hey, Why were the wheelbases so short on British artics. And about the fifthwheel, how much was it general in front of the driveaxle.
And what find experts about the system short,long wheelbases,and the distance of the fifth wheel before the driving axle.
About comfort and weight partition, which would you prefer of distance wheelbase, fifth wheel place and trailer overhang.
I prefer a good distance between cab and trailer not as nowadays,the EU speaks (only speaks ) now about the change the
lenght and only restrict the loading space. So long noses can be used after ceasing to build them , or can we re-introduce
the ERF Sabrina again . Or will they develop the proto which Scania some time ago showed wat a nice looking design .
IIRC,the 10’ 8" WB Atkis we started to buy in '71 had the 5th wheels set at 24" forward of the drive axle.All the tandem trailers had their kingpins set at 30" back,the new tri-axle trailers we got in '83 had 40" kingpin settings.I think it was the UK C & U regulations that caused the peculiar vehicle specs,no doubt others with more technical expertise than me will appear on the thread and quote the C&U regs ver batim ! Cheers Bewick.
Bewick:
IIRC,the 10’ 8" WB Atkis we started to buy in '71 had the 5th wheels set at 24" forward of the drive axle.All the tandem trailers had their kingpins set at 30" back,the new tri-axle trailers we got in '83 had 40" kingpin settings.I think it was the UK C & U regulations that caused the peculiar vehicle specs,no doubt others with more technical expertise than me will appear on the thread and quote the C&U regs ver batim ! Cheers Bewick.
I thought that European trailers had 1.2m (That’s about 40", Mr. Bewick) or 1.6m (64") kingpin positions. Add the extra trailer-corner encroachment that you get with a shorter kingpin position on the trailer, and you can see why French tractors had an extra 700 or so mm in the wheelbase. Someone may post some diagrams, if we are lucky.
hey to all, The big York was one of the best but very expensive and here was Jost the common used. For the long trailers we had first the 1.20 and for the new after '84 the 1.45 and 1.60,and some are set even more backwards with cut corners.The wheelbase depend of the manufacturer and you had a choise for longer if you wished. the fifth wheelsetting was a bit own choise, but was a regulated but after the first MOT lots moved it a bit we had a 15.5m max long reg and had the 12.5m (41 FT) trailers,and a 13 tonnes driveaxle which gave a bit play and about 3FT space between the tractor and trailer was comfortable.
In the beginning we pulled English trailers with short wheelbased nose models (which pulled tippers before in the motorway building time) with the fifth wheel just before the driveaxle otherwise they hit the back of the cab.
Simple answer to our short wheelbase tractors was as Dennis touched on, the Construction and Use Regulations or to be exact the maximum lengths artics were allowed over different periods of change to these regs.
Up to 1955, 33ft 0in was the max length of an artic, 35ft 0in from 55 to 64. From 1964 to 1968 the length increased to 42ft 7in (13m) most on here will remember the 30 and 33ft trailers, didn’t leave a lot for tractor length even allowing for set position of fifth wheel and kingpin. From 68 to 1983 increased again to 49ft 2in (15m), the well known change to 40ft trailer operation.
Then the 1983 regs had a max combination of 15.5m and a max trailer length of 12.2m to consider, a trailer length had not came into the previous regs so the length was dictated by the max artic length allowed and of course the 83 regs saw the emergence again of the three axle tractor with longer wheelbase and more importantly to allow for legal lengths, the sliding fifth wheel. By the next increase to 16.5m, tractor wheelbase lengths were already longer anyway.
It was mainly during the reign of the early Sixties artic that wheelbase lengths of tractor units were short which made for an uncomfortable ride when solo or light and that Kangaroo lift of the front end sometimes when pulling away loaded on an incline, which would have been much worse if the fifth wheel had been positioned directly above the axle centre. Set forward fifth wheel position also made for better weight distribution on the tractor axles. Franky.
Frankydobo:
Simple answer to our short wheelbase tractors was as Dennis touched on, the Construction and Use Regulations or to be exact the maximum lengths artics were allowed over different periods of change to these regs.
Up to 1955, 33ft 0in was the max length of an artic, 35ft 0in from 55 to 64. From 1964 to 1968 the length increased to 42ft 7in (13m) most on here will remember the 30 and 33ft trailers, didn’t leave a lot for tractor length even allowing for set position of fifth wheel and kingpin. From 68 to 1983 increased again to 49ft 2in (15m), the well known change to 40ft trailer operation.
Then the 1983 regs had a max combination of 15.5m and a max trailer length of 12.2m to consider, a trailer length had not came into the previous regs so the length was dictated by the max artic length allowed and of course the 83 regs saw the emergence again of the three axle tractor with longer wheelbase and more importantly to allow for legal lengths, the sliding fifth wheel. By the next increase to 16.5m, tractor wheelbase lengths were already longer anyway.
It was mainly during the reign of the early Sixties artic that wheelbase lengths of tractor units were short which made for an uncomfortable ride when solo or light and that Kangaroo lift of the front end sometimes when pulling away loaded on an incline, which would have been much worse if the fifth wheel had been positioned directly above the axle centre. Set forward fifth wheel position also made for better weight distribution on the tractor axles. Franky.
hey Franky, I agree with you completely it was always due to the regulations. And we saw it with the English trailer we had to pull 30ft with the tandem at the back then 33,36 and at least the 40 ft. We had a more fexible legislation of course on the first MOT it had to be correct and was measured. But afterwards at the MOT they didn’t take the measures anymore and on the road was there no measuring about lenght,hight,but with width you had to be careful. And if it happened you got at ticket and away you were. BUT nowadays .
a big question here. does an artic tractor pull or push the loadâ– â– ? all replies and answers appreciated.an old fitter i worked with 50 years ago posed this question to me and i still scratch my head to this day.answers please.
shirtbox2003:
a big question here. does an artic tractor pull or push the loadâ– â– ? all replies and answers appreciated.an old fitter i worked with 50 years ago posed this question to me and i still scratch my head to this day.answers please.
) now about the change the
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