The trucks – both Arocs 2563s with flat-floored BigSpace cabs and 625bhp in-line six-cylinder engines – pull five-axled Nooteboom low-loader trailers (also new) together worth more than £500,000.
Each rig transports some 80 tonnes – mostly steel ballast counterweights to stabilise the 350-tonne, six-axled crane during operation, although the trucks also carry winches, hook blocks, etc.
According to Southern Cranes & Access director Clive Sadler, key to the firm's decision to buy its first Mercedes trucks was its new turbo retarder clutch, which works with the 16-speed Mercedes PowerShift 3 automated transmission.
"We were looking for a truck with a bit more power, and liked what we'd heard and read about the new turbo clutch," comments Sadler.
"[Local dealer] Rossetts offered us a demonstration unit for a week so we gave it a go and the driver came back singing its praises," he continues.
"The fuel efficiency was at least equal to, if not better than, the less powerful trucks we'd been using, and he really liked the all-round quality and feel of the Arocs."
Sadler says the automatic transmission and turbo clutch are certainly living up to their billing.
"Some of the locations we have to access are very tight, which is why we specify our trailers and other equipment with high steering angles," he explains. "But even fully loaded the truck was very easy to manoeuvre at low speeds."
"We've only had them a couple of weeks but I'm very impressed and the drivers love them," enthuses Sadler, adding that the Arocs certainly looks the part and, with their raised ride height and robust build quality, are "clearly capable of working reliably in rough conditions".
Southern Cranes & Access purchased its two new tractor units with funding support from Mercedes-Benz Financial Services.
Both tractors and their trailers will be inspected and serviced under Mercedes-Benz R&M contracts by Rossetts Commercials' workshop at Worthing.
"We've dealt with Rossetts for years because a number of our cranes have Mercedes-Benz engines," says Sadler, adding that the Dealer provides "very professional" service.
Mercedes' turbo retarder clutch is capable of handling and delivering 3,000Nm of torque, significantly more than a traditional torque converter.
Additionally, it offers fine control and has its own, integrated primary retarder, negating the need for a separate retarder that would otherwise be necessary to assist the high-performance engine brake in bringing a fully loaded rig (up to 250 tonnes gcw)
to a halt.
Most importantly, it also provides for wear-free starting and braking under extreme loads, and makes it possible to move away with maximum control and minimum fuel consumption.
The integral primary retarder offers braking power up to 750kW (1,006bhp) and also functions in reverse.
Interestingly, Mercedes-Benz says its turbo retarder clutch also offers a weight saving of 80kg compared to a conventional torque converter clutch, as well as reduced noise emissions.