Tony Hill advises that :- Contact has been made with former SR & BR WR Railwayman & at one time a Controller at Exeter Central Leo Dolling who advises that all WC & BB locos were originally fitted with the water jets along the rearward cab roof, to keep the coal damp to prevent dust and the sprayer operated when the injector was on.
With many thanks to Tony Hill and of courses Leo Dolling. How nice to have an answer from a former professional expert.
Bere Alston 34065 Hurricane pauses with a down train . Note dust spray over coal. Poor steamer scappped 64Copyright Sid Sponheimer