Disasters - Names		Disasters - Names

Date:	13th June 1888
Colliery:	Murton
Cause:	Boiler explosion
Lives Lost:	1

An explosion of a steam boiler took place at Murton Colliery, the property of the South Hetton Coal Company, Limited, on the 13th June last, causing the death of Archibald Smith, one of the fireman, and injuries to eight others. The explosion took place at 11.30 a.m., doing considerable damage to the other boilers and machinery and buildings about the place. The boiler was one of a range of 14, and known as No. 9, and was situated at what is called the Middle pit. It had been at work for between 40 and 50 years. The boilers are not. insured, but are under the inspection of the Newcastle-on-Tyne Steam Boiler Insurance Company. An inquiry was held on the 26th June before Mr. Coroner Maynard and a jury, and the following is an extract from the depositions of the witnesses :—

John Thompson Shield said : "I am foreman enginewright at Murton Colliery, and on the morning of the explosion I was standing on the gangway in front of the boilers, and about 35 yards off. Looking towards them I saw a sudden rush of steam from the safety-valves of Nos. 12 and 13, and a few seconds afterwards No. 9 blew away. I know of no cause for over-pressure. The boiler was well cleaned on the 10th instant, when I examined it and found no fractures. On the 4th March last I overhauled the whole of the boiler, both internally and externally, and found it in fairly good working order. The steamvalves were properly weighted. The feed-pipe has not yet been found."

Robert Ramsey, said :– "I am fireman at Nos. 13 and 14 boilers at Murton Colliery. They are low-pressure boilers. On the 13th instant, while in the fire-hole, about 11.30 a.m. No. 9 boiler of the Middle pit blew away. I had nothing to do with that boiler and knew nothing of its condition. It has not been repaired, to my knowledge, since I went there about four years ago. One of my boilers (No. 13) leaks a good deal, but I have made no complaint of that or any other of the boilers not being attended to. There is a boiler minder to attend to the feed and other matters. I only attend to the firing. It is heavy firing, and Mr. Shield has complained to me about not keeping up steam. I have never seen extra weights put on the safety-valve levers. The boilers are all connected by one steam pipe. There were 20 lbs. of steam at the time, and the pit had stood a short time before the explosion. The boilers are sludged twice a day. We never use rye-meal to stop a leakage. Some extra low-pressure boilers were put on that day, but there were no additional engines at work. We use duff coal for firing, and it makes a good deal of clinker."

Robert Wilson, said: "I am an engineman, and at present engaged as boiler minder at Murton Colliery, where all the boilers are tinder my charge in my shift. I was at the cross boiler at the time, a short distance off, but could see No. 9 boiler from where I was. There was no extra weight on the safety-valve lever, and all the valves were blowing off steam at the time. It would have been no use putting weights on one boiler as they are all connected. If I wanted to put any additional weight on the safety-valves I would first have to ask Mr. Shield's permission. I have never done anything of the kind. The last witness never mentioned any leakage of No. 13 boiler, and I did not know of any leakage of No. 9. I sludge the boilers twice a day, taking about two inches of water out each time. We use nothing to stop leakages. One engine feeds all the boilers. The middle pit had stood two or three minutes, and the steam was blowing off heavily from the boilers. Men were being changed at the time, so we did not require so much steam. Sometimes we have difficulty in keeping steam up. The boilers sometimes prime a little, but only when the steam is very high. The feed was off No. 9 at the time of the explosion. I had it on about 10.30 a.m. until the float ball came on to the plates, indicating that there was sufficient water then in this boiler, an hour before it blew away. Mr. Shield had been through among the boilers that morning. We feed with water from the Magnesian Limestone, which leaves a considerable deposit. We clean them out every fortnight. I passed over this boiler not more than a minute before it exploded, and I have had a broken arm and been slightly scalded by it. All leakages are reported to Mr. Shield, and attended to.

Cuthbert Burnett, said :– "I am mechanical engineer to the South Hetton Coal Company, Limited, and produce the report, and boiler repairs' hooks. I do not know the precise age of the boiler. I only came here in October last, but I find from a memorandum in the boiler book, that the boiler in question is 30½ feet long, 7 feet 9 inches in diameter, placed at the middle machine, cylindrical, longitudinal plates put in about 1839 or 1840, maximum pressure 20 lbs. Since 1870 there have been 70 new plates put in this boiler, showing that the whole of the lower portion of the boiler has been renewed since that time. The last repairs to this boiler were made in April last, when some fresh rivets were put in, and caulking done. I have only examined two or three of the boilers internally, and had not been in No. 9 until after it exploded. It had been repaired with Tudhoe best best and Weardale plates. Most of them are yet of the full thickness, 3/8ths of an inch. There is not more crystallisation than I expected to find from so sudden a rupture. The boiler was quite clean, having been cleaned out only four days previously. There was one plate four tiers from the top which had thinned 1/16th of an inch. In my opinion the plates were not in a dangerously crystallised state. There are no signs of heating, nor do 1 know any cause for increased pressure, but I think there must have been more than 20 lbs. pressure to the square inch at the time the explosion took place. The boiler is built with the plates placed longitudinally, but in my opinion, it would have been stronger if the plates had been turned what is termed "the hoop way." Apparently the rupture took place about 13 feet from the fire. The plates in that part are "to some extent pitted. I do not think it improbable that iron exposed to hot air and gases for a long time will deteriorate. There is some fibre shown in the iron where I think the rupture took place, and most crystallisation is shown where the tearing is circumferential. I have no actual opinion where the rupture took place, nor does the place I have suggested as the initial point of fracture show any signs of over pressure, nor so far as I know any natural decay. I cannot say how the explosion occurred. If the steam valves had been overweighted, that would cause it. I cannot suggest any other cause for over pressure. Pitting of the plates is very usual, especially with limestone water, but it does not appear to me to exist in this case to any dangerous extent. I produce the lost report of the Boiler Insurance Company's inspection of the boiler in question, which was made on the 5th February 1887 and sent to the colliery owners. It says :–' One of the Inspectors of this Company reported as follows :–This boiler (No. 9) was examined thoroughly on the above date and found to be in fair condition, with the exception that the inside of the boiler from end to end below water line is pitted and reduced from internal corrosion. The second ring seam from end or underside of boiler over the fire allows of leakage and will require to be caulked. The mountings are in satisfactory order with the exception that the flange of the sludge pipe, where attached to the underside of boiler, allows of leakage, and is causing the plates to be pitted and reduced. joint will require to be re-made. – Signed, William Bald Campbell, Manager'"

The coroner having requested Mr. Campbell to examine the boiler and to give evidence if necessary, the latter handed in the following report :– "I examined the exploded boiler on the 13th, 15th, 19th, and 23rd June 1888. It was externally fired with a wheel flue. It was a cylindrical egg-ended boiler 30 ft. 6 in. long, by 7 ft. 9 in. diameter; plates, 3/8th of an inch thick ; rivets, ¾ in. diameter, 2 inches centres; built with plates having continuous seams longitudinally, and fitted with the following mountings externally, viz. Two safety valves, one 5¾ in. and the other 2 in in diameter. One steam stop-valve in. diameter on front end of boiler. One sludge valve 3¾ in. diameter near to back end. One pressure feed valve. One steam pressure gauge. Two water gauge balance floats, and one manhole 15½ by 12½ in. with strengthening ring. Referring to the above official report, I find that the pitting therein named is plainly exposed upon the exploded pieces. It is in the vicinity of the new plate repairs, but it is not itself upon the oldest plates in the shell of the boiler.

A rupture passes across these plates, but there is no indication of its having begun there. There is one long ripping through a row of rivets in a longitudinal, seam on the left side of the bottom of the back portion of the under side of the boiler, but this plate seems to be thick and good. It may have been crystallised, but there is no indication that any seam rip existed there before the explosion.

The boiler is old, has been extensively repaired, and the plates indicate that the boiler has been kept up to good working strength.

Looking at the edges of the fractures some parts of the plates edges show a very flexible quality of iron, and no parts show any particular granulations of brittleness from age. Looking at the general arrangements of all the boilers feeding their steam into one steam pipe, whereby the different boilers equalise the pressure of steam, it seems impossible to see how extra pressure of steam has been got up, or whether that or some other circumstance caused the explosion.

"The action of the explosion was to shoot the front half of the boiler straight and on a level through the wall, and into the engine-house, while the back end half rose forward over the roof of the engine-house, where a portion of it struck the head-gear and threw the rope off the pulley, landing on the top of the screens, the egg end-piece being deposited on the back stays between the pulley frames and the engine-house end. The engine had stopped winding at the time, and the steam would be accumulating during the time it was standing.

"The working pressure was 20 lbs. per square inch, as indicated on the pressure-gauge, which is fixed on the front of the boiler, the safety-valves being weighted so as to blow off at that pressure. The standard of tenacity of riveted, boiler-plates is 34,000 lbs. per square inch of one inch thick plate, working pressure of steam 20 lbs. per square inch of the internal surface of the boiler plate. As the plates are 3/8ths of an inch thick, the strength is 3/8ths of 34,000 = 12,750 lbs. strength. The diameter of the boiler is 7 ft. 9 in. To ascertain the strain upon the boiler, taking the plate at 3/8 in. thick and the pressure of steam at 20 lbs., we have: Radius, 46.5 in. x 20 lbs. = 930 lbs. strain, and 12,750/930 = 13.7 times the bursting strain, which is over twice the usual margin of safety; six times the ultimate bursting strength being the usual working allowance.

"The circumstance of the explosion seems to be that, at a juncture of three metals near the sludge-cock, which is in the bottom of the boiler at the back end, a burst took place and the escaping steam reacting on the boiler seating threw the back end of the boiler up into the air, while the front end, which remained enclosed was thrust forward, as already described. Signed, William Bald Campbell, Engineer and Manager."

Mr. Campbell, on being sworn, said "I am engineer and manager to the Newcastle-onTyne Boiler Insurance Company. The boiler in question is under our inspection, but is not insured. I examined it on the 13th, 15th, 19th, and 23rd June instant. In my opinion the pitting and internal corrosion referred to in the report 'of examination of the 5th February 1887 did not contribute towards the explosion. The caulking was done on the day of the inspection, and the repairs to the sludge-pipe therein referred to were carried out. The age of the boiler did not contribute to the explosion. I should say the proper length of time for a high pressure boiler to be used is 20 years. The boilers were not refused for insurance with us: we would have accepted them. The pressure the boiler has given way at is considerably above the working pressure, but there is nothing to show how, as there is no indication of over-beating. As far as I have seen there has been no great crystallisation, and that should guide me better than its age. So soon as a plate becomes crystallised it should be replaced. In this boiler I have found no extensive re-rivetting; and I can find no sign whatever of any want of care in repairing. The locality of the explosion was amongst the new work, and not among the original plates of the boiler. The steam-valve being 8 inches I do not think the over-weighting of the valves would cause it. There is no indication of over-heating. I saw the valves after the explosion, and there was sufficient arrangement for the steam to escape."

After reading the above evidence and reports, it would seem to be no easy matter to arrive at a reasonable conclusion as to the cause of this explosion. Mr. Campbell makes out that there were no signs of extra pressure, neither had the pitting or thinning of the plates, nor the great age of the boiler, anything to do with the accident. He gives the strength of the plates as over 13 times the bursting strain, and over twice the usual margin of safety. Had this been so I cannot conceive that an explosion could reasonably have taken place, bearing in mind that there was no apparent want of water in the boiler at the time. Probably the strength of the plates given is correct when they were new, but he does not appear to allow anything for deterioration by the constant use and hardships these boilers have endured for a period of nearly half a century. In my opinion all this range of boilers ought to have been replaced by new ones at least 20 years ago, and that similar accidents have not previously taken place can only be attributed to the great care there has always been taken in the repairs and general management of the boilers at this Colliery. There are 12 other boilers of about the same age as the exploded one, now working at Murton Colliery under similar conditions, and as the one in question has exploded, as has been argued; from no extraordinary circumstances (except old age), and as Mr. Campbell puts the life of a high-pressure boiler at 20 years, it is only fair to assume that 50 years is an excessive length of time for one working at low pressure, and it would appear to be a somewhat risky business to continue working these boilers, especially after such an accident as the one in question.

Source:

1888 Mines Inspectors Report (C 5779)

	Smith, Archibald, aged 34, Fireman, scalded by the explosion of No. 9 steam boiler at the Middle pit, eight other men were also injured by this explosion, but ultimately recovered
	All names found

 

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