U Drain, Cable Trench or Box Culvert: Drawing Checklist

A U drain is an open channel; a box culvert forms a closed section for crossings or drainage. A cable trench is specified around utility clearance and access rather than water flow alone. Similar-looking U profiles do not make these products interchangeable. Start with the approved concrete component drawing and its application.

Paras lists U drain configurations from 300 to 1200 mm and modular box culvert sizes separately. Confirm whether each dimension on your drawing describes the clear opening or the external concrete section. A nominal size without wall and base thickness is insufficient to define the mould.

Include the clear width and depth, segment length, side-wall thickness and base thickness. For a culvert, add the top slab thickness. Identify cover seating ledges, rebates, lifting inserts and any connections between adjacent segments. Mark the required tolerances and reinforcement cover on the drawing rather than leaving them to the mould quotation.

For cable ducts, confirm cable clearance and cover access with the utility design. For inspection covers, specify the frame opening and seating surface. Concrete component load requirements must be reviewed by the project engineer; the mould alone does not establish the load rating of the finished concrete.

Discuss how the cured component will leave the mould. A closed culvert needs an inner-core release arrangement with sufficient movement and clearance. Check available lifting height, floor space and handling equipment. Specify whether external shutter vibrators, another compaction system or a combination will be used.

Ask the supplier to identify which panels or cores are adjustable and which dimensions need a different mould assembly. Changing clear width may affect steelwork, concrete volume, reinforcement and handling. Treat a proposed adjustment as an engineering configuration change, not simply a nominal size change.

Send the same drawing revision, quantity, expected production target and destination to each supplier. Compare complete assemblies: outer panels, inner core, base, locking hardware, cover moulds if required, and any vibrator or hydraulic equipment. Confirm exclusions, packing and transport.

The listed U drain and cable trench starting prices are configuration-specific, while the Box Culvert page lists a fabrication rate per kilogram. These figures have different units and cannot be compared as complete mould prices. Request the total for the approved scope, then review installation space and operating requirements before ordering.