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sion." Cowden says, "I saw several flashes of lightning previous to the explosion." Neither say any thing of the nature, or the nearness, of the flash, nor do they seem to have attributed to it any agency in the explosion. On the other hand, two other brakesmen, McGuire and Smith, declare that they saw no lightning, and heard no thunder, which is scarcely reconcilable with the supposition of lightning striking the boiler. Messrs. Weber and Shipp, persons residing near the place of accident, both of whom saw the explosion, agree likewise in the statement that there was no lightning at the time.
In the testimony collected by the committee, it will be found that the storm, which (as is most commonly the case with our thunder storms,) had come from the north-west, had passed off to the southeast, and was almost entirely over before the Richmond had left Reading, so that Mr. Ward had laid aside his outer coat. Mr. Spayd also asserts with confidence, that for some hours previous to, and after, the explosion, there was no lightning to the north of Reading; he heard the explosion, and is sure there was no flash at the same moment. Messrs. Hiester, Herbst, Richardson, and Gruber, all testify to the same absence of lightning. The evidence, therefore, alone is perfectly conclusive, that the explosion was not due to the fact of the engine being struck with lightning.
But there is another cause, which, if we can suppose it to have been in action, is quite sufficient to account for all the effects observed. We allude to the rapid generation of steam of enormous tension, when water is suddenly brought into contact with a part of the boiler unduly heated. The agency of this cause is now so well understood, and its circumstances have already been so carefully investigated by a committee of the Franklin Institute, that we need say no more upon the subject, but proceed to inquire whether such a cause can be supposed to have acted in the present case.
It may be admitted that when the Richmond reached Reading at 7h 18m. P. M., the boiler was filled with water as far as the upper cock, which would give about thirty cubic feet of water above a plane one inch below the crown of the fire-box (the length of the cylindrical part of the boiler is nine feet six inches, and the crown of the firebox is eleven inches below this line.) And the evaporation of the Richmond, as calculated by the Messrs. Norris, from the dimensions of its cylinders, is 525 gallons,=84.24 cubical feet per hour, when running ten miles per hour, with steam of one hundred pounds. To this may be added, according to the opinion of Mr. Kirk, who has great practical experience in these matters, at least fifteen per cent. additional, owing to the condition of the rails, and some additional quantity for the blowing off from the safety valves.
In fact, a carefully conducted series of experiments, upon a very similar engine, tried and recorded long before this accident happened, gave eighty-seven cubic feet as a minimum, and one hundred and thirty-three cubic feet as a maximum, evaporation per hour. While the average of a very extensive series of experiments, made by Mr. Nicolls, the superintendent of the road, with a number of different engines, while they vary very much from engine to engine, give
about one hundred and fifteen cubical feet per hour for engines running at ten miles per hour.
As the Richmond seems to have been engaged in shifting cars for about fifteen minutes before its start, and as the explosion took place about fifteen minutes after it left the depot, the very lowest of these estimates show that its evaporative power was amply sufficient to have reduced the water below the crown of the fire-box, provided the pumps did not work.
What then was the condition of the pumps? It will be recollected that the pumps are beneath the cylinder, and that the pipe leading from the supply valves to the boiler passes between the cylinder and the boiler. All these arrangements are avowedly made for the purpose of keeping the pumps warm when in danger of freezing in cold weather.
That the pumps actually did not work perfectly, there is abundant proof. Thus Mr. Kirk, foreman of the Reading workshops, and Mr. Loeser, a clerk at the depot, both testify that Mr. Ward had several times told them that the pumps did not work well, and that they had given him much trouble."
Mr. Yeager, the engineer of the freight train, which was immediately behind the Richmond when she exploded, testifies to Mr. McCabe's (the conductor's) statement, as to the cause of delay on the Saturday preceding, at the Manayunk tunnel, to which Patrick Nugent, a brakesman upon the train, also testifies; this is, moreover, confirmed by the statement of Mr. Simpson, at the time foreman of the workshops at Richmond, to one of the committee, that he did not see Mr. Ward upon Saturday evening, but that upon inquiring of another engineer, whose train had been behind, as to the cause of the detention, was told that the pumps of the Richmond had given out, and that Ward had to take them to pieces.
Mr. Day, also an engineer upon the road, testifies that Mr. Ward told him, some day of the week preceding the accident, "that his pumps worked badly, and that he never could start them without first unscrewing them, and lifting the caps." He also testifies that he passed the Richmond at Pottsville, upon the day of the accident, that Ward was then just starting, and was engaged in unscrewing the cap of his pump in order to make it work.
Now all those who saw the explosion testify that the engine was running under a heavy head of steam.
Cowden, a brakesman, testifies that "she had a great head of steam, and was blowing it off at the time." Weber, who was standing in his porch says, that "although not very familiar with engines, he could easily perceive that she was working differently from what engines generally work; that she had a very heavy head of steam, and was going fast, and that she appeared to him like an engine trying to go faster than she was able." Mr. Herbst declares that there was a heavy head of steam; and Mr. Gruber, who was standing with him, says that it "had high steam, was making a great noise, and was running faster than he ever saw a coal train go before." Now all this is easily accounted for, if we suppose that, the night
being exceedingly dark, when starting from Reading, Mr. Ward could not tell whether, or not, his pump was in action, the try-cock being nearly the length of the engine from him, and the noise of the empty cars behind him preventing him from hearing the escape. The great increase of the head of steam would at length give him notice, although not until the water had sunk considerably in the boiler. If then he threw on the other pump, and this acted properly, he should have a sheet of water suddenly rising, upon the overheated surface of the crown-plate, and a condition of things existing exactly such as to give rise to a terrible and inevitable explosion.*
This view of the case seems, in the opinion of your committee, to be pointed out by all the circumstances, and suffices to account for all the phenomena which accompanied the explosion.t
The committee, therefore, report that, in their opinion, the explosion of the locomotive Richmond was probably caused by the sudden rise of water over the crown-plate of its fire-box, which had been laid bare by the defective action of the pumps, and had become unduly heated.
NOTE. Since the above report was finished, the committee have had the opportunity, owing to the kindness of Mr. Nicolls and Mr. Baldwin, to see the result of a very similar accident, which occurred upon the Reading Railroad, in an engine built by the latter gentleThe "Hudson" was about the same weight as the Richmond;
a b, the interior of the steam dome; c c, bolts of which the lower parts were sheared off; d d, holes left open by the shearing off referred to; ef, cast-iron bridge-bars as broken; g g, water legs, or sides, of fire-box; h, the fire-box.
The shortness of the bridge-bars would evidently transfer this strain from the surface of the crown plate to the points in which they rested upon it, and thus determine the line of the rupture.
In this connexion it is not to be forgotten that when found, the water was turned on to both the pump pipes of the tender, whereas, it appears, from the testimony of Mr. Kirk, and is well known to all conversant with engines, that one pump, when in action, is more than sufficient to supply the water evaporated.
the bridge-bars were also of cast-iron, but were of greater cross section, and of a less span. This engine, in the absence of her own engineer, was entrusted to one who proved to be not sufficiently cautious, and was left standing upon the track with her valves screwed down "home," and the fire-doors closed, during some detention upon the road. In this case the pressure of the steam broke the cast-iron bridge-bars, and discharged itself by the openings of the stay-bolts, which were driven out, into the fire. The crown-plate of the fire-box was not broken, but was bent inwards to a depth in the centre of five inches.
In this case we see the undoubted agency of steam alone, and the insufficiency of cast-iron as a material for the bridge-bars, while the difference in the intensity of the explosions teaches us the distinction between the effect of a pressure gradually becoming too great for the resistance of the materials, and that of an almost explosive force suddenly generated by water brought in contact and under pressure with highly heated metal.*
The committee have thus ended the task which was entrusted to them, and here perhaps the report should conclude; but we cannot rest satisfied without an endeavor to call the attention of the public to a few points, which, during this investigation, have come prominently under their notice.
In the first place, permit us to draw attention to the total inefficiency of our present system of coroner's inquests. There can be no doubt that had the examination, in this case, been properly and efficiently conducted, much important information upon the subject would have been elicited, which is now forever lost, and much trouble and labor saved in the endeavor to investigate the causes of the explosion; but this subject is without the legitimate province of the Institute, and we pass it with bare notice, to refer to two other points which are entirely within the scope of our powers. In the first place, it has been brought prominently under the notice of your committee, that in consequence of the narrowness of the water-spaces between the fire-box and the outer shell of the boiler, the large engines foam so much, especially when new, that every cock in the upper part of the boiler will indicate water, while the water-spaces are filled with dry steam. In this case the gauge-cocks become worse than useless; they are actually deceptive, while the dangerous state of things around the fire-box requires no comment. Surely our ingenious mechanics will not be at a loss to contrive a remedy for this defect; and, in view of this, the committee would respectfully invite their attention to the new form of boiler devised by Mr. Johnston, and described in the "Practical Mechanic and Engineers' Magazine," vol. ii, p. 407, (September 14th, 1844,) which involves a principle, as
• Since the occurrence of the partial explosion above referred to, we learn with pleasure, that Baldwin & Whitney have returned to their original mode of forming the bridge bars of wrought-iron of suitable dimensions, which, from considerations of economy, they had only abandoned in a few locomotives, after the experiments of other manufacturers with cast iron bridge bars had apparently shown them to be safe.
VOL IX, 3RD SERIES-No. 1.—January, 1845.
it appears to the committee, perfectly fitted to meet the case, especially if the pumps can be made to supply the cold water near the fire-box. The other and last point to which your committee would desire to call attention, is the insufficiency of cast-iron as a material for the bridge-bars, by which the crown of the fire-box is sustained. We are aware that they are not peculiar to any of our manufacturers, but that they have been adopted by more than one of our very best establishments. Their economy is the only excuse alleged in their favor; but though the committee would be sorry to be the cause of increasing, in any degree, the expense of these now almost indispensable machines, they must decidedly protest against weighing a trifling reduction of price in the scale, with the vastly increased risk of life to the engineer and firemen. The committee are glad to learn indirectly, that the officers of the Reading Railroad have already ordered all the cast-iron bridge-bars, in the engines upon their road, to be replaced by others of wrought-iron; and they confidently hope that their example will be followed by other roads, and by all manufacturers, until the very memory of the error shall be obliterated.
By order of the Committee,
WILLIAM HAMILTON, Actuary.
Read October 10; Adopted November 14, 1844.
Questions upon the Explosion of the "Richmond."
1. How long had the Richmond been on the road before it was removed? what maximum load had it carried, and what pressure of steam had it borne?
2. What was the exact objection to the engine, for which it was withdrawn? where was it altered, and how long was it before it again came upon the road?
3. How many trips had the engine made after it was replaced upon the road, before the one during which the explosion occurred? what were its loads, and what pressure of steam had it borne?
4. Had any thing peculiar been remarked in the working of the engine, and if so what?
5. Was there any limit to the pressure to which the safety-valves could be screwed down?
6. At what hour did the engine reach Reading on the evening of the explosion? and what was the state of its steam, and the height of the water in the boiler when it arrived?
7. Did the engine take in fuel and water (or either,) at Reading? and what kind of fuel did the engine use? was a fan of any kind used to increase the draft?
8. How long was the engine detained at the depot? were the firedoors open during this time, and was the steam blowing off?
9. Was the engine detained after leaving the depot, and if so, how long? what was the state of its fires and its steam during this time? what was the pressure of steam?
10. How long, after finally leaving Reading, was it before the explosion took place? and how far was the engine then from Reading?