Fuelling and Combustion
AN OLD LOCOMOTIVE constructed on the “long boiler" plan of Robert Stephenson. This involved the placing of all the axles under the boiler barrel and, while having certain advantages, prevented the use of a fire-
THERE are over 20,000 steam locomotives in railway service in this country, and in the course of a year they run some 531,000,000 miles. Taking the consumption of an express engine as two tons of coal for each 100 miles covered, the total amount of fuel used reaches very large figures. A small saving on each mile covered would mean a very large aggregate saving, with a corresponding reduction of expenses, so that the better use of fuel by enginemen is a subject in which railway companies are keenly interested. In a recent special publication encouraging the economical use of coal, the Great Southern Railways of Ireland point out that roughly half the cost of the Locomotive Running Department is accounted for by the purchase of coal. Since the earliest days economy in fuel has been sought after, and many and various are the devices that have been conceived with this end in view. In this article we propose to deal briefly with some of the developments in this direction that have affected the locomotive fire-
British coal is of excellent quality, and no railway in this country is really situated far from a source of suitable supplies. Abroad, however, different conditions obtain, with the result that specially arranged fire-
In the early days of locomotives coke was generally used as a fuel, for the crude draught and fire-
“Every locomotive steam engine used within the parishes of Burtonwood and Winwick shall be constructed on best principles for enabling it to consume its own smoke and preventing noise in the machinery or motion thereof, and no coal, but only coke or such other fuel as shall be approved by Lord Lilford and the Rector of Winwick, shall be used or consumed on such locomotive on any pretence whatever.”
Gradually locomotive engineers endeavoured to abandon the use of coke, for it was expensive and inferior to coal. Three old-
Of the forms of fire-
The Cudworth fire-
SECTIONAL DIAGRAM of a GWR locomotive boiler showing the smoke-
The illustration above shows the various components of the fire-
In this country it is the usual practice to use a fairly long, but narrow and deep, fire-
With the increase in the size and power of locomotives made necessary by higher speeds and heavier loads, the work of the fireman has not diminished. Abroad, particularly in America, the vast fire-
Such fittings are not yet apparently considered necessary on British railways, although as long ago as 1904 the GWR were experimenting with a mechanical stoker. However, on the “Garratt” type of locomotive used for specially heavy coal and mineral services on the LMSR, the opportunity has been taken of relieving the fireman of any of the coal-
This bunker can be revolved in less than half a minute, if required, and its use in between spells of firing avoids additional labour on the part of the fireman in getting coal forward. The loss of coal and the overloading caused by piling up the fuel in an ordinary tender is made impossible. In addition the coal is completely protected from the weather, which is a matter of more importance than is generally realised.
The burning of pulverised fuel in this country has been confined to experiments only, first on the former GCR in 1920, and more recently on the Southern Railway. Experiments were also made on the GCR at the same time with what was termed “colloidal” fuel, a mixture of pulverised coal and oil. In America many locomotives are fitted for burning pulverised coal; and in Germany successful experiments have been made with the native brown coal, or “lignite”, in pulverised form.
The use of oil fuel is common in regions or countries where supplies are easily available, but in this country in recent times it has been applied only as an emergency measure, when coal supplies have been interrupted owing to strikes. It is interesting, however, that about 30 years ago the former GER had in operation a very successful system of oil burning devised by their then Locomotive Superintendent, Mr J. Holden.
Within its limits the scheme was satisfactory and economical. As a result of the expansion of the system, however, it became no longer an economic proposition, owing to the rise in the price of oil. Among the GER engines fitted with the Holden apparatus were No. 760, specially named “Petrolea”, and many 4-
ONE OF THE LMS “Beyer-