Hongkong and China Gas Company explosion, New Theory Advanced in Gas Disaster Enquiry, 1934
IDJ has sent the following newspaper article. For more information about the West Point gas explosion in 1934 please see our other articles below.
HF: I have retyped the article for clarity sake and to assist searches. The script occasionally uses phrasing which would not be used in contemporary English which I have not changed. I am unfamiliar with the meaning of several terms used e.g.”gallery/seam/ and strake” in the context of a gasholder. I would be grateful if someone could explain or make clear their meaning.
New Theory Advanced In Gas Disaster Inquiry
MR. W. A. BUTTERFIELD CONTINUES HIS EVIDENCE
Gas Ignited In The Watchmen’s Hut!
That the cause of the explosion, was mainly attributable to gas finding its way to the watchmen’s hut where it was ignited and subsequently blown back to the gasometer, was the theory given by Mr. W.A. Butterfield, chief engineer of the Asiatic Petroleum Co. (S.C.) Ltd., at Central Magistracy yesterday when he continued his expert evidence in the enquiry into the circumstances surrounding the tragic gas explosion disaster at West Point on the morning of May 14.
Mr. Butterfield who was asked to examine the gasometer by the Government, also stated that the condition of the plates which he had carefully examined were such that they warranted and necessitated their renewal some while ago. He said that the whole trouble was due to corrosion and caused a slight murmur of laughter by remarking that the patches were stronger than the plates themselves!
Mr E.W. Hamilton conducted the enquiry with the assistance of a special jury comprised of Messrs. P. Tester (foreman), L. Dunbar and D. Drummond.
Mr. W.A. Mackinlay, of Messrs. Deacons, represented the interests of the Hongkong and China Gas Co., Ltd., the owners of the gasometer, and Mr. W.M. Brown of Messrs. Hastings and Co., watched the proceedings on behalf of certain property owners whose property was damaged by the catastrophe.
Patches Stronger Than The Plates!
Continuing his expert evidence from the previous hearing, Mr. Butterfield said that his report was only a fascimile of things which he noticed on his various visits to the gasworks.
On his visit of May 17, he noticed two of the plates were patched, one patch being approximately 14 inches by 14 inches and the other approximately 24 inches by 18 inches. These patches were formed with mild steel plates secured to the shell plate with hooked or split bolts, and had been fitted over a wasted area plate which was, in fact, at the time of the examination, perforated before the patches were put on. Generally speaking the side farthest from the hole was in a better condition.
The watchmen’s hut which was formed of bricks with galvanised iron roof and part galvanised iron side and rought iron poles was about 30 feet away from the gasholder. In one section of the hut there were two gas rings and a gas-light of incandescent type. The condition of the hut indicated that an explosion had occurred within the building, the windows being blown upwards with glass lying on the outside, the roof of the building partly dislodged and fallen into space, and the side sheeting hanging outwards at the bottom. The maximum force of the explosion within the hut was apparently located immediately over the position occupied by the gas rings. At this point, one of the steel joists supporting the roof sheeting was badly bent, in an bent in an upward direction and the roofing lifted well clear of the back wall. Recently used cooking utensils were found within the hut.
In reply to the Coroner, Mr. Butterfield said that the inner lift having been partially raised since his last inspection, he made a further examination from the gallery of No. 5 and No. 6 strakes, counting downwards. The outer skin of the lift was fairly free from scale and recently painted. Five holes about 3/8 by 1/8” were located and these were found to have been caused by corrosion. Four of these holes had been filled in with red lead putty which he removed.
Taking the thickness of the plate in the five holes which were marked by him, he attained the following measurements:
A. 1/20″ in way of seam.
B. 1/20″ in way of horizontal and vertical seam.
C. 1/20″ in way of seam.
D. 1/20″ in way of seam.
E. 1/20″ in way of seam.
In taking the above measurements it was not possible to remove any scale which might have been present on the interior side of the plate.
Coroner: Do you form any opinion about the general state of the plate?
Mr Butterfield: Every part which I found was through corrosion, would indicate a very uncertain condition and which will lead one to think that if one plate could go in that way, any one might. I would always be alarmed if there was hole in the tank which, I think, it should be avoided. In connection with the general tank work, when a tank is in a bad condition one would naturally have an internal examination which is the only thing to do. I am speaking of course, of dangerous goods storage.
He counted in all 17 bolt plate patches. In addition to the bolt patches there were two others, approximately 36 inches by 18 inches each secured with a number of small bolts.
One vertical seam in the fifth strake, two vertical seams distant from the opening caused by the damage on the side of the lift for a length of about 18 inches, was open, due to 16 rivet heads on the inside having pulled through. The opening had been filled with red lead putty to a thickness of about 3/16″ and painted over. The putty had shrunk or the plate had sprung, thus leaving an opening of about 18 long varying from 1/16″ in depth to 1/4″. The plate was in a very flexible state in the way of the opening and it would spring open to a varying extent with very little pressure. It was possible that this was due to concussion before the fire broke out. Personally he considered all wrong to putty up this 18 inch opening. If there were an opening before the concussion he considered a lot of gas would have escaped due to the pressure.
Red Lead Putty
In all cases red lead putty was used in closing the holes: it was fairly soft , and judging by the tarnish which he flicked easily with a knife blade, it probably had been in position for about a month. The red lead had, in all cases, been painted over which he concluded was the usual procedure in closing the holes.
As some of the plates which were lying on the ground had been marked and drilled for outside purposes since the time of his former visit on May 17, he took further measurements with details as follows:
No. 6 plate 1/20″ centre
No. 6 ” 1/20″ joint
No. 11 ” 1.25 upon 20 joint
No. 11 ” 1/20 side
He made a further examination of the watchmen’s hut and checked the distance of the doorway from the gasometer. The two gas rings, the gas light fitting and piping had been removed. The concrete and brick slab which had served as a table for the gas rings was still complete. After the examination he was more convinced that an explosion had occurred within the hut.
On May 24, he made a further examination of the gasometer. On the roof, as well as could be seen from the gallery, at the point where the side plates were planted out, five wind-ties and five lower trusses had been broken. The wind-ties were used for preventing wrecking by high winds. The damage was made possible by the impact of the lower end pf the “king” post with the steel framed stool settled with the sudden release of gas. There might be other damage but he could not go to the scene without the aid of a scaffolding.
He located two additional holes in the fifth and sixth strakes about 3/8 inch by 1/8 inch which he had missed on his previous visit. The five holes which he had located and marked on his previous visit had been filled up with red lead putty!
He examined two small sheds adjacent to the watchmen’s hut and found that hut No.2 which was 18 feet 2 inches from the gasometer had a charcoal chatty of the type used for cooking. Cooking utensils and gas pipes were also there. In the second section of this hut, there was a three-quarter inch gas pipe and a wooden table on which was a circular iron plate, apparently used for putting the gas ring or other form of heating apparatus.
On May 25, he examined several platings which had been removed from the interior of the gasometer, they having fallen from the upper lift. He took the following measurements of six sheetings.
No. 21 1/40″ of seam
No. 22 1/20 of seam
No. 23 1/40 of seam
No. 24 1/20 of seam
No. 25 1/20 of line of rivets
No. 27 1.25 upon 20 of line of rivets
It was shown at all the points which he had examined that due to corrosion, smooth wasting, local and general pitting and age the plates were in a brittle and weakened condition. The original thickness of one-tenth of an inch being in places 1/40.
The container had been sludged out, the material removed consisting of some tons of rust which had fallen from the tank. Eighteen of the 8 inches by 5 inches rolled steel joints forming the vertical side girders of the upper lift showed heavy corrosion. The interior of the plating of the upper lift was in part holding sheets of rust.
Leakage of Gas
From the general condition of the plates in way of seams, small perforations and holes as shown in some plates and with particular regard to the open vertical seams it would appear that an appreciable leakage of gas had been in progress for sometime, which gas, according to air currents, would, in his opinion generally be blown away and safely dispersed.
Coroner: Can you tell us the possible cause of the accident?
Mr. Butterfield: I think it is mainly attributable to gas finding its way to the No.1 hut where it was ignited and consequently blown back to the gasometer.
Mr. Butterfield added that it would be necessary, judging by the mere state of the upper lifts, that the whole of the plating forming the roof and the three lifts be thoroughly examined and drill tested for the purpose of ascertaining their condition. There was also expansion and contraction due to the heat and sun rays. Generally, he was of the opinion that these plates, of which he had made careful examinations warranted and necessitated, in accordance with the general engineering regulations, their renewal some while ago.
Coroner: I think what you object mainly is corrosion? Yes Excessive corrosion is the whole trouble.
If you were asked to examine the gasometer before the explosion what would be your opinion? Having no knowledge of the working of the gasometer, I would never suspect from external appearance that it has internal corrosion. I would myself certainly have said it looked very good as far as external appearance is concerned.
Do you consider that the number of patches are dangerous? It indicates the bad condition on the whole.
With regard to oil tanks how often you have them examined internally? Every year according to the Company’s regulations. The following means can be applied: Steam, water and ventilating fans.
Are your tanks built on the same principles as the gasholder? No. Because we have to provide for a definite hydraulic pressure.
In answer to a further question by the Coroner, Mr. Butterfield caused a murmur of laughter by stating he thought the patches were stronger than the plates themselves.
You said that the holder ought to be renewed some while ago. On what do you base your statement? The plates which remained in position had to do certain work and due, as shown by the holes, to corrosion and through cracks, they were not in a suitable condition to remain where they were. They were incapable of carrying on the work.
At this stage, the enquiry was adjourned until this afternoon.
Source: Hong Kong Daily Press 19th June 1934.
This article was first posted on 1st June 2021.
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