Strength of small manhole covers in construction

April 6, 2010

Letter # 20080505-8425

Re: Whether OSHA construction standards require a manhole cover to support at least twice a vehicle's applied axle load, regardless of the cover's size.

Question: Federal OSHA's 1926.502(i)(1) requires that covers be capable of supporting at least twice the maximum axle load of the largest vehicle expected to cross over the cover. How does this requirement apply to small-diameter manhole covers on which, due to their limited size, only one wheel can fit at a time?

Answer: Title 29 CFR 1926.502(i) states:

(1) Covers located in roadways and vehicular aisles shall be capable of supporting, without failure, at least twice the maximum axle load of the largest vehicle expected to cross over the cover.

(2) All other covers shall be capable of supporting, without failure, at least twice the weight of employees, equipment, and materials that may be imposed on the cover at any one time.

Although §1926.502(i)(1) applies to covers located in roadways, this provision does not apply to this manhole cover. Section 1926.502(i)(1) addresses hazards related to larger covers which would regularly bear the entire axle load of a vehicle. Because of its smaller size, a manhole cover will normally be subject to only a fraction of the weight of the axle loads which are expected to cross over. Therefore, §1926.502(i)(2) applies and requires this manhole cover to be capable of supporting at least twice the weight expected to be placed on the cover at one time. This strength requirement in section 1926.502(i)(2) provides effective employee protection in the case of this manhole cover.

Sincerely,

Bill Parsons, Acting Director

Directorate of Construction