M 41-10 Page 6-181 Bridge Railings 6-066-06 Bridge Railings
6-06.1 Description
This Work consists of providing and building bridge railings that meet the requirements of the Plans, these Specifications, and the Engineer.
6-06.2 Materials
Materials shall meet the requirements of the following sections: Timber Railing 9-09 Metal Railing 9-06.18
6-06.3 Construction Requirements
6-06.3(1) Timber Railings
Wheel guards and railings shall be true to line and grade and framed accurately. The Contractor shall follow Section 6-04 whenever this Subsection does not specify a construction method. Unless the Plans show otherwise, wheel guards shall be:
1.Beveled and surfaced on the Roadway side and surfaced on the top edge. They may be surfaced on four sides (S4S).
2.Laid in sections at least 12 feet long.
3.Bolted through the floor plank and outside stringer (or nailing piece) with ¾ inch diameter bolts spaced no more than 4 feet apart. All rails and rail post material shall be S4S and painted as required in Section 6-07 . Railing members shall be fastened securely together, with the bolts tightened once at installation and again just before the Contracting Agency’s final acceptance of the Contract.
6-06.3(2) Metal Railings
Metal railing includes posts, web members, and horizontal members of the sidewalk and Roadway railing. Unless the Plans or Special Provisions show otherwise, these shall be made of aluminum alloy or steel. Before fabricating the railing, the Contractor shall submit Type 2 Working Drawings of the shop plans. The Contractor may substitute other rail connection details for those shown in the Plans if details of these changes show in the shop plans and if the Engineer accepts them in the Working Drawing response comments. In reviewing the shop plans, the Engineer indicates only that they are adequate and complete enough. The review does not indicate a check on dimensions. Anchor bolts shall be positioned with a template to ensure that bolts match the hole spacing of the bottom channels or anchorage plates. Where specified, cover plates shall fit the bottom channel tightly after being snapped into position. Metal railings shall be installed true to line and grade (or camber). After first setting the railing, the Contractor shall readjust all or part of it, if necessary, to create an overall line and grade pleasing to the eye.
6-06.4 Measurement
Timber railing will be measured by the thousand board feet (MBM) as shown in Section 6-04 . Metal railing will be measured by the linear foot along the line and slope at the base of the completed railing. Page 6-182 M 41-10
6-06 Bridge Railings6-06.5 Payment
Payment will be made for each of the following Bid items that are included in the Proposal: “Timber and Lumber (untreated or name treatment)”, per MBM. “Bridge Railing Type ____”, per linear foot. In case no item is included in the Contract for “Bridge Railing Type ____” and payment is not otherwise provided, all metal railings shall be included in the lump sum Contract price for “Structural Carbon St”. as specified in Section 6-03 .
Source: Washington Standard Specifications for Road, Bridge, and Municipal Construction, 2024 Edition. Pages 535–536 of 1,151.