James Dredge (1794–1863) was an English civil engineer, architect and brewer. He was born in

Bath Bath may refer to: * Bathing, immersion in a fluid ** Bathtub, a large open container for water, in which a person may wash their body ** Public bathing, a public place where people bathe * Thermae, ancient Roman public bathing facilities Plac ...

and was a brewer by trade for much of his life. He designed over 50 bridges and piers in his later years, such as the

Victoria Bridge Victoria Bridge may be a reference to: Bridges ;Australia * Victoria Bridge, Brisbane, a road bridge across the Brisbane River in Brisbane * Victoria Bridge, Devonport a road ridge across the Mersey River in Devonport, Tasmania * Victoria Bridge, M ...

in Bath in 1836, and the Birnbeck Pier in Weston-super-Mare in 1845 (although not built due to early damage). He patented the ' taper principle' on his Birnbeck Pier. This method was based on using

wrought iron Wrought iron is an iron alloy with a very low carbon content (less than 0.08%) in contrast to that of cast iron (2.1% to 4%). It is a semi-fused mass of iron with fibrous slag Inclusion (mineral), inclusions (up to 2% by weight), which give it a ...

suspension chains rather than cables, using inclined hangers, increasing the number of bars, starting with one at the centre and increasing by plus one along each bar's placement within the support system. This method not only weighed less weight but also diminished construction duration. This was a more common practice in

suspension bridge A suspension bridge is a type of bridge in which the deck (bridge), deck is hung below suspension wire rope, cables on vertical suspenders. The first modern examples of this type of bridge were built in the early 1800s. Simple suspension bridg ...

s for which he received notability. Dredge's bridge design was considered "a very significant yet relatively short-lived phase in suspension bridge development". Other bridges attributed to Dredge include the

Bridge of Oich The Bridge of Oich (also known as Victoria Bridge, Aberchalder) is a taper principle suspension bridge, designed by James Dredge, across the River Oich near Aberchalder in Highland, Scotland. The bridge opened in 1854 and was used to take the ...

along the

A82 road The A82 is a major road in Scotland that runs from Glasgow to Inverness via Fort William, Highland, Fort William. It is one of the principal north-south routes in Scotland and is mostly a trunk road managed by Transport Scotland, who view it a ...

Highland Highlands or uplands are areas of high elevation such as a mountainous region, elevated mountainous plateau or high hills. Generally speaking, upland (or uplands) refers to ranges of hills, typically from up to while highland (or highlands) is ...

(1854);

Ness Islands Ness or NESS may refer to: Places Australia * Ness, Wapengo, a heritage-listed natural coastal area in New South Wales United Kingdom * Ness, Cheshire, England, a village * Ness, Lewis, the most northerly area on Lewis, Scotland, UK * Cuspat ...

suspension bridges, since rebuilt in 1975; Victoria Bridge and Lochybridge in Fort William (since replaced); Stowell Park Bridge on

Kennet & Avon Canal The Kennet and Avon Canal is a waterway in southern England with an overall length of , made up of two lengths of navigable river linked by a canal. The name is used to refer to the entire length of the navigation rather than solely to the cent ...

, northwest of Pewsey,

Wiltshire Wiltshire (; abbreviated Wilts) is a historic and ceremonial county in South West England with an area of . It is landlocked and borders the counties of Dorset to the southwest, Somerset to the west, Hampshire to the southeast, Gloucestershire ...

; and the proposal for the

Menai Suspension Bridge The Menai Suspension Bridge ( cy, Pont y Borth, Pont Grog y Borth) is a suspension bridge spanning the Menai Strait between the island of Anglesey and the mainland of Wales. Designed by Thomas Telford and completed in 1826, it was the world's f ...

Anglesey Anglesey (; cy, (Ynys) Môn ) is an island off the north-west coast of Wales. It forms a principal area known as the Isle of Anglesey, that includes Holy Island across the narrow Cymyran Strait and some islets and skerries. Anglesey island ...

(1839). Of the several Dredge-patent bridges built in

Ulster Ulster (; ga, Ulaidh or ''Cúige Uladh'' ; sco, label= Ulster Scots, Ulstèr or ''Ulster'') is one of the four traditional Irish provinces. It is made up of nine counties: six of these constitute Northern Ireland (a part of the United King ...

, almost none are still in existence; the Ballievey Bridge, destroyed in 1988 under the weight of a lorry, was the only one within the Ulster group which was not a

footbridge A footbridge (also a pedestrian bridge, pedestrian overpass, or pedestrian overcrossing) is a bridge designed solely for pedestrians.''Oxford English Dictionary'' While the primary meaning for a bridge is a structure which links "two points at a ...

. In March 1844 James Dredge wrote a short article on the suspension bridge he had built in India the previous Autumn across the river Kubbudduk near Jesson (about 50 miles north of Calcutta). The suspended platform was 261 ft in length with the central span being 175 ft, and the roadway had a width of 11 ft. The main chains were composed of bars 7/8in diameter in links 6 ft 4in long. The number of bars in each link reduced progressively towards the centre of the span so that only a single bar was present in the centre (the 'taper Principle' referred to above). The bars were proof tested in England to ensure they met the Indian Government standard of 10 tons per sq in. The inclined suspension bars that connected the chain to the roadway were 3/4in diameter attached to the roadway at 5 ft 6in spacing. In a footnote to the article he states "I have with the above constructed fourteen bridges upon this plan, all of which practically prove the correctness of my invention." Another Dredge suspension bridge in India was erected over the entrance to the wet docks at Kidderpoor near Calcutta in c1845. This had a 120 ft central span and a 24 ft wide platform."Description and Specification of a Bridge on Mr Dredge's Principle". The Practical Mechanic and Engineer's Magazine, April 1845, pp179-180

Personal life

In the mid-nineteenth century, Dredge lived at 22

Sion Hill Place, Bath Sion Hill Place in the Lansdown area of Bath, Somerset, England was designed by John Pinch the elder and built between 1818 and 1820. Suspension bridge builder and brewer James Dredge, Sr. lived here in the mid 19th century. Summerhill and nu ...

, also known as Gothic Cottage 27, which is now a Grade II listed building. Married to Anne Vine, there were at least three children, including a daughter, Elizabeth, and two sons. The elder son, William, was an engineer, as was a younger son, James Dredge Jr. (1840–1906), who was also a notable journalist of ''Engineering'', until

paralysis Paralysis (also known as plegia) is a loss of motor function in one or more muscles. Paralysis can also be accompanied by a loss of feeling (sensory loss) in the affected area if there is sensory damage. In the United States, roughly 1 in 50 ...

forced him to end his participation in the journal.

References

External links

SABRE article on James Dredge's Suspension Bridges
{{DEFAULTSORT:Dredge Sr, James English brewers English engineers English civil engineers 19th-century English architects 1794 births 1863 deaths Architects from Bath, Somerset Bridge engineers 19th-century English businesspeople