Swedes should look to Oz roadtrain
Demonstration of platooning in Södertälje, Sweden. Photo: Dan Boman
Every now and then someone has a great idea that gets them all excited, and they want to tell everyone they know and see them get excited too. When their friends pause a moment, look at the ground and say, "Mmmm - that's interesting", they then get depressed and wish they'd never said anything.
That's not quite what's going to happen as a result of this story, but the issue of drafting for aerodynamic savings is not new. It's called many things -tailgating is the negative one, but the Europeans have a different title. They call it platooning.
Scania has launched a research project that sounds very scientific and will involve extensive testing and assessment on the highway runs conducted by its own combined research/transport arm, the Scania Transport Laboratory (STL).
It's a separate organisation based in a compound just outside Scania's main production plant in Södertälje. Twice a day, every day, a group of up to five trucks with single trailers leave for the 1400 kilometre run to an assembly plant in Zwolle in The Netherlands with engines, gearboxes and axles. It's an uneventful run, albeit through some very scenic Scandinavian countryside.
The company uses the fleet to trial and test new technology, verify engineering predictions and research driver training effectiveness and fuel efficiency methods.
The latest research is the drafting proposal by engineers to plan deliveries so that a group of up to three trucks can run the double highway sections as close to each other as possible. The drives will establish hard data on the effect of coordinated driving on fuel efficiency.
Scania claims that even if the trucks are 25-metres apart, the drag on the second truck is reduced by 30%. The third truck will benefit from a 40% reduction in aero drag. In addition, the second truck will weaken the low pressure zone behind the lead truck and have a "push" effect on the leader.
In the first phase of testing the vehicles will utilise the existing Adaptive Cruise Control system on Scania prime movers to manage the clearance between the trucks, set at two-three seconds at the European governed speed for trucks of 90kmh.
After review of the results from data outputs, plus feedback from the drivers, and assuming no real issues, Scania will reduce the time gap to one second, or around 20-metres.
If that proves successful, Scania will then set up the trucks and drivers to drive with a gap of merely 0.5 seconds or 10 metres. As the present cruise control technology systems doesn't support distances this close, Scania will use wireless communications between platooning trucks to engage brakes on the following trucks to apply as soon as the lead truck brakes. Fuel savings at this distance are modelled to be as high as 10%.
What seems to have escaped the Swedish engineers is the Australian solution to the problem. It's called the Australian road train and regularly takes three or more trailers on long-distance runs with less than five-metres between them. All the trailers brake at once, accelerate at once and other road users are alerted to the length of the vehicle with extensive warning signs on road train routes and on the rigs themselves.
On this particular run south from Scania's headquarters, with the cooperation of the authorities, they could get three full-size trailers to the destination with one truck, one driver and much less fuel, plus an assembly area and shunt trucks at the ferry crossing. Plus the adaptive cruise control would be focused on keeping the rig away from other road users.
Big Rigs would be happy to be a part of a demonstration road train run on the Zwolle route to set an efficiency benchmark. How about it Scania?