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	Individual Details		Individual Details

Age:
Died:	26th Jul 1856
Accident:	26th Jul 1856
Born:
Colliery:	Craghead
Company:
Occupation:	Brakesman
Notes:	boiler exploded
Buried:	[not known]
Category:

During the night, on the 26th of July, a cylindrical boiler exploded at the Craghead Colliery, killing the brakesman, John Pattison.

The evidence at the inquest in this case, went to show that the brakesman who had charge of the engine and boiler, had been unusually sleepy during the night, not working his engine till the signals for him to do so had been repeated ; he having taken no notice of two signals, given just before the boiler exploded. There was an alarm whistle attached to one of the two floats on the boiler, by means of a lever which was intended to turn a cock, and thus sound the alarm whistle, in the event of the water falling below a proper level in the boiler. This whistle had been heard to sound several times during the night : the last time it was noticed might be three quarters of an hour before the explosion, which happened about five o'clock, A.M., blowing the body of the brakesman fifty or sixty yards away from the engine. The engine had been standing for some time immediately before the explosion occurred. George Smith, the enginewright, had seen the boiler about half-past eight o'clock on the night preceding the morning of the explosion, the deceased having then sent for him, owing to a faulty joint in the suction pipe of the feed-pump connected with the boiler — when the deceased agreed to render time joint tight, if the enginewright sent him some wedges for the purpose — the wedges were said to have been sent accordingly; but the defective joint could not be found after the explosion, owing to the displacement it had caused. The boiler appeared as if all right at the time of the enginewright's visit, except that he noticed a railway chair upon the lever of the safety valve, in addition to the ordinary weight, which he told the fireman to go and remove, as he was leaving the engine. The working pressure was 30lbs. per square inch. It was the duty of the brakesman to attend to feeding the boiler. The whistle was intended to sound before the water reached the lowest working level. The boiler had leaked a little on the night of the Wednesday preceding the explosion, which occurred on the morning of Saturday. The boiler was six feet in diameter, and twenty- three feet long, and the plates were R. B. crown iron, and fully 5/16ths of an inch thick, of good quality, from the Butterley Company's works. It was sixteen years since the boiler was first made.

The steam gauge generally indicated a pressure of 27½ lbs. per square inch, but calculating from the safety valve, the working pressure was 30 lbs. per square inch.

The chair which the enginewright had observed on the safety valve lever might have increased the pressure at the blowing off point, to 40 lbs. per square inch.

The jury, thinking that the neglect of the deceased himself had been the chief cause of the accident, returned a verdict of accidental death.

In this instance there is no very clear evidence as to the origin of the boiler explosion, as the whistle had not been noticed to sound for some time previous to the accident, nor were there any very ordinary appearances of the plates of the boiler having been overheated. It must probably be classed amongst many other explosions of a similar character, of which the causes appear as yet to be little understood, indicating that there is much to be learned on this subject, which at present assumes the form of a mystery, and which it appears to be highly desirable, for the sake of humanity, that experiments should be instituted to unravel. The necessary cost of a series of experiments on the causes of boiler explosions, is probably so great as to deter private persons from undertaking them ; and the almost national interest of the subject, together with the great number of boilers employed in Her Majesty's Navy, appear, I incline to think, to warrant Her Majesty's Government to take up the subject, and have it investigated at the expense of the nation.

If I were to endeavour to account for the boiler explosion now under consideration, I should set out by considering that some very high pressure of steam had prevailed at the moment of explosion, as the boiler was, I consider, capable of sustaining no less a pressure than 295 lbs. per square inch ; a pressure at all approaching which, it may be inferred, could only arise either from the sticking of the safety valve in its seat, or from the too sudden generation of steam by reason of the water having fallen so low in the boiler as to cause some of the plates to be exposed to the fire or flues, where no water was opposed to it on the inside of the plates, resulting in the too rapid generation of steam on the subsequent introduction of water into contact with such over-heated plates.

I beg, however, to observe, that although there were no very decided and ordinary appearances of the plates having been locally overheated in this case, yet the blue tint on the whole of the inside of the steam-room portion of the boiler, appeared to me to be considerably deeper than is usually observed in boilers after explosion from which I partly incline to the opinion that at the time of the explosion, the steam in the upper part of the boiler had been surcharged with heat, and much hotter than the water in the bottom of the boiler the introduction of water amongst which unsaturated steam, either by the feed or the agitation arising from beginning to work the engine after it had been standing some time, might, perhaps, give rise to the too rapid generation of steam, tending to bring it into a state of saturation, and thus rapidly increasing the pressure, owing to the inadequacy of the safety valve to vend the steam as rapidly as it was generated, result in the explosion.

Before attaching any importance to the latter opinion, I consider that it would be necessary to enter into a calculation, to determine whether a given quantity of calorie would produce a greater or less pressure in saturated or in unsaturated ed steam of equal volume, a matter on which practical men at present appear to differ in opinion, and which, up to this time I have not investigated, although I purpose taking an early opportunity of doing so.

The prevailing opinion seems to be, that the greatest pressure is due to saturated steam.

• 1856 Mines Inspectors Report

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