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ROLLS e
Page 38
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OICE
The advantages of having anti-rollover protection as well as EBS (electronic braking) on artic combinations can hardly be overstated. Most modern tractive units already have EBS. but if your trailers are approaching the eight-year-old mark you may have to update the brakes anyway, and a retrofit will give you optimum performance without having to buy new. Bryan Jarvis has been looking at what's available from the system manufacturers.
nvesting in new trailers calls for great faith on the part of both haulier and bank manager, but anyone running elderly trailers With ancient braking systems may not have a choice. According to Construction & Use Regulations No 4 (SI 3208 of 2001), which came into force on 1May, all trailers over eight years old must have an antilock braking system (ABS) powered by an ISO 7638 connection. Preferably it should also be connected via the 24S socket, to allow the ABS to operate when coupled to a tractor without the ISO connector.
EBS retrofit
If you do have to modernise your trailers this is the time to consider investing in an EBS retrofit. There are a number of EBS systems on the market that will not only Jpgrade your elderly trailer's braking system with the latest technology, but will oring in other safety related features too.
For example, Knorr-Bremse's latest TEBS4 conversion (which needs a 28 or 4S-2M brake baseline) combines full EBS with TRSP (Trailer Roll Stability Drogramme). Axle overload sensing and -ide height reset options can also be 3dded, which are particularly useful on :railers with lift-up axles.
The TEBS4 system uses yaw-rate sensors to monitor a trailer's lateral movenent when cornering and automatically Ipplies its brakes as necessary. It works with disc or drum brakes and is also suitible for twin wheels and wide singles.
At around /1,000 a trailer it might not seem a cheap option, but remember that a replacement ABS unit alone can cost nearly half that, so gaining EBS with rollover protection looks like a good investment at the price, and your insurers should be favourably impressed.
This technology is particularly useful on high-centre-of-gravity trailers like car transporters, tankers, hanging-meat reefers and double-deckers.
Modern outfits with air-suspended cabs, seats and axles tend to divorce even experienced drivers from on-road reality; this conversion will ensure that over-exuberant manoeuvring doesn't end in disaster.
Conversions take up to two days to complete, but this can be halved with experience. Knorr-Bremse agent Halls Auto Electrical of Bristol recently carried out the first TEBS4 retrofit in the UK, on a Spitzer powder tanker belonging to Castle Cement. The job was handled by electrical engineer Phil Rdley on the premises of animal feed distributor JE Clark Transport of Yate, Bristol.
"This first conversion couldn't have been a more difficult start point," says Ridley. "There's not a lot of space underneath the tanker's cones and discharge gear to access the existing valves and junctions for removal and re-plumbing."
The conversion replaces 12 components with two: the TEBS4, which effectively combines ABS, EBS, load sensing and TRSP in a single unit; and the park shunt/emergency valve.
"Using the software provided we list the trailer's performance characteristics and enter it on file," says Ridley. "Then, because it's a notifiable alteration to specification, the trailer's new braking calculations are lodged via a VTG10 with the DoT at Swansea." Wabco's EBS retrofit costs around 21,200 fitted; it also suits trailers with disc or drum brakes and single or twin-wheel configuration.
The conversion car include ECAS (Electronically Controlled Air Suspension) and RSS (Roll Stability Support); it replaces an existing brake valve system with three new fitments: the ECU modulator, a park shunt and a relay emergency control valve. The valve is sited close to the coupling head for a ver fast response. Whereas Knorr Brems uses yaw rate sensors, Wabco's RS monitors the roll angles using whei speed differentials; it also insists on a 4 2M brake control baseline.
Casley Diesel of Colchester has car veiled a dozen trailers to date, mostly wit the ECAS option. "We're simply replacin an old chassis' outdated braking with th very latest controls," says director Jaso Casley. "However there's not much spac beneath an aerodynamic race-supper trailer running on 17.5in wheels, so sue conversions can be time consuming work.