DON MILLS, Ont. - Trailer spec'ing decisions are often limited to considerations of massive components such as suspension systems, frame rails and barn doors. But sometimes the little things can have a greater impact on productivity and profitabil...
May 1, 2004
John G. Smith, Technical Correspondent
SIZE ISN’T EVERYTHING: It’s surprising how small things can pay.
DON MILLS, Ont. – Trailer spec’ing decisions are often limited to considerations of massive components such as suspension systems, frame rails and barn doors. But sometimes the little things can have a greater impact on productivity and profitability than you might think.
Consider the following additions that happen to be no larger than a breadbox.
LED (Light Emitting Diode) bulbs can withstand road-related shocks better than their incandescent counterparts, and have a life expectancy of about 100,000 hours – that’s about six times the life span of a bulb that needs a filament.
Their advantages aren’t limited to longevity.
Such lamps will draw about 1/10th of the power required by incandescent bulbs, and a lower amp draw will leave more power for other electrical needs.
They may even save trailers from unwanted accidents.
The University of Michigan’s Transportation Research Institute determined that LEDs respond about 1/5th of a second faster than standard incandescent bulbs.
At 115 km-h, the quicker reaction times to a stop lamp or turn signal could slash the stopping distance of following vehicle by as much as 16 feet (about five metres).
That can be the difference between a close call and someone testing the durability of your trailer’s underride bar.
When selecting an LED lamp, be sure to take a close look at the lens as well. Most designs are acrylic, which can be a good choice on a tight budget.
Premium designs, however, will include polycarbonate lenses that can better withstand impacts from things such as flying stones, notes Mark Assenmacher, Peterson Manufacturing’s director of marketing.
Air dryers and separators
One of the secrets to an effective braking system is to keep your air dry – especially in northern climes, where moisture can lead to frozen valves.
Bendix Commercial Vehicle Systems recently unveiled a new water and debris separator to trap and purge contaminants from the trailer’s air lines.
The Cyclone DuraDrain trailer water separator includes a dual-action, pressure-sealing drain valve, and uses the simple concept of centrifugal force to pull contaminants out of the air, and spit them out before they can continue through the brake system.
“Dollies, trailers with long gladhand hoses, dirt haulers and fleets in high-humidity climates or areas where freezing and thawing regularly occur are particularly susceptible to moisture and debris issues,” adds Russ Brax, air treatment director, Bendix Commercial Vehicle Systems.
Meanwhile, air dryers don’t need to be limited to tractors.
The company’s System-Guard trailer air dryer will mount on cross-members or trailer frames, keep contaminants and moisture from air bags, and protect valves and the ABS system.
Back-up warning devices
Blind spots behind the barn doors have long been considered a fact of life, and the posts and other obstacles around loading docks have led to more than their fair share of damage.
After all, West Coast mirrors can’t see through the walls of a trailer. Sometimes you need a spotter to guide you.
Modern technology, however, can allow drivers to keep a close eye on the spaces behind them.
An array of backup warning devices can sound an alarm when you’re about to back into an obstacle, or even feed a video image into the cab.
Groeneveld’s Greensight system, for example, uses ultrasonic sensors to cover an area about three metres behind a trailer.
A signal unit in the cab is fitted with green, yellow and red lights to offer a warning whenever an obstacle is too close for comfort.
Want to question the value of an on-board scale? Add up the cost of tickets for overweight loads.
This equipment can play a key role in offering drivers the opportunity to make a quick check of weights.
Air Weigh’s AW5802, for example, is a stand-alone scale that mounts on a trailer’s frame rail, allowing users to read weights on an incorporated screen, or let the magic of multiplexing feed signals along the J560 connector’s blue power line into any in-dash Air Weigh display that’s been installed in the last two or three years.
More than 80 North American trailer manufacturers now offer the scale as an option, says Peter Powell, Air-Weigh’s vice-president of marketing.
A design pre-calibrated for 20 suspension systems makes installations that much easier, he adds. And a quick connection into the trailer wiring, as well as a simple way to tap into the air line between your air bags, can allow a retrofit in 20 to 30 minutes.
Consider how much easier it will be to adjust a slider if you can see the final weight without having to drive over a traditional scale.
Rubber gladhand seals will break down from exposure to ozone, leading to loose connections and potential air leaks.
Polyurethane designs are better equipped to resist chemical-related breakdowns. This is probably one of the cheapest components you’ll ever buy, but it can ensure a steady air supply.
…and protection for
Tread designs and compounds shouldn’t be your only focus when you’re looking to extend the life of trailer tires.
Low inflation pressures can mean a short life for your Number Two operating cost.
Let’s face it, trailers tend to be neglected when they’re shuttled from one tractor to another, and it can be months before they darken the bay of a maintenance shop. That means tire pressures will probably go unchecked for longer than they should.
A central tire inflation system such as the Dana Spicer Tire Maintenance System or Meritor Tire Inflation System by PSI can make all the difference.
Air from your tractor’s compressor is routed through a control box and through each axle, into a rotary union assembly at the end of the spindle.
The air is then fed to each tire, as it’s needed. (A protection valve should ensure that the air system continues to offer enough pressure for brakes. And check valves will keep other tires from losing pressure if you have a blow out.)
Another option may be to inflate tires with nitrogen rather than air.
Traditional air will bleed out of a tire at a rate of about two psi per month, but those using nitrogen claim their tires will lose about one psi over six months. Proponents of systems that generate nitrogen for this purpose say it will also fight corrosion. Keep in mind, however, that the promised benefits disappear once regular air is added to one of these tires , so it may not be appropriate for linehaul ops that will see tires topped up on the road.
Brake stroke indicators
When it comes to roadside inspections, out-of-adjustment brakes continue to be one of the trucking industry’s biggest maintenance related woes. During an unannounced North American brake blitz last May, 13.2 per cent of inspected vehicles were taken out of service because of adjustment problems. Part of the problem may be related to the fact that it can be a pain to crawl under equipment to mark and measure brake stroke. (And, really, is that being done with every drop and hook?)
Visual brake stroke indicators will make checks much easier to conduct – all you have to do is watch the movement of a pin or another form of marker, and ensure that it doesn’t move outside an allowable range when the brakes are applied. There are several versions on the market, but there is a common fact that shouldn’t be forgotten. Brake applications used for the tests shouldn’t be made with a parking brake. It’s still important to find someone to put their foot to the pedal, and ensure a 90 to 100 psi brake application that’s required by Commercial Vehicle Safety Alliance inspectors.
– See next month’s Truck News for our special Mid-America Trailer Section.