lS-17.-] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



•.'3 



It will be understood, that the apparatus used for trying the experimentg 

 must be made of pretty large proportions, and all the parts must be suffl- 

 cieutly strong to resist the action, the effects of which it is intended to 

 prove. 



The details of this apparatus must be carefully attended to; but the ex- 

 pense cannot be estimated at less than from 400/. to 500/. In order that the 

 experiments may lead to results worthy of interest, it will be necessary to 

 try, comparatively, axles of at least three dilferent diameters, and to act 

 upon two axles of each kind, in all six axles, furnished with their wheels, 

 the expense of which will be about 90/. 



Lastly. — The working of the apparatus will require a certain amount 

 of power, constant attention, and the renewal or repair of some parts of the 

 mechanism, such as the brass bearings for the axles, or the tyres of the 

 wheels. 



In conclusion, the Commission is of opinion that, in order to make ex- 

 periments in a suitable manner, an outlay of at least 800/. will be required. 

 It is evident that these experiments will occupy a considerable time ; but 

 this dues not appear to be a sufficient reason for abandoning them. 



It was observed by the Commission, that in locomotive engines there 

 were many parts subjected to considerable strain and violeiice, the rupture 

 of which would be of minor importance, and that they might therefore, 

 without much inconvenience, be allowed to remain in use until nearly worn 

 ont : of this kind are the rods which connect the locomotive to the tender, 

 and also the bolts which serve to fasten them. By manufacturing several 

 similar pieces with care, pulling some of them in use, and keeping the 

 trtliers for the purpose of comparison, the Commission is of opinion that 

 interesting results might soon be arrived at. 



To conclude, as regards axles, — it only remained for the Commission to 

 inquire into the precautions to be taken iu the case of breakage of axles, 

 in order to prevent any accidents arising therefrom. Plans have been pro- 

 posed for this purpose by a great number of inventors, which it may be as 

 well to make mention of here. 



These plans may be divided into two categories ; the first of which con- 

 sists in the employment of wheels running on the rails in front of the 

 engine, and serving as guides. The second consists iu the employment of 

 guides on the rails, the rods of w hich, being attached to the framing of the 

 ungiue, are intended to keep the train in its place on the rails. Neither of 

 these plans appeared to the Commission susceptible of useful employ- 

 ment. The guide-wheels would have the inconvenience of preventing the 

 engineer from perceiving the breaking of the axle iu time to stop the 

 train. 



With regard to the guides, if they were made as proposed, in the form 

 of drags, they would cause shocks and serious accidents ; they also would 

 not offer any resistance to the oscillations of the engine ; if made light, 

 they would readily be broken when subjected to a violent shock ; and if 

 heavy, they would evidently facilitate the running of the train off the 

 rails. 



As regards the working of railways, another not less important question 

 occupied the attention of the Commission. Ou the occasion of the Ver- 

 sailles accident the general opmion was, that nothing fatal would have 

 happened if the locomotive " iNIatthew Murray" bad been mounted on sis 

 wheels instead of four. This appeared also to be the opinion of Govern- 

 merit, as one of the first precautionary measures was to prohibit the com- 

 panies in the environs of J-*aris from making use of locomotive engines 

 with four wheels. Before, however, this measure was made general (the 

 immediate application of which would prove ruinous to many other com- 

 panies besides those in the environs of Paris), the Commission thought 

 proper to inquire into it as regards safety, and for this purpose took an 

 account of the number of accidents which had happened upon railways 

 worked with locomotives, either of six or four wheels, and the conclusion 

 they came to was that, as regards public safety, the six-wheeled engine 

 possessed some advantage over the four-wheeled engine, especially when 

 the two driving-wheels are provided with flanges; this advantage is not, 

 however, so great at present as entirely to do away with the four-wheeled 

 engines. The attention of engineers must be especially directed to the 

 improvement of the six-wheeled engines, and there is no doubt that when 

 these engines have undergone the improvements which may be suggested, 

 they will be generally preferred. 



The parlies in favour of the four-wheeled engines brought forward, in 

 support of their opinion, the fact that, in six-wheeled engines, the centre 

 of gravity of the whole was always before the cranked axle, and that, 

 therefore, in case of the front axle breaking, these engines would fall as 

 easily as the four-wheeled engines. On the other hand, by placing the 

 framing which supports the four-wheeled engines inside, the fall of the 

 wheels is prevented when an axle breaks, and there is no further fear of 

 accident : but the Commission observes, that if in most of the present six- 

 Vfheeled engines the centre of gravity is in front of the cranked axle, there 

 is no practical impossibility in bringmgit upon the axle itself. The front 

 axles are, besides, not the only ones the rupture of which is to be feared ; 

 the cranked axles frequently break, and such accidents, which are not 

 much to be feared in a six-wheeled engine, may have serious consequences 

 ia a four-wheeled. 



With regard to the advantage attributed to placing the framing inside, 

 it is, perhaps, sulficieut to observe, that this arrangement does not apply 

 particularly to four-wheeled engines, and that nothing conclusive can be 

 arrived at as regards the safety of the engines fitted up in this manner. It 

 does not appear certain that this will prevent the running off from the rails 

 on the breaking of an axle. 



Fires can only arise from two causes : — 1st. The sparks escaping from 

 the chimney of the locomotive : 2nd. Portions of incandescent or ignited 

 fuel falling from the furuace, which falling pieces, even should there be no 

 wind, are driven along by the current of air produced by the rapid move- 

 ment of the train. 



As regards the sparks which issue from the chimney, the Comraissiou 

 observes, that since railways were first worked, the chimneys of locomo- 

 tives have always been furnished with a woven wire guard, which stops 

 the sparks, and at the same time returns into the smoke-box a portion of 

 the pulverulent substances, which, when allov^'ed to escape, cause great 

 inconvenience to travellers. This guard has since been somewhat im- 

 proved ; for instance, it has been formed of a closer fabric ; also the chim- 

 ney has been formed trumpet-mouthed, with iron wires stretched across it, 

 whereby a stronger guard than the ordmary one is formed. The employ- 

 ment of the guard not having, however, always produced satisfactory 

 results, other methods have been resorted to, which it will perhaps be 

 advisable here briefly to describe : — 



A strong metallic basket was placed at the lower part of the chimney, 

 in the form of a truncated cone with its small end downwards. By this 

 arrangement the portionsof cinder and ignited fuel are presented obliquely 

 to the meshes of the fabric, and therefore the smoke will have great diffi- 

 culty in drawing them up. A horizontal cover was placed in a part of the 

 chimney to arrest the portions of cinder and fuel, and throw them back to 

 the bottom of the chimney, and the smoke escaped by lateral openings. In 

 some cases, these two plans have been combined in one chimney, one above 

 the other. Lastly. — A plate of iron pierced with round holes, about one- 

 third of an inch in diameter, was placed in the smokebox, in a horizontal 

 position; whereby all the sulid portions of fuel, which were not presented 

 directly to the orifices, were immediately thrown back to the bottom of the 

 smoke-box. 



To these may be added another method tried in Germany, which ap- 

 peared to produce satisfactory results. It consists in placing a fan, or 

 wheel furnished with wings, on the top of the chimey, at an inclination of 

 4,5°, which, being put in motion by the heated air issuing from the chim- 

 ney, drives the sparks to the sides of the chimney, where they are extin- 

 guished and fall back. 



The Commission having ascertained the advantages of these several 

 plans, was of opinion that there was no occasion to recommend any one 

 of them in particular, but that it would be advisable to submit each to 

 regular experiment ; and until it should be shown by experience which 

 was the best, the railway companies should be obliged to use one of 

 them. 



With regard to the ignited fuel falling from the furnaces of locomotives, 

 the only means known of preventing ihe accidents which may result there- 

 from, is by employing an ash-pan to calch the cinders, and thereby prevent 

 them from falling to the ground. Tliereare, however, several disadvantages 

 attending their use, such as — preventing the draft; being too near the 

 ground ; causing the bars of the furnace to wear away more quickly, and 

 rendering the cleaning of the furnace more difficult; and, lastly, prevent- 

 ing the engineer from immediately putting out his fire, should it be neces- 

 sary to do so. 



An arrangement might, however, be contrived to do away with these 

 disadvantages, either wholly or partially, in which case the ash-pans might 

 be employed with great advantage ; but in the present state of things, the 

 Commission is of opinion that there is no occasion to recommend their 

 employment, and can only propose to await the result of longer expe- 

 rience. 



III. On the mode of attaching the engines and carriages together, the 

 kind of break employed, and the method of deadening shocks. 



A very important question was next discussed by the Commission, viz., 

 whether more than one locomotive ought to be allowed to be attached to a 

 train. The conclusion arrived at was, thtLt there was always disadvan- 

 tage, and sometimes danger, attending the use of more than one engine. It 

 is, in fact, impossible that the engineers of the different engines should 

 always act iu concert ; and moreover, if the foremost engine should meet 

 with any accident, rendering it necessary to stop, the hinder one, continu- 

 ing to progress, would most likely throw it off the rail, if the speed were 

 considerable. 



The Commission is therefore of opinion that more than one engine ought 

 not to be used to one traiu, except, in certain cases, ou railways in the 

 environs of Paris, or other large cities, where there are an immense num- 

 ber of passengers. 



Under these circumstances, when it is absolutely necessary to use two 

 engines, how are they to be attached? If one of them is a six-wheeled 

 engine, which of them is to be placed in front; and if both are six or 

 four-wheeled engines, should the heaviest or the lightest be placed in 

 front ? 



In order fully to answer these questions, the Commission thinks fit to 

 remark that the principal danger consists in the probability, iu certain 

 cases, of the front engine being pushed forward by the hinder one ; in 

 which case it is liable to go off the rails, aud might thereby cause very 

 serious accidents. Under these circumstances, as the six-wheeled engines 

 are more firm than the four-wheel, and are for that reason less likely to 

 get off the rails, when two engines, one of six aud the other of four 

 wheels, are to be employed in one train, the six-wheeled one should be 

 placed iu front. For the same reason, when two engines of ditfereo': 

 weights are employed, it is desirable to place the heaviest foremost. 



