Rollover of commercial vehicles
Rollover of commercial vehicles
(OP)
I would know if a road test exists about the limits of commercial vehicles' center of gravity height in terms of rollover threshold.
thank you in advance
belondo
thank you in advance
belondo
RE: Rollover of commercial vehicles
Judging from the time this post has been up without response, I would guess that there are no standard tests. I don't think NHTSA tests commerical vehicles because the private vehicle segment is bigger, and statistcally, more accident prone.
Come to think of it, I drive for a living, and the private sector IS more accident prone, statistics or not!
I read an article in Discover magazine about how they test SUV's for rollover safety specs. I'm sure it's in Discover's archives if you go to their website. Also, National Highway Traffic Safety Administration board itself may be able to help.
I inquired some months ago about finding the center of gravity of a vehicle, and Evelrod gave me a "rule of thumb" way, which he probably explains better than I do. See if you can track him down by e-mail or something.
Hope this helps!
EMc
RE: Rollover of commercial vehicles
Rod
RE: Rollover of commercial vehicles
In England they DO (or did) test some commercial vehicles for rollover potential, by putting them on a big platform and lifting one edge until the vehicle topples.
They may do some dynamic tests as well, akin to the SUV tests, or just on a very large skid pan at constant speed.
Anyway, to a first approximation the important characteristics are the height of the CofG above the contact patch, and the trackwidth. (actually this is a lousy approximation if you've got a flexible chassis or a trailer, or a long travel suspension).
Measuring the height of the CofG strikes me as a tricky process, I'll ask the lads.
Cheers
Greg Locock
RE: Rollover of commercial vehicles
The main problem is people driving an SUV like its a sports car. Physics will always win.
RE: Rollover of commercial vehicles
While one of the most important parameters is the height of the CG, there are a number of factors which affect the dynamic response of the vehicle (suspension, tires, articulation points & type etc).
Currently there are no federal motor vehicle safety standards in the US or Canada which directly regulate the CG height.
RE: Rollover of commercial vehicles
Cheers
Greg Locock
RE: Rollover of commercial vehicles
www.monash.edu.au/oce/roadsafety/abstracts_and_papers/ 054/roadsafety%20conf%20police%20paper_revised.pdf -
RE: Rollover of commercial vehicles
NHTSA has also been conducting a considerable amount of research regarding passenger vehicle rollover. You can check out:
http://www-nrd.nhtsa.dot.gov/vrtc/ca/rollover.htm
The star rating system can be viewed at:
http://www.nhtsa.dot.gov/hot/rollover/fullWebd.html
However, there is not yet a requirement under FMVSS.
RE: Rollover of commercial vehicles
Cheers
Greg Locock
RE: Rollover of commercial vehicles
Kevin
RE: Rollover of commercial vehicles
Second, the government's so-called "roll-over ratings" are as Greg says, "schoolboy physics" and are worse than meaningless in the real world. They consider ONLY cg height and track width.
For example, a Corvette has the best roll-over rating according to NHTSA, but per an analysis of crash data done by a writer for Car Driver magazine, the Corvette is something like 187 times more likely to be involved in a roll-over crash than the much-maligned Explorer. And for that matter, the two-door Explorer was 50 times more likely to overturn than the four-door, when both have identical NHTSA ratings.
According to his analysis, roll-over correlated to the number of doors better than to any vehicle dynamics factor.
i.e., a two-door vehicle is much more likely to be driven in a fashion that would produce a roll-over than is a four-door.
Sorry, this doesn't have as much to do with commercial vehicles as you might like. Without a study of the trailer, since most commercial vehicles have semi-trailers, I don't think you could make any meaningful conclusions about comm vehicle dynamics.
And load-shifting is probably more of a factor in roll-overs than any vehicle characteristic you can name.
RE: Rollover of commercial vehicles
http://199.79.179.82/sundev/list_results.cfm?RECCOUNTER=1&CFID=80564&CFTOKEN=14221499
Hope you find something useful!
RE: Rollover of commercial vehicles
As usual, NHTSA wants to legislate equipment rather than consider that maybe just maybe the driver bears some responsibility for roll-over crashes.
As I hinted earlier, when driver factors correlate to rollovers several hundred times better than vehicle design factors, NHTSA is barking up the wrong tree.
About the only times I've heard of commercial vehicles overturning it has been as a result of load shifting, or falling asleep and running off the road.
RE: Rollover of commercial vehicles
There is a European standard for rollover of N2, N3 O3,O4 (N=goods; O=trailers)tanks that carry dangerous goods. The standard you require is ECE111. It is very simple, either a tilt test, or a calculation
Del