The Atmospheric Railway: Observations on the Report of Lieut. Colonel Sir Frederick Smith, R.E., and Professor Barlow, on the Atmospheric Railway. Addressed to Francis Low, Esq., Chairman of the Dublin and Kingstown Railway Company

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Hodges and Smith, 1843 - 86 Seiten
 

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Seite 59 - ... combined with the break, which from the much less weight and momentum of the atmospheric train, I know by frequent trials, (even at full speed, and with the full motive pressure in operation,) to be much more effective than with a locomotive engine) I believe it practicable to bring to rest a train moved by atmospheric pressure, in as short a space as is consistent witk the materiali of the carriage holding together.
Seite 58 - The presence of the engine, it is too well known, has not always proved a source of safety, as no inconsiderable portion of the very worst of railway casualties have been solely occasioned by it. The latter part of the sentence is generally true; but in this respect there is no difference between the locomotive and the atmospheric systems ; or if there be, it is in my opinion in favour of the latter, inasmuch as the means of turning off the power are still more certain ; the regulator or steam-cock...
Seite 48 - This objection is answered by Mr. Bergin as follows : — " Assume for a moment, which however I altogether deny, that it was necessary to vary the size of the main on every ascent, and to stop the train at the foot thereof, for the purpose of changing the piston, I should say the cases are very few indeed in which the engineer, when laying out a line of railway, could not so arrange his plans that these stopping places should be the most desirable for stations, and thus render the accommodation...
Seite 58 - What elements of danger are there? — collision is impossible, all recognized causes of fracture of parts are almost altogether absent In speaking on this subject, the Reporters say, ' On railways, it is a great element of safety that the source of power is present with the train, and may be almost instantly turned off if any necessity shows itself for the stopping...
Seite 22 - PXA pounds, and the distance through which this pressure acts- is L feet. The work done is the force multiplied by the distance, or PA XL = PA L foot-pounds. But AL equals the area of the piston multiplied by the length of the stroke, which equals the volume displaced by the piston during its movement from one end of the cylinder to the other. Let V represent this volume expressed in cubic feet. Then, letting W represent the work in foot-pounds, we have W=PAL = PV.
Seite 59 - ... piston to the train, and in which no difficulty of separation, nor apprehension of any derangement, can possibly exist. Besides, even were this not the case, this separation or casting off is not the only means at the command of the conductor ; in common with the locomotive-train he has the break, and in addition he has the power of instantly opening a communication between the exhausted main and the atmosphere ; this latter of course is not so immediate in its action as shutting off the steam...
Seite 49 - Reporters* investigation. Further, this reduction of vacuum does not materially affect the velocity of travelling, which is essentially dependent on the discharging power of the airpump. Such being the fact, an engineer, when looking out a line of railway, and starting with the knowledge that he is not restricted to levels or even to moderate gradients, would find few districts in which he -would not be able to form the railway almost on the very surface of the country ; for...
Seite 49 - ... economical working of the line. But I do not agree in supposing it necessary to change the dimensions of the main on every steep incline ; the less the exhaustion in the main, the greater the quantity of air extracted at each stroke of the pump in proportion to the power expended ; or, in other words, the less the exhaustion (within proper limits) the diameter of the main being proportionately increased, the greater the economy of the system ; and in this assertion I am fully borne out by the...
Seite 8 - That we consider the principle of atmospheric propulsion to be established, and that the economy of working increases with the length and diameter of the tube. " 2. That the expense of the formation of the line in cuttings, embankments, bridges, tunnels, and rails, will be very little less than for equal lengths of a railway to be worked by locomotive engines ¡ but that the total cost of the...
Seite 57 - We shall further quote a passage from Mr. Bergin's pamphlet, in which he notices a remark made in the Parliamentary Report, — that it is a great element of safety for the source of power to be present with the train. " There remains but one other matter to which I think it necessary to advert ; but that one is, in my judgment, of such paramount importance, that, more than any other, it characterizes the atmospheric system ; I mean the safety of the passengers ; not merely relatively to other modes...

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