The Mine Safety Health Administration (MSHA) issued a Program Policy Letter (link has been removed since we wrote this article years ago) that was intended to provide guidance for guardrails or other restraint systems. The Policy Letter highlights different requirements based on the elevation profile of the weighbridge of a truck scale.

– If the profile is 16 or less, then standard 8 high guide rails are satisfactory.
– If the profile is greater than 16, then it must be treated differently.

Several standard offerings for a double-high rail system, with the top rail at 24 above the deck, reaches center-of-axle on a vast majority of over-the-road vehicles, but as the regulation states, any guardrail should extend to at least mid-axle height of the largest truck using the scale. Therefore, it becomes the responsibility of the end user to advise their sales person and the truck scale manufacturer on their actual height requirement based on the largest trucks to be weighed.

Keep in mind that rail systems provided on a typical truck scale are referred to as guide rails or rub rails or sight rails, but definitely not guardrails as MSHA chooses to define them. Therefore, most if not all, scale manufacturers do not claim that any of the guide rail systems attached to truck scales are fully MSHA compliant as there are simply too many application variables identified in the regulation and it really must be evaluated on a case-by-case basis. Continue reading →