Traditionally, in road transport of very large and heavy cargo on multiple trailers, two or four trucks can be required at the front to pull and steer and two or four trucks at the back to push or brake assist. The trucks and trailers are mechanically connected, increasing pulling and braking power but limiting their maneuverability. Instead of trucks heavy haulage prime movers are also used – but all of them need to drive back empty.

The new TPA-system has been initiated by Mammoet and developed in cooperation with SCHEUERLE, the leading manufacturer of heavy transport vehicles. TPA is based on the SCHEUERLE K25 trailer, which is fitted with a Power Pack Unit (PPU) that hydraulically powers 4 of the 6 axle lines. The PPU is mounted at one or either end of the trailer, depending on the configuration – or can be placed on the prime mover to replace the counterweight for traction. Each PPU is powered by a MTU V12 diesel engine, compliant with all emission requirements, that generates 1,000 horsepower and a traction power of over 40 tons. The TPA system is specified for all weather extremes. The draw bar pull of the TPA is the equivalent of two fully loaded prime movers – meaning that one TPA can replace at least two trucks. This has a number of advantages. It reduces the length of the transport and greatly enhances maneuverability by requiring only one truck at the front to pull and steer. One single truck driver operating the system virtually eliminates communication errors – the key safety concern with multiple operators – greatly increasing safety on long haul transports. TPA power can be multiplied by adding more TPA trailers and PPUs, greatly enlarging efficiency compared to using multiple trucks. After on-site delivery the TPA can be operated by remote control in ‘creep mode’ for maximum maneuverability and positioning. One truck can return the empty TPA units in frictionless ‘free-wheel’ mode of the hydraulic drive system. The assisted road speed of TPA is at least five times higher with only a third of the fuel consumption compared to a transport using only SPMTs (Self-Propelled Modular Transporters) – considerably reducing the carbon footprint. Above the maximum speed of 25 km/h the PPUs shut off and the truck can pull the trailer combination to highway speeds of up to 80 km/h. This means larger loads can be transported over longer distances with safer higher average speeds. In future, exceptionally large transports of over 2,000 tons over longer distances using multiple rows of trailers with one truck at the front and one at the back could become a reality.