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Washington "Glebe" Colliery, usually known as the Glebe Pit, was established only four years ago, the shafts being sunk through the surface deposits by the freezing process, and is one of two collieries, the other and much older colliery being known as the F. Pit, owned by the Washington Coal Co., Ltd., a private limited company of which Mr. F. Stobart, who is a mining engineer and a certificated colliery manager, and who had at one time taken an active part in the management of the F. Pit, is Managing Director and Agent. Mr. Stobart and Mr. Scott Gunn, the Secretary to the Company and a shareholder, were present at the adjourned inquest.

Mr. Mark Ford is certificated Manager for both collieries. Mr. John Cockburn, holder of a first class certificate, is the Undermanager of the Glebe Pit. Both these gentlemen I have found careful and efficient in their conduct of the mine, and the explosion came as a great surprise and grief to them. Under the Manager and Undermanager there was a sufficient staff of under officials.

There are two shafts at the Glebe Pit (see Fig. 4, Plate I.) both sunk to the Low Main seam at a depth of 114 fathoms, passing through the Main Coal seam at 94 fathoms and the Maudlin seam at 104 fathoms. The downcast and principal coal drawing shaft is 14 feet diameter, and is traversed by two cages between the surface and the Maudlin seam; from the Maudlin seam to the Low Main seam, 10 fathoms below, it is fitted with ladders. The upcast shaft, surmounted by a fan, is 12 feet diameter, and a single cage, with wire rope guides, runs in it between the surface and the Low Main seam, by means of which the coal was raised from that seam and the workmen passed to and from their work.

The top of the upcast shaft, above the level of the fan drift, is enclosed by a square wooden erection carried up nearly to the pulley and closed at the top except for a hole through which the winding rope, worked; a door in this erection on the ground level afforded access to the cage. Added on to this enclosure is a wooden porch, entered by an outer door, in which the banksman works and where persons stand preparatory to descending the shaft.

Four or five days before the explosion a stone drift driven upwards from the Low Main seam to the Maudlin, formed a third connection between these seams.

The explosion originated in and was confined to the Low Main seam.

There are extensive workings in both the Main Coal and Maudlin seams, and a road in the latter scam connects the Glebe Pit underground with the F Pit.

The Hutton seam, lying 10 fathoms below the Low Main seam, had been worked many years ago from an abandoned colliery at Oxclose, and these workings shewn on Fig. 3, one of the small scale plans on Plate I., extended under the Glebe shafts, and had been bored into by two vertical bore holes from the bottom of the upcast shaft.

The working of the Low Main seam in the first or whole working of the bord and pillar system only commenced in October, 1906, and the passages formed are shown on the Plans on Plate I. ; the operations were more for the purpose of development than for obtaining a large output, and the raising of the coal by the single cage in the upcast shaft was a temporary expedient to be replaced by a permanent engine haulage which would bring the coal up the stone drift to the Maudlin seam, from whence it would be raised to the surface by the cages in the downcast shaft.

The Low Main seam at the Glebe Pit has the section shown on Plate I., and produces gas and bunker coals of a good quality. The floor consists of a few inches of inferior sagre clay followed by laminated sandstone, and the roof is a good average roof; a layer of shale or blue metal rests directly on the coal, and above it is laminated sandstone. There is an area which the workings to the South East of the shafts had almost reached, where all the seams have apparently been subjected to considerable subterranean heat and been deprived of most of their volatile matter; this area has been proved from the adjoining collieries of Hylton to the East, Usworth to the North East, North Biddick to the South and Harraton to the West, as well as in the upper seams at the Glebe Pit where it was being explored in the Maudlin seam. The coal in the Low Main seam as it approached this area became somewhat softer and easier to work.

The dip of the Low Main seam as indicated on the large scale plan on Plate I. is about 1 in 12 to the East.

The leading of the coal was performed by five ponies – all of which were killed by the explosion – drawing wooden tubs carrying 10 cwts.

The ventilation of the colliery depended on an exhausting Waddle fan 25 feet in diameter placed on the surface near the upcast shaft and running at 40 revolutions per minute and there was satisfactory evidence that it had been running at its usual speed up to and for some time before the explosion.

Before the completion of the stone drift, the ventilation of the Low Main seam had depended altogether on air descending the downcast shaft direct to the seam and this air was distributed as shown on one of the small scale plans on Plate I., Fig. 2. The principal split passed, as at the time of the explosion, through a hole about a foot square in the brick framework of a door placed in the road extending eastward from the downcast shaft and then passed in-bye by the left hand of the three main winning places extending to the south-east as shown on the plans, returning to the upcast shaft by the right main winning except as regards scales of air, which leaking past the canvas doors, returned by the centre road which was also the road over which the coal was led. On the opposite side of the downcast shaft to the door already mentioned was a brick stopping, and from it six air pipes 12 inches diameter (only three of which had been used) were carried across the main road and passing through another stopping on the opposite side allowed a current of air to pass, which ventilated some temporarily abandoned workings and the stone drift to the west and north of the shafts.

This current passed to the north-west along the back main winning and splitting at the point shown on the small scale plan, one part, passing to the left, ventilated the workings between the point of splitting and the fault shown on the plan and returning to the upcast shaft was regulated at the point marked R on the small scale plan.

The remainder of the current passed to the right and was again split, one portion ventilated the few excavations in the coal, in one of which some fire-damp had been met with and the air from which it was not thought prudent to take up the stone drift, and this current was therefore brought across the road near the bottom of the stone drift by an air crossing (formed of a single tube 12 inches diameter), and then passed direct to the upcast shaft. The other portion was carried up the stone drift by means of a brick brattice, and joining the air coming over the single tube air crossing passed with it to the upcast shaft.

When the third connection from the Low Main seam was formed by the completion of the stone drift the ventilation had been rearranged on the system shown on the large scale plan on Plate I., Fig. l. As already stated the main current remained as before, but the split passing through the pipes had been replaced by air descending the drift from the Maudlin seam. Two wooden doors placed on the main road between the foot of the stone drift and the shafts, supplemented by other doors and stoppings, carried this current round the temporarily abandoned places to the north and west of the shafts.

It does not appear that the change had any effect either on the origin of the explosion or its extension. The overman stated at the inquest that after the change was effected he examined the working places on the morning of the 20th February and found them well ventilated and the deputies' reports since the change were to a similar effect.

No measurement of the air, however, was made after the change, the last measurement made before the explosion being on the 15th February, 1908, and the result as recorded in the ventilation book is given below :—

	Point of measurement on the small scale plan, Fig. 2, Plate I.	Cubic feet per minute.
Low Main, South-east	M	11,740
Low Main, East	M²	5,610
Low Main, West	M¹	5,210

On the same day the water gauge was recorded at 0.7 inch, the revolutions of the fan at 40, and the total quantity of air measured in the fan drift 74,580 cubic feet per minute.

The ventilation of the Low Main seam was attended with no difficulties and the quantity of air circulating could easily have been much increased.

The main split of air was carried forward along the left of the Three winning places to the south-east by brick stoppings and on arriving at the working face was carried round the workings by canvas sheets and doors and into the culs-de-sac where necessary by canvas brattice, returning along the right and centre main winnings to the upcast shaft. The air descending the stone drift was similarly dealt with, but did not ventilate any working place.

The workings lying to the east and dip of the shafts were ventilated by no special system; small scales or leakages of air appear to have circulated and no difficulty as regards the ventilation of this part of the seam had been experienced.

The Low Main seam is moderately fiery but fire-damp was not often reported by the deputies and had only been reported once, on the 28th January, in the month preceding the explosion and that was in the place where the explosion originated.

After the date on which the gas had been reported the manager made an examination on the 12th February and found a slight show in the place, he directed more brattice to be put up, and called the attention of the undermanager to the place and also instructed the surveyor, who was going down the pit to survey the seam on the evening of the 12th February, to examine it; the surveyor did so and reported it clean.

The seam itself did not make much water and was dry on the whole, although the old workings in the Hutton seam partly underlying the area affected by the explosion were drowned.

The boreholes to the Hutton seam were arranged to deliver water into the sump of the upcast shaft and from thence it was pumped to the Main Coal seam by two hydraulic pumps placed near that shaft and actuated by columns of water taken from the delivery pipe of a steam pump in the Main Coal seam which forced water to the surface. Pipes fitted with cocks were wedged into the top of each borehole so that the water coming up them from the Hutton seam could be cut off and at the time of the explosion only one hole was delivering water.

The pressure of the Hutton seam water at the Low Main seam was equal to 52 lbs. per square inch at the time of the explosion, but it had been much higher. The water from the Hutton seam had a smell of sulphuretted hydrogen, but no fire damp had been seen accompanying it. Three weeks after the explosion on opening the valve after it had been closed for a considerable period a little gas of some kind had come up one of the boreholes. The flow of gas lasted for about half a minute, and was followed by water. There was some water standing in the dip workings which had been specially driven for standage, a bord to the North of the foot of the stone drift contained a small quantity of water, and just outbye preparations had been made for putting in a dam in case the quantity increased, but this had not been found necessary; there was dampness about both shafts which it was stated at the inquest extended to the south east along both the intake and return air ways as far as the fault shown on the plans. After the explosion owing to a burst power pipe and to the continued delivery of water up the open borehole there was probably more dampness about the shafts than before that event, and a considerable quantity of water had collected in the left main road next the fault. The haulage road near the upcast shaft did not, however, appear damp.

The seam is moderately dusty, but the dust present was almost entirely confined to the floor and mixed with coarser particles. There were probably no deposits of the fine dust on the roof, sides and timber so often found on intake air ways and mechanical haulage roads and due to (1) dust blown from tubs passing at a high speed against the air current and (2) dust from the screens on the surface and from the tubs ascending the downcast shaft; but was of the nature of the dust found in working places and pony or horse haulage roads.

The manager and some of the outside expert witnesses stated at the inquest that they did not consider the seam dusty, although they did not dispute there was some dust and remarks were made as to its dustiness compared with some other seams, the Busty seam being particularly mentioned. The general appearance of the workings over which the explosion had extended showed they were dry and dusty, and the hygrometrical observations recorded on the table below and taken after the explosion confirms this view

Hygrometrical observations taken at Washington Glebe Pit on 22nd February, 1908.
No.	Place.	Time.	Dry bulb.	Wet bulb.	Remarks.
			°F.	°F.
1	Surface in shade	11.25 a.m.	45	43	Dull windy weather.
2	Downcast shaft. Low main seam.	12.05 p.m.	52	49
3	Centre winning. Opposite 1st South.	12.35 p.m.	53	51
4	At shot	1.20 p.m.	63½	62

It is not really a question of how much dust, but rather is there sufficient to be dangerous ? and that the quantity present was dangerous was practically admitted by all the expert witnesses.

I do not think that an excess of dust has much effect on the extension or violence of an explosion after it is once established; so long as there is sufficient line dust cap able of being raised as a cloud and enough to combine with the oxygen of the air, which is always a limiting factor, the part the excess plays is doubtful. An excess of dust insures that there is sufficient of the finer particles and probably has considerable influence on the initiation of an explosion whether due to dust alone or dust and fire-damp in combination, but, after an explosion is fully established, my experience is that the excess of dust (unlike an excess of fire-damp) neither increases nor retards the explosion. At the inquest Mr. W. C. Blackett stated he thought an excess of dust might arrest explosion, but he gave no proof of this.

The coal was moderately hard and was blasted by the Permitted Explosive Bellite No. 3 fired by electric battery. In all the ordinary working places about 16 inches of the bottom stone was shot up at night to make height for the ponies and tubs. On the main roads, top canches of 30 inches on the main haulage roads and 16 inches on roads intended to act as main return air roads, were shot down, the Permitted Explosive Bellite No. 1 fired by electric battery being used by the stonemen in both cases. T he Company provided the explosive but the stonemen, who were all on bargain work, paid for it.

Bellite No. 1 is described in the Explosives in Coal Mines Order of the 17th December, 1906, and has the following composition.

Nitrate of ammonium	82 to 85	parts by weight.
Di-nitro-benzol	15 to 18	"
Moisture	0.75	"

Among five provisos as to its use is one requiring the use of a No. 7 detonator and the following – "That the explosive shall be used only when contained in a case of linen paper thoroughly waterproofed with a mixture of carnanba and paraffin waxes."

No naked lights were allowed in the seam, the lamps used by the workmen were bonnetted Clanny lamps with one gauze and a cap and were locked by lead rivets. Some of the officials used bonnetted Davy lamps similarly locked.

During the day from 4 a.m. to 4 p.m. the seam was occupied by the fore and back shift of hewers numbering 12 persons altogether and these two shifts were overlapped by an ordinary haulage shift of three persons extending from 6 a.m. to 4 p.m.