Don't let your own trailer push you around

Towing a heavy trailer around worksites can be a potentially hazardous, high maintenance undertaking - especially where vehicles have to cope with the slopes, loads, roads and surfaces encountered around mines, quarries, infrastructure and landscaping sites as well as farms.

Trucks, tractors and specialized machinery can be subjected to loads that will place unusual stresses on standard components, including high demands on braking systems in situations where operators need to selectively and powerfully apply stopping and holding power.

"If you are going down a one-in-four slope with a 90-degree turn at the bottom, you really(sure) don't want your trailer trying to push you straight ahead or off the road. You need to have the best control you can get out of the tractor and trailer brakes. And to be able to apply it simply and quickly from within the operator's cab," says site remediation, landscaping and farm contractor Ray Galdes of Mel-Ray Industries.

Mr Galdes - whose major remediation projects include work for the Penrith Lakes Development Corporation - has optimized safety, performance and reliability in his Massey Fergusson tractors and their trailers by installing a dual-line air/hydraulic braking system from Australian Brake Controls.

His latest system - applied to his Massey Fergusson 74/85 180 hp 4wd tractor so it can safely tow trailers up to 12 tons - enables the driver to simultaneously control both the tractor's hydraulic brakes and trailer's air brakes from the same brake pedal - as well as giving the operator the flexibility to operate the trailer brakes separately using an in-cab hand control.

"We wanted to use air brakes on the trailer because they are the most effective," says Mr Galdes. "We could burn out brakes really quickly on slopes otherwise, and we obviously didn't want reliability and safety issues. But the challenge was to synchronise trailer brake control with the hydraulically braked tractor to get braking that was smooth, progressive and powerful. We wanted it to be locally engineered for serviceability and we wanted it to be simple to operate."

Australian Brake Controls' solution for Mel-Ray drew on their experience of more than 20 years in engineering braking systems for owners of trucks, tractors and trailers who need optimum braking for specialist applications. Their brake specialist team works with leading vehicle and machinery distributors and individual owners to fit a wide variety of systems to new and used vehicles.

The system engineered for Mel-Ray incorporates a tractor-mounted half horsepower electric compressor feeding a nine litre pneumatic holding tank linked by airlines to the trailer brakes. This pneumatic system is synchronized with the tractor's hydraulic system via a reaction (retention) valve that automatically senses the amount of pressure being applied to the hydraulic system and turns this into an air signal for the trailer's air system when the brakes are applied. It pneumatically (electronically) transmits this information to the trailer's air system (feed), so it operates in tandem with the hydraulic system to provide smoothly modulated power.

As a further development of an earlier system fitted to a smaller Massey Fergusson operated by Mel-Ray, the new system incorporates a hand control through which the tractor driver can operate the trailer's brakes independently. This is a major safety and control asset when working on sloping ground where the trailer might otherwise act to push the tractor and impose high loads on its braking system. The complete braking system is neatly and unobtrusively engineered into the limited space available on hard working machinery.

This hand control valve also allows the operator to control the braking ratio between the tractor and trailer ensuring the correct amount of braking is applied no matter what load is in the trailer.

The system is similar in principle to systems engineered for hydraulically braked light and medium trucks so they can tow air-braked trailers.

"You might get a water authority tanker vehicle that is subject to widely varying loads, for example, or a contractor vehicle that is carrying both wet and dry organic matter for site remediation work, as Ray's does.

"Organisations such as mining, quarrying and landscaping companies are highly safety conscious - and their contractors are industry leaders in safety awareness. In addition, none of them wants to lose time because of vehicle downtime or reliability issues."

As well as the safety and efficiency advantages of his tractors' braking systems, Mr Galdes says the local engineering has saved his company a lot of money. "If we had brought a new tractor with the braking system I wanted already installed, it would have cost us near enough to $200,000. Even with a trade in of more than $100,000 on my current tractor - which is only a couple of years old - we would have been up for costs of $70-$80,000.

"The system we had engineered through Australian Brake Controls cost a fraction of that. Even after we had bought the air-braked truck axle, and spent the same again on the system, we were way out in front. We made inquiries about what was the best system around, and both vehicle safety people and machinery dealership people were very positive about our choice.

"And I like the idea of using a local Australian supplier, instead of an imported system. We're working on weekends and operate all over the place, so we like to know we can ring up to get any service we need where and when we need it to keep the machinery working.

"All the parts that go into the system are readily available through Australian Brake Controls - and they are always available with personal knowledge of my system. There is not a long, expensive supply chain and that makes a big difference for me."

Founded in 1987, Australian Brake Controls (ABC) is a specialist brake company servicing the mining, industrial and transport sectors with an extensive range of parts and services. ABC is the Australian distributor of Mico hydraulic products, Bendix and Knorr Bremse, Bosch Chassis System (PBR Commercial) Wabco and many others. Based in Smithfield, Sydney, the company has in-house engineering experience extending over 20 years, with an intimate knowledge of brake design and industry specific regulations, coupled with state-of-the-art testing equipment for optimized design and support of new or existing brake systems. Australian Brake controls can design and test systems to suit individual needs and submit them for statutory approval. Kits can be made for basic air brake use, antilock brakes, or electronic brake systems complete with stability control.

Workshop services include installation of dual-line air brake systems for trucks and trailers, including PBR CA300 valves; antilock brake systems for trucks and trailers; electronic brake systems for trailers; trailer brake release systems for prime movers that keep tip-over-axle trailers moving while operators are tipping; hydraulic and air/hydraulic brake lock systems; and specialized systems required by customers.

For more information, please contact Mr Vinh Lam, Australian Brake Controls, 103 Long St, Smithfield NSW 2164, ph 61-2- 9604 4400, fax 61-2-9725 3181, vinhl@austbrake.com.au