Titanic's boiler-room fans came from a tea planter's works

A description of the propelling machinery of the Olympic and Titanic, reproduced by Encyclopedia Titanica, lists twelve Sirocco fans to force air into the boiler rooms, two for each room. They were "supplied by Messrs. Davidson & Co., of Belfast"⁹. Eight were 55 inches across, two were 50 inches and two were 40 inches, and each ran on an Allen motor.

Samuel Cleland Davidson, once an assistant manager on a tea estate in Cachar, founded the Belfast works that made them, and it began by developing machinery for processing tea.

A planter in Cachar

Davidson was born in County Down in 1846 and worked in the office of a Belfast civil engineer until 1864. That year he took the post in Cachar, according to his 1921 obituary for the Institution of Mechanical Engineers, reproduced by Grace's Guide¹. The Dictionary of Ulster Biography² says he went to India that year to work the family's tea plantation.

The Families in British India Society indexes names taken from "the diaries of Samuel Cleland Davidson, Tea Planter, Cachar, India"³ in a dataset titled Tea Planters Cachar 1865-1875.

Cachar is a district in the southernmost part of Assam⁴, in the Barak Valley, and the district's own government page calls it the home of a large number of the state's tea gardens.

The obituary says he "soon realized the inadequacy of the primitive methods then employed"¹ and proposed mechanical apparatus for drying the leaf at the plantations. A 2021 talk on Davidson, reported by the Bangor Historical Society⁷, put the problem in one line: "the main problem was to get a draft for drying the tea leaves."

The Tea Exporters Association Sri Lanka dates "the manufacture of the first 'Sirocco' tea drier"⁵ by Davidson to 1877.

The obituary says Davidson gave up planting, returned to Ireland and founded the Sirocco Engineering Works in Belfast in 1881 with "one small workshop and seven workmen"¹, where he evolved a complete range of machines for every process in tea production. Grace's Guide describes the young company as developing machinery for processing tea⁸.

National Museums NI⁶ says the works sold convection stoves that blasted hot air across a room. It says a colleague's comparison with the "Sirocco winds" of the Mediterranean gave the product and the company their name. The Bangor talk has the remark as "like the Sirocco, a hot wind that came from north Africa"⁷.

From drier to fan

The Bangor talk says Davidson came to see that "a fan was needed and his future lay in inventing, not tea growing."⁷ The obituary says he was not satisfied with the centrifugal fans then in use, experimented, and brought out the Sirocco fan. Grace's Guide dates the forward-bladed centrifugal "Sirocco" fan to 1898⁸.

Davidson held around 120 patents, at first for tea-processing machinery, and their uses later extended to other fields, ships among them, according to the Dictionary of Ulster Biography². The same entry puts the works at about 1,000 workers by 1900, against the seven it started with.

Aboard Olympic and Titanic

Beyond the twelve boiler-room fans, the same description lists four more electrically driven Sirocco fans⁹, each 30 inches across, for the engine rooms. Three were for the reciprocating engine room and one for the turbine room.

Olympic, Titanic's sister ship, used them in its accommodation as well. "Sixty-four fans were installed for ventilation of the accommodation, all 'Siroccos'"¹⁰. They were made by Davidson & Co. and driven by Allen motors to Harland & Wolff's specification, Mark Chirnside writes for the Titanic Research and Modeling Association.

After the ships

Davidson was knighted shortly before he died on 18 August 1921, aged 75, according to the Dictionary of Ulster Biography² and his obituary¹.

A 1961 listing of its products⁸ still includes tea estate machinery. In 1988 James Howden and Co acquired the company, and its name became Howden Sirocco.