Speed and Power of the Locomotive
The following article is taken from a report in the Morning Herald on Monday 15th June 1846 by one of their staff reporters. On Saturday, a public experiment for the purpose of “exhibiting the economy and tractive capacity of the broad gauge locomotive” was made on the Great Western line to and fro between London and Bristol. The experiment was an extremely valuable one, inasmuch as it is the first by which the Great Western Company have had it in their Power to test the capacity of the broad-gauge engine against that of the narrow-gauge engine. In the experiments made on the Great North of England Railway under the superintendence of the gauge commissioners, the narrow gauge party worked their passenger trains of 50 and 80 tons with a locomotive that had had applied to it every improvement of which the narrow-gauge engine was considered to be capable to enable it to run at high velocities. But with 50 tons not more than a maximum velocity of 56 or 57 miles per hour, nor more than an average of about 48 miles per hour, could be attained, with 80 tons the maximum speed was about 50, and the average speed about 44 miles per hour. At these speeds the motion of the engine was considered so dangerous that Professor Airy, one of the commissioners, declined to ride on her a second time. These speeds, it will be recollected were some miles per hour below those attained by the old broad-gauge engine upon similar gradients, and with similar loads. The world has now to compare them with the working of the new broadgauge engine - the first of a class - called the "Great Western," some details of the speed and power of which were given a few days since in the Morning Herald. It will be found, from the comparative working given below, that the "Great Western" takes a passenger train of something more than one hundred tons at seven miles faster per hour than the new narrow-gauge locomotive propelled fifty tons; that she took the one hundred tons eleven miles faster per hour than the new narrow gauge engine carried the eighty tons, and that the work was done at less than half the cost at which the narrow gauge engine works. The great national importance of these two facts must be evident to those who consider that the amount of railway traffic on the trunk lines of this country is increasing with extraordinary rapidity, that the London and Birmingham cannot manage its present traffic with the speed and regularity which the public have a right to expect, and that in
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The Great Western
truth the propriety of constructing a second double line between Euston Square and Birmingham has for some title past been seriously contemplated. Such a passenger train, as the "Great Western" can propel at a maximum speed of 70 and an average speed of about 50 miles per hour would require two or three narrow-gauge locomotives to propel it at 38 or 40 miles per hour. But the use of more than one engine has been pronounced by Sir Frederic Smith himself to be dangerous, and the expense of their use shuts them, in a commercial point of view, entirely out of comparison with the economical working of the new gauge engine. The other important advantage of the “Great Western" arises from the amount of surplus power she would always have at command in running passenger trains of - say 80 tons, at an average rate of 45 miles hour; that is, from platform to platform - a performance utterly beyond anything that the new narrow-gauge engine could approach in the ordinary working of a train; This surplus power is of the most serious commercial advantage. It enables the engine driver to keep his time at the stations, and therefore ensures regularity, a matter of as much moment as speed itself. Punctuality at stations in railroad travelling is the means of avoiding accidents, many of the most serious of which have, if I recollect rightly, arisen from trains being late between station and station. A locomotive like the "Great Western" - able, as she has proved herself, to run under a serious disadvantage, with 100 tons 116 miles (as she did down on Saturday), viz., from the 1st to the 117th mile post, including 9 minutes lost in stoppages, in 142 minutes, or at about 49 miles per hour, and to run she did likewise on Saturday) from the 118th to the 1st milepost, including upwards of 16 minutes' stoppages, in 111.7 minutes, or at 45 miles per hour, will, when she gets into proper order, be able to maintain in ordinary seasons
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