Strides taken in the design of refrigerated trucks – and changes in techniques and materials used to produce insulated bodies – saw Durban-based trailer manufacturer Serco win a gold award for innovation at last month’s Automechanika Johannesburg
Since 1970, Europe and the United Kingdom have adhered to legislated standards for temperature-controlled vehicles, with strict thermal tests conducted to establish compliancy with regard to the transportation of perishable foodstuffs.
There, it is illegal for road hauliers to transport perishable fresh or frozen products across international borders unless the vehicle carrying the goods is ATP certified – which means it has a permit that indicates it complies with standards laid down in the International Carriage of Perishable Foodstuffs, commonly known by its French initials, ATP.
In 2017, the South African Bureau of Standards (SABS) commissioned a test chamber at its Pretoria facility, based on ATP requirements, to undertake thermal testing of temperature-controlled vehicles in South Africa – and a refrigerated trailer produced by Durban-based manufacturer Serco has become the first to achieve compliance.
Clinton Holcroft, managing director of Serco, says the SABS’s aim in establishing the test facility – apart from measuring the thermal efficiency of a refrigerated vehicle – was to ensure improvement in the cold supply chain and also to reduce, through an improvement in thermal insulating, the amount of carbon emissions pumped into the atmosphere as a result of the work the refrigeration unit had to do to keep foodstuffs within a particular temperature range.
“The Pretoria test chamber is managed and run by the SABS as an independent body,” Holcroft says. “The standards and procedures put in place are based on those contained in Europe’s ATP agreement, though in South Africa the standards remain a guideline. Still, the objective in establishing the test facility was to improve the standard of vehicles being used in the transport of perishable foodstuffs, to improve food safety, and to reduce carbon emissions.”
In developing its thermal trailer, Serco went to great lengths to ensure that all aspects of the unit met the highest standards. “Achieving compliance required a body in which insulating materials played a huge role. In terms of design, the unit’s structural integrity had to be maintained despite difficulties caused by a reduction in the number of heat bridges along its length,” he says.
The thermally insulated panels Serco used to manufacture the trailer – which measures about 15-m long and four-and-a-half metres high – were produced at the company’s Durban factory in a 900-t panel press specially bought for the job. “Insulating polyurethane foam is injected under controlled pressure in a system specifically designed to meet our particular requirements,” says Holcroft, adding that the elimination of heat bridges in the trailer’s body proved to be a challenge, since structural strength couldn’t be compromised.
“We did a significant amount of research and, in the construction process, used a selection of carefully considered components – among them steel, aluminium and fibreglass – together with special bonding agents and adhesives. A number of prototypes were sent for evaluation before we identified the most effective way to make the improvements and achieve compliance without sacrificing structural integrity.”
Holcroft says that in meeting the SABS’s requirements, Serco has reduced the amount of diesel consumed by the refrigeration motor, effectively cutting CO2 emissions by about eight percent. Additionally, the number of CFCs emitted has been cut substantially.
“The reductions allow transporters to shrink their carbon footprints – a significant emerging trend in South Africa’s road haulage industry. The trailer also helps to cut distribution costs and helps to improve the shelf-life of perishables, while innovative climate-friendly refrigeration technologies reinforce factors relating to the reliability of supply and the quality of fresh produce,” he says.
According to Holcroft, the new trailer is about 30-percent more thermally efficient than previous units manufactured by Serco. “We’ve done a number of temperature comparisons,” he says. “The results are excellent – but not surprising. Changes in techniques of manufacture and materials used to produce insulated bodies have developed at a rapid rate in recent years.”
Holcroft says official thermal ratings have been a mandatory requirement in the industry in Europe for nearly half a century – and are long overdue in this country. “Introduction of the SABS’s test chamber will play a major role in helping to raise the standard of refrigerated trucks and trailers built in South Africa,” he says. “It will also result in improvements to maintaining the effectiveness of the cold chain. Overall, consumers will benefit from the delivery of better-quality fresh produce.”
In winning Automechanika Johannesburg’s Innovation Awards competition last month, the trailer was praised by judges for being the first in South Africa to achieve SABS approval, and which, in their estimation, represented a benchmark for the country’s refrigerated transport industry.