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194 
THE ART OF COUPLING
Page 58
Page 59
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ro truckers, tales of tractors losing their trailers are as much a part of urban
-nythology as seeing Elvis in Tesco. But unlike sightings of the King, trailer
oss is no fantasy. Now Jost is trying to take the hassle out of hitching.
While it's easy to blame coupling accidents on novices or the industry's favourite scapegoats, gency drivers, the wider issue of poor oupling practices hears closer examination. lesides damage to a tractor or trailer caused y brutal reversing, or the even more extreme ractice of skipping the kingpin over the fifth /heel (it happens), there's also the risk of hysical injury to drivers when dropping a -alien The HSE doesn't hold any statistics on -ie number of accidents involving artic oupling in Britain, but fifth-wheel and landing ;g manufacturer Jost reports there are plenty f figures elsewhere in the EU.
Jose Algticra, Jost's manager for design and development,reports in France alone there are up to 300 cases a year of drivers who injure themselves by leaping out of a truck to unhook a trailer. And in one year in Germany, there were more than 10,000 registered incidents, including everything from physically losing a trailer,to drivers damaging their backs while winding up landing legs or trapping their fingers. It makes you wonder how many similar incidents go unreported every day in the UK.
With those figures in mind Jost has been actively developing a safe coupling system since 2000.The first stage was a simple sensing arrangement.called SKS, which confirms the kingpin is held properly in place.That's now been expanded into the KKS (Komfort Kuppling System) that can be linked to self-raising/ lowering landing legs.At last year's IAA Hanover Show Jost showed off both versions, which are now optional on Mercedes tractors.
Alguera reckons that in the future KKS could even automatically connect or disconnect the trailer's air and electrical suzies, but first, he says: "We want to get the market familiar with this philosophy We need to make it a two-step process. We also need to talk to trailer manufacturers — it will take at least two years to make such a great step. The real issue is doing away with any visual checks."
Nonetheless,Algtiera hints a prototype auto-suzie unit could appear in 2006. SKS/ KKS can be fitted to any tractor or trailer from new or as a retrofit. However, it's currently only available with Jost's fixed JSK-42 light cast fifth wheel.
Trial units are rimming in the UK and Jost GB boss RoyTaylor reports KKS will make its official British debut at the NEC in April.A JSK42 fifth wheel incorporating a fulIKKS system will cost about /2,900 including fitting, but there will be discounts for fleet orders.
How it works
Jost's safe-coupling kit incorporates a series of sensors in the fifth wheel. On the base SKS model (Sensor Kuppling System) two sensors detect if the kingpin is in position and the locking handle is properly engaged, while a third monitors the height of the fifth wheel in relation to the rubbing plate, so the driver knows he's at the right coupling height. Information on all three functions is shown in a display unit in the cab.
SKS also incorporates a pneumatic cylinder in the fifth wheel plate which works on the locking lever. Using the in-cab control unit the driver can remotely 'pull the pin' when dropping a trailer. Pneumatic power ensures the coupling can he opened even when the tractor and trailer link is under tension, so no more tugging and pulling on recalcitrant locking handles while getting plastered with fifth-wheel grease.
The unit can't he activated on the move, and once the driver has pressed the button in the cab to disconnect the trailer he also has to press an'OK' confirm button for it to happen.
What SKS won't do is disconnect the suzies or wind up the landing legs —this is where KKS comes in. By adding a fourth sensor close to the edge of one of the fifth wheel's jaws, and an innovative wedge-shaped connector revolving around the kingpin. KKS provides direct power from the tractor to Jost's own'E-power' electrically operated landing legs. This enables the remote coupling/uncoupling functions of SKS to be extended to automatic operation of the landing legs with KKS.
Once the driver's reversed his tractor under the trailer and the fifth wheel has locked, the connection between tractor and trailer is made via a confirm button on the dash.The driver can then elevate the landing legs while still in the cab. He can also lower them without leaving his seat when uncoupling.
Jost describes KKS as being "idiot-proof". An ECU ensures that once the electrical connection is made between the fifth wheel and a trailer equipped with KE.S/E-power the driver can't release the fifth wheel before the legs are down Even if he selects kingpin 'open' on the control unit the legs will automatically lower before the kingpin is released. E-power legs can be wound up manually if there's a problem or when running with a non-KKS tractor. Likewise, a KKS-equipped tractor hauling a conventional trailer would simply lose the auto-landing leg function.
About the only thing KKS can't do is disconnect the air and electrical lines, so operators might have to suffer the odd set of "twanged" suzies before drivers realise they can't do everything from the cab.
However, there's clearly a potential saving in time, as the driver doesn't have to climb in and out of the cab so often — which has to be good for health & safety too. What's more, KKS allows you to park that little bit closer to another vehicle, thereby freeing up more space in the yard. And you can avoid clobbering your arms while trying to wind up a set of landing legs in a confined space. Luxury! •