Dredging and excavating with longreach excavators

Dredging is normally undertaken from either the large barge or small barge and the method of dredging is very much dependent on the access and ground condition. Both barges may be used together depending on the nature of material. The large barge is equipped with a drag line bucket, grabber bucket, or our long reach excavator can be operated from the barge. Alternatively for soft silt or sand type ground submersible pumps can be used to dredge: these are operated by divers or mounted from the barge excavator arm.
For shallow dredging the small barge is equipped with a diesel driven hydraulic power pack which drives a 270 degree excavator arm with a 2m reach. This allows approx. 10t of spoil to be excavated, and put into a skip on board. The barge can then be moved to allow tipping or digging out to place elsewhere. Alternatively the hydraulic tipping skip can tip onto a beach for land based excavators to remove.
The small barge is widely used on the canal by British Waterways and contractors like Dew Construction, Galliford and Morrison since it is 3.7m wide and means that the canal does not need to be closed.

Each dredging job is different and the equipment is chosen to match the conditions. The rate of excavation depends on the soil conditions, depth and haulage distance, however on the work carried out on Ullswater for Ullswater Navigation Transit Co. at the Pooley Bridge jetties in November 2001, average rates of 80-100t per day were achieved.

Dredging in Tenby harbour for RNLI	Dredging at Rufford, Leeds-Liverpool canal using the small barge, with the 270 slew capability on the excavator arm, ideal for spot dredging, piling or towpath work	Dredging at Pooley Bridge, Ullswater for lake steamers
	<- Left, excavator with little barge in combined land & water based excavation   Little barge with excavation in background at tarn close, Right ->