HC Deb 17 March 1887 vol 312 c561

The principle adopted by successive Boards of Admiralty since 1870 of selecting as their legend weight of coal, in new ships that they proposed to build, an amount considerably less than that which the bunkers were constructed to carry, originated when compound engines began to be used in Her Majesty's ships.

The substitution of improved engines for the older types effected such an economy of fuel in relation to the engine-power developed, that a very much less quantity would carry a ship so fitted the same distance as a ship of identical form and size with the simple engines previously in use.

This seems to have influenced the Admiralty to accept, when designing new ships, as the legend weight of fuel, a quantity which gave as great a radius of action which was possessed by earlier ships, though it was at the same time decided to provide for exceptional conditions by the construction of reserve bunkers.