James Mansergh

James Mansergh (29/4/1834-15/6/1905) was the second son and child of John Birkit Mansergh, a draper of Lancaster. He was one of eight children, all baptised at High Street Independent Chapel, Lancaster [6]. James must have shown good promise at a local Lancaster school, for when he was aged 13 he was sent to Queenwood College, in Hampshire. This was a newly-created school specialising in mathematics and science, and was the first school in Britain to have a chemistry laboratory.

The buildings of Queenwood College dated from 1841 as Harmony Hall, built by Robert Owen as a socialist (an early communist) community. It was financed by considerable donations. The venture lasted barely 5 years, and failed. Participants from the north of England did not like the isolated country position. The building was then let to the famous Quaker educator George Edmondson (1798-1863) and in August 1847 he

became the first headmaster of Queenwood College [internet information]. James Mansergh entered at that time. The college was on south-facing chalk downland a mile or so SSW of the village of Broughton, grid reference SU 299-311, and was burnt down in 1903. Queenwood Farm is near the site.

James Mansergh worked his way rapidly up the civil engineering ladder, and travelled the world advising on sewerage and water-supply works. His major project was planning the huge Elan Valley Water Scheme for Birmingham, which involved building an aqueduct in which the motive power was by gravity only. There were “inverted siphons” of strong pipes crossing the river Severn and several other valleys, and the final destination was a reservoir at Frankley, in the SW outskirts of Birmingham, still at a good height for gravity delivery. He planned the first sewage farm, at Carlisle. In 1859 James Mansergh married Mary Lawson, and by her had two boys and two girls. The boys, Ernest Lawson Mansergh and Walter Leahy Mansergh, both became civil engineers and latterly joined their father as partners in a successful business. Two of Ernest’s sons attained high rank in the Royal Navy – Admiral Sir Maurice Mansergh (1896-1966) and Vice-Admiral Cecil Aubrey Lawson Mansergh (1898-1990). In 1898 Mansergh married the widow Harriet Irons (née Branford). For many years the family lived at 51 Fitzjohn’s Avenue, Hampstead, in a large house he named “Lune Lea” in its own large grounds, where he died in 1905.

On his death he left an estate of £103,600, a massive fortune for that time. 

The name is derived from the village of Mansergh, mentioned in the Doomsday Book, on the western bank of the river Lune, above Kirkby Lonsdale. In the 1600s three brothers went to Ireland, and a branch of the family is now well established there, but James is more likely to have descended from those that stayed in the Lune Valley, Lancashire area.

The President of the Institution of Civil Engineers represents and promotes the institution and the civil engineering profession in the UK and around the world.

Past Presidents

37 James Mansergh, FRS November 1890 November 1901

Caban Coch Dam, Elan Valley

In 1892 the Birmingham Corporation Water Act authorised the construction of reservoirs in the Elan and Claerwen valleys, south-west of Rhayader, and of an aqueduct to convey water to the city. James Mansergh was the Engineer. The initial works in the Elan valley comprised three reservoirs which were built by direct labour and completed in 1904.

Caban Coch is the first dam up the valley from Rhayader. It is 610ft long, 122ft high and 5ft wide at the crest and is built of cyclopean mass concrete faced with block-in-course masonry. The downstream face has an inwardly curved batter, struck to a 340ft radius, to within 15ft of the top, from which point to the crest the curvature is reversed.

The area of the reservoir is 500 acres with an impounding capacity of 7,815 million gallons. A novel feature of the scheme was the submerged dam built across the reservoir at Garreg Ddu, about 1½ miles upstream from Caban Coch. At times when the reservoir is very low this keeps the water at the required level to feed the aqueduct, while the water impounded in the reservoir below it can be used to provide compensation water.

Mansergh, E L. and Mansergh, W L. The works for the supply of water to the City of Birmingham from mid-Wales. Min. Proc. Instn Civ. Engrs, 1911-1912, 190, 23-25.