Part 8

Marine Multitubular, 5ft. 8in. long, and 6ft. 6in. diameter, with two internal tubular furnaces, which joined to an internal chamber of large size, and small tubes passed to a smoke box and chimney in the front over the fire doors. Both ends were flat.

The flat back end was insufficiently stayed, and was blown completely out and torn into two pieces, the lower portion remaining in the vessel, and the upper part falling in the water, and the reaction of the issuing contents caused the boiler to be thrown on to the side of the quay.

_No. 46. Hull. (Fig. 21.) August 25th. 1 injured._

One Tube Cornish, 24ft. 3in. long, and 6ft. diameter, taper tube 3ft. 5in. diameter, for about 7ft. 6in. in length, and 2ft. 6in. diameter for the rest of the length, 33 lbs.

The tube was much corroded, and the fireplace gave way on left side, and was so much torn, that the plates were forced out of the front.

_No. 47. Morecombe. August 27th. 3 killed, 1 injured._

Marine, of the usual construction, and had been tested to 60 lbs.

It gave way at the lower portion of the back, and the issuing steam and water scalded those near.

A seam rent, 6ft. 6in. long, had not been detected by testing.

_No. 48. Tuddenham. August 29th. 2 killed, 2 injured._

Agricultural. It burst during a temporary stoppage from accumulation of steam, causing undue pressure.

_No. 49. Glasgow. August 31st. 3 killed, 6 injured._

Upright Boiler, 36ft. high, 5ft. 6in. diameter, 7/16 inch plates, 45 lbs.

The bottom gave way from shortness of water, and the main bulk of the boiler was thrown straight up into the air to a great height, but descended again on its seating.

_No. 50. Chatham. (Fig. 22.) September 7th. 2 killed, 30 injured._

Two Tube Cornish, 22ft. long, 7ft. 6in. diameter, with tubes, 3ft. diameter, 7/16 inch plate, 60 lbs.

Some rents took place at the under side of the shell, allowing the central portion to open out and blow away. The portion containing the dome was thrown to the left, and the other to the right. The front end, with 3 rings of the shell, with the tubes and back end, were but little moved from their original position. The tubes were dented in on the top and bottom, by the fall of some large coping stones upon them, but the crowns of the furnaces were uninjured, and there was no sign of shortness of water or overheating.

Extensive corrosion on the under side of the shell, where it rested on the brickwork, had so reduced the strength, that it was unable to bear the working pressure.

In the sketch the fragments are drawn so as to show their position when in the boiler.

_No. 51. Newark. September 21st. none injured._

One tube Cornish. The tube collapsed from shortness of water, and the escape of the steam and water blew off the door frame.

_No. 52. Ashton. September 23rd. 1 injured._

Plain Cylindrical Boiler, 7ft. long, and 2ft. diameter, 3/8 inch plates, 30 lbs.

The upper part of the boiler at the first ring of plates was torn off, and the front end was blown out.

Extensive external corrosion, where the plates rested against the brickwork, rendered the boiler too weak to bear the ordinary pressure.

_No. 53. Norwich. (Fig. 23.) September 25th. 7 killed._

One Tube Cornish, 20ft. long, 4ft. 6in. diameter, tube 2ft. 6in. diameter, 3/8 inch plates, 100 lbs. It was double-rivetted, and the crown of tube was strengthened with angle iron. The shell was formed of six rings, each of two plates alternately jointed top and sides. The third ring from the front had stripped off, and was thrown to the right and forwards against a wall. The line of rent was confined to the plates forming the ring, which was an outer one, and covered the two adjoining rings in the laps, the rent being from the edge of the inner lap to the nearest rivets. The first rent had taken place in the solid iron, about 1 inch from the rivets of a seam on one side, and from this the rent had extended along the seams on either side, and of course the whole ring soon tore off when the equilibrium was destroyed by the first rent.

The fittings of the boiler were sufficient, except that there was only one safety valve, and that was so constructed that it could only open a very little way.

The cause was a defect in the iron at the point of the first rent, and accumulated pressure during the time of standing.

_No. 54. Macclesfield. September 25th. none injured._

Multitubular Boiler, with large internal fireplace, 60 lbs.

The furnace crown became overheated from shortness of water, and was crushed down and torn across two seams. The boiler was lifted from its seat and thrown back against a stone wall.

_No. 55. Chelmsford. October 5th. 1 killed, 7 injured._

Agricultural, 45 lbs., and had only just been set to work.

The crown plate to the fire-box was so deeply corroded from long wear that it gave way, and the issuing contents scalded those near.

_No. 56. Greenwich. (Fig. 24.) October 8th. 2 killed, 2 injured._

Marine, 16ft. long, slightly oval, front end flat, 8ft. 6in. wide, 7ft. 10in. high, and the dimensions of the back hemispherical end were 2ft. less each way, 3/8 inch plates, 26 lbs. There were two internal fireplaces, of irregular shape, uniting at the back into one flue of similar shape, which did not come to the front, but passed through the steam space, and out at the top of the boiler.

While the vessel was waiting to start, with steam up, the wing furnace of the starboard boiler collapsed on the wing side, as shown by the dotted lines, and allowed the steam and water to escape into the stoke hole.

The side of the furnace next the shell was rent along the edge of a longitudinal seam in a line, which was slightly nicked in the caulking. This rent extended about 5ft. 6in. from the front, and then at a cross seam it went along the line of rivets from the crown to the bottom of the furnace. Beyond this cross seam the furnace was collapsed, until it nearly touched the other side of the furnace, and the bulge died away towards the back end. There was also a rent in the lower part of the front of the shell, as shown in dotted line.

The cause of the explosion was the weakness of the shape of the flue, which was not stayed to the shell. It had evidently gradually been giving way some time before the explosion, and eventually collapsed at nearly the ordinary pressure. Symptoms of the same alteration of shape were noticed in the corresponding flue of the other boiler.

_No. 57. Liverpool. (Fig. 25.) October 9th. 7 killed, 1 injured._

Crane Boiler, 5ft. 6in. high, and 2ft. 6in. diameter, with internal conical fire-box, with two cross tubes and a chimney at the top, 1/4 inch plates, 75 lbs.

The outer shell of the boiler was rent into many pieces, leaving the central conical fireplace intact. The nature of the rents showed that the plate round the manhole, which was unstrengthened by a ring, had first given way, and all the other fractures had led away from that point. This is confirmed by the fact, that the manlid was thrown a good distance, with force enough to make its way through the timber walls of a cabin. The front plate divided into many pieces, and scattered right and left, while the back plate was thrown through a cabin in the opposite direction to the manhole.

The central flue showed a slight indication of overheating, but the construction was such that the upper portion passed through the steam space, and was always exposed to the action of the fire, without the protection of the contact of water. The manhole without a ring on its edge to strengthen the plate, and held in by two clamps, which caused additional strain when carelessly screwed up, was by far the weakest place. The engine was standing after a short time of working, and as the safety valve was very defective, and could be screwed down until tight, against almost any pressure, it is most probable that the pressure mounted much higher than usual, when the weakest part gave way, and led to the sudden tearing up and scattering of the whole fabric.

Faulty construction of both boiler and fittings, rendered it unable to bear that accumulated pressure, which the safety valve ought to have made impossible.

_No. 58. Durham. October 13th. 1 killed._

One Tube Cornish, 14ft. long, 6ft. diameter, internal flue 3ft. 3in., by 2ft. 10in., 3/8 inch plates, 27 lbs., standing on three saddles, with a bearing surface of 3ft. by 4 inches.

A portion of plate 20in. by 18in., at the bottom of the boiler, was so corroded that it was blown out, and the issuing contents scalded a man to death.

_No. 59. Bristol. (Fig. 26.) November 1st. 7 killed._

Two Marine Boilers exploded simultaneously. They were 16ft. long, 6ft. 6in. diameter at the flat front ends, and somewhat less at the hemispherical back ends. Each had two internal fireplaces, united in one flue, which returned nearly to the front and passed up through the steam space, and out at the top of shell into the funnel. The central fireplaces were not circular, and the outside fireplaces and the return flues were still more distorted, but the weakness of the shape was somewhat compensated for by stays between the tubes, and from the tubes to the shell. The mountings to the boiler were of the ordinary kind and efficient.

The under sides of the shells were so deeply corroded that they were rent longitudinally for their whole length, allowing the sides to open out and tear away from the front ends. Each shell fell at a considerable distance. The furnaces, with parts of the front ends attached, fell into the water, but except one of the side flues that was a little collapsed, they were uninjured. Small pieces of the front ends were thrown to a great distance. The sides of the vessel were so completely blown out that she sank.

The corrosion was no doubt caused by the leakage of the vessel, keeping the shells of the boilers constantly wet.

_No. 60. London. (Fig. 27.) November 3rd. none injured._

Agricultural, barrel was 3ft. 9in. long, and 2ft. 6in. diameter, 70 lbs. From the internal fire-box the heat passed through a number of 1-inch tubes to the front smoke box and chimney.

During a stoppage for breakfast, the fire-box end was torn from the barrel, and from the position of those fragments that could be found, the boiler appeared to have turned over. Part of the fire-box was sent through the stage upon which the boiler was travelling, and the barrel with the tubes remaining in it, first struck a rail which caused it to be dented in, and then rebounded to a point about 100 yards from its original position.

Enough of the fragments were not recovered from the river to trace the cause of the explosion, but it is presumed that, although when the boiler was left, only 20 lbs. pressure was shown by the gauge; the fire door being left closed, the pressure must have risen to a point much above the working pressure, and to more than the boiler could bear.

_No. 61. Bilston. (Fig. 28.) October 1st. none injured._

One Tube Cornish, 22ft. long, 6ft. diameter, tube 4ft. 6in. diameter, 3/8 inch plates, 12 lbs. There was an unusually large dome at the back end, 5ft. diameter, and the whole of the shell was cut out from under it, so that the construction was peculiarly weak.

The boiler had been off for cleaning, and steam was being got up in the night, and it was said that an extra pressure was caused by the stop valve being left closed, but it could not have been very great, or the large tube would have collapsed.

The dome was split in two, in the line marked in the sketch, owing to the extreme weakness of the shell at the juncture of the dome, and the shell was a little ruptured on each side of it, and so large a rent was suddenly made, that the contents of the boiler passed harmlessly into the air, without moving the boiler on its seat.

_No. 62. Preston. (Fig. 29.) November 11th. 1 killed, 1 injured._

One Tube Cornish, 16ft. 3in. long, and 5ft. 8in. diameter, tube 3ft. 1in. diameter, 7/16 inch plates, 60 lbs.

The tube collapsed from end to end, from over-pressure, as the man in charge had fastened 3 bricks to the lever of the safety valve causing 27 lbs. extra pressure, under the impression that he could thus accumulate a quantity of steam during the night, to be available on commencing work on the morrow.

_No. 63. Tamworth. (Fig. 30.) November 20th. none injured._

Revolving Steam Chamber, 12ft. 6in. long, and 5ft. diameter, 12 lbs.

The manhole was large, to facilitate filling and emptying, and was rectangular and unstrengthened on the edges, and measured 3ft. 6in. in length, and 1ft. 6in. in width, and the lid fitted on the inside and was held by clamps.

The boiler was much out of repair, and a crack shown in sketch, from one corner of the manhole to the commencement of the hemispherical end was only temporarily prevented from leaking by a screw-patch, which did not restore the strength.

The explosion happened when in revolving, the manlid was downwards, and the lid was driven nearly through the floor, and the shell was rent from opposite corners of the manhole, and blown through the roof.

The large manhole cut away nearly all the strength on one side, and the fastenings of the lid were not contrived to compensate at all for the loss of strength. The constant strain when revolving, also tended to weaken it. These two causes together were sufficient to account for the explosion, at the usual working pressure of 12 lbs., although it is possible that it might have been increased to 35 lbs., as that was the pressure in the boiler supplying the steam, although the pressure was regulated by a check valve.

This explosion (and also No. 41 in this year) clearly show that a mere vessel of steam not exposed to the fire, or any chance of overheating of the plates, can burst and cause very great destruction, although there could be no sudden _increase of pressure_ which is so often supposed necessary to account for the havoc caused by explosions.

_No. 64. Manchester. November 26th. none injured._

This Boiler was 28ft. long, 7ft. diameter, made of 7/16 inch plates, and worked at 50 lbs. pressure, with two internal fireplaces united into one tube beyond.

The sides of the oval chamber forming the junction of furnaces and tube, crushed inwards, being of such a weak shape as to be unable to resist the ordinary working pressure.

_No. 65. Hull. (Fig. 31.) December 1st. 3 killed, 2 injured._

Agricultural, 7ft. 6in. long, and 3ft. 8in. diameter, 1/4 inch plates, 35 lbs., fire-box 2ft. long, and 2ft. 10in. broad. Two 11-1/2-inch tubes led to an internal chamber at the other end of the boiler, and three 8-1/4-inch tubes led back again to an external smoke box and chimney fixed over the fire door.

The bottom of the right hand side lower tube was forced upwards, and rent along to within 12 inches of the fire-box.

The tubes were so corroded from leakage of patches, that they were unable to bear the slight increase of pressure during a short stoppage.

_No. 66. Glasgow. December 4th. 2 killed, 6 injured._

Two Tube Cornish, 22ft. long, and 7ft. 6in. diameter, tubes 3ft. diameter, and strengthened with rings in the approved manner.

The second from the back of the seven rings, was ruptured at the bottom and torn off by a rent through the line of rivets on each side, and the boiler was thrown from its seat, and turned completely over, so as to lie in a contrary direction to what it was before.

Extensive corrosion, from leaking of the seams beneath the brickwork, where hidden from view, was the cause of explosion.

_No. 67. Willenhall. December 7th. none injured._

Plain Cylinder, with hemispherical ends, 9ft. long, 3ft. 3in. diameter, 20 lbs.

The boiler was rent all along one side, and the reaction of the issuing contents caused it to be thrown some yards away, and one of the ends became altogether detached, and flew to a considerable distance.

The plates were so thinned by corrosion, that they gave way on a very slight increase of pressure during a temporary stoppage of the engine.

_No. 68. Glasgow. December 12th. 1 killed, 1 injured._

This Boiler was 14ft. long, with hemispherical ends, and 7ft. diameter, 30 lbs.

The cause of the explosion was over-pressure and thinness of plates, wasted by corrosion.

_No. 69. Manchester. (Fig. 32.) December 15th. 5 injured._

Two Tube Cornish, 24ft. long, 6ft. 6in. diameter, tubes 2ft. 8in. diameter, 7/16 inch plates, 50 lbs. The boiler was fired in each of the tubes in the ordinary way, and also the heat from two furnaces passed from the back, one on each side of the outside shell.

Both the internal furnaces collapsed, until the crowns almost touched the fire bars, as shown in dotted lines, but without fracture. The back of the shell, on the right side, had evidently been overheated, and had rent along the centre of a bulge, and this rent had extended along the line of rivets of the transverse seam on each side, allowing two rings of the plates of the shell to open out flat as shown. There was a bulge on the plate, on the right side of shell, corresponding with the one which parted on the opposite side.

The cause of the explosion was overheating of the plates from shortness of water.

_No. 70. Aberdeen. December 24th. 1 injured._

No particulars have been obtained.

BOILER EXPLOSIONS IN 1867.

_No. 1. Hull. January 2nd. 1 killed, 1 injured._

A small Boiler to heat a bath. It exploded, causing great damage, because the connecting pipes were frozen. All such boilers should have a proper safety valve.

_No. 2. Durham. (Fig. 1.) January 2nd. 3 killed, 3 injured._

Plain Cylinder, 33ft. long, 6ft. diameter, 33 lbs. pressure. Only set two days, but was old and deteriorated, and had worked before at another place. It had been turned 1/4 round, and old fitting-holes stopped. First rent was supposed to be in a seam at front end, over the fire. Main portion of shell was driven back, and front end forward, and torn in its flight. The cause of explosion was, that the seam in front was overheated and injured, and also incautious working without a steam gauge.

_No. 3. Sheffield. (Fig. 2.) January 2nd. 1 killed, 4 injured._

One Tube externally fired, 30ft. long, 6ft. 6in. diameter, with dished ends. Tube 2ft. 9in. diameter, slightly oval. Pressure 60 lbs. Tube collapsed sideways from end to end, because it was not strengthened by hoops or other means, which were the more needed, because it was slightly oval, and the longitudinal seams were nearly in one line.

_No. 4. Preston. January 3rd. 1 killed._

Boiler for heating apparatus. Fire was lighted without noticing that as there was no safety valve, and that all escape of steam was prevented by the connecting pipes being frozen.

_No. 5. Westerham. January 5th. 1 killed._

Cast-iron Boiler for heating water for a horse shower bath, fixed behind an ordinary fireplace. Burst and caused great damage, owing to the pipes being frozen. There was no safety valve.

_No. 6. Barr. January 9th. 1 killed, 3 injured._

Kitchen Boiler, which burst because the supply pipes were stopped by frost, and there was no safety valve.

_No. 7. London. January 11th. 1 killed._

Cornish, 12ft. long, 4ft. 6in. diameter, tube 2ft. 4in. diameter, pressure 40 lbs. Small piece of plate was blown out near the bottom, and the boiler was displaced by the reaction of issuing contents. The cause of explosion was extensive external corrosion on the lower part.

_No. 8. Preston. January 16th. none injured._

Kitchen Boiler. Burst and did great damage, because pipes were frozen preventing escape of steam. There was no safety valve.

_No. 9. Brechin. January 23rd. 1 killed._

Kitchen Boiler. Fire had been out some days, and the boiler burst soon after re-kindling it and did much damage, because the supply pipes were stopped by frost, and there was no safety valve for escape of steam.

_No. 10. Sunderland. (Fig. 3.) January 26th. 3 injured._

Plain Cylinder, 30ft. long, 6ft. 2in. diameter. Pressure 30 to 35 lbs. Rent into four pieces, which were flattened out and scattered on to other boilers, but are arranged in sketch so as to show their original position in the boiler. It had worked a very long time, and was overheated and injured along the fractured line.

_No. 11. Exeter. (Fig. 4.) January 30th. 2 killed, 2 injured._

Elephant Boiler, 16ft. long, 5ft. diameter, tubes 1ft. 10in. diameter, 45 lbs. pressure. Flat end blew out, throwing boiler upwards by reaction, but shell and tubes were not injured. The flat end was not sufficiently stayed, having only one stay-rod to the centre, the bolt of which was broken.

_No. 12. Glasgow. February 8th. 1 killed, 4 injured._

Small Boiler to 6-horse power engine. Gave way at centre of furnace, and water forced out at both ends, and it was suspected that the water was low.

_No. 13. Sheffield. (Fig. 5.) February 11th. 4 injured._

Cornish, about 30ft. long. Tubes 3ft. unstayed. Tube collapsed sideways, and was rent from grate bars to end, without injuring front plates or shell. It was said to be short of water, but most likely the true cause was the weakness of the tube.

_No. 14. Manchester. February 15th. none injured._

Two flued, 28ft. long, 6ft. 9in. diameter, slightly oval; plates 3/8 inch; tube 2ft. 8in. diameter, pressure 45 lbs. Shell had once been externally fired. Rent along the seams which were in one line, and a large piece of the plate blew away, leaving tubes uninjured. The cause of explosion was defective form and worn out state of shell.

_No. 15. Weymouth. (Fig. 6.) March 12th. 1 killed, 3 injured._

Agricultural, 45 lbs. pressure. Fire-box blew off, and the outer shell separated from it. The cause of explosion was over-pressure from the safety valve being screwed down.

_No. 16. Lynn. (Fig. 7.) March 19th. 8 killed, 4 injured._

Agricultural, 45 lbs. pressure. Fire-box and tubes blew out. The cause of explosion was over-pressure, as the safety valve was tied down with string.

_No. 17. Blackbraes. March 23rd. 3 killed, 1 injured._

Colliery Boiler, 30 lbs. pressure. Rent in two while the engine was standing, but no details obtained.

_No. 18. Barnsley. (Fig. 8.) March 29th. 2 killed, 2 injured._

Small plain Cylinder, with ends nearly flat, 4ft. 7in. long, 2ft. 4in. diameter, plates 3/16 inch. No emptying plug or feed-pipe, and only a very small hand-hole. Front end attached by slight angle iron, which gave way, leaving the shell unmoved. The cause of explosion was the internal corrosion of front end owing to very bad water being used. The plates were reduced to a knife edge in line of fracture.

_No. 19. Cornwall. (Fig. 9.) April 10th. 1 killed, 1 injured._

Cornish, one tube 32ft. long, 6ft. diameter, tube 3ft. 10in. diameter, plates 3/8 inch, pressure 25 to 40 lbs. It was 20 years old, but just repaired and reset. Furnace tube failed and collapsed from one end to the other, except about 4 feet of front, owing to its weakness, being unstrengthened by hoops or cross tubes.