Found by Ian Suddaby at the old Heathfield Fireclay Works site. I am not in possession of this example. Possibly have been manufactured by Heathfield Fire Clay Works for the Coppee Coke Co (however a similar firebrick was found at the James Dougall Fire Clay Works at Bonnybridge and therefore Dougall could be the manufacturer?)…
Manufactured by James Dougall & Sons Ltd, Bonnybridge, Stirlingshire.
Fire brick cement and wash.
A combination of letters and numerals has been used to describe each of the Dougalenes in the new range. This combination indicates at a glance the type and recommended range of use for each Dougalene. It is hoped this will greatly assist the customer in recognising and ordering the new qualities.
B – Indicates that the Dougalene is a finely ground air setting CEMENT specially designed for bonding firebricks and for wash coating surfaces.
C – refers to the specifically graded hydraulic setting CASTABLE range of Dougalenes.
M – describes the MOULDABLE Dougalenes supplied in stiff plastic form ready for use.
R – indicates that the Dougalene is a RAMMING MIX and supplied in a granular form ready for use.
S – is added to any of the above letters to indicate that silicon carbide is a major constituent of the Dougalene.
X – is included in the descriptive lettering when the Dougalene is a special type not listed in the general range.
The numerals 12, 13, 14 etc are used as an indication of the temperature range of use of the Dougalene. The number multiplied by 100 gives the recommended maximum temperature of use in degrees centigrade. However, these temperatures are only a guide and can be exceeded, but only when there is sufficient heat dissipation to ensure that only a thin section of the hot face is at the excessive heat.
By using this method of descriptive letters and numerals, it can be seen that Dougalene C14 is a castable with a recommended working temperature of 1400 degrees C.