1845.] 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



371 



ATMOSPHERIC RAILWAYS. 



ABSTRACT OT THE BVIDENCE BEFORE THE COMMITTEE OF THE HOUSE 

 OF COMMONS. 



("Continued /rom page 312 J 



Stoppngei. — On the Great Western line five minutes are lost by stopping 

 at a station, besides the lime during which the train is stationary. Instead 

 of a delay of five minutes, a stoppage on an atmospheric line would not 

 amount to more than a minute and a half. The dill'erence between the 

 fast and the stopping trains on the Groat Western Uailway consists not so 

 much in the actual speed as in the loss of time and speedy stoppages — 

 (Urund.) 



Immense delay which would be caused by stoppages on a long atmos- 

 pheric line, running frequent trains, with a single line of tube. A double 

 set of engines would go far to meet the difliculty, a double line of tube 

 icoulil iimuve icitness's ohjection allugetlur. Average length of the stop- 

 pages at (he Grst-class stations on the London and Birmingham line — 

 ISteplunson.) 



" At the first-class stations upon the Birmingham line, the average loss 

 of time in stopping is about five minutes ; that is, not that the actual 

 stoppage is five minutes, but the time lost in stopping, and also in gaining 

 the velocity again, is five minutes. To take two engines, one running by a 

 station without stopping, and the other stopping, they would be five 

 minutes apart at the end of their journey ; the practical eflect of every 

 stoppage is a loss of about five minutes." 



Upon the atmospheric principle the speed is recovered more rapidly 

 than the locomotive, after stopping, if the vacuum be raised — (Stephenson.) 

 Each train must stop a short time at every crossing station, to allow the 

 vacuum to be made — {Cubitt,} 



Stopping of Tndns. — On the atmospheric plan, if a train overshoot the 

 station it can be brought back by a small capstan. Experiments were 

 made in pulling up a train rapidly and within a short distance ; it can be 

 effected more readily than with a locomotive train— (Sami/Jii) 



In the case in which the piston carriage on the Dalkey line started 

 without the others by accident ; it was stopped by the break — ( Gibbons ) 



Traffic. — On the London and Birmingham line about 2,000 tons are 

 carried daily ; on a sinsle atmospheric line over the same ground 7,900 

 tons could be carried — (Samuita.) 



On the Dublin and Kingstown line, the result of a greater frequency of 

 trains has been a greatly increased number of passengers. While the 

 number of passengers has doubled, the expenses have only increased one- 

 fourth— (Berlin.) 



The atmospheric system could not he adapted to a railway of consider- 

 able Iraflic, say the London and IJirmiugham line; main objections to 

 such application of the system — {Bidder.) 



"Mr. Samada commences by takuigthe costof working \!> trainsperday ; 

 now upon the London and Birmingham the number of passenger trains is 

 14 trains at this moment, and there are three goods trains besides, there- 

 fore there are 17 trains a day, of wliich three consist of goods ; and on the 

 London and Birmingham the passenger trains take 120 tons, and the 

 average of the goods trains is 160 tons. One hundred and twenty tons 

 useful weight? — That is the weight of the carriages and passengers, not 

 including the engine ; 1 would observe that tliat is the weight of the 

 passenger trains, but there are large goods trains which have to be pro- 

 vided for. On the opening of parliament the traffic is almost all towards 

 London ; the trafiic is all coming in one direction, and the balance is there- 

 fore destroyed. The same takes place when Parliament is adjourned ; 

 the traffic all travels in the opposite direction ; the consequence is that Ihey 

 have frequently lo send up 50 or CO empty wagons to eslablish the 

 balance. Or during the Doncaster races? — Yes; but here Mr. Samuda 

 assumes that 15 trains will only do the work, and those trains are to work 

 night and day, and only one man to a train. Now one man to large trains 

 is not sufficient ; nor do I think it would be sufficient on the almospheric 

 principle for an ordinary train, because one man, having no assistance 

 from the engine to stop the train at the station, or in case of obstruction 

 upon the line, could not stop the train in all cases by means of the break. 

 I know a case in point : when I was at Ualkey they used three breaks, 

 with the rails in the very best condition for stopping the train, and wlien 

 the vacuum was applied the train was all but starting olf ; it moved once 

 or twice and then stopped again ; and to suppose that under the circum- 

 stances you could send a train with one man, and ensure the stoppage of 

 that train in case of emergency, is an opinion which I sni sure no person 

 practically acquainted with railways would entertain ; therefore I should 

 treble that number lo commence with. Then Mr. Samuda takes the con- 

 sumption of coal for the 30 trains, 1] tons a day. As I stated before, on 

 tbe Ualkey Railway itself, the consumption for the day trains was I J. 

 Now, as regards the London and Birmingham line, you could not carry on 

 the traffic of that railway by day only, you must have night trains inevi- 

 tably ; therefore, instead of I {(/. per train per mile, you shall assume the 

 consumption of the engine at three tons per engine. If you trike it, without 

 adding anything for extra expenditure, at three tons per engine [ler diem 

 for 3'J engines, that makes a consumption per annum of 40,000 tons in- 

 stead of 18,000; and I say that that must be the consumption of coal in 

 respect of the multiplicity of trains. Then Mr. Samuda takes his coals at 

 9s. a too. Now where is be to get his coal at 'J«, a ton I do not koovv. 



That company pay 24*. for coke ; whereas, if they could get coal at <Js., 

 they could make their coke at IGs. Therefore, if you take Us. as the price 

 at which they can get coal, you ought to give the company credit for coke 

 at lUs. But if you take it at that which I consider is the price of coal, 

 and you take my quantity of coal, you will find, that instead of 8,000;., the 

 cost of fuel upon the London and Birmingmara will be 28,000/. per annum. 

 Ihen this estimate is based altogether, so far as I can comprehend it, upon 

 the assumption that on the London and Birmingham, engines of the same 

 power as those on the Dalkey would work the traffic of the line. Now I 

 think I can show that that Is quite out of the question ; if you run 15 trains 

 a day, whether you run them every hour, or at whatever interval you run 

 them, you must be subject to the same inequality of trains that you are now 

 subject to, and you must therefore have a power adequate to convey be- 

 tween London aud Birmingham the heaviest trains that you may have lo 

 convey, combined with the worst stale of circumstances, that is, a high 

 wind. Now, assuming that you must provide for passenger trains of 120 

 tons weight, you must be able to take that 120 tons weight up the steepest 

 incline on the line, and be adequate to meet the resistance from wind, 

 l-rom the experiments which I have tried myself, I have ascertained that 

 tlie resistance may be increased upon the London and Birmingham Rail- 

 way to 401b. per ton, that the engines have had to overcome that ; if you 

 take 401b. per ton, and take ihe gross load as 120 tons, you must have a 

 tractive power equal to 4,H001b. Now assuming that you had the power 

 to raise the vacuum to 24 inches, and will require a tube of 22 inches 

 diameter, instead of 15, and require an engine of 500-horse power, thai is, 

 2a0 commercial power, instead of 80 or <.»0, and with less power than that 

 yoii never can carry on the traffic of the London and Birmingham line ; but 

 the moment you increase the engines, and increase the tubes, you increase 

 Ihe fixed charges ; you increase all the fixed working expenses to a certain 

 extent coinmensurately. And if you were to make any addition commen- 

 surate with the scale of working expenses, you would find, even taking 

 this as the basis, that that would make the actual current expenses of the 

 London and Birmingham altogether, upon the lowest calculation upon the 

 atmospheric system, very much exceeding what they are now paying for 

 their whole locomotive establishment. But the question has been mooted 

 of carrying the enormous traffic of the London aud Birmingham Railway 

 upon a single line. Now I have considered that; in fact I have had it 

 before me for the last 12 mouths, and the conclusion that I have arrived at 

 is, that no person acquainted with the nature of that traffic, with all the 

 circumstances attending it, would entertain that opinion for a moment, for 

 this reason, they have 14 passenger trains per diem, and the amount of the 

 goods traffic is about 800 tons per diem. They have just commenced a 

 new system ; they have now arranged to carry coals at \d. a ton per mile, 

 aud they expect 500 loos a day from one colliery only ; they have elfected 

 a great reduction in iheir traffic, not only as regards passengers (which it 

 may be reasonably anticipated, aud in fact they doanticipate, will produce 

 a corresponding increase in their traffic), but they have also reduced their 

 tariir for goods, and any system which will provide for a less tonnage than 

 2,000 tons per diem upon the London and Birmingham, would, I think, be 

 altogether admissible. You have then to consider that you have to provide 

 for 2,000 tons a day, in addition to I4or 15 passenger trains a day. Then 

 again they are going to open new branches. The Northampton and 

 Peterborough is about to be opened. The Leamington branch is just 

 opened. The Trent Valley Railway is to come in at Rugby, and another 

 will come in at Coventry, and there is a branch coming iu at Hampton. 

 The London and Birmingham line will therefore have five or six railways 

 working iuto it, all of them bringing in traffic of different sorts requiring 

 different treatment, and all that traffic would have to be arranged upon a 

 single line of railway. It would be impossible in this place to point out 

 how all those trains would clash with each other ; but if you took any time 

 table and endeavoured lo work it out, you would find that you could not 

 carry on this traffic without every train upon a single line making 10 or 12, 

 or 20 stoppages, aud the consequence would be, ihat you would make the 

 London and Birmingham, instead of a fast railwaw, one of the slowest in 

 Ihis country, besides which, the question of collision would come into the 

 account. It is perfectly true that I see no difficulty iu having the trains lo 

 meet where the stations are, but there is no means that one can contrive, 

 there is no means that it is possible for human ingenuity to contrive (if it is 

 a self-acting apparatus, so much the worse), but which must depend at 

 last upon the train arriving at a particular moment, and at that moment in 

 Its right position. Now that regularity has never yet been attained on any 

 railway iu this country." 



rniias. — It is the direct interest of the owners of an atmospheric line to 

 run frequent trains, as nearly all the expenses are the same whether they 

 do so or not — {Samuda.) 



The number of carriages to each train would be reduced, rather than 

 the number of trains, to suit the traffic. Trains might be run on the South 

 Devon line conveniently each way every half-hour— (iirunei.) 



On the London and Croydon line trains will be started every half-hoar 



—{Cubitt.) 



Tubes.— The diameter of the tube on the South Devon line is 13 inches. 

 Upon the London and lipsom the diameter is 15 inches. On the South 

 Devon hue the tubes vary in size aud the engines in power, according to 

 the nature of the country— (.S'umiido.) 



Means by which a train could pass at full speed from one part of a tube 

 to another of a diflerent diameter— (finint-i.) 



