Designing roads for better energy efficiency is an opportunity for the mining and construction industries. Fuel savings are achieved from road design that reduces rolling resistance via paved surfaces.
Improved design allows vehicles to travel at optimum speed with minimal stops and takes into consideration factors such as intersections, expected load weights and up/downhill transport activities.
Energy savings across a mining operation have been estimated in the range of 15 000 GJ per annum. The savings achieved through improved road design are significant due to the type of vehicles used as well as the long operating hours in the mining and construction sectors. The most significant savings are made in mining haul trucks. These vehicles typically carry up to 200 tonne payloads from the face of a mine to an onsite processing facility.
Sectors and common applications
- Mining and construction, where vehicles are often operating around the clock.
Energy saving across sectors is 7 PJ (2014 estimate).
|1. Energy saving and cost achievement|
|1.1 Energy saving||12/15|
|1.2 Cost effectiveness||6/10|
|2. Market contexts|
|2.1 Sector energy savings||6/10|
|2.2 % of industry $ gross added value||8/10|
|3. Originality and innovation|
|4.1 General applicability||4/5|
|4.2 Ease of implementation||5/5|
|4.3 Ability to integrate external resources||4/5|
|5.2 Social awareness||2/3|
Fortescue Metals Group Ltd undertook the removal of one stop per cycle per truck. An assessment identified this as an opportunity to enable trucks to achieve and maintain an optimal speed. It was noted a considerable fuel saving would result from the removal of particular stop signs where this does not compromise safety.
The truck were asked to do modelling for a fully loaded vehicle to accelerate from stationary for 100 metres, and to advise the final speed at this distance. They then modelled the same truck operating at this final speed for a distance of 1 km, so that the steady state fuel consumption could be calculated. The fuel saving as a result of the truck not having to stop is the difference between the two scenarios.
Evaluation of this opportunity revealed that for each stop removed from the load cycle, estimated saving of 361 kL (13,935 GJ) per annum for Caterpillar 777 haul trucks could be achieved and 407 kL (15,710 GJ) per annum for the Terex 3700 AC haul trucks.
Savings are based on the removal of one stop-sign intersection. However, with careful consideration of traffic safety, FMG will continue to look for opportunities to remove additional stop signs.
Newmont Australia Pty Ltd identified the potential to optimise the South Pit haul road at its Boddington gold and copper mine in WA. The existing profile of the road comprises a combination of downhill and level sections. Real-time monitoring of variables on the fleet showed that the trucks consumed more fuel on the level sections.
Modelling of a modified haul road showed that fuel consumption could be reduced on both downhill and uphill journeys for the truck fleet. The potential saving was estimated at 750 kL of diesel per year for the truck fleet.
Other companies that have identified road design as a means of energy savings include:
- Aurizon Holdings Ltd
- Norton Gold Fields Ltd
- Rio Doce Australia Pty Ltd
- Sonoma Mine Management Pty Ltd
For more information, see:
Analyses of Diesel Use for Mine Haul and Transport Operations (PDF, opens in a new window)