Abstract: A surface drainage culvert of the type comprising a pipe section which is cut longitudinally forming an aperture along the upper surface of the pipe and which has an upstanding grate assembly lodged within the aperture. The aperture consists of a series of longitudinally spaced slots in the pipe with unslotted pipe portions separating each slot. The grate assembly consists of a pair of spaced, parallel sidewalls which form an inlet drainage passage to accept drainage water inflow at the top of the passage and discharge the water at the bottom of the passage through the aperture into the pipe. Lateral stiffeners maintain the spacing of the top of the drainage passage, while a spacer means, situated within a guide formed in the grate assembly sidewalls, maintains the spacing of the sidewalls at the bottom of the drainage passage.

Abstract: A surface drainage culvert of the type comprising a pipe section which is cut longitudinally forming an aperture along the upper surface of the pipe and which has an upstanding grate assembly lodged within the aperture.The aperture consists of a series of longitudinally spaced slots in the pipe with unslotted pipe portions separating each slot. The grate assembly consists of a pair of spaced, parallel sidewalls which form an inlet drainage passage to accept drainage water inflow at the top of the passage and discharge the water at the bottom of the passage through the aperture into the pipe. Lateral stiffeners maintain the spacing of the top of the drainage passage, while a spacer means, situated within a guide formed in the grate assembly sidewalls, maintains the spacing of the sidewalls at the bottom of the drainage passage.