Jack-knifed COE truck tractors on winter Highway

Well the longer the wheelbase the safer it is, gives you more time to react in a jackknife situation and more time to recover from it.

 

we use tandem axle tractors because of weight limits.

allowed 34000 # on tandem axle of the tractor in usa, 37500# in canada

allowed 20000# on single axle tractor drives.

http://en.wikipedia.org/wiki/Federal_Bridge_Gross_Weight_Formula

 

Tandem drive axles mean more weight up front compared to single axles. It looks like to much of gross weight is on trailer bogies for ice driving/stopping. Tap the brakes and the cab slows faster than the trailer. I always load winter loads heavy on tractor drives so my trailer doesn't push me around "as much".

 

yes it does.. when on dry roads if the hitch is a little dry and you turn the wheel the tire friction will make the truck turn but on slick roads you have less tire friction and a less than slick hitch will make the trailer push the drivers straight just a little before it (the hitch) lets the truck turn.... that little stick, release and BUMP of the trailer will push the truck sideways in a heart beat. and remember we're not talking about a big movment of the wheel.... just think about how much you move the wheel when driving straight down the road

 

16.5 meters (54') is a maximum length including tractor. I beleive there is many factors that have something to do with these kind of accidents.
Not sure, but believe euro tractors do not have a hand trailer brake, that might help lock trailer wheels to stop trailer and keep truck moving to prevent jack-nife. Load limits are different too...believe it is 9 tons on steer and 13 on drive axle compare to 5.5 tons on steer in Canada and 17 tons on tandem drive axle. Also euro truck have no brake presure limiter for front axle like north american trucks have.
Never been jack-nifed so hard to explain law of fyzics on my own experience, but been many times close to it, specially when going down hill with jakes on...truck brakes and trailer no, in curves you have a problem. Euro trucks have much more powerfull retarders than US junk jakes, so you might have answer right there. Also noticed that some trailers airbrakes have longer lag, so tractor brakes a second earlier than a trailer what sometimes might cause a problem too.

Euro cab over are getting similar or better fuel milage than US aero trucks, but there is different regulations and logistics needs.....and space on the road

Might be wrong, but that my 0.02

 

rule #1 never EVER use jakes on slick roads.... rain, snow or ice.... they can and will cause a jack-knife...
rule #2 wheels that are sliding will go faster on snow and ice. using the trailer hand brake will make the trailer slide MORE....
rule #3 3 axle trucks have better traction than 2 axle trucks. in the u.s. 2 axle trucks MUST CHAIN when 3 axle truck don't
rule #4 DRIVE SLOWER
rule #5 have a very soft and slow foot on the brakes (see rule #4)

if i did the math right ml to km and gl to imp gl (4 L pre gl right) you are saying that Euro coe are gettig at or better then 12.04 km per gl...?

 

....agreeee....In Western Canada All trucks chain up....often . We just hypoteticlly speaking for what cause jack-nife. I drive Canadian Rockies so I see jack-nifed trucks on daily basis, while in Europe I did not see it so often. I'm from Europe, so....can compare some stuff.One thing is drivers skills, but that's other story.

Euro truck are more advanced compare to US, but also depends on point of view. Some stuff is coming here but slow.
US gallon is 3.78 liter
Mile is 1609 meters or 1,609 km

There is so many differences between EURO and US regulations, that I believe is to very hard to answer Lars-gunnar question, specially if he asking on Canadian forum about euro trucks. Also those accidents might be cause by fatigue, bad tires,bad roads of course and many many other factors, while in west coast it cause mostly by......people who drive between vancouver and calgary know what I.m talking about...No offense

 

Agreed, there are so many variables that could trigger this kind of incident, only the driver could give you an idea what happened. I would be very surprised if 5th wheel dryness is a factor in many jack knifes. I would suggest the majority of the time it is driver induced, more than likely involving the wrong speed and braking habits for the conditions! Of course, there are exceptions! The Euro trucks btw are pretty much all autos now with incredible fuel management systems enabling the new generation of DAF, Scania, Volvo etc to average anything from 7-13 mpg depending on the weight obviously! I'm about to embark on Canadian driving soon and must say I'm looking forward to it, with just a hint of trepidation! I intend to stay safe and won't be rushing for anybody!! lol.