Sliding trailer has split personality
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If operators such as building materials suppliers need a long trailer on one leg of the journey and a shorter one on the other, Raven can help.
by Bryan Jarvis • Building material suppliers unable to use their semi-trailers for return loads should take a second look at Raven Trailer's unusual Conqueror retracting semi-trailer.
Raven's first trailer is a conventional triaxle flatbed brick or block carrier that retracts from 13.7m to 9.14m. With a shorterreach—and much cheaper9.1m (30ft) crane it is capable of unloading itself in two stages.
The crane can be fitted either behind the cab or over the neck of the trailer. Having arrived at a customer's yard with a full quota of pallets, the first 1.6m is unloaded then the trailer is shortened for the rest of the load to be taken off, The Conqueror can be used for single or part loads and having a full set of ISO twistlocks the trailer can return with either two 20ft (6.1m) containers or a single 40 or 45-footer (12,2/13.70. In its shortened form it can also handle a heavy 6.1m container so for Channel crossings lower ferry charges apply. Reduced to 9.0m in length and with the front axle raised the outfit becomes much more manoeuvrable, too.
Raven has built the brick/block carrier to a high spec with Hiab 140 ANW crane and brick grab, Rockwell airsprung running gear, Truck-lite lighting and harness plus Groeneveld auto-lube.
The Hatz donkey engine has been added to let operators without PTOs on their units try the trailer.
The Conqueror concept can also lend itself to the movement of portable buildings and containers but designers Paul and Kevin Raven believe it could be suitable for waste skip movement, high-cube trailers or even for military uses.
A prototype logging version is in build with stakes at 3.04m (10ft) intervals but it can be designed in lengths up to 24.4m (80ft) and equipped with a solid floor, which would certainly interest Special Types hauliers.
Raven's new trailer comprises two chask frames with a 120mm step to accommodate the two sliding-floor sections.
The forward platform sits on four air bags lying flush with the main rear section and is held in position by four lateral pneumatic locking pins and a pair of patented Double-C locks.
As the trailer retracts or extends the C-locks clamp the inverted kingpin fitted to the main frame and, together with the four locking pins, hold the frames securely.
A control box with simplified Norgren Martin Visivvink pneumatic switches is mounted at the front of the trailer and each is operated sequentially, but only after a self-check ensures it is safe to continue.
To shorten the trailer the park brake is applied and the locks released. The driver then reverses the unit, pushing the front half of the trailer rearwards on six heavy-duty rollers and under the main deck. Once positioned the two are secured in position using the same locking pins and Double-C clamp.
Raven has specced the trailer for longevity using ferry side raves from Fruehauf along with the extruded aluminium flooring and rollers. All metal-to-metal surfaces affected by the slider have nylon wear strips.
Raven Trailers, based near Ipswich, Suffolk, is a relatively new company but with 930m2 of floor space, a spray paint shop and ISO 9000/BS 5750 in the pipeline. It aims to turn out around four a week and the Ravens say: "We have the backing to raise our output still further. Should this not be enough we could have the trailers built by a licensee."