Traction in Euro Single Screw Truck

Discussion in 'Trucks [ Eighteen Wheelers ]' started by Quiettime, Dec 21, 2014.

  1. Quiettime

    Quiettime Bobtail Member

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    Nov 29, 2011
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    As a trucker in Alaska, traction is something I tend to stress out about. I run 600 hp on two drive axles with locking differentials, siped tires, and 42K lbs+ on the drive axles, and I still slip all the time. Can't help but wonder how the European trucks with only one drive axle manage to get up a hill in the winter. Would you guys care to share your secrets?
     
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  3. 98989

    98989 Road Train Member

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    traction have lot to do with different things it is not everything in number of drive axles, type of tires , and weight on drive axles (of course those are most important ), but lot of small things counts as well



    -4x2 +3 axle semitrailer is not good combination at all , whatever you do it is not good, you can shift some weight but letting air from 1st axle on trailer , ( EU law allows 30% axle overloads up to 30kmh) , some drivers raise airbags on tractor and let air from trailer, than trailer to sit on rear axles and allows to raise front axle , some raise trailer and lower tractor , but nothing helps it is still worst combination

    -some 6x2 twin steer tractors have no axle lift they can be even worst as 5th wheel is far from drive axle they tend to dig its front and rear axle can lose grip

    -42000lbs would be 19000kg on drive axles, european law allows 19t on 2axles ,
    but 6x4 here is not used in winter,as here 6x4 is used only only on construction trucks, heavy haulage and timber, for winter you need 6x6 in forest , although some 6x4 still works , so it is hard to compare 4x2 with 6x4 during winters

    -last winter there was lot of snow here in my city and we were loading them on tippers and unload into river , we had lot of problems to get out of street with 8x4 one 90degres curve and uphill , it is too light when empty , just 16500lbs on rear two axles , and it stays on surface without contact with road

    -solution for road and winter is tag axle in air as they do in scandinavia and here before, they get from 42000lbs on drive axle, in some cases even 50000lbs ( on rigid trucks)
    6x4 is ok when it is loaded but empty not,


    -solution for offroad and winter is AWD
     
  4. 98989

    98989 Road Train Member

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    -our trucks from 1992-2003 were hauling salt for roads and grain in other direction and had right to pass as salt was priority in winter months so if it is possible to pass on anyway our trucks were on roads.

    those were mostly 4x2 tippers with 3axle drawbar (full trailer), two 6x4 tippers + 2/3 axle drawbar trailers , and one 6x2+2axle drawbar trailer for short time, but most of time 2+3 setups were used

    -those combination of 4x2 +3axle trailers are on some strange way much better than tractors with semitrailers , i have no idea why,

    on hills it make sense as load shifts in semitrailer to trailer axles and left 5th wheel with lower weight, in curves make sense because drawbar trailer make less drag than semitrailer , but they were better in straight flat road as well and i cant explain why

    -here they often close mountain roads during winter, mostly because of wind, as it is impossible to clean roads as wind blow new snow
    my father was once in 1999 stuck for 10 days in daycab even he had right to pass,
    they would usually stop at place where other trucks had to stop to tighten tarpaulin and get in mountains, once wind blown his trailer into ditch because it was ice on road although trailer was low

    -he says his scania was somehow better in winter than our other ( german) trucks , he cant explain why but also german trucks are better on terrain in soft so i think those little things makes difference, he always put new summer michelin before winter, but he always had no less than 29-30000lbs on drive axle and total weight anything from 101000-123000lbs gross and depending how much snow stick to frame and tipper bodies but could be even 132000

    -he used snowchain just once, and only on right wheel, because police did not allow him to pass as there was snow ahead in hills, as he dont know how to put them he put it opposite and chain breaks , i have a picture of that , it was on cover of largest newspapers

    today scania is not good in traction because it uses 2bag solution while most of competition uses 4bag , their axles are too stiff to chassis



    my brother works in company that hauls asphalt and clean roads they have about 700 workers but whole group have 11000 employers , group do everything from winter service asphalt , garbage, clean streets,......

    he drives a 4x4 iveco tipper , and he clean steep/narrow part of city , have winter tires and dont have much problems,

    but in some very steep places even when it is not winter 4x4 got problems with traction if it is wet , or leaves on road

    for those places they use unimog for winter service

    in my birthplace in bosnia, they got even more serious problems with winds , they use 6x6 tatra trucks with independent suspension, if they cant clean than there is no sense even to try
     
  5. Exiled

    Exiled Light Load Member

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    Apr 20, 2013
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    Freightliner columbia single axle 178" wheelbase perform exactly like MAN tga single axle on sandy offroad . My other tandem axle freightliner 235" wheelbase, get stocked more often because no enough weight on the wheel to create enough traction.

    by the way if de-inflate your tires to lower pressure, you gain more traction.
     
  6. 98989

    98989 Road Train Member

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    sorry i could not answer earlier i spent last week in bars , this is very questionable thing, it is not black and white like with sand or any soft surface as there are difference variations and really depends on situation

    most of times normal recommended pressure is best, conditions on winter can change within hour or less

    most of anything i hate when when road is warm and when wet snow is falling , and it immediately melt, and than 30 or more new cm fall on that , anything except that is ok for me

    this is exact most common situation here with snow, 2days ago it was hard to move , than temp went below zero and it was frozen , you could drive almost fast as on dry , now during day it melts and now temp is again below zero this make thin layer of ice

    this can be very dangerous , especially if you are drunk , friend of my brother crash his car from all 4sides and roof on christmas
     
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