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On Steam-loiler Legislation. By LAVINGTON E. FLETCHER, C.E. Although the Committee of the British Association " appointed to consider and report on the various Plans proposed for Legislating on the subject of Steam-boiler Explosions, with a view to their Prevention,” are compelled, from the reasons stated in their ad interim Report, to postpone the consideration of the measures recently recommended by the Parliamentary Committee, yet it is thought that it would be well to take advantage of the present opportunity to discuss those
The Report of the Parliamentary Committee is briefly as follows:
The Parliamentary Committee had it laid before them in evidence that there were not less than 100,000 steam-boilers in the country, and that from these there sprung on an average 50 explosions per annum, killing 75 persons and injuring many others, from which it appeared that one boiler in every 2000 explodes annually. It was further stated that steam-boilers were in many instances situated in much-frequented parts of towns and cities, under pavements in thronged thoroughfares, in the lower storeys of houses, and in the midst of crowded dwellings; that such boilers, notwithstanding their dangerous position, were often faulty in construction, and frequently so set that inspection was impossible without removing the brick-work setting, while they lacked proper gauges and necessary fittings.
The Parliamentary Committee arrived at the conclusion that the majority af explosions arise from negligence, either as regards original construction, inattention of users or their servants, neglect of proper repairs, and absence of proper and necessary fittings, while they further considered that the several voluntary associations formed with a view of securing the periodical inspection of boilers had been useful in preventing explosions.
The Parliamentary Committee recommend, not that inspection should be enforced by law in order to render its adoption universal, but that it be enacted that every steam-user should be held responsible for the efficiency of his boiler, the onus of proof of efficiency in the event of explosion being thrown upon him; and further, that in case of a servant being injured by the explosion of his master's boiler, it should be no defence to plead that the damage arose from the nege lect of a fellow-servant. The Committee further recommend that coroners in conducting their inquiries on steam-boiler explosions should be assisted by a competent engineer appointed by the Board of Trade, and that these inquiries should not, as at present, be limited to fatal explosions, but be extended to all others, while reports on the result of each investigation should be forwarded to the Secretary of State for the Home Department, and also be annually presented to l'arliament.
The effect of these recommendations, if carried into practice, would be to render the steam-user readily amenable to an action for damages, so that those who suflered from the consequences of an explosion would become the prosecutors. Thus the Parliamentary Committee do not recommend direct prerention by the enforcement of inspection, but indirect prevention by penalty.
It will be seen from the foregoing that the evidence laid before the Parliamentary Committee endorses the statements made in the Reports to the British Association on the number and fatality of explosions*, while that Committee speaks favourably of the effect of periodical inspection for the prevention of explosions.
Also the opinion of the Parliamentary Committee with regard to the cause of explosions corroborates the views already expressed in the Reports to the British Association on this subject, viz. that explosions are not mysterious, inexplicable, or unavoidable; that they do not happen by caprice alike to the careful and the careless; that, as a rule, boilers burst simply because they are bad—bad either from original malconstruction, or from the condition into which they have been allowed to fall; and that explosions might be prevented by the exercise of commen knowledge and common caret. It is satisfactory to have this principle endorsed by the Parliamentary Committee. Explosions have too long been considered acci
* See Transactions of the British Association, Norwich Meeting, 1808; Exeter Mecting, 1869; and Liverpool Meeting, 1870.
+ Transactions of the British Association at the Exeter Mecting, 1869, p. 50.
dental, and to be shrouded in mystery, and this view has seriously arrested progress. Where mystery begins prevention ends. It is now trusted that it will be thoroughly recognized that explosions are not the result of the freaks of fate, but of commercial greed; and this fundamental principle being firmly established, it cannot be doubted that these catastrophes will ultimately, in one way or another, be prevented. Thus it is thought that a most important step has been taken which is a considerable matter for congratulation.
It is also satisfactory that the Parliamentary Committee has recommended that coroners, when conducting inquiries consequent on steam-boiler explosions, should be assisted by scientific assessors, a practice which was strongly urged in the Report laid before the British Association at the Exeter Meeting *It may, however, be open to question whether it would be better that the engineer, as the Parliamentary Conīmittee recommend, should be appointed by the Board of Trade, or that the coroner should be empowered to appoint two competent independent engineers to investigate the cause of the explosion, and report thereon, as suggested in the Report referred to. But whichever course be adopted, if competent reports be ensured, a public service will be rendered.
Not only, however, should the “ result ” of each investigation be reported to Parliament, but also all the evidence of an engineering character, accompanied with suitable drawings to illustrate the cause of the explosion, so that all the information to be derived from these sad catastrophes might be disseminated as widely as possible.
Further, it is presumed that the reports on explosions which occur in Scotland, where coroner's inquests are not held, will nevertheless be presented to Parliament.
It is most important that the Bill embodying the recommendations of the Parliamentary Committee should provide for other engineers having an opportunity of making an examination of the fragments of the exploded boiler, as well as those appointed by the Board of Trade, otherwise the intervention of the Board of Trade will have a seriously harassing effect. The system practised in Scotland, where the Procurator-Fiscal appoints an engineer to report to him officially, is found very much to impede other investigations; and engineers who have gone all the way from England to visit the scene of explosions in Scotland with the view of giving the facts to the public have been forbidden access to the scene of the catastrophe, so that the Procurator-Fiscal receives information which he does not circulate, while he withholds the opportunity of gaining information from those who would circulate it, and thus he stands in the way of the public good. It is most important that care should be taken that investigations by Board of Trade officers do not have the same obstructive effect in England; and to this end there should be a special provision that the coroner be invested with a discretionary power to admit any suitable parties to make an investigation.
Passing over the consideration of details, it is certainly considered that the three following conclusions arrived at in the Parliamentary Report, first, that as a rule explosions are not accidental but preventible; secondly, that on the occurrence of explosions a complete investigation of the cause of the catastrophe should be promoted by the appointment of a scientific assessor to assist the coroner; and, thirdly, that reports of each investigation should be presented to Parliament: these three conclusions, it is cousidered, form a foundation from which a superstructure will spring in course of time which must eradicate steam-boiler explosions.
What the precise character of that superstructure should be is a question on which opinions may differ. Some, among whom are the Parliamentary Committee as already explained, prefer a system of pains and penalties to be inflicted on the steam-user in the event of his allowing his boiler to give rise to an explosion. Others prefer a system of direct prevention by the enforcement of inspection, on the following general basis :—They would recommend a national system of periodical inspection, enforced but not administered by the Government, that administration being committed to the steam-users themselves, with a due infusion of ex officio representatives of the public. For this purpose they propose that steam-users should be aggregated into as many district corporations as might be
* Transactions of the British Association at the Exeter Meeting, 1869, p. 50.
found desirable; boards of control, empowered to carry out the inspections and levy such rates upon the steam-users as might be necessary for the conduct of the service, being appointed by the popular election of the steam-users in each district, the different boards being affiliated by means of an annual conference in order to promote the harmonious working of the whole system. Its advocates consider that in this way a system of national inspection might be mildly, but at the same time firmly administered, and that it would then not only prevent the majority of steam-boiler explosions, but prove of great assistance to steam-users in the management of their boilers; that it would be the means of disseminating much valuable information; that it would promote improvements; that it would raise the standard of boiler engineering, and prove a national gain.
The question of the relative merits of the two systems, the one, that of direct prevention by enforced inspection, the other, that of indirect prevention by the infliction of penalty, is one of a very complex character, and the more it is discussed the better, and therefore the fullest expression of opinion is requested at this time.
A further topic for discussion on the present occasion is suggested, viz. whether it might not be well to fix a minimum sum, be exacted absolutely in the event of every explosion, that fixed sum, however, when inadequate to cover the damage done, not to limit the claim for compensation.
Several advantages it is thought would spring from the adoption of this course, both as regards compensation to those injured and the prevention of explosions.
It frequently happens, on the occurrence of disastrous explosions, that boilerowners are quite unable to compensate those who have been injured. Such was the case last year at Liverpool, where an explosion occurred at a small iron foundry, in October, killing four persons, laying the foundry in ruins, smashing in some of the surrounding dwelling-houses, and spreading a vast amount of devastation all round. The owners of the boiler, which had been picked up second-hand, and was a little worn-out thing, were two working men, who but a short time before the explosion had been acting as journeymen. They were possessed of little or no capital, and were rendered penniless by the disaster. Another very similar case, though much more serious, occurred at Bingley in June 1869, where as many as fifteen persons were killed, and thirty-one others severely injured by the explosion of a boiler at a bobbin turnery. In this case the user of the boiler was only a tenant; and, judging from the ruined appearance of the premises after the explosion, any attempt to gain compensation for the loss of fifteen lives and thirtsone cases of serious personal injury would have been absolutely futile. The plan of imposing a fixed minimum penalty would tend somewhat to meet this difficulty, as the surplus of one would correct the deficit of another, and in this way a compensation fund might be established for the benefit of the sufferers.
Further, this measure would have a good effect upon steam-users, inasmuch as they would then incur a positive liability, which would act as a more definite stimulus than the vague apprehension of an action for damages, in which they might hope to get off. Also, if this penalty were rendered absolute, it would sare a vast amount of litigation, and boiler-owners would then see that it was as much to their interest to believe that explosions were preventible as that they were accidental; and such being the case they would soon find out the way to prevent them*.
This definite minimum penalty would also tend to meet the present tendency of boiler-owners to seek to purchase indemnities from Insurance C'ompanies in the event of explosions, rather than competent inspection to prevent these catastrophes, since, if the penalty were made sufficiently high, it would pay an insurance company as well to make inspections and prevent explosions as to adopt comparatively little inspection, permit occasional if not frequent explosions, and pay compensation. As pointed out last year at Liverpool, the principle of steamboiler insurance by joint-stock companies does not, under the influence of com
* Steam-users, however, should be exempted from penalty in those cases of explosion resulting from the direct intention of some evil-disposed person, for which the user could not be held responsible, and which might be regarded as an act of conspiracy, intrigue, or plot.
petition, necessarily insure inspection, inasmuch as the number of explosions being one in 2000 boilers per annum, it follows that the net cost of insurance is only one shilling for every £100, which must evidently be inadequate for any description of inspection by way of prevention. Insurance, therefore, as previously pointed out, is cheap, while adequate inspection is costly; so that inspection is opposed to dividend, for which joint-stock companies are clearly established. Some corrective, therefore, is plainly necessary, and this it is thought would in some measure be found by the establishment of a tixed substantial penalty in the event of every explosion, irrespective of the amount of damage done. Also the imposition of a penalty on every inspection-association or insurance company failing to prevent the explosion of a boiler under their care, might have a most wholesome tendency, this penalty being equal and in addition to the one imposed on the owner, and, in like manner, devoted to the support of the compensation fund *.
In conclusion, although entire assent cannot be accorded to the Parliamentary Report, yet it is most cordially wished that every success may attend the adoption of the measures recommended therein, and that they may result in preventing many explosions, and in diminishing the lamentable loss of life at present resulting from the constant recurrence of these catastrophes.
On Designing Pointed Roofs. By THOMAS Gillotr.
Description of a Salmon-ladder meant to suit the varying levels of a Lake or
Reservoir. By JAMES LESLIE, M.I.C.E. (Communicated by ALEX. LESLIE.)
So long as the reservoir or lake is full and overflowing the fish may ascend the waste weir if not too steep, and if otherwise properly constructed and furnished, where necessary, with a salmon-ladder; but whenever the water ceases to overflow the waste weir, the means for the ascent of the fish are generally cut off.
The sluices at the outlet of a lake used as a reservoir are in general (though there may be exceptions to the rule) placed at or near the lowest level of the outlet, and the velocity of the current through them is consequently, in most cases, so great that no fish can swim against it until the surface of the water be run down so low as to be near the level of the outlet, and the velocity be thereby reduced; and in that latter case the power to ascend' into the lake is of no great value, as the salmon have little or no disposition to run during droughts.
This design consists of a series of sluices placed side by side at different levels, each sluice opening by being lowered instead of by being raised, as is the general mode, and each commencing with the salmon-ladder, which passes along in front of the sluices, and is composed of alternate pools and falls. In this design it is contemplated that on all occasions the whole outflow required to run down the stream should be through only one sluice at a time, and over the top of that sluice, which would open by lowering, and shut by being raised, except in extreme tloods, when, for the sake of keeping down the level of the lake, so as to . aroid flooding the adjoining lands, or for any other similar reason, it may be necessary to provide a lower outlet, or the means for a more rapid discharge for the water.
Assuming an instance of a lake with a rise and fall on the surface of 12 feet, and that it is full, or just up to the level of the waste weir, the uppermost sluico of the series is opened so that the water may flow over it to the depth of, say, 9 or 12 inches, which depth we may assume to be necessary to give the statutory compensation. The water will then run down the ladder, which is composed of a series of pools formed by stops reaching quite across from wall to wall, the fall from surface to surface of those steps being 18 inches, and the depth of the pools not less than 3 feet. A fish may then easily leap over the successive falls from the lowest to the highest, after which they must take the last leap over the outlet sluice into the lake, that last leap being at first like all the others, 18 inches, but
* The exemption described above in favour of steam-users should also apply under similar circumstances to Inspection Associations or Insurance Companies.
diminishing in height as the level of the lake is lowered, till at last it is nothing, when the level of the lake comes to the same as that of the highest pool. After that, when the surface of the lake gets too low to give the statutory or requisite supply of water over the uppermost stop, the uppermost sluice is shut, and the one next in order of descent is opened, when the fish would have one leap iewer than before, entering the lake by leaping over the second sluice, and then in succession as the level of the lake falls over each of the other sluices, having a leap less at every change, till at last, when the lake comes to be lowered to nearly the level of its lowest outlet, there would be only one leap to take.
On a new System of Warming and Ventilation. By J. D, MORRISON. The author called attention to his paper which was read at the Exeter Meetins, and stated that he introduced improvements which had been approved of by the Highland and Agricultural Society of Scotland. He had also built an experimental room, where his system of ventilation might be tested practically.
Chain-Cable Testing, and proposed New Testing-Link.
By R. A. PEACOCK, C.E., F.G.S. It is proposed to provide " testing " -links for each new cable, one link to be connected with the cable at each of its ends, and another link to form part of the cable at every 15 fathoms. Each new link will be a flat oval piece of wrought iron, whose thickness will be equal to the diameter of the metal of each ordinary link. The new links will be cut out of a plate of iron, by means of a steam-punch, and will be left by it of the oval form and having three circular holes through, one in the centre and another halfway to each end. The use of the centre hole, which will be 11-inch diameter for a 1-inch cable, is this :-a piece of cylindrical bar iron, about 6 inches long and a shade less than 11-inch diameter, is to be inserted into this hole, and by means of this bar one of the 15-fathom lengths can be connected with a hydrostatic press, the other end of the “length" being fastened at the opposite end of the platform by means of another 6-inch bar, and then the testingstrain may be applied. The two other holes are to connect the testing links with the adjoining parts of the cable.
A cylindrical bar of South-Wales iron was tested by the late Mr. Telford, and its increase of length was found to be 11.68 per cent. After the test, and its diameter was reduced from 13 inch to 1), it was torn asunder by 43 tons 11 cwt. Therefore if the length ” of 15 fathoms is increased by testing to an amount erceeding (say) 8 per cent. of its original length, its diameter, and consequently its strength, will have been too much reduced, and'it ought to be condemned. When the stretching is confined within moderate limits so as to justify the tester in stamping and passing it, the actual length may be stamped on the testing-link; and then, when the cable has been exposed to severe strains on service, it may be laid straight along the pier, and each length be remeasured to ascertain if the strain has been too great, and if any part ought to be condemned.
Links have been found to be cracked after having apparently withstood the test: therefore each length, after being tested (before being stamped), should be lifteil upon a well-lighted bench of the height of a table, and then every link should be examined carefully all over with a magnifying-glass. If any link is found to be cracked, or otherwise defective, the “length ” of course ought to be rejected.
On the Carbon Closet System. By E. C. C. STANFORD, F.C.S.
On the Steam Blast. By C. WILLIAM SIEMENS, F.R.S., D.C.L., 11. Inst. C.E.
After describing what had previously been done by others, including the researches of Professors Zeuner and Rankine, the author explained an improved steamblast apparatus which he had invented. This apparatus consisted of three principal