Road Science is one of the preeminent suppliers of bitumen emulsion to road-building contractors nationwide. The company‘s now embarked on a replacement programme for its fleet of tanker trailers, entering a shiny new era.

Late last year we reported that Road Science had taken delivery of the first new, state-of-the-art tanker trailers to enter its fleet. OK, that‘s not entirely accurate, the first B-train entered the fleet in August, but that was mainly to iron out any teething problems that may have snuck through a thorough engineering job that followed an extensive consultative, design and build process between Road Science, Downer Fleet and Plant, its carrier partners (Tranzliquid, McEwan Haulage and Freight Haulage), Tieman Tankers of Australia, and New Zealand‘s own Total Transport Engineers. The highly collaborative process meant all partners had an equally important role to play in getting the high-tech bitumen emulsion tankers rolling on New Zealand tarmac, kicking off Road Science‘s ongoing, accelerated replacement programme. Seven new units have now entered the fleet and are operating in both the North and South Islands.

“The average age of our trailers was about 25 years, the oldest was 35 years old. R&M was going through the roof and we had nothing that could utilise the HPMV network. There‘s smarter tech now to get bigger loads out the gate,” says Stuart McFadyen, transport logistics manager for Road Science. There were numerous requirements the new trailers had to fulfil but those at the top of the list included increased productivity and increased safety. Addressing the former, B-train and tri-axle semi-trailers were specced so that they could take advantage of the HPMV network and work with the prime movers used by their carrier partners.

“The kilometres we do don‘t justify them getting new equipment for us, so we built the trailers to the profile of the vehicles used in the Tranzliquid fuel fleet,” Stu says, adding that the prior quad-axle trailers were limited in their ability to meet the HPMV network desires of the company. This is where Craig Gordon of Total Transport Engineers came into the picture, whose job it was to design the tankers so they could split into two singles and be towed legally on any sub roads.

Photo: All the safety equipment one could need – and then some.

Photo: 3am and ready to leave the Mount for Auckland after an early morning wash down. Note the orange power cable for overnight heaters.

Photo: Driver Neal Watson-Paul primes the pumps.

“As it stands now, the vehicles can be configured as HPMV B-trains and then can go back to the standard VDAM rule. So, travelling to two destinations with one B-train unit, one tanker can be dropped off to be drained while the driver takes the other to the next job. One driver, two trailers, two deliveries – makes a lot of sense,” Craig comments. The men explain that while this doesn‘t mean they‘ve doubled up on payload, Tranzliquid is able to move much higher payloads per unit per day than by sending out a single. “With traffic and delays, we can‘t get two loads to Auckland in a day anymore. So now we‘re getting a much higher payload to Auckland per unit,” Stu says. Speaking of which, working on 57 tonnes per B-train unit sees payload max out at about 30 tonnes (about 15,000 litres per tank). “Most of the old units moved about 20 tonnes or less.

We‘re getting 50% more out the gate,” he says. “The combination is a heavier mass, but the payload gain is what it‘s all about. Because we can split on 30 tonnes we‘re still gaining on standard legal limits for smaller deliveries,” Craig adds. That‘s increased productivity taken care of and increased safety was subject to the same levels of consideration. The trailers feature an assortment of equipment that is both mandated and optioned by Road Science. Soap dispensers and hand-washing water are available in case of hazards, as are showers either side of the tanks, which Stu says was an idea nicked from Australia.

“We‘re keen on those and want to retrofit the old tankers with them,” he says. Fitted to all units are Hendrickson axle and suspension assemblies with the Hendrickson TIREMAAX tyre pressure management system, which keeps the trailers‘ tyres at consistent pressures and temperatures. Should there be a loss of pressure, an indicator light on the side of the tanker warns the driver. He can carry on driving, though, as the system will maintain the pressure rather than forcing him to stop en route to repair the tyre. “This is important as sealing crews won‘t be delayed and the tyre repairs can be done after the delivery. It will also extend tyre life,” Craig says. Operationally, there is much less working at height involved for the driver, who no longer has to open the lids to vent the tanks when pumping; an automatic valve mechanism atop the tanks does the job instead.

(Tieman liked this idea so much it‘s now fitting them to its Australian tankers.) He also doesn‘t have to climb up and peer inside to check they‘re empty; the Wabco SmartBoard onboard scales take care of that. The job of unloading is different, too. Whereas before the job was done with an overhead arm hard-piped over the top of the receiving tanker, it‘s now done by way of a pump and a hose. While Stu‘s happy with the new system (it‘s much tidier and no overhead arms means no dripping over the tankers), his ultimate dream would be for the sealing crews to be able to suck the emulsion from the tankers, eliminating the need for pumps and hoses on the part of Road Science. “Not having to carry pumps means less weight on the trailers and prime movers (no hydraulics and other systems) and more product out the gate,” he explains.

Photo: Under the gantry at the bitumen plant is one of the only times a driver needs to get on top of the tanks.

Finally, all units are fitted with reversing cameras and driveaway protection, which locks the brakes when a hose is hooked up so the rig can‘t be moved, in a similar vein to fuel tankers. Overall, feedback from the drivers has been positive, according to Tranzliquid operations coordinator Jamie Lim- Yock. “Tieman sent out trainers to go over the operational procedures with the drivers. It didn‘t take them long to adjust and adapt; the guys like to not have to climb up and down the ladders all the time. Their feedback has been good,” he says. Keeping the units clean on the inside was also considered, as Stu explains. “Annually, we get inside them and inspect them. The confined space is a big issue.

Most tankers don‘t have access through each baffle, but these have an accessway on each. They also have a big outlet at the bottom to drop out all the cleaned-out gunk.” It‘s clear that all the needs of Road Science were taken care of, and all aspects of the tanker design accounted for. This raises the question, given the differences in design and legislative requirements between New Zealand and Australia, were the tankers difficult to engineer? “Once Tieman had copies of the New Zealand regulations they could work it out. They needed to understand the different parameters of our designs and sometimes it took some time to gain an understanding of New Zealand rules,” Craig says.

One particular parameter was in regard to heating. Bitumen emulsion must be maintained at temperatures between 80 and 85°C for optimum transfer to the road surface. However, compared with Australia, additional insulation is required because the lower ambient temperatures of New Zealand mean higher heat loss. Here‘s where the final design really came good as the spec of the tankers, cladding and insulation has meant a heating energy cost saving of two-thirds compared with the old units. “For us that‘s major. They told us it would retain the heat a lot better and that‘s proving to be so,” says Stu. At the end of the day, it was the collaborative effort between all parties that ensured the finished units would be truly up to the task. “Everyone who‘s been a party to it has been with it all the way through. Tieman rectified any design queries and stood behind everything we wanted to change without qualms,” Craig says. A safer, simplified system with added features that make the job easier is probably the best way to describe what Road Science, Tieman Tankers and TTE have been able to achieve with its new fleet of tankers. And they‘re impossible to miss, too.