 Bertha at the Exeter Maritime Museum in 1989 | |
| History | |
|---|---|
| Owner | |
| Builder | Lunnel, G & Co,Bristol |
| Laid down | 1844 |
| Status |
|
| General characteristics | |
| Tonnage | 60a |
| Length | 50 feet (15 m) |
| Beam | 15.5 feet (4.7 m) |
Bertha is a steam-powered boat built in 1844 to remove silt from thePort of Bridgwater inSomerset, England. It is the oldest operational steam vessel in Britain,[1] and possibly in the world.[2] It is part of theNational Historic Fleet.[3]
The boat was built, of riveted iron,[4] inBristol by Lunnel, G & Co copying a design, by John McLean,[5] developed byIsambard Kingdom Brunel to deal with silt in theFloating Harbour.[2] It is abed leveler or plough dredger, with a large metal blade, which could be lowered at the stern of the boat, below the water similar to a bulldozer on land.[5][2][6]
Bertha is 50 feet (15 m) long and 15.5 feet (4.7 m) wide, with a tonnage of 60 tons.a[7] The power is from a coal fired single cylinder steam engine providing steam at 40pounds per square inch (280 kPa).[2] A large flywheel and drive shaft drove a single-reduction spur wheel drive.[7] It moved by being pulled along chains anchored on the quay.[1]
Bertha worked inBridgwater Docks, after the connection of theBridgwater and Taunton Canal to theRiver Parrett, from 1844 until 1969. The vessel was initially owned by theGreat Western Railway and thenBritish Railways.[7] She was then taken to theExeter Maritime Museum, where she was shown working with the help of John Selby (welder and fabricator in Spaxton, Somerset). In 1997 it moved to theWorld of Boats atEyemouth where it was restored. The Eyemouth Maritime Museum closed and Bertha is now in Bristol, but not on public display.[5]
