78 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[March, 



of 40 miles an hour, tliere is no great dilTerence between tlie two, but that 

 for speeds of 5(1 or GO miles an hour tlic dilference may be wortliy of 

 COtice. It becomes iiiipurlant, then, to intjuire what may be the preatest 

 speed that will probably be desired or mainiained on railways for ordinary 

 purposes. 



It is certain that the wishes of the public will be limited only by consi- 

 derations of economy and safety. Tlie greater llie speed the Krcater will 

 be the cost ; and it ajipears to be the opinion of many of the oflicers of 

 railways, that it would be diflicult to maintain wilh safely the present 

 express speeds upon the great trunk railways. 



The chief impediments to mahitaiuing tite present exjiross speeds are — 



1. The diniculty of arrangiuclhe trains, where the traffic is frequent, so 

 that the first traiiis shall be entirely protected from the chance of inter- 

 fering with or coming into collision wilh the slower trains, or those that 

 slop at numerous stations. 



2. The difficulty of seeing siEtials, especially in foggy weather, in time 

 ■to enable the engine-driver to stop the fast trains. 



We feel it a duly to observe here, that the public are mainly indebted 

 for the jircseut rale of speed, and Ihe increased acconimoduiinn of the 

 railway carriages, to the genius of Mr. Brunei, and the liberality of the 

 Creat Western liaihray Company. 



As regards ihe applicability of the atmospheric principle of traction, 

 or of any oilier priueiple differing from the locomotive, we see no difference 

 between the two gauges. 



4. The Question of Ecnnomij .—V ai'.er this head we have to consider the 

 cost of constructiou.the purchase of the plant, which consists of engines, 

 of carriages, and of other carrying stock ; aud lastly, the cost of working. 

 There can be no tjueslion that, in the lirst construction of a railway, the 

 narrower tlie gauge, the smaller will be the cost of the works. This ap. 

 plies to tunnels, bridges, viaducts, embankments, cuttings, sheds, work- 

 shops, turn-tables, transverse sleepers, and ballast, aud the purchase of 

 land; but it does not affect the mils, fences, drains, aud station houses. 

 The exact difference, however, must depend in a great degree upon local 

 circumstances, and no ojiiuicin can be given of the precise ratio of dif- 

 ference without going inlo a very minute calculation of each line on which 

 the two systems are to be compared ; for instance, in a line free from tun- 

 nels or viaducts, and in a flat country, where there are neither cuttings 

 nor embankmenls, the difference would be limited very nearly to the 

 quantity of land to be purchased (llie severance and damage being about 

 equal in both cases), the amount of ballasting, and some increase iu the 

 cost of Ihe sleepers; whereas, in a very undulating country, the dilference 

 ■would be more considerable. 



As to the cost of the maintenance of way, supposing the construction to 

 be the same, that of Ihe broad gauge must be rather the greater of the two. 

 Cost of Locomotive Puiccr.— In respect to the cost of the engines and 

 carrying slock, we have to observe that they are generally more expensive 

 on the broad than on the narrow gauge. But, on the other hand, it is as- 

 serted by the advocates of the broad gauge system, that as the engines 

 ■svill draw greater loads, as the carriages will accommodate a grealer 

 number of passengers, and as the wagons are capable of conveying a 

 larger amount of merchandise, the work can be, and is done, at a less 

 charge per ton, and ihat a compensation is thus obtained for the increased 

 outlay. How far this is found to be practically the case is the next sub- 

 ject for inquiry. 



We were very desirous, if it had been found possible, thoroughly to in- 

 vestigate this part of the subject by means of the official data called for 

 by us, and furnished by some of the principal companies, containing a 

 statement of their working expenses ; but we find the circumslances so 

 different, tliat very little satisfactory information can be thus obtained, 

 tliat has been obtained, Ihat has slriclly a reference to the economy of the 

 two gauges. There are, of course, various matters Ihat have an influence 

 on the actual cost of locomotive power aud general traffic charges, ihat are 

 in no way connected wilh the breadth of gauge; such as the nature of 

 the curves and gradients, the price of coke, the general nature of the 

 traffic, the mode of working that traffic as adopted by diderent companies, 

 the employ nient of en-ines of greater or less power, that increased accom- 

 modation to the pulilic which involves an extra expense for return car- 

 riages, &0. 



The London and Birmingham, and the Great Western Railway, as me- 

 tropolitan lines of great traflic and of considerable length, would at first 

 .sight appear to furnish the best means of comparison, and there is, iu fact, 

 j!0 diflicully iu comparing the actual expenses; but these lines differ es- 

 sentially in the character of their gradients and in the amount of traffic, 

 estimated at per mile, aud, above .ill, they dili'er in the character of the 

 engines they employ. 



Four Wheel Engines. — The London and Birmingham Company have, 

 from the commencement, persevered in the use of light four-wheeled en- 

 gines, while the Great Western, availing themsehes of the facilities their 

 gau;;e all'ords, have adopted large aud powerful engines, which are 

 worked at nearly the same cost per mile as the former; and if such en- 

 gines, as those on the London and Birmingham line, were essential to the 

 narrow gauge, the question, as to the economy of working, might be at 

 OBce decided iu favour of the broad gauge ; but this is by no means the 

 cas^'.; several narrow gauge lines employ engines of great power, and 

 work, in cunsequente, much more cheaply than the London ami llirming- 

 Jiain ; therefore, the comparison between the working expenses of this line 

 aud of the Great Western can only be considered as a test of the prin- 



ciple of working wilh light and with heavy engines, and not as furnishing 

 a test of the working ecouomy of the two gauges. 



It is a common practice wilh different railway companies, in their half- 

 yearly reports to their proprietors, to stale the per centage of their various 

 expenses, under a few distinct heads, as compared with their revenue ; and 

 from these it appears Ihat on the Great Western, the locomotive charges, 

 during a period of three years, have varied between 8 8 and 11.1, ave- 

 raging 9.7 per cent on their income, and on the London and Birmingbatn 

 they liave varied, within the same period, between 7.'J and 9.3G, ave- 

 raging about 8'G per cent, on their income ; and, therefore, on a superficial 

 view of Ihe (juesiiun, tlie London and liirminghani would appear to have 

 worked their line at a cheaper rate ; but valid objections have been made 

 to this comparison on the part of the Great \lestern; because it is obvious, 

 from the several returns we have received, thai the London and Birming- 

 ham Company has far the more abundant traflic per mile, and ought, 

 therefore, to be expected to perform its work at a less per centage on its 

 income. It has been stated by Mr. Gooch, that as locomotive superin- 

 tendent on the (Jreat Western, he is called upon to supply a certain 

 amount of locomotive power, and that the cost of such power is almost 

 entirely irrespective of the load or number of passengers it is made to 

 draw ; but that these numbers are of great importauce in comparing the 

 locomotive evjienses wilh the revenue. 



In page 27 of the appendix to this report, an abstract and comparative 

 table are given, founded on returns furnished by the Great Western and 

 Loudon and Birmingham Hailway Companies, showing that the revenue 

 derived from the passengers' Iraiu is 01 per cent, greater per mile worked, 

 on the latter tlian on the former line. It must, therefore, be obvious that, 

 as a test of economy for working, we cannot adopt the principle of a per 

 centageon the revenue, neither will the cost per mile run give a more just 

 comparison as to the ecouomy of the two systems, because it is a well- 

 known fact Ihat the London and Birmingham Company have been con- 

 veying their traffic wilh engines of inadequate power, and that great eco- 

 nomy would result to them by the adoption of larger engines. 



Other dilliculties also occur in the comparison of these expenses on dif- 

 ferent lines, in consequence of the difference in the form of the accounts, 

 aud of the circumstauee of oue company adopting Ihe principle of having 

 a reserve fund for renewals, and other companies having no such fund. 



Probable Cost of Locomotion on Great Western if made uitk Narrow 

 Gauge. — We are, therefore, of opinion that the most satisfactory compa- 

 rison that can be made of the economy of working the two guages, will. 

 be, by applying to first principles, endeavouring merely to determine what 

 the working expenses of the Great Wesleru line, wilh their present 

 amount of traflic, would have been, provided it had been made a narrow 

 gauge line, aud worked with such engines as iHiose employed on the South 

 Western and some other narrow gauge lines. 



The average weight of a passenger-train on the Great Western Railway 

 (independent of llie engine and lender, which weigh 22 tons) appears, by 

 the returns sent to us, to be C7 tons ; aud the average number of passen- 

 gers per train for the half-year ending the SOlli of June, 1845, as appears 

 by our comparative table, page 27, is only 47"2, whose weight, including 

 their lu:;gage, may be estimated at about 5 tons. 



Mr. Gooch estimates Cttch carriage and its passengers on the broad 

 gauge, to weigh about U-3- tons, and therefore there would be seven carriages 

 to make up the G7 Ions above specified. The most commodious carriage 

 on the narrow gauge lines, such as those on the .South Western, weigh less 

 than 5 tons ; seven such carriages would therefore weigh about 34 tons, 

 and being capable of containing 12G first-class passengers, weighing, with 

 their luggage, iL'J tons, the total load would be only 4GJ tons. Now we 

 find, that even niUi a traflic as large as that on the Loudon and Birmingham 

 liaiUvay, the average per train would only be 81-9 passengers, weighing 

 about 8 tons ; so that, under the supposition of a traffic of this extent, 

 the luad of the seveu narrow gauge carriages so occupied would only be 

 42 Ions. 



But JNIr. Gooch estimates, from his own experiments, the relative powers 

 of traction of the broad gauge engines, and of the narrow gauge engines of 

 the Souih Western Kailway, wiien working at the same speed, as 2.067 to 

 1,39s, or as GT per cent., the load of the broad gauge iu tons, to 45 tons 

 whicli would be Ihe corresponding load for the narrow guage, so that the 

 narrow gauge engine has more power over the 42 tons it would have to 

 draw than the broad gauge has over its average load of 07 tons, both ex- 

 clusive of the weight of the engine and tender, the narrow gauge carriage 

 in this supposition being supposed to contain 84'9 passengers, and the 

 broad gauge only 47*2. 



If, however, it were necessary, 224 first-class passengers might be placed 

 iu the seven broad gauge carriages, and, as it has before been said, 120 in 

 the seveu narrow gauge carriages; but it appears likely that this extent 

 of accoinmodalion would only be called for on such rare occasions, that the 

 question of providing for it, except by assistant power, cannot betaken 

 into consideration in the present comparison. 



It is obvious, from the foregoing statement, that the narrow gauge en- 

 giiie of the class we have been considering has more power over the seven 

 narrow gauge carriages, and a load of 120 passengers, than the broad 

 gauge engine has over the seven broad gauge carriages, and the load of 

 Ihe same number of passeugers ; and that, therefore, if the Great M'estern 

 had been a narrow instead of a broad gauge line, the South \\estern en- 

 gines would have had the same command over the existing passenger 

 traffic of the Great \\ estern as its owa.,engines now have with the present 

 construction of that railway. ,,.■ . 



