As a low cost and practical option for concrete lining watercourse size canals a Subgrade Guided Towed Boat Liner can be used. The towed boat takes its grade and alignment (steering) reference from the trimmed canal subgrade prepared by trapezoidal trencher. Because the towed boat traces the trimmed grade a towed boat liner is very effective for keeping concrete losses to the absolute minimum.

Small Towed Boat Liners for canals under approximately 1.1m (42”) deep are typically towed by a front end loader or motor grader. They are small and light enough to be lifted by a boom truck crane or a front end loader in and out of the canal. Generally, the higher concrete slump used on canals does not require vibration; however, if vibration is required a separate power unit can be provided on the towed boat liner. On a smaller towed boat liner, a concrete distribution system is not required. Ideally on one side of the canal, the embankment / fill should be wide enough for truck mixers to pass the towed boat and discharge directly into its hopper.

Larger Towed Boat Liners for canals ranging 1.1m (42”) to 2.13m (7 ft.) deep require a diesel engine powered, cable winch which is mounted low and in the front of the towed boat liner to supply the towing power required to move the unit. A ‘dead man’ needs to be supplied (typically a tractor or front end loader required on site) for the winch to pull against. The diesel power unit is also required for the concrete distribution system on larger towed boats. And like the smaller towed boat, if vibration is required the power unit supplies power for the vibrators.

If the embankment is too small for the concrete trucks to discharge concrete directly into the hopper of the towed boat then an optional concrete charging conveyor can be supplied to deliver the concrete to the towed boat.