An Invention for Thoroughly Ventilating the Tunnels and Stations of Underground Railways. Shafts and Levels of Mines, Collieries, Main Drainage Works, and other places.
Year: 1890

page_text: Date of Application, 23rd June. 1890
Complete Specification Left, 20th Mar., 1891--Accepted, 23rd May, 1891
PROVISIONAL SPECIFICATION.
An Invention for Thoroughly Ventilating the Tunnels and Stations
of Underground Railways. Shafts and Levels of Mines, Collieries,
Main Drainage Works, and other places.
I CHARLES HENRY DAVIES of the Firm of C. H. Davies & Co. Estaba. 1866
Consulting Engineer and Artist in Parqueterie to Her Majesty the Queen of
No. 20 Newman Street London, W. do hereby declare the nature of this invention
to be as follows being improvements upon the invention described in my former
Specification 8298 A.D. 1886 :-
The perfect rapid and economical ventilation of underground railways mines etc.
under various exacting requirements and restrictions has heretofore baffled and
defeated every attempt to effect this long desired result. The Patentee however
has expended considerable time and money experimenting and perfecting a complete
practical system & apparatus and my invention has made it perfectly practicable
to run underground railways beneath cities at any depth the shafts and levels of
mines etc. and completely change the whole atmosphere underground every few
minutes at a nominal cost, besides being able to drive & regulate by moving a single
lever powerful engines & other motors several miles distant from the source of the
power.
My invention comprises a complete system producing and distributing com-
pressed air motive engine power from central stations and apparatus for thoroughly
ventilating the tunnels and stations of underground railways and others, the shafts
and levels of mines, collieries, main-drainage works &c. and for distributing motive
engine power by means of compressed air and producing ventilation on a stupendous
scale wherever necessary, particularly the metropolitan railways for which this
Patent is designed to produce the maximum results with the least possible expen-
diture, at the same time securing thorough efficiency with the greatest economy in
working; the object and process of my said invention being to constantly, rapidly
and thoroughly extract all the vitiated air from the tunnels and stations of under-
ground railways &c. which has been deprived of its life-supporting gas oxygen and
loaded with sulphurous-vapours and carbonic acid and oxide gases the products of
combustion in the furnaces of the locomotive engines, and thereby rendered unfit
for breathing which when cooled down in the tunnels is specifically heavier than
the air in the public roads, and will not rise therein unless intelligently directed
mechanical force is constantly applied thereto-independently of the trains! some
of the features of my invention may thus be stated.
A. The whole of the machinery, including the powerful high-pressure (145 lbs.)
condensing silent main engine over eighty standard horse power-compressing air
to 70 lbs. per sq. inch pressure (and double the quantity) being the motive power
for driving fifteen or more smaller self-starting and self-controlling compressed-air
engines working silently and without vibration (in small engine rooms provided)
upon the long girders supporting each pair of centrifugals," and situated between
the public road and the crown of each section of tunnel; and not requiring any
chimney, boiler or engine-house whatsoever!! thereby saving several thousands of
pounds in first outlay, besides the consequent current expenses thereon!! and at
same time rendering the railways unobjectionable throughout their route.
B. Every such compressed-air engine driving two single or duplex, "centri-
fugal," screw air pumps, about 15 ft. diameter and 3 ft. 6 in. deep according to
circumstances revolving horizontally in two circular openings a little larger,
situated midway between the stations, in the thickness of the crown of tunnel

page_text: (made in five rings of brickwork so as not to weaken the said tunnel) and con-
stantly discharging the air therefrom almost in a pure state, at the rate of three-
quarters of a mile per minute if required; but the speed of which can be precisely
regulated throughout the railway by moving a single lever !!
C-The said machinery being distributed throughout the line from Kensington
to Aldgate (6 miles), and from Baker Street to Finchley Road (34 miles) midway
between the several stations, can all be fixed on the Metropolitan Railway Com-
panies present property without requiring any more land whatever! But on the
contrary will enable the company to create perpetual rents and revenues to a large
amount besides a greatly increased higher class traffic.
D-The whole of the above-mentioned apparatus would all be under the absolute
control of one man in charge of the powerful self-contained silent main engine,
eighty standard horse power (the boiler being fed with distilled water 160° Fahren-
heit from C. H. Davies' perfect vacuum pumpless condenser) and therefore con-
suming only about 224 lbs. coke, cost 1s. 4d. per hour situated near the main line
at Baker Street Junction, and not requiring any engine or boiler house whatever!!
and which will effectively drive by compressed air the six engines and twelve
centrifugals eastward to Aldgate, six engines and twelve "centrifugals" west-
ward to Kensington, also three engines and six centrifugals northward to Finchley
Road (ie. over ten miles of railway) the whole being driven and regulated from
Baker Street Junction as aforesaid, by moving a single lever!!
66
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E-The motive power of 70 lbs. per sq. inch air pressure being conveyed by means
of a very strong perfectly air-tight compressed air pipe, carefully prepared and
clothed (provision automatic being made for condensation) and laid in a pitched
wooden trough along one side of the tunnel, and connected by curved branches
provided with effective throttle valves and governors to the aforesaid compressed
air engines placed on the roof of the tunnels, between the "centrifugals" which
silently revolve horizontally in the thickness of the crown of same under the
public road along the railway, having a netting of wire under each opening.
All the said compressed air engines being self-starting and self-controlling
and only requiring a few minutes attention to their bearings and oil-reservoirs once
daily!
G-By my improved invention I am euabled to dispense with the long driving
shafts and tubes with consequent weight of same, also to place the compressed air
engines driving the "centrifugals" in a perfectly clean place free from grit and
dust and also to keep the tunnels quite clear of the ventilating machinery which
will be situated above the wire netting beforementioned which will be firmly
secured under the lower bearings of the "centrifugals" whether single or duplex in
the crown of the tunnels, as a precaution against any possible accident.
J
may also obtain the necessary power for constantly extracting the vitiated air
from the large centrally situated openings in the tunnels of underground railways
&c. by means of powerful currents of air produced by equidistant jets of com-
pressed air generated as beforementioned (or by steam) driven into a series of
short cylindrical tubes about three or four feet long having the jets laid on from
a main pipe and discharging into the centre of each tube aforesaid.
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I may also in cases where the tunnels on railways are several miles distant from
each other produce the constant exhausting power required for continually extract-
ing the vitiated air therein by means of tall air shafts situated centrally between
the two open ends of the tunnel, having a series of air & gas atmospheric burners
spread over the base of the said air shaft, but my duplex "centrifugals with
conical hubs in centre and bevilled rims at about 60° in lower centrifugals and the
blades of both centrifugals arranged so as to cut the air obliquely as the said
blades pass each other with a minimum resistance and without vibration really
possess a power of extracting air heretofore unknown which power can be multi-
plied at pleasure, and of the utmost value in the ventilation of deep and other
mines where a very strong exhausting power is indispensable. The grand result
that will be obtained by the adoption of my improved invention on the metropolitan

page_text: railways &c. will be that the whole of the atmosphere underground throughout all
the tunnels and stations from Kensington to Aldgate also from Baker Street to
Finchley Road containing over twenty-one millions cubic feet of air will be
entirely changed every few minutes and that by silent non vibrating machinery
completely out of sight and securely fixed, with wire netting under each centri-
fugal making it impossible for any accident to happen the tunnels being kept
quite clear of machinery and the speed or degree of ventilation will be under
complete control wherever my improved Patent is applied!!-both in railways &
mines. Every train will run into a fresh, pure, clean and healthy atmosphere the
same as that in the public roads, and further the air constantly discharged at the
rate of three quarters of a inile per minute if required through thirty circular
openings about 15 feet diameter (made in five rings of brickwork as aforesaid) and
partly domed over will constantly rise from fifteen long narrow outlets situated
midway between the sixteen stations almost in a pure state in consequence of the
rapid and thorough ventilation of the tunnels and stations &c. &c. obtained thereby
and not in a foul and poisonous condition as heretofore !!
That my improved invention comprises a thorough and complete process and
apparatus for the ventilation of underground railways mines, collieries &c. by
compressed air motive engine power generated and distributed from central stations
will confer a benefit of great public utility as well as health, comfort and cleanliness
to those who travel by the metropolitan railways and others wherever my invention
is applied and will be the means of greatly increasing the traffic and revenue of
the railway company adopting my improved invention for thorough ventilation by
compressed air power &c.
Dated this 23rd day of June 1890.
CHARLES HENRY DAVIES,
Consulting Engineer.
COMPLETE SPECIFICATION.
An Invention for Thoroughly Ventilating the Tunnels and Stations
of Underground Railways, Shafts and Levels of Mines, Collieries,
Main Drainage Works, and other places.
I CHARLES HENRY DAVIES of the Firm of C. H. Davies & Co. Estab. 1886,
Consulting Engineer and Artist in Parqueterie to Her Majesty the Queen of
No. 20 Newman Street in the Parish of St. Mary la Bonne London, W. do
hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement being improvements on my former Specification 8298 A.D. 1886 :-
The perfect rapid and economical ventilation of underground railways, mines etc.
under various exacting requirements and restrictions has heretofore baffed and
defeated every attempt to effect this long desired result. The Patentee however
has expended considerable time and money, experimenting and perfecting a complete
practical system and apparatus. My invention making it perfectly practicable
to run underground railways beneath cities at any depth, the shafts and levels of
mines etc. and completely change the whole atmosphere underground every few
minutes at a nominal cost besides being able to drive and regulate by moving a
single lever, powerful engines & other motors several miles distant from the source
of the power.
My invention comprises a complete system producing and distributing com-
pressed air-motive engine power from central stations and apparatus for thoroughly
ventilating the tunnels and stations of underground railways & others, the shafts
and levels of mines, collieries, main drainage works &c. and for distributing motive
engine power by means of compressed air and producing ventilation on a stupendous
scale wherever necessary, particularly the metropolitan railways for which this

page_text: Patent is designed to produce the maximum results with the least possible expen-
diture at the same time securing thorough efficiency with the greatest economy in
working the object and process of my said invention being to constantly rapidly
and thoroughly extract all the vitiated air from the tunnels and stations of under-
ground railways &c. which has been deprived of its life supporting gas oxygen
and loaded with sulphurous vapours and carbonic acid and oxide gases the products
of combustion in the furnaces of the locomotive engines, gas lights &c. &c. and
thereby rendered unfit for breathing-which when cooled down in the tunnels
underground is specifically heavier than the air in the public roads and will not
rise therein unless intelligently directed mechanical force is constantly applied
thereto independently of the trains-some of the features of my invention may
thus be stated as being thoroughly efficient and in every way suitable to he
practically applied on the underground railways, levels of mines and wherever
enormous volumes of vitiated air have to be rapidly removed at a small cost. For
obtaining this desirable result I build one or two large circular bevilled openings
in the crown (or side) of each section of the tunnel about 14 or 15 feet diameter
at the bottom and about 17 or 18 feet diameter at the top and six or seven feet
apart according to circumstances and situated nearly midway between two of the
stations (or inlets) and rapidly extract or force the vitiated air constantly through
the said opening or openings so made as aforesaid in the crown (or side) of tunnel
and carefully keep all other apertures closed between the two stations save and
except the large central opening or openings (made in rings of brickwork so as not
to weaken the tunnel) and the two open ends or inlets of each section of the same,
to compel the whole volume of vitiated air contained therein to rapidly travel half
the length of each section of tunnel from each several station (or inlet) towards
the one or two large central openings for each section above described; and
for the purpose of rapidly extracting or forcing the vitiated air constantly through
the said opening or openings I employ either of the following methods-the first
hereinafter described being the best, most convenient and economical; with regard
to first cost, efficiency and unparalled economy in working expenses ! !
In all cases I make direct communication with the large opening or openings in
crown (or side of tunnel; with my powerful, single or duplex centrifugal screw air
pumps about 14 or 15 feet diameter at lower part and about 17 or 18 feet diameter
at the top, with gently curved rims, having triangular opening below the blades to
freely admit the vitiated air, the whole being made very strong and light of thin
sheet iron or steel having according to circumstances 12-16-or 24 partially tapered
blades each about 7' 0" x 5' 3" or 7' 0" x 4' 0" (which will vary with the number
of blades adopted) and so arranged that they shall cut the air as the blades pass each
other obliquely to avoid vibration in the duplex centrifugals, the same having.
conical hubs in the centres of each and bevilled rims with a series of fixed blades
in which the centrifugal screw air pumps will revolve to develop to the utmost all
the centrifugal force generated by the same in rapid revolution. The spokes being
of steel wire about 3" diameter passing through the conical hub in each centri-
fugal to two or three steel pulleys firmly secured to driving shafts and braced
diagonally so as to revolve perfectly true and rigid the outer ends of the said stecl
wire spokes passing through half round steel rims having a countersunk head to
each spoke the thin steel (or copper) blades being fixed at an angle of about 45°
next to the hubs and at an angle of about 37° inside the gently curved rim or rins
which may be about 6', 4' or 2′ 9″ deep, according to circumstances and may be
skeleton or otherwise and a similar centrifugal in the case of the duplex with the
blades fixed the reverse way (when both are used in one of the openings) also at
an angle of 45° next the hub and at an angle of 374° near the outer steel rim, in
such case revolving in opposite directions, the lower centrifugal being driven by
a solid shaft about 24" diameter which would pass through a short steel tube
2" diameter inside & " thick forming the driving shaft of the upper centrifugal,
each of which will have two or three half round steel rings at periphery and between
the centrifugals (to make their touching each other impossible) there will be

page_text: another steel ring or hoop having about 16 steel wire spokes screwed tight into
the central bearing & having about 3 concentric flat steel rings fixed thereto-a
bearing with oil reservoir being provided for the inner shaft exactly in the centre
of the highest part of each opening above the long girders. and another bearing
exactly in the centre of roof of tunnel for lower end of steel driving shaft, which
will work in oil, and be driven by single or double cylinder (steam or) compressed
air engines have designed for the purpose, which would be situated on the
girders above the centrifugals in small engine rooms between the public road and
the roofs of tunnels (unless driven from below) and connected with the main
pipe conveying the compressed air of about 70 lbs. pressure from central stations
by curved branch pipes having quick acting governors and throttle valves actuated
by each engine and controlling their speed, the said engines will only need
attention to their bearings and oil reservoirs once daily, or I may drive the
centrifugals in some cases by means of gearing consisting of bevilled or mitre cog
wheels, but it is best to drive direct from the engines wherever practicable. The
said centrifugals whether single or duplex discharging overhead through gratings
in the public roadway (which is much the best) or carried to one or both sides by
means of horizontal air shafts above the tunnel immediately under the public road
to outlets as near as possible; the air constantly discharged being only very
slightly vitiated in consequence of the thorough, rapid and perfect ventilation of
the tunnels and stations obtained thereby and not in a foul and poisonous condition
as heretofore!!-vast volumes of pure air being continually drawn in by pneumatic
power through the stations and other inlets provided and made to traverse,
throughout all the tunnels from end to end simultaneously and rapidly and constantly
discharged in a comparatively pure state ! !
By this arrangement and using compressed air as a motive engine power, several
of my self acting and controlling steam or compressed air engines compactly
constructed each fitted with effective quick acting throttle valves and governors as
aforesaid for driving my powerful "centrifugal" screw air pumps, the whole
working silently and without vibration, may all be driven along the whole line of
railway from Aldgate to Kensington and Baker Street to Finchley Road and
elsewhere by one or two locomotive, firebox, tubular boilers centrally placed
according to distance cach driving their own or separate air compressing engines
all the cylinders of which will be "jacketed" the steam cylinders with steam
"jackets," and the air compressors with cold water "jackets," there being two air
compressors to each steam cylinder of the same length of stroke and preferably of
the horizontal type (the steam from the main engine of eighty standard horse
power would be condensed a vacuum produced and a distilled water boiler feed
160° Fahrenheit furnished to the boilers by my pumpless condenser, saving about
one third of the fuel) and the whole ventilating apparatus would be under the absolute
control of one man in charge of the main engine as to speed or degree of ventila-
tion &c. &c. throughout the railway wherever my invention is applied by moving a
single lever, and the working expense reduced to the cost of firing the said boiler
or boilers!!
The (steam or) compressed air pipes leading east and west and northward from the
central station where the air compressors will be situated will be of sufficient size to
convey and maintain the pressure of about 70 lbs. per sq. inch for the small engines
furthest from the main engine, without any loss of pressure in transit, the ends of the
main pipe being capped, and automatic provision being made along the route for the
discharge of any water that may become condensed from the compressed air on the
way; all the joints of the main pipe being carefully made as also the branches
communicating with the compressed air engines driving the "centrifugals" the
said main pipe being very carefully clothed with several thicknesses of very thick
brown paper felt or other nonconducting substance well pitched and enclosed in a
pitch pine wooden trough and buried in the ground close to the foundation on one
side of the tunnel, the power of about 70 lbs. per sq. inch being conveyed there-
from, by the curved branches to the engines on the roofs of the tunnels

page_text: throughout the railway, the greatest care being taken to make every joint
perfectly air-tight so that there shall be no loss of power in any way: there
will also be the further precaution of firmly fixing a strong wire netting underneath
every centrifugal" in the roofs of the tunnels to make any accident to the trains
from them quite impossible.
<<
By my improved invention I am enabled to dispense with the long driving
shafts and tubes in the tunnels, with consequent weight of same also to place the
compressed air engines driving the "centrifugals" in a perfectly clean place free
from grit and dust, and also to keep the tunnels quite clear of the ventilating
machinery which will be situated above the strong wire netting before-mentioned,
the same being firmly secured under the lower bearings of the driving shafts of the
centrifugals whether single or duplex, when in the crown of the tunnels, making
it impossible for any accident to happen, and I am enabled to produce a much
stronger constantly exhausting power with less engine power, through the great
improvements made in my single and duplex "centrifugals" together with my
improved system of driving them all simultaneously throughout ten miles of
railway by the motive air power generated and distributed from central stations
and thus brought under the control of one man by moving a single lever!!
I may also obtain the constant necessary exhausting power for continually
extracting the vitiated air from the large centrally situated openings in the tunnels
of underground railways levels of mines, main drainage works &c. by means of
powerful currents of air produced by a series of equidistant jets of compressed air,
generated as hereinbefore mentioned at central stations (or by steam) driven into
the centres of the lower ends of a series of conical or cylindrical tubes about
3 or 4 feet long arranged vertically or horizontally in the large opening or
openings in the centre of each section of tunnel or level of mine as the case
may be.
I
may also where the tunnels on railways are several miles distant from each
other or as circumstances may require produce the constant exhausting power for
continually extracting the vitiated air therein, by means of tall air shafts situated
centrally between the two open ends (or inlets) of the tunnel, and having heat
applied at the bases, either fire or a series of air and gas atmospheric burners,
distributed over the bases of the said air shafts-But my improved single and
duplex centrifugal "screw air pumps really possess a power of extracting air
heretofore unknown which exhausting power can be multiplied at pleasure, and of
the utmost value in the ventilation of deep and other mines where a very strong
exhausting power is indispensable.
22
The grand result that will be obtained by the adoption of my improved invention
on the metropolitan railways &c. will be that the whole of the atmosphere
underground throughout all the tunnels and stations from Kensington to Aldgate
and also from Baker Street to Finchley Road containing over twenty-one millions
cubic feet of air will be entirely changed every few minutes, and that by silent
non vibrating machinery completely out of sight and securely fixed, with strong
wire netting under each " centrifugal making it impossible for any accident to
happen; the tunnels being kept quite clear of machinery, and the speed or degree
of ventilation will be under complete control wherever my improved patent is
applied both in railways and mines:-Every train will run into a fresh, pure,
clean & healthy atmosphere, the same as that in the public roads, and further the
air constantly discharged at the rate of three quarters of a mile per minute if
required, through thirty circular openings about 15 feet diameter (made in rings of
brickwork as aforesaid) and partly domed over will constantly rise from fifteen
long narrow outlets situated midway between sixteen stations almost in a pure state,
in consequence of the perfect rapid and thorough ventilation of the tunnels and
stations &c. &c. obtained thereby and not in a foul and poisonous condition as
heretofore!!
When my invention hereinbefore described is applied to mines; collieries &c. it
is only necessary to fix the same in the main horizontal or vertical shaft or shafts

page_text: as circumstances may require in each case so as to draw fresh air down one shaft
and drive the vitiated air "fire damp or choke damp up the other; the steam
or compressed air engine working my centrifugals being supplied by compressed air
or steam pipes well clothed as aforesaid direct from the boiler or from air com-
pressors driven by the winding engine at the head of the mine.
Having now particularly described the nature and process of my said improved
invention and in what manner the same is to be performed I declare that what I
| claim comprising my said invention is—
Firstly. My improved single and duplex, centrifugal screw air pumps with the
application thereof for thoroughly ventilating the tunnels and stations of under-
ground railways in particular, and the shafts and levels of mines &c. together with
my system or process for thorough ventilation substantially as described in detail
by my Specification herewith including the rapid extraction or forcing the most
vitiated air constantly through one or two large openings only in the crown
(or side) of each section of tunnel situated nearly midway between two of the air
inlets and stations and in keeping all other apertures closed save and except the
one or two large central openings aforesaid and the two open ends (or inlets) of each
section of tunnel, substantially as described by my Specification herewith.
Secondly. I claim my system of driving all my self acting and controlling
engines, which I have designed expressly for silently driving without vibration my
powerful "centrifugal "screw air pumps, along and upon the whole line of railway
or elsewhere from one or two centrally situated boiler, engine and air-compressing
stations according to distance and specially clothing the pipes conveying the
compressed air (or steam) therefrom substantially as described by my Specification
herewith.
Thirdly. I claim my improved system or process for converting the exhaust steam
from my special engines, when steam is used for driving the same, into a hot
distilled water boiler feed and supplying the boilers with distilled water therefrom,
substantially as described by my Specification.
Fourthly. I claim the application to the tunnels of underground railways in
particular of a series of equidistant jets of compressed air (or steam) driven into
the centres of a series of conical or cylindrical tubes, at one end of each tube
arranged either vertically or horizontally as the case may require in the large
opening or openings in centre of each section of tunnel between the fresh air inlets
in tunnel or level of mine as each particular case may require, substantially as
described by my Specification.
Fifthly. claim the application to the tunnels of underground railways in par-
ticular of tall air shafts in direct communication with the centrally situated openings
aforesaid with heat applied at their bases by means of fire or gas and air, Bunsen
or other atmospheric burners equidistantly arranged for constantly extracting the
vitiated air from the tunnels and stations such arrangement of burners not requiring
attention after starting, substantially as described by my Specification.
Sixthly. I claim the application of my improved single or duplex centrifugal
screw air pumps and other methods hereinbefore described to the horizontal and
vertical main shafts of mines colleries, main drainage works &c. and for producing
ventilation on a stupendous scale at a small cost wherever necessary.
Seventhly. claim the application to the tunnels of underground railways of the
wire netting &c. under each "centrifugal" whether single or duplex making it
impossible for any accident to occur from any of my ventilating machinery and
substantially as hereinbefore described.
That my improved invention comprises one thorough and complete system or process
together with machinery for the perfect ventilation in the most economical manner
of the tunnels and stations of the underground railways, mines collieries, main
drainage works and other places will confer benefits of great public utility, besides
health comfort and cleanliness to all who travel by the metropolitan or other
underground railways and will be the means of increasing both the traffic and the

page_text: revenues from rents and other sources hitherto unattainable, but which benefits
public and financial are rendered perfectly practicable by the adoption of my
invention for thorough ventilation at any depth underground as hereinbefore
described and can now with certainty be accomplished to the mutual benefit of all
concerned.
Dated this 20th day of March 1891.
CHARLES HENRY DAVIES, .
Consulting Engineer.