NA TURK 



97 



THURSDAY, NOVEMBER 29, 1S94. 



LOCOMOTIJ'E CONSTRUCTION. 

 The Construction of the Modern Locomotive. liy George 

 Hughes. Pp. 260. (London : E. and F. N. Spon, 

 1S94.) 



OK all the many branches of engineering, that of 

 locomotive engineering has been generally over- 

 looked by the writers of te.\t-books, and until quite 

 recently the only works on this important subject were 

 the classic. il works of Z. Colburn and D. K. Cletk, 

 " Locomotive Engineering and the Mechanism of Rail- 

 ways," and " Railway Machinery." These works are 

 more than twenty years old, and do not now represent 

 modern practice, although the rules and formula; given 

 are largely made use of to this day, besides which the 

 experimental data obtained by D. K. Clerk on the old 

 Edinburgh and Glasgow Railway, some time before the 

 year 1S55, may still be regarded as of great value. 



Locomotive engineers in this country owe more to the 

 late Mr. William Stroudley than they care to admit. To 

 Mr. Stroudley is due the thoughtful and careful designing 

 of every part of the locomotive, from the valve motion 

 to the damper on the ash-pan, and, thanks to his example, 

 locomotive design has become as near a science as it is 

 possible to be, always bearing in mind that abstract cal- 

 culations are nearly useless for this purpose. A very 

 important point in the design of a locomotive is that of 

 facility of repairs in the running-shed. It is possible 

 to point to more than one type of British engine where 

 the draughtsman appears to have had entirely his own 

 way in the design, and consequently an ordinary repair, 

 such as changing a spring, entails the partial stripping 

 of the engine in order to lift it high enough to 

 effect this : whereas it should be possible to do it 

 with a couple of jacks, just to ease the weight off the 

 spring, take the pins out, and then replace the spring. 

 Another similar case may be quoted. Some heavy main 

 line passenger tank engines have recently been con- 

 structed ; and should a copper stay leak badly on the 

 side of the fire-box, the side tanks cannot be removed to 

 get at the leak without cutting out rivets and removing 

 the angle-iron supporting the side platform ; whereas had 

 the draughtsman been an engineer, he would have fore- 

 seen such an emergency, and provided for it. These 

 examples are sufficient to show that when designing an 

 engine, the position of every pin and bolt should be care- 

 fully considered, so that their removal, if necessary, will 

 be an easy matter in the running-shed. 



The volume before us, unfortunately, does not deal with 

 design, but treats only with the manufacture of a locomo- 

 tive in the works of the Lancashire and Yorkshire Rail- 

 way Conip.'iny at Horwich. As these works are compara- 

 tively new, it is only fair to expect to find the practice 

 thoroughly up to date, and as the author is an assistant 

 in the chief mechanical engineers' department, the in- 

 formation given may be considered to be authentic. The 

 title chosen for the book is a little misleading, because 

 only one type of engine is discussed ; moreover, this engine 

 is fitted with the Joy valve gear, a type of motion cer- 

 tainly not generally adopted by locomotive engineers. 

 NO. 1309, VOL. 51] 



Thework is divided into six sections,and these areagain 

 subdivided when necessary. Each section describes the 

 actual progress of the work done in that section. Taken 

 as a whole, this book is unique ; it is the only one we 

 know of that appeals to the locomotime engineer in 

 the language and phraseology of the works, and without 

 the cant usually found in text-books of to-day dealing 

 with mechanical subjects. The book being of a thoroughly 

 practical nature, it may be as well to follow its contents 

 in order. 



Section i. deals with the boiler, the materials used in 

 its construction, and the methods of manufacure. Steel is 

 the material used for the shell in most cases. The author 

 observes that if a plate is buckled, this buckling is got 

 out of the plate by planishing, or by a multiple roller 

 straightening machine. The former method cannot 

 be recommended for boiler-plates, but for tank side, cab, 

 or splasher-plates it is the common practice. The ques- 

 tion of locomotive boiler drilling is thoroughly well gone 

 into, but the methods described are not those of most 

 recent practice, which may be concisely stated to be— 

 the edges of all plates must be machined, rivet and other 

 holes to be bored after rolling the plates to shape, and drill- 

 ing all holes out of the solid. Many complicated multiple 

 drilling machines have been constructed to meet these 

 requirements, but it is questionable whether such com- 

 plicated tools are necessary, especially when the self- 

 pitching attachment is used, because the holes in each 

 seam must be set out in order to find the position of 

 the holes for the "holding together" bolts, which 

 are usually placed 12 to 14 inches pitch, and which are 

 usually drilled through a template in bunches before the 

 plates are rolled. Further on the author describes a plate- 

 bending machine capable of rolling a plate to the very 

 edge. As such a machine is certainly very badly wanted 

 it may be here questioned whether the one described 

 is really capable of doing this. The old method of setting 

 the last 4 or 5 inches with a "former" has long been 

 condemned, but with vertical rolls the ends of the plates 

 may be rolled to the true radius by means of a curved 

 packing piece which holds the plate up to the movable 

 roll, resting against the smaller live rolls behind. 



We are told that the inside and outside butt strips are 

 sheared to size, and not machined on edge ; unless they 

 are afterwards annealed, this practice cannot be com- 

 mended. One cannot help being astonished at the free 

 use of cast-steel in the boilers. This is very much up to 

 date ; but what gain there can be in using a cast-steel tee- 

 bar in place of a rolled one for the longitudinal and sling 

 stay attachments, cannot be seen. The crown of the fire- 

 box is stayed with cast-steel girder-stays or roof-bars, 

 and ferrules are used to preserve the proper distances. 

 Surely these ferrules might be replaced by bosses cast on 

 the stay-bar, into which the bolts would be screwed, thus 

 strengthening the bar, and being less complicated. The 

 foundation rings are also of cast-steel ; these castings 

 evidently require much setting and " paening." Surely 

 they are machined inside and out, as required by good 

 practice ? 



The paragraphs dealing with flanging plates and the 

 tools used, leave nothing to be desired ; they are concise 

 and to the point. Reasons might have been given for 

 the adoption of the " Webb " fire-hole ; it seems to 



