changing gears without using clutch
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recently saw a bus driver change gear without stepping on the clutch. can anyone tell me how come it works
btw he need to step clutch for the first gear
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Ask the bus fans in the bus forums.
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Wikipedia is your friend.
Trucks, buses, and trains
Semi-automatic transmissions have also made its way into the truck and bus market in the early 2000s. Volvo offers its I-shift on its heavier trucks and buses, while ZF markets its ASTronic system for trucks, buses and coaches. In North America, Eaton offers the "AutoShift" system which is an add-on to traditional non-synchromesh manual transmissions for heavy trucks[1]. These gearboxes have a place in public transport as they have been shown to reduce fuel consumption in some specific cases.
In the UK though, semi-automatic transmission has been very popular on buses for some time, from the 1950s right through to the 1980s, an example being the well known London Routemaster, although the latter could also be driven as a fully automatic in the three highest gears. Most heavy-duty bus manufacturers offered this option, using a gearbox from Self-Changing Gears Ltd of Coventry, and on urban single- and double-deck buses it was the norm by the 1970s. This coincided with the development of city buses with engines and transmissions at the rear rather than the front, which was beyond the capability of a manual gearchange/clutch linkage from the driver's position. Leyland manufactured many buses with semi-automatic transmission, including its Leopard and Tiger coaches. Fully automatic transmission became popular with increasing numbers of continental buses being bought in the UK, and more and more British manufacturers began offering automatic options, mostly using imported gearboxes, and semi-automatic transmission lost favour. These days, very few buses with semi-automatic transmission remain in service, although many are still on the roads with private owners. Modern types of semi-automatic transmission though is becoming more common, mostly replacing manual gearboxes in coaches and small buses.
The Self-Changing Gears semi-automatic gearbox was also fitted to the several thousand diesel railcars built for the British railway system in the late 1950s-early 1960s, which lasted in service until the 1990s-2000s. Their whole engine-transmission system was based on that from the main bus manufacturers of the period such as Leyland and AEC. Gear selection was by the train driver with a hand-held lever as the train accelerated. Such trains were formed of a number of such railcars coupled together and each power car had two engine/semi-automatic gearbox units mounted under the floor. Synchronising controls by control cables connected through the train ensured all the gearboxes under all coaches of the train changed gear together.
http://en.wikipedia.org/wiki/Semi-automatic_transmission#Trucks.2C_buses.2C_and_trains
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thanks!
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there is clutchless system for normal cars on the road too fyi .