Note: While it is often the practice to use "duct" and "conduit" interchangeably, "duct," as used in 220 CMR 126.32, is a single enclosed raceway for conductors or cable; "conduit" is a structure containing one or more ducts; and "conduit system" is the combination of conduit, conduits, manholes, handholes, and/or vaults joined to form an integrated whole.
Exception: Where this is impractical, or for further other reasons, this clearance may be reduced by agreement between the parties concerned and the Department. In no case, however, shall the top of the conduit or any conduit protection extend higher than the bottom of the ballast section which is subject to working or cleaning.
Exceptions: When conduit crosses a manhole, vault or subway tunnel roof, it may be supported directly on the roof with the concurrence of all parties involved.
Exception: Lesser separations may be used where the parties concerned concur.
Recommendation: Backfill within six inches of the conduit should be free of solid material greater than four inches in maximum dimension or with sharp edges likely to damage it. The balance of backfill should be free of solid material greater than eight inches in maximum dimension. Backfill material should be adequately compacted.
Conduits passing through a bridge abutment should be installed so as to avoid or resist any shear due to soil settlement;
Conduit of Conductive material installed on bridges shall be effectively grounded.
Note: Loads imposed by equipment used in road construction may exceed loads to which the completed road may be subjected.
V = Variable spacing -- 14 feet to 30 feet. Spacing to be used is that which results in vertical and lateral structure loading which produces the maximum shears and bending moments in the structure. Click to view image
A clear working space sufficient for performing the necessary work shall be maintained. The horizontal dimensions of the clear working space shall be not less than three feet. The vertical dimensions shall be not less than six feet except in manholes where the opening is within one foot, horizontally, of the adjacent interior side wall of the manhole.
Exception 1: Where one boundary of the working space is an unoccupied wall and the opposite boundary consists of cables only, the horizontal working space between these boundaries may be reduced to 30 inches.
Exception 2: In manholes containing only communications cables and/or equipment, one of the horizontal dimensions of the working space may be reduced to not less than two feet, provided the other horizontal dimension is increased so that the sum of the two is at least six feet.
A conspicuous warning sign,
A protective barrier over the cable,
A fixed ladder.
In vaults, other types of openings may be located over equipment to facilitate work on this equipment.
Exception: 220 CMR 126.00 does not apply where the only means of locking is by padlock and the latching system is so arranged that the padlock can be closed on the latching system to prevent unauthorized locking from the outside.
Exception: This does not apply to enclosed areas under water or in other locations where it is impractical to comply.
220 CMR 126.32