and Part 5
Additionally, and especially for the Branch Chairman, in Part 4 there is a close up of the port-side steam-engine driven Howden FD fan. which resided on the platform at main deck level at the forward end of the engineroom. Originally, the ship was fitted with a double-ended Scotch Boiler, built by the enginebuilder, Rankin & Blackmore, at their Eagle Foundry in Baker Street, Greenock. The boiler had six furnaces (3 at each end) originally each being fitted with firebars in a grate for coal firing. The boiler draught (air flow) containing the oxygen for oxidation (burning) of the carbon and hydrogen in the coal was maintained by creating a relatively steady pressure differential between the boileroom and the flue exit at the top of the funnesl both of which were for creation of boiler draught in those days (the separation of Waverley's funnels are typical of that required for the ubiquitous Scotch boiler). As a safety measure, to reduce the chance of blow-back of combustion products from the furnaces, the area around the boiler firing positions was maintained at a pressure higher than the ambient air pressure. Effectively there was a sealed chamber around the lower half and the twin steam engined forced draught (FD) fans blew air from the engineroom into boilerroom through two openings in the bulkhead that separates the two compartments. To prevent dipping the pressure in the boilerroom stokehold twin-door air locks were needed for access and egress of the boilerroom. The systems was well known as 'Forced Draught on a Closed Stokehold'. One of the pioneers of this innovative improvement in the firing performance of boilers was the Glasgow engineer James Howden who was working in the industry from the 1850s onwards. Originally building marine engines and boilers to supply the large and rapidly expanding Clyde shipbuilding industry, Howden was a very original-thinking innovative engineer, proposing several improvements that fate has subsequently credited to others. The Howden company established a large manufacturing works in Scotland Street, Glasgow, adjacent to the site subsequently occupied by Charles Rennie Mackintosh's renowned Scotland Street School (now the Glasgow Museum of Education.
Former Howden Design Offices and Manufacturing Works
8-18 Scotland Street, Glasgow.
This part of the works still exists but it has been under threat of demolition for redevelopment recently, The Scottish Industrial Heritage Trust has an alternative plan to save the premises and develop it as a working Museum dedicated to industrial heritage