THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



49 



practical level, for the ostensible purposs of obtaining higher velocities, or 

 diminished resistance. 



Between your maximum parliamentary gradient, vehich was 1 in 528, or 

 10 feet per mile, and your present proposed gradient, which is 1 in 1320, or 

 only 4 feet in a mile, the question stands thus. 



Calling friction, resistance from the atmosphere, &c., lOlbs. per ton, and 

 adding gravity, the resistance on 1 in 526 will be 14. 21bs. per ton, on 1 in 

 1320 it will be 11 "lbs. per ton, making a diminution of resistance, when 

 ascending, of 17 per cent. Now, supposing your railway was one inclination 

 throughout between the e.\treme termini A and B ; in rising from A to B the 

 increased resistance of 17 per cent, would be felt, and a corresponding in- 

 crease of steam would liave to be expended; but in descending from B tu A 

 there would be a diminished resistance in tlie same proportion, and a smaller 

 quantity of steam would be required ; and in such a case, as it regards cost of 

 working, there wovild be very little advantage in one gradient over the other. 

 The maximum load that an engine could draw on an incline of 1 in 528, 

 would be less than on 1 in 1320 ; but on an incline of 1 in 528 all average 

 loads could be taken. 



On an incline of 1 in 528 also, to carry /Ac same load, an engine would 

 have to be a trifle heavier than on 1 in 1320; but on 1 in 528, to carry full 

 average loads, an engine could be made of as light weight as they ever are, 

 or perhaps can be made, consistent with the requisite strength. 



If, instead of having one inclination, the line consisted of a series of in- 

 clinations greatly undulating, the advantages of the flatter line would approach 

 nearer to the 1 7 per cent. ; not but that it would still follow, that in going up 

 the steeper gradients tliere would be increased resistance, and in going down 

 there would be diminished resistance in equal proportion ; yet in practice it 

 has been found, that unless the inclines be of very great length, advantage 

 cannot be taken of the diniinishtd resistance in going down, as regards steam ; 

 for though it is not wanted to an equal extent, yet a great portion is wasted 

 by blowing off at the safety valve. 



But your line corresponds to neither the latter nor the former of these cases ; 

 it is neither composed entirely of one plane, nor of a series of planes ijreutly 

 vndutalhiri ; but in result it will approach nearer to the form^case than the 

 latter ; for it may be said to be composed of two great planes, one rising up to 

 the summit, the other descending from it — one upwards of 70 miles in length, 

 the other upwards of 40, and dividing your line at the summit into two 

 parts ; it would then be analogous to the former case, in which it appears that 

 practically, and as regards cost of working, there would be no very material 

 difference between the inclination cf 1 in 528, and of 1 in 1320, iWieii so cir- 

 cumstanced. If in your line, therefore, the advantage of one gradient over 

 the other be put at 8.5 per cent., it will, in my opinion, be the fun 

 equivalent. 



Now, if the whole cost of working a railway was expended on locomotive 

 power, by reducing the gradient from 1 in 528, to 1 in 1320, a saving of 8.5 

 per cent, would be effected, and therefore an increase of 8. 5 per cent, to the 

 capital to obtain it would not be expended uselessly. 



But the expense of working railways does not consist entirely of the cost 

 of locomotive power. There are other expcnces that remain constant, what- 

 ever saving be effected in the locomotive department ; and this fact should be 

 kept constantly in view during the remainder of this report. 



Taking the Liverpool and Manchester Railway as a standard, it will there 

 be seen that the cost of power does not form one-third of their half-yeavly 

 expenses. It is upon this item only, therefore, that an alteration of the 

 gradients of the nature I have been describing would effect a saving of 8.5 

 percent.; and 8.5 per cent, upon one-third of the annual expenses will be 

 only 2.8 per cent, on the whole of the annual expenses, and therefore a 

 company would do wrong in increasing their capital more than 2.8 per cent, 

 to effect such an alteration. 



But the small saving to be obtained in many cases by reducing gradients 

 below a certain inclination may be proved by an appeal to actual practice; 

 not experiment only, but the every-day results of lines in operation, which is 

 far better, for it is upon the every-day business that the saving must be 

 effected, if it is to be. 



Contrasting your line with one which opened about the same time, which 

 also has continuous bearings, upon which an equal velocity has been main- 

 tained, and which, as will appear from the statement below, has very different 

 gradients, it will be seen that in a case like yours 1 have put the advantage of 

 a gradient of 1 in 1320 over 1 in 528, high enough. 



GRADIENTS ON GREAT WESTERN RAILWAY, 



1700 

 1320 



1760 

 1320 



1980 

 1320 

 2040 

 2040 

 2112 

 1320 

 1980 

 1830 



Tlie foUoiiiiig arelfhe results of Four Weeks' Traffic on each of these Lines, 

 eitdjng the I'Ath of September. 



GREAT WESTERN RAILWAY. 



Average number of ti'ains per day . . . - 



On Sundays 



Tiines of nuining ..---.- 



.\verage number of can-iages per train 



Average number of passengers per train . . - 



.\verage weight per train 



14 



- - 12 



8,9,10,12,4,5,6,7 



. - 6. S 



- HI 



Cwt. 



5 



Average consumption of coke per mile ------ 



Average consumptiou of coke per ton per mile 

 .\verage consumption of coke per passenger per mile - 



Length of trip 



.-Vverage lime, 5.5 minutes, \\ith two stoppages. 



MANCHESTER AND BOLTON RAILWAY. 



.Vverage number of U'ains per day 



On Sundays ..._...- 



Times of running 



.\verage number of can'iages per train 

 Average number of passengers per train 



Average weight per train 



Tons, 

 40 

 lbs. 

 51. 00 



1. 20 



0. 4.5 

 22i miles. 



20 

 4 



7, 8,9, 10, 12, 2i, 4, 5,0, 



Tons. 

 24 



Cwt. 

 1 



Average consumption of coke per mile .__--- 27, 00 



Average cousuniptiou of coke per ton per mile - - - - - 1. 16 



Average consumption of coke per passenger per mile - • - - 0. 36 



Length of trip ....... ... 10 miles. 



Average time of making if, without stoppages - - - - - 27 minutes. 



Average time, 35 minutes, with 5 stoppages. 



From the foregoing statement it would appear that the consumption of coke 

 is considerably less on the line with steep gradients. But the average weight 

 per traiir is in each case exclusive of the engine and tender. 



The average weight of engine and tender, in working order, on the Great 

 Western Railway, will be 27 tons. 



On the Manchester and Bolton Railway the engine and tender, in working 

 order, weigh 16 tons 4 cwt. 



Adding these to the respective trains, the average u-eight of the Great 

 Western train, including engine and tender, will be 67 tons 5 cwt. 



The average weiglit of the Manchester and Bolton train, including engine 

 and tender, is 40 tons 5 cwt. And 



Consumption of coke per ton per 

 mile on the Great Western, including 

 weight of engine and tender, is 

 0.75lbs. 



Consumption of coke per ton per 

 mile on Manchester and Bolton, in- 

 cluding weight of engine and tender, 

 is 0.671bs. 



And on the [Leeds and Selby Railway, with the following gradients, (he 

 results of a month's working, ending the 13th of September, are as under: — 



57 



32 tons 5 cwt. 

 lbs. 



- 36.00 



- 1.1 



- 0.63 



- 20 miles. 



Average number of trains per day, 7. 2 on Sundays. 

 One train extra on two market days per week. 

 Average number of passengers per train 

 Average weight per train, exclusive of engine and tender 



Average consumption of coke per mile ... 

 Average consumption of coke per ton per mile 

 Average consumption of coke per passenger per mile - 

 Length of trip ----.... 

 Average time 1 hour 7 minutes, with 4 stoppages. 



The next subject for consideration is the increase of gauge. In examining 

 this question, it will be necessary to put aside useless and erroneous objec- 

 tions ; for the enquiry is one on which I am not only anxious to arrive at a 

 proper conclusion myself, but I am desirous of enabling others to do so also ; 

 and throughout this report I shall rather aim at developing the process by 

 which the opinions it contains are arrived at, even at the risk of being tedious, 

 and aware though I am, that this will be laying it more peculiarly open to any 

 who should be disposed to cavil at it ; yet, on such a subject, it is better that 

 it should partake more of Uie nature of demonstration than of mere assertioa. 



