Development of trucks over 40 years

B-double with Xperion CNG containers.

Reading an industry magazine about the recent removal of an identity from the industry reminded me of having met him in the early 1980s and the state of the industry then.

It was definitely a different world for me as a new member of the engineering department at Kenworth Trucks and the trucks were very different from what we know now. In the early 1980s, the “standard” line haul truck was a COE with an engine of around 300hp, nine-speed transmission, bias ply tires, was limited to a regulated maximum overall length of 16.5 m and could not grow more than 38.5 tons.

The common front suspension had a rigid 52-inch multiple leaf spring and the tandem drive axles were mounted on a pendulum suspension.

Not very conducive to good driving for the driver, especially since the cab suspension was non-existent at the time. The brake systems were dual circuit, but the third edition of ADR 35/00 and 38/00 was not promulgated and did not come into full force until 1988.

In the meantime, the anti-lock brakes had not been released and were not mentioned in these ADRs.

Another problem faced by operators was installing sufficient fuel capacity on these short wheelbase drive engines.

There simply wasn’t much space in the wheelbase for more than a pair of 550-liter tanks that were constrained by then-current ADR testing to be cylindrical.

These tanks had to withstand a drop of 9 m on its corner without leaking afterwards!

The offending ADR17 / 00 was withdrawn in 2005 and since then the use of rectangular tanks that could not pass the drop test has become standard even on conventional cowled drive motors. In 1985, the NAASRA (now Austroads) released its “Review of Road Vehicle Limits” (RORVL) report that changed the world as we know it.

The review was extensive and investigated road damage caused by repeated heavy truck passes, associated costs, and investigated weights of vehicles using roadside weighing equipment.

While trucks today generally comply with axle load limits, back then large overloads were not uncommon, so any review of load limits had to include these roadside checks.

The recommendations (later adopted by state road authorities) increased axle load limits to those used today under general mass limit conditions.

In addition, the bridge formulas have been changed and have included axle spacing tables for B-double combinations.

This set the stage for the adoption of B-doubles across the country and the establishment of systems for the operation of CML and HML and the PBS system. In the late 1980s, the development of trucks continued with suppliers and manufacturers responding to a competitive market with the first electronically controlled diesel fuel injection systems offered.

While in some cases these were relatively rudimentary electromagnetic actuators controlling the fuel racks of the injection pump, the market quickly shifted to electronically controlled, camshaft-driven diesel injectors.

The major challenge for these systems for truck manufacturers was to integrate the electronic control components and harnesses into the architecture of the wiring systems.

Control modules of the day had limited compute and memory capacity, so some systems had ECMs mounted in the cabin as well as on the engine.

There was also perhaps some caution about the durability of these early ECMs if they were mounted in the hot, vibrating environment of a diesel engine.

The initial distrust and caution of customers was quickly overcome by the performance of these engines, both in terms of horsepower and reliability.

And we now know the engine block mounted ECMs as common practice.

New engines designed from the ground up around electronic fuel systems emerged, such as the Detroit 60 series, Cummins’ Signature range and more from US and European suppliers, all of which offered improved performance and fuel economy.

But what motivated all this development?

Colin Blanc.

Operators were looking for a business advantage, but engine manufacturers were forced to change through sweeping changes to engine emissions regulations.

Until 1996, when ADR70 (Euro 1) came into force, engine emissions were only controlled by the ADR30 smoke control rule, but at that time more stringent rules were in place. force abroad and engines meeting these rules have made their way here.

As emissions regulations have become stricter, one would have expected fuel economy to be affected, but in practice the opposite has happened and fuel economy continued to improve.

Competition between suppliers has pushed them to offer their most recent engines in terms of emissions, ahead of the current ADR, to meet customer demand for cleaner or “cleaner” engines.

One manufacturer even advertised using a white cloth held at the end of the exhaust pipe to demonstrate the absence of soot in the “clean” exhaust. But of course, the engines weren’t the only ones to change.

Trucks and trailers quickly adopted air suspensions to take advantage of their improved roll stiffness and better handling under all load conditions.

And innovative operators have collaborated with trailer manufacturers to take advantage of the new regulations to maximize payload capacity in both increased mass and deck length.

Other innovations were adopted ahead of regulations to improve safety and reliability, including automated manual transmissions, the wider adoption of fully automatic transmissions in light and medium segments for distribution applications, and trailer EBS. (TEBS) with roll stability systems.

Electronic stability systems for trucks have also infiltrated the market, surprisingly initially in the low-end light vehicle market segment.

And electronic stability control became widely available in all segments before regulators acted to impose it.

In fact, in my opinion, most developments in the industry have been driven by customer demand to reduce costs and improve the efficiency of operations, and not by regulations or ADRs. As a result, the trucking industry now operates sophisticated vehicles with complex electronic systems and diesel powertrains that provide reliable, high-productivity services to the country.

And this productivity continues to grow with the growth of specialized coveralls operating under performance-based standards approvals.

What about the future? With the decarbonization of the world and eventually Australia, the transportation industry is going to face huge changes and the trucks of the future will likely have a variety of transmissions to power them.

Will a low-carbon industry be able to operate trucks with the high gross masses that we now accept as the norm?

Or will rail become a more important part of the interstate transport mix?

Looking at trends abroad, not only are electric vehicle solutions offered, but carbon neutral systems using renewable methane and biodiesel are becoming mainstream. But I believe these are transitional solutions. In all likelihood, there will be a variety of solutions for different transport tasks.

Full battery EV solutions are already being introduced for light and medium trucks that operate in pickup and delivery operations in our cities.

There, the usual daily distance before returning to base is approximately 200 km, an achievable range for these electric vehicles. But what about longer journeys?

The concept of fast charging stations may be feasible for passenger cars, but recharging trucks would be a tedious process.

Australia is moving towards a hydrogen economy, and heavy transport may well have an electric motor transmission powered by hydrogen fuel cells.

There are still many questions and problems to be resolved, and the transportation industry will face massive changes in equipment, training and operations on the path to a diesel-free future.

Colin Blanc,
Commercial Vehicle Engineering Consultant,
ARTSA-i life member

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