Page 30 - Commercial Vehicle Engineer - October 2019

NEWS FROM THE NORTH
Not much to it; a pedal, a wire and potentiometer.
One step further
Many truck manufacturers now offer an automated transmission as standard. Volvo Trucks has gone one step further; for the past two years there has been
no manual available for its heavy truck range, only a six-speed manual for the FL and nine-speed range change for FE.
Ronnie McGrouther is the transport manager of Thompson’s of Prudhoe
in Co Durham, which delivers services and materials to the construction, demolition, land reclamation, property and recycling industries.
He is in charge of more than 100 truck drivers, who pilot everything from tippers to heavy haulage. When it comes to speci cation his take is pragmatic. The eet of Scanias and Volvos all have one thing in common; the automated transmission. He hasn’t bought a truck with a manual since 2006.
“With an automated transmission you are more or less guaranteed 450,000 to 600,000km with a single clutch. It takes away the pain and the cost. You cannot even predict how long a clutch in a manual will last because it is down to the driver,” he explains.
“With more younger people coming into the industry, many have never even driven a manual. You could spend your life educating them on how to use it.
Why bother if you can put an auto in there and guarantee the life of the clutch? It is a percentage game. Why take the risk? I don’t think you can afford to do it.”
Drivers like it, says Phil Rootham
at Scania, because it gives them
a little more control when they need it for traction.
While both McGuinness Feeds and Thompson’s of Prudhoe take different approaches, there is also a third way. In 2017 Scania introduced its ‘Clutch on Demand’.
While the majority of automated transmissions include a time limited manual override and/or a manual option allowing the driver to change gears, neither offer the driver access to the clutch.
Clutch on Demand is an option over the standard two-pedal automated transmission, in this case Scania’s own
Opticruise, with a third clutch pedal. This allows the driver to make ‘physical’ gear changes where the driver considers it is bene cial to ‘feel’ the traction being laid down, for example, when manoeuvring on loose surfaces in demanding off
road situations.
In-house Opitcruise
So, why is Scania able to offer a manual clutch? It is down to how Scania has developed its in-house Opticruise automatic clutch using electro hydraulic actuation whereas others use an electro pneumatic solution.
Phil Rootham is the pre-sales technical manager at Scania (GB). He says there isn’t much to it. Clutch on Demand consists of a pedal, a wire and potentiometer and supporting software, which sends a signal to the electronic clutch actuator.
Phil explains: “A pneumatic clutch actuator uses an air signal to open and then a spring to close the clutch. It is quick and effective, but it is dif cult to control incrementally. It is either open or closed.
30 OCTOBER 2019 > COMMERCIAL VEHICLE ENGINEER
Barry McGuinness: “When at the mills to get the full load the truck needs to edge small distances forwards and backwards. For that we need a manual.”