Working in Manholes, Utility Tunnels, and Vaults

DOE-HDBK-1092-98

8. The manhole shall be ventilated continuously when occupied.

9. An attendant is required topside with the means to summon help without leaving his or her

station. The attendant shall be capable of instituting a rescue without entering the manhole.

The attendant on the surface is responsible for the safety of the persons in the manhole.

10. The topside attendant can perform other duties outside of the enclosed space if these duties

do not distract the attendant from monitoring employees within the space. All manholes over

4 ft. deep should be entered with the use of a ladder as required by 29 CFR 1910.269 (t)(1).

11. Workers should open all entrance bars or chains on the topside of manhole guards before

entering or leaving a manhole. All chains or bars should be closed at all other times, except

when raising or lowering tools or materials.

12. Operations involving chemical cleaning agents, solvents, volatile chemicals, cutting and

welding equipment, and other hazardous agents or tools require additional consideration.

Consultation with and concurrence of appropriate industrial safety and industrial hygiene

personnel are required.

13. The employee shall enter or leave a manhole by means of a ladder. The employer shall not use

a cable, cable hanger, or manhole rack as a support for climbing. A manhole ladder should

never be removed while a worker is in the manhole unless absolutely necessary. In the instance

of a ladder being removed to make it easier to rescue a worker, the topside attendant shall fully

devote his or her attention and efforts to instituting a rescue using the worker's body harness

and lifeline if necessary. The ladder shall be replaced as soon as practical.

Note: The other worker(s) in the hole should be warned that the ladder is to be removed in time

to allow him or her to exit the hole if necessary.

14. Materials, tools, and equipment should be kept at a sufficient distance from the entrance to the

manhole to avoid any hazard to the occupant from falling objects or from hot metal or spilled

compounds.

15. Blowtorches and furnaces should be ignited before being lowered into manholes unless this

creates additional hazards.

16. Rags, tape, refuse, and combustible and flammable materials should not be allowed to

accumulate in a manhole.

17. Instrumentation shall be calibrated per manufacturer's instructions. [See 29 CFR

1910.269(e)(8)]. A record of calibration should be maintained.

18. Ground-fault circuit interrupters (GFCIs) shall be used for 120-V ac power unless such power

is supplied by a portable or vehicle-mounted two-wire, single-phase generator rated not more

than 5 kW, where the circuit conductors of the generator are insulated from the generator

frame and all other grounded surfaces. (See Section 6.4).

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