Haire Truck and Bus Repairs finds solutions to suspension woes – Words and images by Warren Caves.
Australian ingenuity has been an important contributor to the growth of this nation, no doubt dating back to the first fleet, when the early colonists were faced with vastly different farming conditions to that of Mother England. Stump-jump ploughs, Hill’s Hoist washing lines and Victa lawn mowers have all been born out of a desire to turn an arduous task using ill-suited equipment to a more refined and improved way of doing things.
Bill Haire of The Haire Truck and Bus Repairs based in the Victorian border town of Wodonga is known for his problem-solving skills. His ability to identify inherent problems with standard airbag suspension systems used in heavy-truck applications resulted in his belief he could improve on the design of the original set-up. The result speaks for itself, with Bill’s Haire Bag system solving the problems of uneven pressure resulting in loss of traction that can result in reduced braking ability, handling instability, and poor load distribution.
“The problem was that the original airbag suspension systems being used for multi-axle configurations were not load-sharing,” said Bill. “So back in 1985 I started experimenting with different ways of setting up a load-sharing air-bag suspension system. By 1999, after many years of development work, I had the final design of our current Haire Bag Suspension system.
“We believe that what we developed is the only dynamic load-sharing airbag suspension system in the world, which is now covered by a global patent,” added Bill.
Let’s take a bogie-drive prime mover axle set-up as an example. Traditional design sees air pressures within the bags remain fairly constant until road conditions change. If, for example, the truck drives over a speed hump, the front axle hits the hump and transfers shock, via the airbag, back up into the chassis and subsequently to the cabin before it has time to expel air via the ride-height valve. This action also results in uneven pressure being distributed to the road via the tyres, as the rear axle loses contact pressure because the chassis has been lifted. This process happens again shortly after as the rear axle hits the hump switching the adverse actions to the front axle.
The Haire Bag system works a little differently. In the same scenario as above, as the front axle hits the hump it then transfers air extremely quickly to the rear airbags, in the process reducing harsh loading to the chassis and improving ride comfort. By increasing the air volume and pressure in the rear airbags, the system maintains even road pressure via the tyres.
“Our system can move an airbag 80 mm in as little as 1/28th of a second, which is far quicker than any ride-height control valve can exhaust and re-inflate airbags to try and counteract adverse road surfaces,” said Bill.
Once the correct ride height is achieved there is no air dump throughout the suspension operation. Air is simply transferred within the system dependant on road input to the wheels. This lessens compressor run time, which can save on maintenance and fuel.
The system can be fitted to any OEM airbag suspension equipped truck, trailer or dolly, including road trains. By altering the airbag plumbing and by fitting larger bag to bag transfer hoses and patented fittings, this fitting by way of its design then controls air flow from bag to bag, and also has a dampening effect further improving ride, handling and stability.
Bill explains further, that his system virtually renders current ABS and EBS systems redundant, as these features only engage when a tyre breaks traction with the road surface.
“Our systems maintain even pressure with the road, greatly eliminating slippage of tyres and improving traction. As ABS actually has to release the brakes to avoid lock-up, we see vastly improved stopping distances achieved with our system. When fitted with a Haire Bag Suspension system a multi-combination truck and trailer set can pull up from 100 km/h in a 16 metres shorter distance than the equivalent ABS-equipped vehicle,” said Bill.
“We also see increases in tyre life by 25 percent, less transit damage from poor road surfaces, less road damage and an increase in dynamic stability, particularly with multi-trailer combinations and road trains. Tail wag and dolly kick-out are virtually eliminated. Driver fatigue is also reduced by way of the lower vibrational frequency transmitted into the cabin, and there is less correctional input required from the driver to keep combinations running true”.
On PowerTorque’s visit, the Haire workshop contained a Mack Super-Liner that Bill and his staff had stripped down in order to fabricate and replace the corroded chassis rails, remove the rear spring hangers from the front springs and to then fit the Haire Bag Suspension system on the drive.
“In addition to vastly improving the ride and reducing harshness for this truck, it will now benefit from a 20 percent increase on its GCM of up to 250 tonnes and enable it to be put into service on heavy haulage work,” said Bill.
Also in the workshop, having arrived directly from Kenworth’s Bayswater manufacturing facility, were two new Kenworths – a T659 and a T909 – awaiting fitment of Haire Bag Suspension systems. Where applicable, all GVM and GCM increases and necessary engineer certification are all carried out in-house before the vehicles leave.
Suspension enhancements are not limited to trucks. Bill recently carried out a chassis extension and dual-axle fitment to an Isuzu D-MAX ute, fitting his load-sharing airbag system. The report from the owner was that in its new 6X4 configuration the D-MAX went everywhere it went previously in 4X4 format.
Ben Glasson, of the sales team at ADTRANS HINO at Smeaton Grange, recently had a client requiring extra front axle load-carrying capacity for two new 8X4 FY 3248 model Hinos. After unsuccessful attempts to source a suitable company capable of completing the modifications, Ben contacted Haire Truck and Bus Repairs. Both Hinos were then dispatched to Wodonga where Bill and his team removed the rear hangers off all four front springs and fitted the appropriate Haire Bag Suspension system, converting the front suspension design to load-sharing and gaining the extra 1000 kg capacity required over the front axles.
“After the initial run-around we got from other businesses, it was a seamless procedure with Bill, and the trucks were returned certified and are now ready for their bodywork, I would definitely use them again,” said Ben.
Over the years, Bill has seen more than his fair share of resistance to his Haire Bag Suspension system, spending large sums of money on design testing and evaluation with outside independent certification bodies in order to get approvals and load increase certification.
“While PBS combinations are being given approvals for weight increases, we are not getting the same increase approvals,” said Bill.
“Interestingly though, we have had PBS approved, truck and quad-dog combinations rated to 55 tonnes in our workshops suffering from a complaint reporting poor dynamic stability issues. After we have modified these to our load-sharing system on the truck, dolly and trailer, the customers reported total satisfaction, saying that they have never handled better,” he added.
Private enterprise can only do so much with regard to development without support from major manufacturers. Despite demonstrations of the ability of the Haire Bag Suspension system and independent analysis and confirmation, Bill’s designs and suspension systems have largely been ignored by major companies. With government and regulatory body support, this type of dynamic suspension system could go a long way towards the reduction of heavy vehicle accidents.
“I believe there has been a lot of investment in EBS, ABS and stability control systems, which those financially concerned want to see continue. As our system, I believe, virtually eliminates the need for these electronic control methods, I wonder if that has something to do with the stonewalling we have received,” said Bill.
The proof, they say, is in the pudding. There are a growing number of customers who have converted their vehicles to the Haire Bag load-sharing suspension with nothing but praise for the benefits it has provided.
Bill Haire has a great deal of pride and passion for what he has developed, he is, perhaps, a little disappointed that it has not gained a wider market acceptance; however, he is content to carry on as always with the knowledge that those who have experienced his suspension systems know its true worth.