On thin ice

by James Menzies

HOUGHTON, Mich. – It’s cold and blustery on the Upper Peninsula of Michigan and a small group of Bendix engineers and truck journalists are gathered along the edge of a runway in Houghton, Mich. There’s a sense of urgency, as air traffic control just radioed to inform us a plane was approaching the lone runway at the fully-operational airport.

This doesn’t stop Bendix senior staff engineer Charlie Ross from speeding down the runway and veering suddenly – first to the left and then to the right – to simulate a sudden lane change. The truck leans dangerously to each side and puffs of blue smoke appear from the outrigger’s tires. Outriggers consist of long arms that protrude from each side of the truck with a wheel on each end – think training wheels for tractor-trailers. In this case, the outriggers were the only thing that prevented the double-trailer configuration from sliding down the runway on its side.

Next, before being chased off the runway by the incoming plane, Ross pulled off the same maneuver, with the same tractor-trailer combination, but with a vastly different result. With the Bendix ABS-6 Advanced system with ESP activated, the truck’s own rubber never left the pavement and Ross easily maintained control of the vehicle. No outriggers required on this run.

As the plane buzzed overhead like an angry bee, we scurried off the runway and headed to the adjacent Keweenaw Research Center, where Bendix does much of its winter testing. Conditions at the test site are perfect – for testing, that is. It’s a chilly 8 F (- 13 C), much better than when this event was first scheduled in late January. That test had to be called off because above seasonal temperatures had turned the ice and snow to slush.

The Keweenaw Research Center features: three vehicle handling loops; several packed snow vehicle dynamics pads; a 200×1,200 foot ice rink; and packed snow/ice circles of 300-, 600- and 900-foot diameters. Today we would be focusing on the packed snow pads, the ice circles and the rink.

First up was the packed snow pad. Vehicles available for testing included a Prevost motor coach, a Pete 357 mixer truck and a Volvo VN with a set of doubles behind it.

To start with, we piled into the Prevost motor coach. Bendix electronics engineer, Ryan May, said “This is a very stable vehicle” as he increased our speed to 35 mph. However, with the ESP system turned off, it felt anything but stable as the we slid from side to side on the hard-packed snow. The avoidance maneuver we were executing was meant to simulate a sudden and unexpected lane change but there would undoubtedly have been a path of carnage left in our wake if we were pulling this off in a real-world scenario.

We then executed the same maneuver with the ESP system turned on and the bus remained relatively stable, despite May’s best efforts to lose control. To ensure there was no driving trickery going on to enhance the system’s performance, I climbed behind the wheel and mimicked the actions performed by May. The effect of the ESP was even more noticeable while behind the wheel.

So how does it work?

The Bendix ABS-6 Advanced with ESP system intervenes in the event of a potential rollover as well as oversteer and understeer situations. The system has the ability to detect a potential incident and interact immediately by reducing power to the engine and providing the optimum braking pressure to each individual wheel end, allowing the driver to recover from the situation and regain control of the vehicle.

“This system doesn’t replace a good driver,” pointed out Fred Andersky, marketing manager, electronics with Bendix. “If you take a 30 mph curve at 70 mph, no system is going to help him.”

What it does do, however, is allow the driver to regain control of the vehicle faster and minimize the possibility of ending up in a rollover or jacknife. The system is catching on.

Bendix’s ABS-6 Advanced with ESP is now standard on Volvo tractors. Meanwhile, Kenworth, Mack and Peterbilt offer the system as an option. In all, five of the seven major truck OEMs offer ABS-6 Advanced. ABS-6 Advanced with ESP will be available on 60-70 per cent of Class 8 tractor configurations sold by those five OEs in 2006, Andersky predicts.

Availability of the system is expanding and it can now be used on vocational trucks as well as double trailer configurations – as demonstrated by Ross. As I climbed into the passenger seat of the Volvo VN driven by Ross, he explained that the ABS system on the rear trailer wasn’t working. When we made our first charge down the packed snow pad with the system off, he steered wildly from side to side. I watched the side mirrors as the trailers tried their best to overtake us. With the system turned on, however, the trailers remained relatively straight.

“The system reduces the whipping of the last trailer in avoidance maneuvers,” explained Kevin Romanchok, Bendix’s product line director, electronics. The system is currently being offered for double trailer applications, he pointed out. Only the power unit must be equipped with the ESP system and the trailers will be stabilized regardless of whether or not they have ABS, he added. Double trailer configurations use the existing ABS-6 Advanced with ESP system with no special reprogramming or switching required.

Electronic stability is also a new offering for vocational vehicles such as mixers, which have a high center of gravity. I drove a Pete 357 mixer along the packed snow and very nearly had a panic attack when I got the vehicle completely sideways at 40 mph with the system turned off. With the system on, I made the same maneuver, maintained control and recovered without incident despite my best efforts to beat the system. I tried my best to override the system by keeping the throttle buried, but the ESP system would have none of it, and got the vehicle whoa’d down all on its own.

The ABS-6 Advanced with ESP system works equally well on glare ice as we soon learned at the ice/snow circles and the ice rink. The ice/snow circle featured an inside lane that was glare ice as well as an outside lane consisting of packed snow.

We were able to change lanes from snow to glare ice with relative ease in a Volvo VT 880 tractor, keeping the vehicle out of the high snowbanks that lined the track. However, from the passenger seat of the VT 880 I had a great view of what can happen without ESP. A Bendix engineer driving a Pete 387 with the system turned off lost control and stuffed the tractor comprehensively into the snowbank. ‘Nuff said.

I was back in the tractor with Ross when we visited the ice rink. Ross was touted as the best driver on the Bendix engineering team and I believed it when he demonstrated a ‘system off’ run along the ice.

Hitting the ice rink at 25 mph with the system off, we were sent on a wild ride that featured several 360 degree spins. But he kept it out of the snowbank – well, almost.

A closer look revealed the front fender just kissed the snowbank, leaving a small dent in the snow as the only sign of contact.

With the system activated, we were still at a loss for traction, but we glided down the ice with the nose pointed forward and minimal movement from side to side.

With the increased availability of electronic stability systems, will there come a time when it becomes a standard feature on all Class 8 tractors? At a cost of about $2,000 per tractor, it’s difficult to say. The value proposition is quite different for an owner/operator compared to a 100-truck fleet.

Romanchok admits it’s difficult to measure the payback time because “How do you calculate the accidents you never have?”

But with the average rollover costing $100,000 or more, even preventing one such accident can result in a solid return on investment.

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