Electronic braking systems are now generally regarded as a great thing, but there can be problems if truck and trailer systems aren’t properly matched
Chris Loose is a pretty funny bloke for a truck engineer.
His definition of a truck driver is someone who transports stuff you can’t. And an engineer is an organism who solves a problem you didn’t know you had in a way you don’t understand.
And everybody can relate to what he calls the “bum-ometer”.
“The bum-ometer is no longer calibrated to the road,” laments Loose, senior engineering advisor with the Australian Trucking Association.
“The trucks now have air suspension seats, they have air suspended cabs, they’ve got huge taper leaf springs and air bag suspension.
“The driver is no longer connected to the road so he no longer feels it.
“The driver is becoming more and more remote from his vehicle and the feel of the road.
“He is inherently as a result driving harder and faster through potholes because he no longer feels them, and it’s a huge issue.
“Unfortunately guys, it’s a male problem, testosterone, we want to get there faster.”
And for Loose that’s one of the reasons why electronic roll stability is such an important thing.
Roll stability is part and parcel of the electronic braking systems (EBS) that have become more common in recent years.
Loose gave an entertaining rundown on electronic braking and stability technology at this year’s Comvec technical conference in Melbourne, organised by Heavy Vehicle Industry Australia.
Life saver
As far as the ATA is concerned, the jury is no longer out on electronic stability control (ESC): it’s a great and proven life-saving technology.
ESC automatically slows the vehicle down via both the throttle and brakes if it senses the risk of a rollover.
The ATA points to a Monash University Accident Research Centre study from a couple of years ago which concluded that mandated ESC in heavy vehicles could reduce fatal heavy vehicle crashes by 4 per cent.
In turn, ESC can be the foundation technology for the even more advanced Autonomous Emergency Braking Systems (AEBS) that we’ve heard so much about for both cars and trucks in recent years.
Monash estimates mandated AEBS could prevent up to an incredible 25 per cent of fatal heavy vehicle crashes.
Meanwhile the Victorian Government says log truck and trailer rollovers have been virtually eliminated thanks to stability control on B-doubles in key logging areas of that state. That’s from an average of 40 rollovers a year previously.
The ATA is advocating that for most applications, electronic stability control should be compulsory in all new truck and trailer models from 2019.
As things stand, the lesser technology of ABS – anti-lock braking – is mandatory on all new trucks and trailers.
This is under the Australian Design Rules 35/04 (trucks) and ADR 38/04 (trailers, with load sensing valves as an alternative.)
Loose doesn’t agree with it, but dollies are exempt from ABS or load sensing valves. However “through” power must be provided to the following trailer.
In the US and Europe most trailers have ABS; here most trailers don’t.
Ironically, there may be a safety problem with the latest technology, if there is incompatibility between truck and trailer braking systems.
If the truck has a “smart” brake system with ABS and better still EBS as well, and the trailer or trailers are “dumb”, that can create a safety issue in itself.
The most obvious example is stamping on the brakes in an emergency: the trailers may not stop as well as the truck, thereby risking a jack-knife situation.
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