This steam powered bucket dredger was built in 1925 for the Sharpness New Docks & Gloucester & Berkeley Navigation Company by N.V. De-Klop at Sliedrecht, Holland for dredging their docks and canals. Upon nationalisation of the waterways in 1948 the dredger was transferred to the British Waterways Board and in the 1960s renamed "No.4 Dredger", finally ceasing work in 1981.
In 1987 it was restored to full working order and the name reverted to the original (SND No.4). It is owned and operated by the National Waterways Museum, Gloucester.
Part 1 - SND No.4 Steam Dredger in Action
(formerly Compilation 25a, running time 59 mins.)
In early 1990 the Sharpness New Docks No.4 dredger was put into steam and started dredging mud from Gloucester Docks basin.
Detailed views of the Dutch DeKlop inverted vertical compound steam engine are shown along with close-up shots of the bucket train in action, from parts of the vessel usually inaccessible to members of the public. It was during this recording that the dredger was worked to fill a mud boat for the first time in many years.
Part 2 - Raise the Dredger!
(formerly Compilation 25b, running time 42 mins.)
On the night of the 14th of June 1990, SND No.4 sank at her moorings in Gloucester Dock. Salvage operations began and in the second week of August they reached their climax, when divers managed to seal the vessel and pumping-out began.
This is a record of the divers in action, with a floating crane, winches and powerful pumps working together to save the unique working museum exhibit.
Produced with support from the National Waterways Museum at Gloucester.
Technical Details - Vessel
Length Overall: 26 metres (85 feet)
Maximum breadth: 7.6 metres (25 feet)
Engine: 80 IHP, Inverted vertical compound steam engine, by N.V. De-Klop, Sliedrecht, Holland.
Valve gear: High Pressure cylinder has piston valves, Low Pressure cylinder has slide valves.
Reversing gear: Stephenson Link reversing gear.
Boiler: 1950s oil fired Scotch boiler.
Working pressure: 130psi.
The images on this page are taken from the video.