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four of which were down the road from Pottsville to Philadelphia, drawing an average load of six hundred and five tons, and four were up the road, drawing, on an average, two hundred and thirty-two tons gross. (It will be recollected, that the road is so constructed as to have no ascending grade in the passage from Pottsville to the Falls of Schuylkill: the loads down are generally cars laden with coal, the loads up, the empty cars.) No defect was found in the working of the engine, except that, as will be seen by the evidence, the pumps had been found to give even more trouble than is usual in new engines. The pumps in the Richmond were placed immediately under the steam cylinders, the supply valves being at the forward end of the cylinders, and the check valve at the point where the water enters the boiler, a short distance behind the cylinders. The pipe leading from the supply valves to the boiler passes between the cylinder and boiler: the try-cock is upon this pipe, and just behind the cylinder. On Saturday, August 31st, upon the down trip, it was found necessary to stop the engine near Manayunk, and take the pumps apart; and it will be found, by the testimony of Mr. Day, that upon the very day of the explosion, at Pottstown, Mr. Ward, the engineer of the Richmond, was occupied in unscrewing the caps of his pumps, in order to get them to work.
Upon the 2d of September, the Richmond reached Reading from Philadelphia, at 7h. 18m. P. M. At this time there is every reason to believe, (although there is no direct testimony to this effect, that the water was high in the boiler:—the steam was low, and the valves were not blowing off. At the depot at Reading, the engine took in a supply of fuel, (oak wood) and filled its tank with water. No fan was used upon the engine to increase the draft.
It was detained at the depot sixty-seven minutes, during the latter filteen of which it was shifting cars, and preparing to start; whether the fire doors were left open during this time is not recollected, but when the engine left, the steam was blowing off moderately at both valves, at a pressure of about one hundred and twenty pounds. During the period of the detention of the engine at Reading, a violent thunder storm from the north-west was raging at that place, but before the engine left it had passed off to the south-east, and the rain had so far ceased, that Mr. Ward had laid aside his water-proof overcoat: the night, however, remained exceedingly dark.
After leaving the depot, the engine hauling a load of eighty-eight empty coal cars, (weighing two hundred and eleven tons) passed up the road, through the borough, at the rate of four, or five, miles per hour. Filteen minutes after leaving Reading, and at a distance of 2.02 miles from the depot, the boiler exploded. The time of the explosion is indicated by the stoppage of the conductor's watch, which was crushed in his pocket, by his fall upon the sills. The road at the point at which the explosion took place, runs upon an embankment five feet bigh, and has an ascending grade of six feet per mile. At the exact place of explosion the road is straight, but the train behind lay in a curve of three thousand feet radius.
The condition of things, as found immediately after the explosion,
was as follows:-(The accompanying diagram, kindly furnished by Mr. Nicolls, the superintendent of transportation of the Reading Railroad, will render the description more intelligible.) The road at this point runs nearly north and south; the boiler itself, with its cylinders, dome, and fire-box, was thrown to the north-west, a distance of two hundred and forty-nine feet; its distance in a perpendicular direction west of the centre of the track being seventy-eight feet.
a, spot where the engine exploded; b, body of fireman; c, body of engineer; d, body of fireman; e, body of conductor; $, spot where the engine lodged; h, foot of embankment; i, ditio.
a b, 20 feet; a c, 54 feet; a k, 32 feet; a d, 155 feet; a e, 326 feet; ag, 249 feet; k c, 44 feet; fg, 78 feet; e, to the rail is about 4 feet.
The embankment is five feet high at a, and eleven feet at s ; the line is straight, and rises from a, towards f, at the rate of six feet per mile.
This sketch is not drawn by a scale, though the measurements were taken on the ground.
The boiler was found lying with its cylinders to the north, and its fire-box towards the south, its axis nearly parallel to the track, its dome was downwards, and its safety valve seat broken at its upper edge; the blow, in lighting, had taken effect upon the hinder part of the boiler, and near its right side, and by this blow the fire-box, and the part of the boiler surrounding it, had been driven to the left and front, and very much flattened, so as to present the appearance shown in the accompanying section, made by the draughtsman of the Messrs. Norris. The body of the conductor, who, when the engine left Reading, was sitting upon the sand-box, which is on top of the boiler, and just behind the smoke-pipe, was found lying close upon the east side of the track, at a distance of three hundred and twentysix feet forward, or northward, of the point of explosion; one of the firemen was found upon the track, at a distance of one hundred and fifty-five feet north ward; the body of another fireman was found twenty feet to the south-west; and that of Mr. Ward, the engineer, at a distance of fifty-four feet to the south-east of the position of the engine.
The tcnder was found scarcely damaged, and with the water turned on to both of the engine pumps. The condition of the boiler gave signal evidence of the energy of the force which had caused the accident. The crown of the fire-box had been torn off just inside of its edges, and outside of the ends of the bridge-bars: this rupture appears to have taken place instantaneously all around, except at one point, where the iron had resisted sufficiently long to twist, or fold, the crown at right angles as it fell, so that the bridge-bars were seen, by looking in through the fire doors, in a vertical, instead of a horizontal, position. These bridge-bars, which, as before stated, were of cast-iron, and had a cross section of three and three-fourths inches, by one and seven-sixteenths inch, had broken off at the stay-bolts, and never at the bolt in the middle of the bar, but always at the first, or second, bolt from the ends.
The violence with which the crown was driven down, is indicated by the fact of a rupture of the iron of the front of the fire-box, evidently caused by a fragment of one of the bridge-bars being driven through it from within. (Below this, and to the right of it, another rupture exists in the outer shell of the boiler ; the force which produced this has evidently acted from without in wards, and it doubtless was caused by the fall, as it exists in that part which first struck the ground.) The rivets by which the plates of the fire-box were connected, are cut off as smoothly as wax would be by a pen-knife, and this is the case also with some of the screw-bolts, by which the footboard was suspended from the boiler; the copper tubes, or flues, of the boiler were good, with the exception of one, or two, which had been bent, and slightly broken at the fire-box end, and the existence of a slight incrustation upon them, showed that they had not, at least for any length of time, been heated to a temperature much above that usual in a locomotive boiler.
The cylinders and accompanying valves were still good; the framing of the engine, and the stays, or knees, by which it was supported upon the frame, were broken, and the connexions of the engine broken and twisted exceedingly. The ash-pan had been driven down upon the track with such force as to mould itself over one of the sills of the road, whilst its upper surface was marked by the indentations made by the grate-bars when driven down upon it. The foot-board was also much torn by the violence with which it had been driven downwards. The rails of the track, upon which the engine was running, were spread outward; the rails of the opposite track were broken in two places; the leading wheels of the engine are marked each by a deep cut in the flange, and one had a portion of its tyre cut out as though by a plane.
In reference to the quality of the materials of which the engine was made:
As the outer shell of the boiler had suffered no fracture, except where it was battered and ruptured by the fall, the committee had no hesitation in assuming both its materials and its construction to be good. The iron of the fire-box was found to be very much laminated, dividing into four, or five, distinct and entirely separate layers, as the accompanying specimens will show. The fractures of the pieces broken by the committee, were not indicative of an excellent material, but as we possessed the means of ascertaiving the actual tensile strength, we were, of course, not satisfied without submitting it to that test. Accordingly, four pieces were taken from the crown sheet of the fire-box immediately along side of the line of fracture, two of which were cut in the direction of the grain of the iron, and two against it. These pieces were reduced, by filius, to a proper cross section, and placed in the apparatus belonging to the Franklin Institute, when the breaking weights were found to be as follows: 1 Across the grain, ŞBreaking weight 51.120 lbs. pr. sq. in.
50.280 No. 4,5
51.120 Average of No. 1, and No. 2,
53.220 No. 3, and No. 4,
50.700 the four pieces,
51.860 The fracture in each case was fibrous, (the weight having been applied very gradually,) but it was dull. It will be observed, that since the rupture took place, in the short space between the bend of the edge of the plate, and the ends of the bridge-bars, the iron was not, in fact, subjected to a force in the direction of its length, but to a twist and cross strain, which might cause it to yield to a less force than that stated above. Two other pieces of the iron, in the possession of the Messrs. Norris, have suffered themselves to be bent double, the one while hot, and the other when cold, without indicating any signs of fracture.
The bridge-bars, by which the crown of the fire-box was supported, were made of cast-iron, and had a cross section (as before stated,) of
No. 3,1 With the grain,
33 inches by 1: = 5.4 square inches; but this cross section was somewhat diminished at the stay-bolts, at which they broke. They had a span of forty inches, and were slightly arched, and their operation would, in consequence, be to transfer the whole strain upon the upper surface of the fire-box, to the points at which they rested upon the crown. The iron of which they were made, was, as will be seen by the specimens, very soft, and dark gray.
The committee believe, from the fact, that not a single portion of the joints had given way, except where the rivets had been shorn off by the lateral expansion, and from the general appearance of the remains of the engine, when examined, that it will, on all hands, be admitted, that the workmanship of the boiler was such as to sustain the reputation which the Messrs. Norris have acquired in their business; and it is evident that the experiments, cited above, refute any supposition of insufficient strength in the crown plate—the laminated structure of which is one of those contingencies, against which the most careful precautions are not always sufficient to guard.
It is not then to weakness of materials, or defects in the manufacture of the boiler, that we are to look for the cause of this explosion: the committee believe that the strength of the engine would have proved adequate to any working pressure which could have been placed upon it
On the other hand, the engineer, Mr. Joseph Ward, was reputed one of the most capable and trustworthy upon the road, and his character for carefulness and sobriety was such as to forbid the suspicion of any inproper tampering with the valves: we have besides evidence that the valves were free.
The whole results of the explosion moreover seem to indicate, not the slow and gradual rise of the pressure of the steam to a force which the engine was unable to bear-a force, be it remarked, not easily obtained upon a well built engine while in motion—but rather the action of a force of great intensity, and generated with such explosive suddenness as to render the safety valves and cylinders of the engine useless as means for giving it vent.
In the first accounts of this explosion much stress was laid upon the fact of its having occurred during a thunder-storm, and the agency in the accident has been attributed to electricity; but in what manner it may be conceived to have acted; whether by heating the boiler, or the steain, within it, or in what other way it increased the tension of the steam, or diminished the strength of the material, the committee cannot conjecture. If there are any experiments, or observations, on record, tending to show the power of electricity to produce such effects in a good continuous conductor, as a locomotive engine, running too, be it observed, upon a wet rail, the committee are in ignorance of them; and, independently of this, the evidence to the contrary is as plain as could be desired.
In the testimony before the coroner, two of the brakesmen, Powell and Cowden, declare that they saw lightning previous to the explosion : Powell says,—“I saw a flash of lightning previous to the explosion, but I could very easily see between the flash and the explo