TOM LEITH, one of the most respected and outstanding Scottish engineers in the second half of the twentieth century, has died at the age of 79.

Leith was able to bridge the gap between his vast years of experience with that of the modern breed of engineer - equally comfortable with a computer or at a high-level policy or design meeting, solving complex technical and commercial issues and not always in the rough conditions some people still mistakenly think are the engineer's natural habitat.

In 1942, he joined G and J Weir Ltd, nowWeir Pumps Ltd, at Cathcart, Glasgow, as an apprentice marine engineer.

Even then, as a young trainee, he was never happy to accept, without question, what was presented to him and the company's management noticed his energy and enquiring mind.

He continued his studies at the Royal Technical College, now Strathclyde University, Glasgow, and graduated there in mechanical engineering in 1950. At Weir, he studied marine engine systems and equipment and was never content merely to admire his designs on the drawing board or even in the confines of the factory.

More often he was to be found in the engine room of a frigate, destroyer or merchant ship to ensure his designs were sound or to offer his knowledge and experience to those following in his footsteps.

He was building up a formidable body of experience and, in 1966, was appointed a director and general manager of the Weir Pumps Turbines Division, followed in 1980 by a transfer to the company's Power Division.

Following reorganisation, he was appointed director of contracts. Because of his tenacity and leadership he was instrumental in winning international contracts for his company, achievements recognised by the award, for services to exports, of the Order of the British Empire in the 1988 New Year Honours List.

In the same year, he was appointed managing director of WeirWestgarth Ltd, the desalination and project management company of the Weir Group Plc.

Dedicating his lifetime's work to the Weir Group and, in particular, to products required by emerging countries in the 1970's and 1980's, it was in this phase of his career that Tom Leith may have done his most significant work.

Where there is no fresh water, there is no human life and people like Leith and his company devoted vast resources to ensuring supplies of fresh water were available.

In many parched countries, where civilised life was until recently all but impossible, plants producing millions of gallons of pure water a day are now commonplace, yet the technology to produce them in such quantities has existed for only 40 years or so.

Much of that pioneering technology was developed by Leith and his team at Weir.

His peers and those who were fortunate to have worked with him held Leith in the highest regard. His infectious ability to get the best out of everyone was due to his own exacting personal standards and good humour.

He led from the front and expected nothing less than for others to push themselves that extra mile.

As well as a vigorous business life, Leith was an influence in many professional and community organisations. He was a chartered engineer, a member and leader of the technical committee of the Institution of Mechanical Engineers and a member of the Royal Academy of Engineers.

In 1962, he joined the Institution of Engineers and Shipbuilders in Scotland (IESIS) and involved himself in the work of this, the oldest professional institution in the country.

He became a fellow of the institution and was elected its president in 1987.

He worked tirelessly on the various committees and executive councils for many years and remained an active member of the executive right up to his last few days.

In recognition of the personal commitment he made unstintingly to IESIS, he was made an honorary fellow in 2004.

Tom Leith was recognised by many colleagues and fellow professionals, not only here in the west of Scotland but in many parts of the world, for his technical capability and leadership qualities.

In many drought-stricken areas of Africa, the Middle East and Asia that are now enjoying fresh water and modern sanitation "Tol" was a major influence in making it all happen.

He was, and remained to the end, one of the most committed individuals to promote the value of professional engineers and engineering in general as a real driver for economic growth in local, national and international communities.

Tom Leith is survived by his wife, Margaret, children Leslie, Lyne, June and Douglas and four grandchildren David, Michael, Kirsty and Euan.

Thomas Orr Leith OBE, mechanical engineer;

born March 23, 1926, died November 7, 2005.