impacts on the roads, the environment and other road users.

Simply put, the aim is to improve payload efficiency and performance using technology to break the bounds of prescriptive legislation, says Des.

The first two PBS vehicles developed in South Africa increased the payload by around eight tons per load, and made their first appearance on the roads hauling timber for Sappi and Mondi almost two years ago. These vehicles have a gross combination mass of 64 tonne (Mondi) and 67 tonne (SAPPI), they have eight axles, and are slightly longer than the standard heavy vehicles. There are several other improvements as well, such as underslung drawbars, a lower centre of gravity and air suspension for improved stability.

The vehicles were developed in a unique partnership between the national Department of Transport, the KZN Department of Transport, the CSIR, Sappi and Mondi, as well as vehicle and trailer manufacturers.

In order to be allowed onto the roads, the vehicles' design and dynamic mechanical and safety performance had to comply with the stringent rules and regulations of the Australian PBS system. These requirements were laid down by the SA Department of Transport.

The performance of the vehicles and their impacts are being closely monitored over a three-year period by the CSIR, the timber companies and the transport contractors, Supergroup and Timber 24, who are operating the vehicles.

The good news for timber industry stakeholders is that the performance of the first two PBS vehicles has been encouraging enough to prompt the Department of Transport to authorise Sappi and Mondi to increase the test units to 30 PBS vehicles between them. This will add value to the PBS evaluation process by providing much larger statistical sampling of performance data under a wider operating range.

Des was careful to point out that this expansion of the project is still part of the testing phase and the full commercialisation of PBS vehicles is a long way off. However, if the testing phase is successful, he said Mondi's long term objective is to convert vehicles, where appropriate, to PBS status.

So what impacts do PBS vehicles have on the industry, the environment and the roads?

First off, the increased payload per trip would lead to a reduction of between 12% and 14% in the number of heavy timber trucks on the roads. This would reduce the wear and tear on the roads themselves, reduce vehicle congestion, which in turn would improve safety for all road users and reduce vehicle emissions.

From a business point of view, bigger payloads significantly reduces the cost per ton of timber delivered to the mill.

Des maintains that converting Mondi's entire heavy transport fleet to PBS vehicles would reduce fuel consumption – currently one of the single biggest costs – by nearly 15%.

The overall impact of this would be to make the South African forestry industry more competitive in the global marketplace. In fact, it is a pre-requisite if our industry is going to keep pace with international trends. Already country's like Australia, New Zealand, Canada and Sweden are using PBS vehicles for timber transport and are reaping the benefits from the cost efficiencies.

Des says that Mondi plans to roll out the additional PBS vehicles over the next 12 months or so. He said that all Mondi transport contractors who are RTMS accredited would be invited to participate.

The pioneering role that the South African timber industry has played in the implementation of the Road Transport Management System (RTMS), a self-regulatory programme focusing on load optimisation, driver wellness, vehicle maintenance and productivity, has paved the way for the introduction of PBS. RTMS accreditation is a pre-requisite for any transport contractor wishing to operate a PBS vehicle. Without RTMS there would be no PBS.

In terms of heavy transport at least, the timber industry is leading the way.

Published in July/August 2009