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At 02:02 16/03/2011, Ken J Smith wrote: > From the early C20th, Welsh smokeless steam coals (as given in the Admiralty >'A' List for, eg, 1912) were used by the Royal Navy's top fighting ships >because, inter alia, they gave a tactical advantage; if your fleet made less >smoke than an enemy's, you were likely to become aware of his presence >before he became aware of yours. Further, most of the smoke from burning >coal comes from its volatiles. (The rest is from the fly ejected during >charging.) But most anthracites had lower volatiles than most smokeless >steam coals (&, being harder, made less dust & hence less fly), so ... why >didn't the Royal Navy use anthracite? Anthracite was used on occasions but it suffered from the disadvantages of having a short flame length and its tendency to damage the fire bars due to the high temperatures reached when it was burned - steam engines on the Pembrokeshire coalfield had to import (and, up to the mid 19th century, pay duty on) suitable coal from further east in the main South Wales coalfield. The story (locally) is that Queen Victoria insisted on the use of Pembrokeshire anthracite in the royal yacht and there are reports that North Devon anthracite was used successfully in a similar role, in the reverberatory furnaces at the Combe Martin lead smelter in the mid 19th century. But, overall, the lower volatile content of anthracite was a disadvantage for boiler firing and other uses, like the reverberatory furnace, where a long flame length was required Peter Dr Peter Claughton, Blaenpant Morfil, nr. Rosebush, Clynderwen, Pembrokeshire, Wales SA66 7RE. Tel. +44 (0)1437 532578; Fax. +44 (0)1437 532921; Mobile +44 (0)7831 427599 Hon. University Fellow - College of Humanities, University of Exeter http://people.exeter.ac.uk/pfclaugh/about.htm E-mail: [log in to unmask] Co-owner - mining-history e-mail discussion list. See http://www.jiscmail.ac.uk/files/mining-history/ for details. Mining History Pages - http://www.people.exeter.ac.uk/pfclaugh/mhinf/ _____________________________________________