1032

THE COLLIERY GUARDIAN.

June 1, 1917.

MIME MANAGERS’ EXAMINATIONS.

We have received from the Secretary of the Board
for Mining Examinations copies of the questions set at
the examinations for certificates of competency as
managers and under-managers of mines and for certi-
ficates of qualification as surveyors of mines, which
were held by the Board on May 22 and 23 at Edin-
burgh, Newcastle, Sheffield, Cardiff, Wigan, and
Birmingham.

The text of the papers is given below. (Note.—The
figures in parentheses against each question indicate
the maximum number of marks obtainable.)

For First-Class (Manager’s) Certificate of Competency.

Subject No. 1.—Winning and Working.

(Six questions only to be answered. No. 3 is compulsory.)

1.	Fig. 1 is a plan copied from an ordnance Geological
Survey map on a scale of 6 inches to 1 mile, the surface
lines being left out for simplicity. Explain as exhaus-
tively as you can the information conveyed by the map,
and what it tells you of the stratification and geological
features of the area covered by the plan. The surface is
approximately level. (40)

2.	Describe fully the cementation process of sinking.

7. Indicate by means of the usual symbols how you would
ventilate the workings of a mine shown on the accompany-
ing plan (fig. 2). with 8 splits. (30)

Subject No. 3.—Explosions in Mines, Underground Fires,
and Inundations.

(Five questions only to be answered.)

1.	Where coal-cutting machines are cutting in the coal,
how would you deal with the coal dust at the working
face? (30)

2.	Stone dust has been regularly used in a road subject
to deposits of coal dust, and you require to know whether
the result is satisfactory. Describe your method of taking
samples of the- mixed dust, and the nature of the test or
examination to which it should be submitted. What result
would satisfy you that the conditions are safe? (25)

3.	An explosion of considerable extent has occurred in
a large colliery. You are investigating the circumstances,
and it is important to define the parts of the workings
traversed by flame. What evidence would you collect for
the purpose? (25)

4.	An unexpected case of gob-fire has occurred in a dis-
trict of a mine in which large quantities of firedamp are
given off. No preparation has been made, and, owing to
the risk 'of explosion, temporary stoppings have to be put
in as quickly as possible with materials at hand. Describe

by a somewhat circuitous horse road some 400 yds. long.
Describe fully the work necessary to enable you to fix the
starting point and the line of the road. To what base line
would you connect your survey? The seam is level. (30)

3.	If the chain used in measuring in Question 2 were
found to have been, from the first, 3 in. too long, through
uniform stretching, would you think it necessary to correct
the error in working out the results ? What would you do ?
Calculate the correct length of a line which measured 535
links with that chain. (25)

4.	Write out the quadrant bearings corresponding to the
following circular readings on a dial figured to read from
left to right, the readings being those of the north end of
the needle, with the north, or zero, point of the dial lead-
ing :—313 degs., 1174 degs., 175 degs. 25 mins., 54 degs.
17 mins., 180 degs., “ 198 degs. 10 mins., 90 degs., and
269 degs. 55 min. (25)

5.	Draw the section of a round bar of iron 2 in. in
diameter, as cut by a plane at 45 degs. to its axis. The
section is to be a view at right angles to the plane. (25)

6.	At the close of a day spent in levelling in the work-
ings of a seam dipping at a steep inclination, the cross
hairs of your dumpy level are accidentally broken while
you have*200 yds. of approximately level road to cover to
complete your check. Describe fully how you would
finish. (30)

Fig. 1.—Subject No. 1.—Winning and Working.

(Referred to in Question No. 1 First Class.)

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Fig. 2.—Subject No. 2.—Ventilation.

(Referred to in Question No. 7 First Class, and Question No. 1 Second Class.)

The open working faces requiring to be ventilated are distinguished by a
thick black line; the open airways and haulage roads, by two parallel lines.
All the rest of the space within the edge of the solid coal is filled with stowing.
There are to be eight splits of air. The seam is level—coal is raised only at the
downcast shaft.

Under what conditions can it be most successfully
applied ? (40)

3.	Compulsory Question.—Two shafts 500 yds. deep
intersect a seam 5 ft. thick dipping 1 in 4. The shafts are
100 yds. apart, and are sunk in the centre of the coal field,
which is 1 mile square. Coal is wound from the downcast
shaft only, which is sunk 30 yds. below the Seam, and a
level tunnel is driven from this point to the seam. Lay
out longwall workings to yield about 700 tons of coal per
day of 8 hours. Indicate the main haulage roads and
direction of the main ventilating currents. What number
of men would you employ in each district? Show roughly
the size of pillar you would leave for the protection of the
shafts. (50)

4.	Sketch and describe various arrangements at the shaft
bottom with which you are acquainted for speeding up the
loading of coal tubs into cages with more than one deck,
and where the loading is done at one landing. (40)

5.	Two roads 9 ft. wide by 5 ft. 6 in. high cross each
other at the same level at right angles. These roads are to
be enlarged to 12 ft. wide and 7 ft. high. Show in detail
how you would do this work, using steel girders and brick-
work, and how you would temporarily support the roof
whilst the work is proceeding. Give sizes of girders and
distances apart. The roof is of a soft nature. x (40)

6.	Give a detailed description of two methods of percus-
sive power boring : (a) by rope, (6) by rods. Illustrate
your answer by sketches. Compare the advantages and
disadvantages of each system. (40)

7.	Two shafts are sunk to a depth of 800 yds. Coal is
wound from the bottom of one shaft, and from a depth
of 500 yds. in the other. What arrangements would you
make for withdrawing the men in case of a breakdown at
either of the shafts ? (40)

, Subject No. 2.—Theory and Practice of Ventilation.

(Six questions only to be answered. No. 1 is compulsory.)

1.	Compulsory Question.—A mine is being ventilated
with three splits of air, each of 30,000 cu. ft. per minute,
and a water gauge of 3 in. Assuming the horse-power and
internal resistance of the ventilator to remain unaltered,
how much air will pass through each split if the height of
the water gauge is increased to- 5 in. ? (50)

2.	Describe the process of diffusion of gases, and calcu-
late to the second place of decimals the relative time
required for equal volumes of firedamp and carbon dioxide
to diffuse into air. (30)

3.	Suppose the average maximum summer temperature
of the air in a downcast shaft to be 60 degs. Fahr., the
top of that shaft to be 50 ft. higher than that of the
upcast, the bottoms of the two shafts to be on the same
level, and the average temperature of the air in the upcast
to be the same as that of the workings (assume 1 deg.
Fahr, per 60 ft. in depth), what minimum depth would the
two shafts require to have in order that an air current
would flow through them continuously in the same direc-
tion all the year round ? If at a given time the average
temperature of the air in the upcast shaft were 75 degs.
Fahr., that in the downcast 55 degs. Fahr., and the average
weight of a cu. ft. of air in the latter 0-08 lb., what would
be the pressure of the motive column in lb. per sq. ft. ?. (30)

4.	Sketch the Hailwood safety lamp with, or without,
the inner combustion tube in sectional elevation, on a scale
of about one-half its natural size. Show the manner in
which air circulates in its interior. Describe the advan-
tages claimed for it. (30)

5.	What height of water gauge is required to produce
100,000 cu. ft. of air per minute in a mine whose equiva-
lent orifice is 16 sq. ft. (30)

6.	Sketch in sectional side elevation and plan a com-
pressed air injector blower; or, alternatively, a small
auxiliary fan actuated by an electric motor, suitable for
ventilating a heading in a mine. Show the course of the
air entering, passing through, and leaving the apparatus.
Show the details of the joint between the outlet of the
blower, or fan, and a range of sheet iron air pipes; and
state upon what principle the production of an air current
by the apparatus which you sketch depends. (30)

the work, the number of men required, and the time
required. When would you complete the work with per-
manent stoppings ? (25)

5.	Describe fully the equipment and organisation you
would establish at a large colliery for dealing with fires
on the surface. (25)

6.	Old workings containing water under pressure are
being approached by headings and boreholes. The bore-
holes have failed to tap the water, but a quantity is
coming through fissures in the coal at the side of one of
the headings near the face. What would you conclude had
happened, and what steps would you take? (25)

Subject No. 4.—Machinery.

(Five questions only to be answered.)

1.	Describe a condensing plant suitable for a large steam
turbine. What degree of vacuum, expressed in figures,
would you aim at obtaining? (28)

2.	If called upon to provide 1,000 kw. of electric power
for use underground, a fair proportion of the power having
to be transmitted one mile or more underground, what
kind of electric power would you adopt, and at what
voltage ? Give reasons for your answer, and describe in
outline the power house with its equipment of plant. (28)

3.	The drawing (fig. 3) shows a two-throw crankshaft in
plan and side elevation. Draw in your answer book an end

Eleva t/on.

Plan.
A '

Fig. 3.—Subject No. 4. Machinery.

(Referred to in Question No. 3 First Class.)

elevation of the crankshaft, looking in the direction of
arrow B, to a scale of 1J> in. equals 1 ft. Indicate the
position of the two keyways on your drawing. (38)

4.	Describe an air hammer drill as used for boring holes
in shale or rock. In particular say how the piston is caused
to reciprocate, and how the drill is caused to revolve. (28)

5.	Compare a turbine pump with a three-throw pump for
dealing with 600 gals, per minute of water at a head of
600 ft., stating the advantages and disadvantages of each
type. (28)

6.	Describe the inlet and outlet valves and seats of the
air cylinder of any modern compressor. Illustrate your
answer by simple sketches. (28)

Subject No. 5.— Surveying, Levelling, and Drawing.

(Five questions only to be answered. Candidates for
surveyors’ certificates must answer Questions 1 and 2.) '

1.	Draw a section on the line A C B on the plan (fig. 4),
showing the several shale and coal seams. The depth to
the Raeburn shale in bore C is 100 ft. Assume that the
surface is level, and that a thickness of 50 ft. of drift
covers the rocks throughout the area. The section is to
be drawn to the scale of the plan. (30)

2.	A straight haulage road is to be extended in the goaf
or waste, on the line of the part already existing, by driv-
ing backward and forward from a point in the workings in
advance. The end of the haulage road and the point from
which the proposed extension is to be driven are connected

7.	In measuring a long line in a surface survey you find
it to pass through a building. How would you surmount
the difficulty ? State the check you would apply to your
method. (25)

Subject No. 6.—General Management, and Mining
Legislation.

(Five questions only to be answered. No. 1 is compulsory.)

1.	Compulsory Question. — You are sent to examine
and make a report on the general condition of a colliery,
more especially on its condition as to safety. Draft such
a report. (30)

2.	What is the definition of the word “ mine ” in the
Coal Mines Act, 1911 ? (25) ,

3.	State the different conditions under which the use of
safety lamps is made compulsory in a coal mine. (25)

4.	How are the abstract of the Coal Mines Act, and
Regulations under the Act, to be published at a colliery,
and what are the orders in connection therewith ? (25)

5.	What is meant by the term permitted explosives,”
and under what circumstances is their use compulsory ? (25)

6.	What are the stipulations as to the provision of wash-
ing and drying accommodation for workmen at collieries,
and what is your opinion of the advantages or disadvan-
tages of their adoption? (25)

For Second-Class (Under-Manager’s) Certificate of
Competency.

Subject No. 1.-—Mine Working.

(Five questions only to be answered. No. 1 is compulsory.)

1.	Compulsory Question.—Lay out in detail a small
district of longwall and pillar-and-stall workings respec-
tively. Give a section of the seam, the roof, and floor in
each case. (60)

2.	Describe fully how a length of shaft lining is put in
with (a) brickwork, (5) concrete. What advantages are
claimed for the latter system ? (60)

3.	State the classes of explosives you would prefer for
hard rock and coal respectively, and why. What pre-
cautions ought to be taken with explosives in winter, and
with which class in particular ? (60)

4.	In a longwall system of working, to what points would
you specially direct your attention in order to economise
in the use of timber, with due regard to safety ? (60)

5.	Two roads, 9 ft. wide by 5 ft. 6 in. high, cross each
other at the same level at right angles. These roads are
to be enlarged to 12 ft. wide and 7 ft. high. Show in
detail how you would do this work, using steel girders and
brickwork, and how you would temporarily support the
roof whilst the work is proceeding. Give sizes of girders
and distances apart. The roof is of a soft nature. (60)

6.	Describe the various systems of working coal with
which you are acquainted, and the reason why the par-
ticular methods have been adopted. (60)

Subject No. 2.—Theory and Practice of Ventilation.
(Six questions only to be answered. No. 1 is compulsory.)

1.	Compulsory Question. — Indicate by means of the
usual symbols how you would ventilate the workings of a
mine shown on the accompanying plan (fig. 2) with eight
splits. (50)

2.	What relations exist between the angular velocity
(velocity of revolution) of a fan, the head, measured by
the height of the water gauge, and the quantity of air
passing through the fan ? (50)

3.	Sketch in sectional side elevation and plan a small
auxiliary fan actuated by an electric motor, suitable for
ventilating a heading in a mine. Show the course of the
air entering, passing through, and leaving the apparatus.
Show the details of the joint between the outlet of the
blower, or fan, and a range of sheet iron air pipes. (50)

4.	Make a careful sketch of an air door, showing all the
details of its construction as well as those of the frame to
which it is attached, and the brick and mortar wall in
which it is secured so as to constitute an airtight parti-
tion in an important heading. Show these details in plan
and in front elevation, and include in your drawing the
sides, roof, and floor of the heading. (50)