Part 6

2. That no form of boiler, however well constructed and fitted, is free from the liability to explosion, if allowed to get out of order; and that boilers which bear the hydraulic test may still be dangerous.

3. That the condition of a boiler can be satisfactorily ascertained only by periodical examinations, and that no boiler should work without being thoroughly examined at short intervals.

4. That the cost of periodical examination is so little as to be far outweighed by the greater security obtained; and that the settings of all boilers should be constructed with a view to facilitate examination.

5. That the surest way to make systematic examination general is to spread as widely as possible correct information as to the facts and ascertained causes of boiler explosions, and to inform boiler owners and minders what dangers to guard against; and that this is preferable, and more likely to lessen explosions than enforcing any system of inspection by legal enactment.

TABLE I.

_Summary of Records of Steam Boiler Explosions_ _up to 30th June, 1870,_ _showing Description of Exploded Boilers._

+------------------++-----------------------++-----------------------+ | Description of || Explosions up to June || Explosions in the 4 | | Boiler. || 1866. || years from June 1866 | | || || to June 1870. | + |+--------+--------+-----++--------+--------+-----+ | ||English.|Foreign.|Total||English.|Foreign.|Total| +==================++========+========+=====++========+========+=====+ |Marine || 57 | 203 | 320 || 12 | 64 | 76 | +------------------++--------+--------+-----++--------+--------+-----+ |Cornish, || 140 | 1 | 141 || 84 | 3 | 87 | |Lancashire, or || | | || | | | |others with || | | || | | | |internal flues || | | || | | | +------------------++--------+--------+-----++--------+--------+-----+ |Locomotive || 91 | 29 | 120 || 10 | 68 | 78 | +------------------++--------+--------+-----++--------+--------+-----+ |Plain Cylindrical || 114 | 2 | 116 || 54 | 3 | 57 | |externally fired || | | || | | | +------------------++--------+--------+-----++--------+--------+-----+ |Balloon, || | | || | | | |Haystack, Wagon, || 62 | 2 | 64 || 5 | 2 | 7 | |Butterley, || | | || | | | |British-Tube || | | || | | | |Elephant, or || | | || | | | |Trevithick || | | || | | | +------------------++--------+--------+-----++--------+--------+-----+ |Portable, || | | || | | | |Agricultural, || 28 | 1 | 29 || 17 | 17 | 34 | |Upright, Crane, || | | || | | | |or very small || | | || | | | +------------------++--------+--------+-----++--------+--------+-----+ |Heating, Kitchen, || 14 | .. | 14 || 22 | 14 | 36 | |Domestic, Rag || | | || | | | |Steamers, &c. || | | || | | | +------------------++--------+--------+-----++--------+--------+-----+ |Furnace-upright || 10 | .. | 10 || 8 | .. | 8 | +------------------++--------+--------+-----++--------+--------+-----+ |Not sufficiently || 203 | 29 | 232 || 7 | 175 | 182 | |described to be || | | || | | | |classified || | | || | | | +==================++========+========+=====++========+========+=====+ |Totals || 719 | 327 |1046 || 219 | 346 | 565 | +------------------++--------+--------+-----++--------+--------+-----+

TABLE I (continued)

+------------------++--------------------------+ | Description of || Total Explosions | | Boiler. || up to June, 1870. | | |+--------+--------+--------+ | ||English.|Foreign.| Total. | +==================++========+========+========+ |Marine || 69 | 327 | 396 | +------------------++--------+--------+--------| |Cornish, || 224 | 4 | 228 | |Lancashire, or || | | | |others with || | | | |internal flues || | | | +------------------++--------+--------+--------+ |Locomotive || 101 | 97 | 198 | +------------------++--------+--------+--------+ |Plain Cylindrical || 168 | 5 | 173 | |externally fired || | | | +------------------++--------+--------+--------| |Balloon, || | | | |Haystack, Wagon, || 67 | 4 | 71 | |Butterley, || | | | |British-Tube || | | | |Elephant, or || | | | |Trevithick || | | | +------------------++--------+--------+--------+ |Portable, || | | | |Agricultural, || 45 | 18 | 63 | |Upright, Crane, || | | | |or very small || | | | +------------------++--------+--------+--------+ |Heating, Kitchen, || 36 | 14 | 50 | |Domestic, Rag || | | | |Steamers, &c. || | | | +------------------++--------+--------+--------+ |Furnace-upright || 18 | .. | 18 | +------------------++--------+--------+--------+ |Not sufficiently || 210 | 204 | 414 | |described to be || | | | |classified || | | | +==================++========+========+========+ |Totals || 938 | 673 | 1611 | +------------------++--------+--------+--------+

TABLE II.

_Summary of Records of Steam Boiler Explosions_ _up to 30th June, 1870,_ _showing Causes of Explosions._

+-----------------++------------------------++------------------------+ |Cause of || Explosions up to June || Explosions in the 4 | |explosion. || 1866. ||years from June 1866 to | | || || June 1870. | | |+--------+--------+------++--------+--------+------+ | ||English.|Foreign.|Total.||English.|Foreign.|Total.| +=================++========+========+======++========+========+======+ |Worn out, || 92 | 53 | 145 || 89 | 5 | 94 | |corroded, or || | | || | | | |burnt plates || | | || | | | +-----------------++--------+--------+------++--------+--------+------+ |Undue pressure, || 132 | 5 | 137 || 25 | 6 | 31 | |overloaded || | | || | | | |valves, || | | || | | | |intentional or || | | || | | | |from carelessness|| | | || | | | +-----------------++--------+--------+------++--------+--------+------+ |Bad || 136 | 108 | 244 || 69 | 8 | 77 | |construction, || | | || | | | |weak tubes, || | | || | | | |defective || | | || | | | |fittings or || | | || | | | |stays, or want || | | || | | | |of repair || | | || | | | +-----------------++--------+--------+------++--------+--------+------+ |Shortness of || 106 | 8 | 114 || 28 | 2 | 30 | |water, formation || | | || | | | |of scale or mud, || | | || | | | |or external || | | || | | | |flues set too || | | || | | | |high || | | || | | | +-----------------++--------+--------+------++--------+--------+------+ |Extraneous || 6 | 3 | 9 || 2 | .. | 2 | |causes, || | | || | | | |lightning, fire, || | | || | | | |gas, &c. || | | || | | | |-----------------++--------+--------+------++--------+--------+------+ |Too uncertain to || 247 | 150 | 397 || 6 | 325 | 331 | |be classified || | | || | | | |=================++========+========+======++========+========+======+ |Totals || 719 | 327 | 1046 || 219 | 346 | 565 | +-----------------++--------+--------+------++--------+--------+------+

Table II (continued)

+-----------------++------------------------+ |Cause of || Total Explosions up to | |explosion. || June 1870. | | || | | |+--------+--------+------+ | ||English.|Foreign.|Total | +=================++========+========+======+ |Worn out, || 181 | 58 | 239 | |corroded, or || | | | |burnt plates || | | | +-----------------++--------+--------+------+ |Undue pressure, || 157 | 11 | 168 | |overloaded || | | | |valves, || | | | |intentional or || | | | |from carelessness|| | | | +-----------------++--------+--------+------+ |Bad || 205 | 116 | 321 | |construction, || | | | |weak tubes, || | | | |defective || | | | |fittings or || | | | |stays, or want || | | | |of repair || | | | +-----------------++--------+--------+------+ |Shortness of || 134 | 10 | 144 | |water, formation || | | | |of scale or mud, || | | | |or external || | | | |flues set too || | | | |high || | | | +-----------------++--------+--------+------+ |Extraneous || 8 | 3 | 11 | |causes, || | | | |lightning, fire, || | | | |gas, &c. || | | | |-----------------++--------+--------+------+ |Too uncertain to || 253 | 475 | 728 | |be classified || | | | |=================++========+========+======+ |Totals || 938 | 673 | 1611 | +-----------------++--------+--------+------+

TABLE III.

_Analysis of Steam Boiler Explosions in the United Kingdom_ _during the Four years ending 30th June, 1870,_ _showing the Causes of Explosion of Boilers of different descriptions._

A = Faults in construction or repair. B = Faults which should be detected by periodical examination. C = Faults which should be prevented by careful attendants. D = Causes extraneous or uncertain. E = number of Explosions. K = number of persons Killed. I = number of persons injured.

CORNISH, LANCASHIRE, _or other Boilers with internal flues_.

_E_ _K_ _I_ {Weak Tubes 26 17 41 {Weak combustion chambers 5 8 7 A {Weak ends 3 10 10 {Weak dome 1 0 0 {Weak manhole 1 1 1 {Bad repair 3 5 2 _E_ _K_ _I_ ------------ 39 41 61 B {External Corrosion 18 42 101 {Internal Corrosion 6 4 5 ------------ 24 46 106 {Shortness of Water 14 11 23 C {Scale of mud 3 1 0 {Undue Pressure 4 14 4 ------------ 21 26 27 _E_ _K_ _I_ ------------ 84 113 194

PLAIN CYLINDRICAL, _or other Boilers without internal flues_.

_E_ _K_ _I_ {Weak flat ends 8 9 12 {Weak manhole 1 0 2 {Frequent repair producing } A { seam rip in boilers with } 15 18 28 { plates arranged lengthways} {Do. with plates arranged in } { rings } 8 11 25 ------------ 32 38 67 B {External Corrosion 11 5 19 {Internal Corrosion 5 5 6 ------------ 16 10 25 {Shortness of Water 2 1 0 C {Scale 1 1 0 {Undue pressure 3 4 3 ------------ 6 6 3 ------------ 54 54 95 ------------

MARINE BOILERS.

_E_ _K_ _I_ {Weak flues 3 6 3 A {Weak ends 2 6 5 {Bad material 1 3 _E_ _K_ _I_ ------------ 6 15 9 B {External Corrosion 2 10 3 {Internal Corrosion 3 1 4 ------------ 5 11 7 C Shortness of water 1 11 7 ------------ 1 11 7 ------------ 12 37 23

LOCOMOTIVE BOILERS.

A Boiler used as frame for engine 2 1 2 ------------ 2 1 2 B {External Corrosion 2 1 4 {Internal Corrosion 2 0 3 ------------ 4 1 7 {Broken connecting-rod } D { pierced boiler } 1 2 1 {Dome caught by railway bridge } 1 1 0 {Uncertain causes } 2 0 4 ------------ 4 3 5 ----------- 10 5 14

AGRICULTURAL BOILERS.

A Weak manhole 1 1 4 ------------ 1 1 4 B {External Corrosion 2 3 3 {Internal Corrosion 1 1 7 ------------ 3 4 10 C {Shortness of water 1 0 0 {Undue pressure 6 15 15 ------------ 7 15 15 ----------- 11 20 29

FURNACE UPRIGHT BOILERS.

{Too much flame on one part 1 2 0 A {Frequent repair producing } { seam rip } 1 13 2 ------------ 2 15 2 B {External Corrosion 2 13 11 {Internal Corrosion 2 15 6 ------------ 4 28 17 C Shortness of Water 2 3 8 ------------ 2 3 8 ----------- 8 46 27

ELEPHANT BOILERS.

A Weak ends or want of stays 1 2 2 ------------ 1 2 2 B External Corrosion 1 0 4 ------------ 1 0 4 ----------- 2 2 6

CRANE BOILERS.

_E_ _K_ _I_ A Weak manhole 3 7 3 _E_ _K_ _I_ ------------ 3 7 3 B External Corrosion 1 4 2 ------------ 1 4 2 C Shortness of water 2 2 0 ------------ 2 2 0 ----------- 6 13 5

RAG STEAMERS, &C.

{Weak manhole 3 2 5 A {Bad material 1 1 5 {Want of stays 1 1 0 ------------ 5 4 10 C Undue Pressure 1 2 6 ------------ 1 2 6 ----------- 6 6 16

FEED-WATER HEATERS.

D Uncertain causes 2 0 6 ------------ 2 0 6 ----------- 2 0 6

DOMESTIC BOILERS.

A Weak shape 3 4 7 ------------ 3 4 7 B Corrosion 2 0 5 ------------ 2 0 5 C Undue Pressure from } freezing of Pipes } 9 7 9 ------------ 9 7 9 ----------- 14 11 21

BALLOON BOILERS.

B External Corrosion 2 1 2 ------------ 2 1 2 C Undue Pressure 1 1 0 ------------ 1 1 0 ----------- 3 2 2

BOILERS OF UNCERTAIN DESCRIPTION.

A Weak manhole 1 0 0 ------------ 1 0 0 {Steam entered through blow- } { off pipe from another boiler} 1 1 2 C { while cleaning } {Steam pipes broken 2 4 3 {Shortness of Water 1 1 4 ------------ 4 6 9 D Uncertain causes 2 0 3 ------------ 2 0 3 ----------- 7 6 12 ---------- _E_ _K_ _I_ TOTALS 219 315 450

TABLE IV.

_Summary of causes of the Steam Boiler Explosions comprised in Table III._

+-----------------------------------+-----------+---------+---------+ | | E | K | I | | | Number |Number of|Number of| |Causes of Explosion. | of | persons | persons | | |Explosions.| Killed. |Injured. | +-----------------------------------+-----------+---------+---------+ |A Faults in construction or repair | 95 | 128 | 167 | +-----------------------------------+-----------+---------+---------+ |B Faults which should be detected }| 62 | 105 | 185 | | by periodical examination }| | | | +-----------------------------------+-----------+---------+---------+ |C Faults which should be prevented}| 54 | 79 | 84 | | by careful attendants }| | | | +-----------------------------------+-----------+---------+---------+ |D Extraneous or uncertain causes | 8 | 3 | 14 | +===================================+===========+=========+=========+ |Totals | 219 | 315 | 450 | +-----------------------------------+-----------+---------+---------+

BRIEF ABSTRACTS FROM REPORTS ON STEAM BOILER EXPLOSIONS, PRESENTED TO THE MIDLAND STEAM BOILER INSPECTION & ASSURANCE Co., BY EDWARD BINDON MARTEN, CHIEF ENGINEER TO THE COMPANY.

_Description is shortened as much as possible, and facilitated by slight sketches, showing the position of the fragments or line of fracture, and the general construction of the Boilers._

REPUBLISHED BY THE PERMISSION OF THE COMPANY.

STOURBRIDGE: B. BROOMHALL, PRINTER, HIGH STREET. 1869.

BOILER EXPLOSIONS IN 1866.

_No. 1. Nottingham. January 1st. none injured._

Locomotive, 110 lbs., standing with steam up near a platform. All but the fire box was blown away, the main portion being thrown a distance of 400 yards. The first rent took place at a longitudinal seam of the barrel where grooving had gone on very rapidly, which was not discovered when examined and tested a short time before.

_No. 2. Walsall. (Fig. 1.) January 2nd. 2 injured._

Butterley, 26ft. 6in. long, and 9ft. diameter. The wagon-shaped top to the fire place was 8ft. 6in. long, and was attached to the bell-mouth of the internal tube, which then continued circular to the back of the boiler. The tube was 3ft. 6in. diameter. All the plates were about 7/16ths inch thick, and although the boiler was an old one, they were nowhere reduced in thickness by wear. The usual pressure of steam was 18 lbs., and a self-registering gauge showed that at the time of explosion it did not exceed 20 lbs.

The top of the fire grate on the right side rent longitudinally, and the upper part of the shell consisting of four rings of plates, and also the top of the fire place opened out and blew away to a considerable distance.

The front end also blew away. The bell-mouth of the tube was blown to the front, and the tube which remained in the back part of the shell collapsed upwards.

The cause of the explosion was most likely the intrinsic weakness of boilers of this shape, especially over the fire, where the top is only retained in its shape by numerous stays. The boiler had been very frequently repaired, at this the weakest place, and its strength had been thus so reduced as to make it unable to bear even a few pounds more than the ordinary working pressure.

The whistle was found to have been gagged by hemp, carefully inserted, so that there is ground for supposing there had been intentional unfair usage.

_No. 3. Blyth. (Fig. 2.) January 8th. 1 killed 1 injured._

Marine, 20ft. long, and 5ft. diameter, with internal fire place and return flue, 14 lbs. There were altogether three rents in the tube over the fire, as a small band was held in its place by a stay from the tube to the shell. The escaping contents scalded those near, but no damage was done to anything but the boiler.

The cause was stated to be shortness of water. There was no water gauge.

_No. 4. London. January 9th. 1 killed._

One tube Cornish, 28ft. long, 6ft. 6in. diameter, with one tube 3-6 diameter, 3/8 inch plates, 45 lbs.

The tube collapsed in an incline direction from weakness without strengthening rings.

The appearance after explosion was nearly the same as that shown in sketch given at No. 12 explosion.

_No. 5. Glasgow. (Fig. 3.) January 13th. 4 killed, 4 injured._