November 10th, 2013

Great Eastern Railway Prussian Blue.


Although the Holden F5 Steam Locomotive Trust is very much preoccupied with the project to move the frame components to Tyseley for machining and assembly, thought is being given to marketing and the launch livery of our locomotive.

The existing identity of British Railway’s F5 67218 is entirely down to the availability of that particular smoke box plate and readily resolved the dilemma of choosing a number; the dilemma being that had we gone for the next consecutive number we would be constructing an entirely different class of locomotive.

Very recently the renowned artist Eddy Dodwell painted an excellent picture of F5 67218 in the guise of GER789 entering Dunmow station in Essex. A print of the painting was presented to Bob Meanley, Chief Engineer at Tyseley. Bob and others (including Trust chairman Steve Cooper) agreed that the Great Easter Railway (GER) livery of Prussian Blue (Ferric ferrocyanide) would be very appealing from a marketing perspective and to both enthusiasts and casual visitors to preserved railways therefore Trust members are soon to be consulted on this seemingly less urgent matter.

The Science.

Prussian blue was one of the first synthetic pigments. It is employed as a very fine colloidal dispersion as the compound itself is not soluble in water. It is famously complex owing to the presence of variable amounts of other ions and the sensitive dependence of its appearance on the size of the colloidal particles formed when it is made. The pigment is used in paints and it is the traditional “blue” in blueprints.