Denny and Brothers Ltd built all the ferries that operated the Queensferry Passage from 1934 to 1964.
The Robert The Bruce was the first all welded vessel as well as the first with diesel-electric paddles. Details of the Paxman engines used on the Robert The Bruce and Queen Margaret have kindly been supplied by Richard Carr.
The ferries only had a draught of approximately 4 ft 6 inches which made them difficult to manoeuver in high winds. Newspaper articles record how the ferries on occasions ran aground during gales. The number of times this occurred however was relatively few.
Their service speed was 8 knots and the 6 crew consisted of a Captain, Mate, Engineer, Ticket Clerk and two Deckhands.
Despite high winds, sea fog and the occasional breakdown the ferries ran at a 99.97% efficiency.
The ferries were making 40,000 trips a year and carrying 900,000 vehicles. The Forth Road Bridge which replaced the ferries had 4 Million crossings in its first year increasing to an annual figure of approximately 24 Million. Construction of a further bridge across the River Forth was required, this opened in 2017 and is called the Queensferry Crossing.