Fred Griffiths' notebook for colliery exams"

1910

Fred Griffiths' Work Diary.

Fred Griffiths worked at the Mountain Colliery and on May 4th 1910 took part one of a mining exam. This is the text in the notebook he kept during his course. The notes were written in pencil, with some sketches which have been omitted here. The notes for the second part of his exam sarted October 18th 1910 and were for the geological background to coal. The notes were followed by revision questions from December 20th to mid-January 1911. The section from February until April covered notes on the construction of shafts and revision notes. The last date is May 2nd 1911.

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HOMEWORK

The points to be carefully watched in long wall working are:

That packs are worked firmly well, also, that there are no props left in the way.

APRIL 1^st 1910

SYSTEM FOR**ADVANTAGES *************DISADVANTAGES

WORKING

Bord (?) 1. Suitable for fairly thick seams 1. Colliery kept on low

& Pillar output until pillars

can be worked

2.Suitable for faults seams 2. Extra costs for yardage

3. Suitable for wet seams 3. Large mount of slack

made

4. Suitable for a fairly thick seam 4. Harder work for colliers

under important property as in cutting

water

5. Suitable for seams that 5. Coals in pillar loses its

as (sic) no packing material value by standing

Long Wall 1. Large output is possible in a 1. Cannot be adopted in

short time very wet seams or

or very faulty ones

or where the roof is

very bad

2. Coal got in better conditions 2. Cannot be adopted for

working under

important property

3. Coal got cheaper as there is no

cutting price

4. It's a very suitable method for

working thin seams by coal cutters

APRIL 5^th 1910

The atmosphere of these two gas mixed together is call ? 79% nitrogen 21% oxygen.

Gases when under mines.

The following dangerous gases are found in mines (first) Carbonic Acid CB2 (second) Carburetted Hydrogen CH4 (3) Carbonic Oxide CO (4) Sulphuretted Hydrogen SH2.

Carbonic and Gas or Carbonic Dioxide is found in mines or Black Damp chokes lamp and stipe (?) is composed part Carbonic Acid is brought on in mines by the breathing of men and horses and by burning by lamps and by the explosion which takes place in blasting. In some mines is also emitted from the strata, and sometimes it is driven from water which penetrates in the mine. It is more common in shallow mines than in deep ones. Its specific gravity is 1.52 or a little more as 11/2 or water. So that is has a tendency to settle neat the floor, its presence should always … so that it ascends to roofs or lodges in holes or cavities.

APRIL 8^th 1910

S Y

CO2 Carbonic Acid 1.52

CH4 Marsh Gas .55

CO Carbon Monoxide .97

SH2 Sulphuretted Hydrogen 1.17

Experiments made with safety lamps in mixtures of fire damp and air, were as follows:

(one volume of FD in 50 volumes of air = 2pct faint cap 1/8 inch high)

1 vol. of FD in 30 vols. of air 31/3 pct cap 3/8 inch high

1 vol. of FD in 20 vols. of air = 5% 1 ¼ inch high caps

At 6 2/3% Gas begins to be faintly explosive at a 11 to 12 ½% it is then at its highest explosive force. At 20% it ceases to be explosive. At 25% it immediately puts out lights. Carbonic Oxide or CO is not a common gas. It is suppose (sic) of 1 part of carbon & 1 part of oxygen. Its SG is .97. It may be produced whenever a great amount of blazing is carried out so that it should be looked for in stone drills and sinking pits. It is not easily detected by the flame of the safety lamp; but often it is a faint sweet smell. CO is dangerous to life when only one % is present.

Sulphuretted Hydrogen is not a very common gas in mines. It consists of 1 part of sulphur to 2 parts of hydrogen, burns with a blue flame. It is slightly heavier than air. Its SG being 1.17 it is produced by water dissolving iron ?, is often found in old workings, badly ventilated places. It is a very poisonous gas. 1 to 2 % breathed in would cause death.

APRIL 12^TH 1910

Natural ventilation may be produced by a difference of surface level between the tops of the shafts. In all cases it is caused by a difference of temperature between the air of mine and that of the surface. Natural ventilation is often made use of in small unimportant mines & in many instances it (is) sufficient of all requirements for such mines. Its advantages are simplicity and absent of cost in upkeep. Its disadvantages are that in some cases the current produced is only feeble and it is liable to reverse at any time in sudden changes of temperature at surface and if the temperature at surface such become the same as that in the mine the flow may cease. It is altogether too uncertain in large mines, the flow in summer reverses its course to that of the winter.

Artificial ventilation includes the furnaces and mechanical ventilation of various kinds, also steam jets.

APRIL 15^TH 1910

Mechanical ventilators consist chiefly of the various kinds of fans, which are also called centrifugal ventilators. Fans generally have two openings, one on each side, through which the air enters and as a fan revolves it discharges the air at the tips of blades or veins. The Guibal fans consist of eight or ten of long veins arranged around the circumference. These are set backwards and are secured by bars and angles. These in turn being bolted to a strong cast iron centre or bose. The fans are closed in a casing with a small clearance to allow it to revolve. Generally the top of this chamber is an arch & there is also an invert at the bottom. It is divided with a sliding shutter which regulates the discharge of air.

Guibal fans vary from 12 ft to 45 ft. Windale fan is an open running fan. The principal open running fan is the waddle type.

And the air is charged at all points around its rear or circumference. It consists of an arrangement of a long and short curved blades arranged between 2 iron discs, one disc.

APRIL 19^th 1910

Sole bars of tubs either wooden or iron tubs are made of oak.

Tubs are either made of wrought iron or steel & wood not cast iron.

Size - about 4ft by 3ft by 1ft 9.

APRIL 22^nd 1910

Horses should have plenty of ventilation and water. The stables should be fitted with water pipes. The floors of the stables should be paved with bricks and should slope towards a gutter. Feeding horses, ponies and mules suitable food for pit ponies consists of maize, oats, beans, bran, hay, clover and straw which are grown and mixed at surface and are sent into mines in sacks.

Ropes & chains of various kinds should be made out of the best plough steel for winding purposes Ropes are greased to save rust and also to save water going to the inside wires.

4 tubs carry 10 cwts = 40 cwts

4 tubs emptys 5 cwts = 20 cwts

carve (?) and chain = 45 cwts

500 yds of 4" circ rope

at 8lbs per yard =35 cwts

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Total load 140 cwts

Rope must have a breaking strain of 70 tons.

APRIL 26^th 1910

Gauzes of safety lamps consist of 784 apertures to square inch. Principle of the gauze is to act as an insulating medium, which prevents the flame inside the lamp from getting to the outside atmosphere, except in some cases where the gauze gets red hot, the wires of the gauze conduct the heat of the flame very rapidly away.

Sir H Davy invented the gauze and Dr Glanny improved it by putting….

The Davy lamp consists of cylindrical gauze screwed to a brass ring which in turn is attached to the oil vessel. The gauze is protected by iron pillars passing up from the brass base to a ring at the top as an additional security. The gauze is protected by another..

(rest of page missing)

….enters above the glass, passes down onto the flame, the products of combustion passing up through the gauze and out the top.

The Mueseler Lamp. This lamp is like the blanny in every respect, the chief feature being the use of a tin chimney. The products of combustion pass up through the central chimney which induces a strong draught.

The Hepplewhite-Gray lamp consists four hollow pillars having ? chamber at bottom. The air enters through apertures at the bottom of these pillars, passing into the annular chamber which is lined inside with gauze. The glass which is conical in shape rests on the annular chamber. It is a very useful lamp for testing small quantities of gas which occur near the roof, as, by sliding a shutter, the lamp its air right from the top. This lamp is considerably one of the best gas-detecting safety lamps.

Author: Griffiths, Fred

Fred Griffiths' notebook for colliery exams"

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