Last edited 31 Dec 2020

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Delaval family

This article is part of ICE's Engineer biographies series.

DELAVAL family, members owned estates in Northumberland, including the harbour of Hartley, between North Shields and Blyth.

Sir Ralph Delaval (1622 - 1691), the son of Robert Delaval and his wife Barbara Selby, was born on 13 October 1622 and having been trained in the law he married Anne Leslie in 1646, the union producing a family of 12; he was created baronet in 1660.

As the owner of the port of Hartley his first improvement was the protection of its entrance in 1661 by building piers of both timber and stone. He found that the harbour silted up and to remedy this defect he placed, c.1675, 'a new strong Sluice with Flood-gates upon his Brook; and these being shut by the Coming-in of the Tide' so impounded water which at every low tide 'scoured the Bed of the Haven clean'. From this time the port became known as Seaton Sluice.

Delaval died on 29 August 1691 and was buried at Seaton Delaval.

Sir John Hussey Delaval (1728 - 1808), the second son (of a family of twelve) of Francis Delaval (1692 - 1752) and his wife, Rhoda Apreece, was born on 17 March 1728. In 1750 he married Susan Potter, nee Robinson, the marriage resulting in a family of seven. After her death he married again but this union produced no children.

John Hussey Delaval became a Member of Parliament in 1754 and was created baronet in 1761; at about the same time, as the port's nominal owner, he became responsible for the second phase of its improvement. As a result of the development of the family's nearby coal mines, the trade of the harbour had increased and it was considered expedient, a century after the initial work, to improve it further.

John Smeaton visited Seaton Sluice in 1758, but there is no evidence that he then recommended improvement works. Consultations involving the Delavals and William Brown followed and the harbour was then improved further - to whose designs is not known - by the formation of a cut through rock to the south of the established entrance. The new channel was some 800 ft. long, 30 ft. wide and 52 ft. deep and, protected by timber stoplogs at each end, formed what was, in effect, the first wet dock in northeast England; shipping was further protected by a substantial pier at the seaward end. To permit easier loading, staiths were built so that vessels could lie in the protection of the new channel.

Constructed over a period of some three years, the new cut was brought into service on 20 March 1764.

Delaval was made baron in 1783. He died on 17 May 1808 and was buried in Westminster Abbey.

Thomas Delaval (c. 1730 - 1787), the brother of John, was the fourth son of Francis Delaval and was, with—or perhaps in place of—his brother, responsible for the port's operations. Born c. 1730, he lived for a time in Hamburg where, as a merchant and speculator in coal and iron, he was said to have amassed considerable wealth.

By 1763 the manufacture of copperas and glassmaking—principally the manufacture of bottles—had been established at Seaton Sluice; development of the family's Hartley colliery had included the installation of Newcomen engines.

Thomas Delaval married Cecelia Watson in 1768; within two years he was on the verge of bankruptcy and his ownership of the glassworks was offered for sale to his brother, John.

He died on 31 August 1787 when 'as he was taking an airing on horseback in Hyde-park, he dropped from his horse in a fit, was carried home, and expired immediately'.


  • 1661: Hartley, construction of sluices to scour harbour
  • 1761 - 1764 : Seaton Sluice, formation of new cut, cost £10,000.

Written by R. W.RENNISON and S. M. LINSLEY

This text is an extract from A Biographical Dictionary of Civil Engineers in Great Britain and Ireland, published by ICE in 2002. Beginning with what little is known of the lives of engineers such as John Trew who practised in the Tudor period, the background, training and achievements of engineers over the following 250 years are described by specialist authors, many of whom have spent a lifetime researching the history of civil engineering.

--The Institution of Civil Engineers

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