Highway Trailer Design Codes 1

[chasj]

Does anyone know if the design of a custom highway trailer is governed by any codes or regulatory agencies?

We're designing and fabricating a special use trailer which will be towed on public highways infrequently. We assume we'll need lights, brakes, etc. but are unsure if there are any other requirements.

 

[carnage1]

if it is over a certain size in the U.S. it has to have very specific conspicuity treatments.
it is all hiding somewhere in title 49

http://www.access.gpo.gov/nara/cfr/waisidx_03/49cfrv5_03.html

 

[zeusfaber]

What country do you need to operate it in?

A.

 

[chasj]

The trailer will be used in Ohio, USA and perhaps adjacent states. It will support mining equipment such as a hopper, crusher, and conveyors. It will not be particularly heavy or oversized.

 

[carnage1]

pickup trailer or semi trailer?

 

[rmw]

Lots of good information here regarding lights, brakes, weight classification, etc.

http://www.fmcsa.dot.gov/rulesregs/fmcsr/fmcsrguide.htm

rmw

 

[franzh]

One point to add:
What may not be particularly heavy to you may seem so to any regulatory authorities. In the US, the DOT has certain load requirements, with restrictions, brake and illumination standards, etc. Anything outside of a standard trailer (roughly 18 feet long by 7 foot wide, and over 2000 lbs) would probably require additional braking and illumination, plus load permits. For example, we have two trailers, both 18 feet long and both with tandem axles. One is required to have brakes, the other doesnt. The only difference is the load rating. One is 4,000 lbs GVW, the other 10,000 lbs GVW.
Most larger city police departments and Department of Public Safety sections have a load and weights division who can answer any of these questions (hint: Dont stop on on the road, go to the headquarters!) Also, any state can chooe to make their individual requirements more strict than the federal DOT, but not less so.
Franz (in Texas)

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[chasj]

The trailer is about 60 feet long, tandem axle semitrailer.
I don't know its weight yet.

My main concern is whether there are any structural requirements for the chassis (e.g. allowable stress levels, weld details, etc.)

I've done some web research and found nothing so far but if there aren't any federal or state regulations, is anyone aware of any trade organizations with some standards?

 

[carnage1]

the only structural requirement I know of off the top of my head is the "anti-decapitation bar" rear bumber on large trailers.
it has to be a certain hight off of the ground and built a certain way so a vehicle rearending you doesn't get the top sheared off.
here is the link

http://a257.g.akamaitech.net/7/257/...cess.gpo.gov/cfr_2003/octqtr/49cfr571.223.htm

Also you might want to check the length, i thought that once you got past 40 ft on a single it was considered oversized?
or maybe it is past 60 ft.

 

[carnage1]

here is some definitions for airbrake requirements

http://a257.g.akamaitech.net/7/257/...cess.gpo.gov/cfr_2003/octqtr/49cfr571.121.htm

 

[Steell]

Any trailer over 53' overall length is going to require an oversize permit to operate in Ohio and Indiana (and most other States). Maximum width is 102", maximum height is 13'6". Title 49 does list the requirements, placing of lights and reflectors, fifth wheel construction, braking requirements and brake system specs, etc. Your insurance company is probably going to be the determining authority on structual issues.