When the idea of a system of Performance Based Standards was first discussed 20 years ago in the Australian trucking industry, the pioneers of the scheme had some idea of the kind of innovative vehicles which could be developed. In fact, the main thrust of the PBS scheme, as it developed, was to create a space into which innovative thinkers about vehicle engineering could move and come up with the kinds of solutions which were capable of making a quantum leap in productivity improvements for trucking on Australian roads.
However, the Australian trucking industry is aware of the relatively small impact the actual existence of PBS has had on the trucking scene here in Australia. The scheme created a great space for innovation but, so far, nothing has matched the leap in productivity achieved previously by the introduction of the B-double.
Instead, apart from a small number of highly specialised vehicles designed to suit a particular small niche market, most of the PBS approvals on the highway achieved small productivity gains due to incremental dimension changes, adding axles or steering axles. The PBS system has been approving vehicles in steady numbers but the overall productivity of the Australian trucking industry has not been greatly improved.
Back in the 90s, when the system was being developed, the pioneers of PBS were looking for the silver bullet, a new innovative vehicle which could become a game changer. It had to be something which could make genuine productivity gains but also would not take state and local government, the agencies tasked with maintaining road infrastructure, outside of their comfort zone.
Finally, in 2010 a combination vehicle has emerged with the potential to make the quantum shift required to give the PBS system some credibility and, at the same time, give the Australian trucking industry the kind of productivity boost it has been crying out for. Surprisingly, the new innovative design comes from a type of combination which has had many critics over the years.
The A-double is a very basic multiple combination with two semitrailers linked by a converter dolly between the two trailers. It is the simplest of the multiple combinations, using two trailers which can be used individually with the addition of one single extra component, the dolly. In the past, this combination has been seen as a necessary evil in remote areas, but on road performance has made it unsuitable to come anywhere near large centres of population or busy traffic conditions.
In 2010, all that has changed, the A-double is still a simple basic multiple combination, but now, with one small change, it has become a modern, innovative, high productivity safe vehicle. By concentrating all of the new technology in one element of the combination, the converter dolly, Haulmark Trailers may have come up with the kind of game changer those who initiated the PBS process were looking for 20 years ago.
“The whole thing started in late 2006 after Haulmark had been involved in the PBS process for many years,” says Haulmark’s National Sales and Marketing Manager, Mark Johnston. “We had built a number of PBS approved vehicles, steerable extendable trailers and a 52 foot trailer without a steering axle.
“The concept of PBS had been to provide that quantum step for the industry. The A-double is that solution which comes up with the very elusive quadruple bottom line. It offers considerable improvement in productivity, emissions, congestion and safety for everyone. Those four things provide a huge step forward, the game changer.”
Developing vehicles for PBS requires a deep understanding of how a vehicle performs. Designers need to know where it performs well and where it doesn’t perform well. They have to identify what needs to be worked on and improved to meet the standards. Understanding the dynamics of these vehicles leads to developing the technology to provide solutions.
“We are trying to find solutions for the growing freight task, control emissions, deal with congestion, all of those things,” says Mark. “We take the principles of PBS, our understanding of the dynamics of vehicles and then we try to apply technology to a range of those vehicles to see what was actually going to come up with the real trump card.
“We came up with the A-double concept because it gives us a significant step up in mass, a significant step up in trailer length and by doing that we significantly improve emissions and congestion with a safer vehicle. We had looked at a range of potential vehicles – B-doubles, quads – but every time I looked at it, it didn’t convince me as being the way to go. The vehicles are very specialised and limited by their mass. A quad/quad B-double will only give you a 77 tonnes GCM but when we looked at the A-double we could get 85 tonnes.”
For many years there have pocket road trains running in Western Australia, into Perth and around the industrial areas. They are a different to the design Haulmark has come up with but they do demonstrate their effectiveness in terms of productivity and compatibility with the urban environment.
“The A-double just kept coming up as the one with the most potential,” says Mark. “Then we needed to work out exactly what we needed to do to the dynamics of that vehicle to make it work really well. It’s all to do with the high-speed performance of these vehicles, that’s where the technology is required to make it do what you need. You need to keep the trailers in line and compliant with the standards.
“The important thing is, it’s not just about getting something to theoretically comply, it’s about getting something you know really does work. With that technology, as we have developed it, we have vehicles up to 30m long but also others with shorter overall lengths. Because of their manoeuvrability we have got them operating in areas where they will not let B-doubles operate. They are being allowed there because of their performance.
“Urban distribution is more about low speed and manoeuvrability. It’s about negotiating roundabouts and going into particular streets, those sorts of things. The 27m long A-doubles we are running have a swept path which matches that of a normal six axle semitrailer. That’s Level I PBS performance and it is only precluded from some roads by its length.”
As part of the PBS development process, computer modelling was done and a range of simulations, where Haulmark took a basic non-steering A-double, put it through the system and worked out where it didn’t comply. Haulmark’s priority was not to develop a system which just complied, it was looking for something with which it could say, ‘hand on heart’, was the right vehicle for the job.
A few practical priorities were also identified. It was looking for a solution which could use a standard B-double prime mover and normal trailers with ABS. Dimensions of the trailer would be vital to getting the system to work. However, the plan was to concentrate all of the technological improvements and gadgetry in the dolly.
Keeping the smarts, as much as possible, contained on the dolly, gives operators the opportunity to utilise existing equipment within fleets. This also meant the technology could be expanded to be used with trailers in the wider industry, tankers and bulk tippers, trailers Haulmark don’t make. However, it would be able to supply a dolly which other people could use to make a compliant A-double.
The basic principle of the technology uses sensors to tell the steering dolly which way the first trailer is moving when following the prime mover. This information is then used by the steering control to move the second trailer across to follow the first. At high speed this steering anticipates any ‘whip’ from the trailer and keeps the combination in a straight line. At slow speeds the steering dolly tries to take the second trailer in a wider arc around the corner to follow the first without ‘cutting in’.
“Once we got to the point where we really understood the dynamics of the vehicle, we realised the A-double was the one which was going to work,” says Mark. “It was going to give us the mass and it was going to give us the length. The more we looked, it became really clear this was the area we needed to concentrate on.
“Looking at the overall design you get the dimensional parameters right, so it fits within the 30m. Then you have to look at weight distribution, to make sure it will be able achieve the masses required. We also knew it would be vital for the vehicle to be capable of carrying two 40 foot containers and compete easily with options like the Super B-double.
“The big dynamic benefits are available when you put the technology on the dolly, especially at high speed. That’s why we went down the path of the steering dolly. We needed to take the whip out of the dolly, controlling the dynamics throughout the combination. You need to control the rearward amplification and the high-speed transient off tracking when the combination makes a lane change. There is also a test called a pulse steer where the steering wheel is shifted, held and then returned to the starting position.”
During the development process, Haulmark found there was a possibility the combination could meet the low speed of tracking requirements of PBS without a steering dolly. However, the steering capability was already in place so could be utilised to improve low speed performance. The final A-double out on the road now has a swept path performance better than most 26m B-doubles.
These new combinations are a major step up in vehicle performance, this is not just a design which squeezes into compliance and meets the standards by a small margin. For Haulmark, it was important to demonstrate a considerable safety improvement and show the A-double exceeds the requirements by a clear margin.
“We wanted to put a vehicle on the road which was the pinnacle of road safety and by fitting things like ABS, side underrun protection and spray suppression equipment we have achieved that,” says Mark.
As the ideas for an A-double were coming to fruition on the technical side for Haulmark, it was approached by a customer in the Newcastle area, hauling steel, to have a look of an application which it felt justified a PBS vehicle.
The customer was given a number of options including a B-double and a single trailer with five axles, but Mark did inform them that the A-double looked like the best option. The longest product they were carrying was only 9m long and they were wanting to travel over general access routes so Haulmark would only need to build the combination to a length of 27 m.
Word-of-mouth then got around about what Haulmark was doing and other potential customers expressed an interest in the ideas. Haulmark now has 15 of these combinations on the road, both 27 and 30 metre versions, working in both New South Wales and Queensland. This experience has allowed them to work through all of the reliability issues and have a lot more knowledge about what the combinations are like and how they work.
Before the first customer had approached Haulmark, in late 2006, Haulmark already had its first A-double going through the approval process for the PBS scheme. This is the initial process whereby the vehicle is assessed as to whether or not its performance meets the criteria for the PBS access for which it is intended.
“Back then, they wouldn’t do a route assessment for your proposal until you had an approved vehicle,” says Mark. “This was a bone of contention for me because they were expecting me to go out and spend the money to develop the vehicle without knowing whether the vehicle would be acceptable for the route it was intended to use. The bureaucrats didn’t understand we could change the vehicle to suit the route requirements.
“The route assessment for these trucks was a very long and drawn out process. Although I have to say, in NSW, the Roads and Traffic Authority and the Newcastle Council were very good to deal with. This was probably because the road transport industry is particularly important to the local economy and they could see the 50% reduction in truck trips along with the other benefits in emissions and safety as benefitting all.
“The process of getting route assessments has highlighted the fact these jurisdictions have very little knowledge of their infrastructure and its capabilities. The jurisdictions need to make a more committed effort to analyse their assets. The real issue is for them to develop freight routes for PBS vehicles. The roadblock for us now is route assessments, operators cannot tender for major contracts with innovative vehicles because they don’t know how long permission to use a route will take.
“All the bridges on our highways are not going to be upgraded overnight. We need the information from the jurisdictions to enable us to alter the design of the vehicles to suit the infrastructure we are hoping to use. Sometimes, if we are lucky, the authorities are willing to upgrade bridges on a route. This is what happened with our application for a route between Port of Brisbane and Toowoomba.”
By the end of this year the bridge upgrade work will have been done and A-doubles up to 85 tonnes GCM will be able to use the route. This means they can carry two 40 foot containers, each weighing 31 tonnes from Toowoomba to the Port of Brisbane. It was only when Queensland Transport and Main Roads had to do the route assessments for the PBS application, it realised these particular bridges needed improvement.
“There is a collaboration required between those of us who are designing vehicles and jurisdictions who are responsible for the infrastructure, to get the best out of the infrastructure and identify where it needs to be improved,” says Mark. “We’re not looking for policy change, that’s all in place – it’s all been accepted. It’s just a matter of getting a better focus on the requirements of the trucking industry and directing resources into these departments to develop the networks on which these innovative vehicles can run.
“In the past, it has taken people, like me, who have been willing to make a fuss, thump the table and generally be a nuisance to get some of the progress we have achieved. Now, that time is over, there are routes which have been approved. All we are doing is accessing a system of which all of the regulators have approved.
“Coming out of using these vehicles are really great productivity improvements, a direct reduction in traffic congestion, a reduction in emissions and a direct improvement in road safety. Once transport operators see this is working properly, they will be willing to invest capital to make it work and improve their productivity. There is no reason why everybody shouldn’t embrace this.”