CAPTAIN W. Rennie Stewart OBE, VRD BSc, RNR, who almost single-handedly saved the Frigate Unicorn from being scuttled at sea, has died aged 89.

Captain Stewart was born in Broughty Ferry. In 1935 he obtained a place in University College Dundee, at that time a college of St Andrews University, to study electrical engineering.

While at university he met Irene Henderson. After a long wartime separation they married in 1945.

With his Officer Training Corps and engineering training, he was immediately commissioned into the Royal Army Ordnance Corps and sailed that summer for India on board the troopship City of Nagpur, only to be torpedoed in the very middle of the North Atlantic.

On his eventual arrival in India he was posted to the Northwest Frontier, then to Rawalpindi, and then to Burma, transferring in the meantime to the newly-formed Royal Electrical and Mechanical Engineers (REME).

Rennie Stewart joined his father and younger brother Bruce after the war in the family firm of Wm R. Stewart & Sons (Hacklemakers), and led the firm to become a global supplier of textile machinery parts.

After leaving the army at the end of the war, he joined the Royal Naval Volunteer Reserve as an electrical engineer officer. Against considerable naval opposition, he qualified and transferred to the Seaman Branch, and took huge enjoyment from commanding Tay Division’s Minesweeper HMS Montrose.

In 1966 he was promoted captain and took command of HMS Unicorn, then the headquarters of Tay Division RNR, and thereafter organised the move of the division to its new shore building, HMS Camperdown. At the same time, he moved Wm R. Stewart & Sons from Dens Road to premises more to his liking in the docks.

Captain Stewart’s most lasting achievement was his saving of HMS Unicorn, a 46-gun sailing frigate launched in 1824, and now the oldest British-built ship afloat.

The old Unicorn had become surplus to naval requirements, and, despite being one of the last survivors of the great sailing navy, she was to be scrapped. Captain Stewart was determined that this fate should not befall his ship and put much pressure on the authorities.

In his efforts to form the Unicorn Preservation Society and save this wonderful old ship, Captain Stewart was energetically assisted by his wife Irene and a committee formed from RNR wives.

Captain Stewart was an active and popular president of the Stewart Society, so much so that he was invited to serve a second term, the only president ever so honoured, and he served as a Member of Court of both St Andrews and Dundee universities.

He is survived by his wife Irene, children Morna, Roderick and Catriona and seven grandchildren.