Cutter Suction Dredger

Gloucester Docks &
the Sharpness Canal

Cutter Suction Dredger

For more about Service Craft, see Bucket Dredgers, Fire-float Salamander, SL Sabrina, Steam Packets,
MC Risga

This page features the trial of a new method of clearing silt from the docks at Gloucester using a cutter suction dredger in November 2012.

Dredging
The Land & Water cutter suction dredger has a submersible rotating cutter and suction pump at the bow which stirs silt into suspension and pumps it along a floating discharge pipe to an outlet at the bottom of the small dry dock into the River Severn. At the stern are two paddles that operate independently when manoeuvring.

The dredger at work in the Main Basin with the black floats supporting the discharge pipe at intervals.

The dredger at work below Llanthony Bridge with extra sections inserted in the discharge pipe. (Photo: CRT)

Outcome
Following three weeks operation of the cutter suction dredger costing £115k, a hydro-graphic survey has shown that almost 9000 cubic metres of silt were removed from the Main Basin and the canal down to Monk Meadow, leaving mid-channel depths generally in excess of four metres. As the the silt was pumped directly into the river, by agreement with the Environment Agency, the operation was considered cost effective compared with other projects involving off-site disposal. (CRT)