56 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



between them. Suppose 4 feet, however, to be necessary ; then, with a 7 feet 

 gauge, the distance from centre to centre of the two lines is 1 1 feet, which is 

 the same as on the London and Birmingham, Grand Junction, and other lines, 

 and which has been adopted to give a general increase of space. The width of 

 tunnels, viaducts, &c., are therefore nul iiecessiirili/ nff'ccled by the 7-fcet gauge. 

 Neither do I understand how the cost of tlis permanent way can be sensibly 

 increased. The weight of rail would be the same. The engines, in other 

 respects similar, would be, at the utmost, only a few hundred weight heavier, 

 consequent upon the increased length of axles and breadth of frames — the 

 boilers, fire-bo.x, wheels, cylinders, and working gear (about nine-tenths of the 

 whole) remaining exactly the same ; and even with our present heavy engines, 

 the greatest weight upon one pair of wheels is noL greater than upon the 

 driving wheels of Mr. Bury's engines on the London and Birmingham 

 railway. 



If the strength of the rails be not increased, the mere distance between them 

 cannot afl'ect the expense of construction beyond the cost of a few cube feet of 

 ballast per yard forward, and about eight loads of timber to the mile in transoms. 

 If 150/. per mile is allowed for these sources of expense, it is far more than 

 enough. This, with the liOOZ., assumed by Mr. Havvkshaw for the earthwork, 

 and M. for one quarter of an acre of land, whichhe has not allowed for, makes 

 400/. per mile as the outside of the additional cost incurred in the first con- 

 struction of the road on the 7 feet gauge. As to the consequent increased cost 

 in the engines and increased expense of repairs, they arc treated in so general 

 a way ihat it is diflicult, if not impossible, to meet what is said; but certainly 

 actual experience satisfies me that eventually there will bono material difference 

 in the first cost. The opinion of Messrs. Robt. Stephenson and Company, as 

 quoted page 5'3, is, that it " will not be very considerable." The wear and 

 tear, I am equally satisfied, will be diminished. 



The whole subject of the diminished resistance arising from the increased 

 diameter of wheels, and the opinion of the Irish commissioners in favour of it, 

 is then disposed of in a summary manner. It is assumed that the liearings of 

 the axles must be increased in the same ratio as the diameter of the wheels, 

 and that hence no advantage would be gained, in so far as the friction was 

 concerned ; but such is not intended to be the case. 



It is asserted that the grinding of the flanges against the rails must be more 

 felt with a large wheel than a small one. No reason is given for expecting such 

 a result, nor why this resistance should not be, as one might naturally expect, 

 inversely as the square root of the diameter, and therefore diminishing with an 

 increased diameter. As in the case of the gradients, however, the whole is 

 set aside by one experiment; this experiment (pages 50 and 51) gives 

 nearly the same i-esuU for wheels of 3 and 4 feet diameter. This is not sur- 

 prising, as the dift'erence in diameter was too small to be clearly detected by 

 the very uncertain and unsatisfactory mode hitherto adopted for ascertaining 

 the resistance. It appears to me also that they were not made under similar 

 citcurastances, or even on the same road, and the ratio of the bearings to the 

 wheels seemed to be rather in favour of the small wheels. The experiment, 

 therefore, appears to be perfectly useless and unavailable, and the writer says 

 that he does not think it conclusive. Nevertheless, these are the only expe- 

 riments adduced, whilst the point is assumed to be proved. 



The next inquiry made is on the question of safety. I certainly never 

 thought of the danger of upsetting from the narrowness of base, as a stage- 

 coach occasionally does ; and therefore I need not occupy your time in dis- 

 cussing the manner in which this imaginary argument has been advanced and 

 then demolished. But I must call your attention to the extraordinary and 

 contradictory general assertions (p. 51) that " if A be safe, there cannot be 

 the smallest advantage in making B safer." This is a confusion of words. 

 If safety, commonly speaking, meant a total absence of possibility of danger, 

 then the statement is contradictory, and is not even sense ; for if B is made 

 safer than A, A cannot be perfectly safe. But safety is a term, after, all only 

 used comparatively, and then the statement assumes this extraordinary ahape — 

 that if A be tolerably good, it is useless to seek anything better. Now, 

 although no man, I believe, ever supposed that ordinary railway carriages were 

 much exposed to the danger of being upset, yet no man could witness, as I 

 have had the opportunity of doing, numerous accidents on railways of both 

 dimensions, without being struck with the great difference in the susceptibility 

 of the engines and carriages to being thrown off the rails on the 4 feet 8 inch 

 gauge and on the 7 feet gauge. The reason is obvious enough ; the oscilla- 

 tion and the velocity of the angular motion, or, in other words, the jerk 

 caused by any departure from level in the rails, or from any open joint or 

 obstacle, or from collision, must be much greater when actini;^ on a 4 feet 8 

 inch base than on a 7-feet base, and I have seen many accidents on the 4 feet 

 8 inch rail arising wholly from this cause, while on the 7-feet gauge 1 have 

 seen the same causes operating to a greater extent without producing any 

 serious results. I believe, also, that at high velocities much of the resistance 

 from the friction of the flanges, as well as the strain upon the carriages and 

 liability to accident, arising from lateral motion, which is imparted to the 

 carriage by angular motion, or rolling, and which must be lessened ill the 

 direct proportion as the base is extended. The great difference in the rolling 

 motion of the engine chimney, when running at high speeds upon the 7-feet 

 gauge, as compared with the same eflect on the 4 feet 8 inches, was remarked 

 at once by the engine-drivers sent by several of the manufacturers to erect 

 their engines, and is familiar to all now engaged on the line, although the 

 rails themselves were at that time undeniably in a bad state. Safety, there- 

 fore, may, and indeed must, be increased by the width of the gauge. As to 

 the efl'ects of the adoption of the wide gauge by the main trunks upon the 

 branch lines likely emanate from it, as I said before, these branches have all 

 formed [lart of the general plan, and were considered originally ; and there- 

 fore the assumption of the writer, that there is uncertainty or danger vpon 



this point, is not correct. The Bristol and Exeter Railway, which is the ex- 

 tension of the Great Western to the south-west of England, is well fitted to 

 this gauge. A great extent of it will be the most level line in England, and 

 is nearly straight. On the Cheltenham Railway, for four-fifths of the length 

 it is free from any objectionable curve ; and on the remainder there will be no 

 curves of so small a radius, even in proportion to the 7-feet gauge, as there 

 are on the Grand .Junction and many other lines. The objections taken, 

 therefore, are not applicable ; and it seems to me that none of the grounds on 

 which the writer founds his somewhat startling advice to alter all that has 

 been done, are tenable. In fact they are none of them brought forward 

 in a clear and tangible shape, except the debit and credit account in page 52. 

 I will begin with the last, or the credit account. The first item is the 

 largest, and considering that it constitutes two-thirds of the whole, it is a very 

 important one; yet there is no proof, there is not even one single reason given 

 for supposing any such increase; the only reference to it that I can find is in 

 the middle of p. 50, where these words occur : — " The permanent road will 

 also cost more if of the larger dimensions than if of the smaller ; for it avails 

 nothing to compare a light rail on the larger gauge, with a heavier rail on the 

 smaller gauge ; such comparisons must be made when other things are the 

 same, or they amount to nothing.'' The assertion here made is unsupported 

 by a single argument or proof. What is meant by the truism contained in the 

 allusion to the light rail and heavy rail I am unable to comprehend. I have 

 quoted it lest it should have some reference to a wide and narrow gauge which 

 I may not perceive. 



I have shown, I think clearly, that 130/. per mile instead of 1000/. is the 

 excess ; this makes a reduction of 85,000/. in the assumed saving. The 400/. 

 excess on the engine and tender I equally dispute ; it is also unsupported by 

 anything except the letter from Messrs. Stephenson, and their opinion is even 

 much qualified ; their concluding remark is — " If the power or dimensions of 

 the engine be kept the same, the additional expense consequent upon an in- 

 crcaic of guage will not be vei'y considerable." In fact, the same engine, in 

 all its material parts, and the same quantity of workmanship, answers for the 

 one as the other ; to widen the frame and lengthen the axles is all that is re- 

 quired ; and even making no allowance for any increased facilities in the con- 

 struction, 100/. will amply cover this, — say, 150/., as the increased expense 

 consequent upon the wide gauge. This, of course, has no reference to any 

 peculiar construction of the engine, such as greater evaporating surface, or 

 larger driving wheels, which are not, in fact, consequences of the width of 

 gauge, but which have been adopted with a view to economy of fuel and wear 

 and tear. 



In the next item I should add 50/. per mile for land, although neither upon 

 earthwork, and still less upon land, have we (iO miles upon which we can effect 

 the saving. The tunnelling, as I have shown by actual calculation of the 

 measurement required, is not effected by the gauge. The account, therefore, 

 stands thus : — 



150/. per mile on 100 miles of permanent way . . . £15,000 

 150/. less on 60 engines and tenders ..... 9,000 



250/. per mile on (iO miles of earthwork ani land . . 15,000 



Tunnelling — nothing. . 



£39,000 

 Instead of 156,000/., as given in the Report. 



I now proceed to consider the debit account, in which I find an important 

 umission. The change recommended from the 7-feet guage to the 4 feet 

 SMnch, is supposed to occupy a year and a half ; during this time no advantage 

 cmild bo taken of the extension of the line to Twyford, in the neighbourhood 

 of Reading, which, if the opinions expressed in this Report are to be 

 adopted, must be laid down with the narrow gauge, and it therefore would be 

 useless until one of the lines of the same gauge was open. By this delay at 

 least a year would be lost. 



But besides this loss, another would be experienced by the confinement of 

 the trafSc to a single line. I believe it would be found iuipraeticable to carry 

 on our trade on a single line ; there can be no doubt that it would be mate- 

 rially diminished, which, together with the loss of twelve months' traffic 

 between London and Twyford, cannot fail to make a difference of upwards of 

 30,000/. The gross receipts upon the present line are about 80,000/. per 

 annum ; the extension of the line from Qij to 32 miles, (thereby securing all 

 the long traffic, which is now only partially obtained,) and the natural progres- 

 sive increase of the trafiic which would take place on the present line, cannot 

 be estimated to produce less than 60,000/. more, or 140,000/. per annum. 

 Supposing the expenses to be increased by 25,000/., there remains, as in- 

 creased nett profits, 35,000. ; to this add 15,000/., as a very moderate allow- 

 ance for the reduction, to which I have alluded in our receipts, unavoidably 

 consequent upon the working of only a single line, which would certainly not 

 diminish our expenses. 



The debit account, therefore, will now stand : — 



Expenses of alteration and loss upon stock, as stated in Report 



(page 24) £123,276 



Loss of profits on the extension to Twyford . . . 35,000 



Ditto on traffic to Maidenhead 15,000 



£173,976 



Instead of £123,976. 

 And deducting the amount to be saved, 39,000?., it shows a sacrifice of 

 134,970/. as the'result of the proposed alteration. Even if the assumed in- 

 crease of 4U0?. on each engine were admitted, it would still leave 121,976/. as 

 the balance against the change, instead of anj thing in favour of it. In ad- 

 dition to this clear loss, it should also be remembered, that after the conver- 

 sion of the one line to Maidenhead from the broad to the narrow gauge, the 



