CERTAIN IM- PROVEMENTS IN RAILWAY TURNTABLES
Year: 1847

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
MADIGAN, of Haverstock Hill, in the County of Middlesex, Civil Engineer,
send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, "bearing date at Westminster, the Second day of Sep-
tember, One thousand eight hundred and forty-seven, in the eleventh year
of Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Richard Madigan, my exors, admors, and assigns, Her especial
license, full power, sole privilege and authority, that I, the said Richard
Madigan, my exors, adññors, and assigns, or such others as I, the said Richard
Madigan, my exors, adñors, or assigns, should at any time agree with, and
no others, from time to time and at all times during the term of years therein
expressed, should and lawfully might make, use, exercise, and vend, within
England, Wales, and the Town of Berwick-upon-Tweed, and in the Islands
of Jersey, Guernsey, Alderney, Sark, and Man, and also in all Her said
Majesty's Colonies and Plantations abroad, my Invention of "CERTAIN IM-
PROVEMENTS IN RAILWAY TURNTABLES;" in which said Letters Patent is con-
tained a proviso, that I, the said Richard Madigan, shall cause a particular
description of the nature of my said Invention, and in what manner the same
is to be performed, by an instrument in writing under my hand and seal, to
be inrolled in Her said Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said in part recited Letters

page_text: Patent, as in and by the same, reference being thereunto had, will more fully
and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Richard Madigan, hereby declare that the nature of my said Invention,
and in what manner the same is to be performed, are fully described in and
by the present Specification thereof, reference being had to the Drawings
hereunto annexed, that is to say:-
My Invention has,-
Firstly, for its object, the production of railway turntables of a stronger,
cheaper, and more durable character than those ordinarily in use, and consists
in making the parts thereof partly of wrought iron and partly of cast iron
combined together in the peculiar manner herein-after explained, and in
fitting the same with certain appliances not heretofore made use of.
Figure 1 is a plan of a railway turntable embodying these improvements;
Figure 2 is a vertical section on the line a, b; and Figure 3 is a plan on the
line c, d. The apparatus consists principally of-three parts: first, of an
under framework, which is stationary; second, of the table, which is move-
able round its axis; and, third, of a "motion" or framework for retaining
in their proper places such antifriction rollers as may be employed for enabling
the upper table to be turned readily and smoothly round with its load upon
it. A, A, is the under or stationary framework. It is laid upon a foundation
of masonry, and consists of an external ring B, B, and a set of radial arms
C, C, united by a central boss D. The arms are represented as being eight
in number, but their number may be either more or less, according to the
size of the table. The ring B, B, and the radial arms C, C, are made of
rolled bar iron welded together at their junctions, so that the whole form
together but one piece, to which the central boss D is added by casting; that
is to say, by pouring iron in a fluid state into a suitable mould formed around
the inner ends of the arms. The upper and moveable table E, E, is formed
of the same materials and put together in exactly the same manner as the
lower. F is a central vertical pin which is passed down through holes bored
out in the bosses of the table E and under framework A, and serves to keep
the table, when turned round, within the same circular path. The two tables
are kept at a certain distance apart, which is regulated by means of a cap G,
which is secured by four bolts d, d, to the upper table E, and rests upon the
upper side of a brass H. I is an aperture through which oil is supplied to
the centre pin F. The rails K, K, are secured to top of the upper table E by
means of rivets or bolts passing through both the rails and the radial arms
and the ring of that frame, the intervening spaces L, L, being afterwards

page_text: covered in with planking or iron plates. The motion for enabling the upper
table to revolve readily and smoothly upon the other, is represented in Figure 3
as being effected by means of antifriction rollers of the description known as
"Greenway's patent antifriction spheres;" but antifriction rollers of the ordinary
kind may be substituted, if preferred. In either case, however, no portion
of the roadway must project beyond a vertical line passing down through the
centres of those spheres, the object of which arrangement is to prevent the
table from being shaken about or broken by the passing of a train over it.
M, M, are the antifriction spheres, which, by means of the radial rods N, N,
and the rings 0, 0, 0, are made to preserve an uniform distance from the
centre of the table, in whatever direction it may happen to be turned; besides
which, these spheres are so placed between the rings B and E that the upper
ring or table E may always rest upon them, while they in their turn rest upon
the lower ring B. m, m, are friction pulleys which serve to keep the spheres
at proper distances apart, and to prevent any rubbing of their surfaces.
P, P, P, are a set of friction wheels mounted upon the ends of the radial rods
N, N, which serve to support the rings O, O, and the parts connected there-
with. R is an outer casing to protect the working parts from dust and
rubbish.
Figures 4 and 5 are Drawings, partly in section, of a modification of the
railway turntable which has just been described, but differing from it only in
some minor arrangements for keeping the antifriction spheres in their proper
places between the stationary and moveable tables, and which will be obvious
on inspection of the Drawings.
Figures 6 and 7 are representations in plan and elevation of a railway turn-
table similar to that first described in so far as respects the lower and
stationary table A and the upper and moveable frame or table E, but
differing from it in the "motion" part. A¹, A¹, are radial rods attached at
their inner ends to a ring of metal B', B', which fits loosely around the boss
D, while their outer ends form the axis of a set of friction wheels P1, P¹, by
which the table is supported instead of by antifriction spheres. S, S, are
buckles which are fitted upon the radial rods between the friction wheels
P1, P1, and the collars T, T, the buckle on the one radial rod being connected
by a tension bar U to the buckle on the next contiguous radial rod, and so
on until the whole circle is completed. A front view of one of these buckles
is separately given in Figure 8. One or more of the tension bars U, U,
is divided in the middle, and one portion of the bar so divided is screwed
with a right-hand thread, and the other portion with a left, the junction
between them being effected by means of a coupling W, a view of which

page_text: is given separately in Figure 9. By this arrangement the bars U, U, can be
adjusted at pleasure to any degree of tension required.
Secondly, my Invention has for its object the constructing of railway turn-
tables in such manner that while they shall be capable of transferring
carriages from one line of rail to another line of rail crossing the same, they
shall leave both the main lines of rails unbroken and uninterrupted, instead of
the main lines of rail being, as usual, continued along the tables themselves.
Figure 10 is a sectional elevation of a turntable constructed on this plan;
Figure 11 is a plan of the same; and Figure 12 an end elevation of the
above groundworks, shewing the position which will be occupied by the
carriage while being turned round. A, A, is a central post which supports at
its upper end a strong cap or frame B, B, upon which, and attached thereto, aro
laid two strong longitudinal bars or rails C, C, which are further strengthened
by struts D, D, so that the bars or rails C, C, may have sufficient strength to
bear the weight of any engine, carriage, or truck, &c. which may be placed
upon them, as afterwards explained. This post A is kept in a vertical
position by means of a hollow cylindrical casing E within which it is placed.
The position occupied by the casing E is central to both lines of railway F, F,
and F, F, and it is securely fixed to some solid foundation either of wood or
masonry. G is a lever which has its central bearing in a pedestal H, which
is also secured to some solid foundation below, while its upper end is firmly
bolted to the basement of the cylindrical casing E. The shorter arm of the
lever G terminates in a stud I, which takes into a hollow recess in the bottom
of the pillar A, while the longer arm of the lever terminates in a weight H',
which, together with the other parts connected to the same end of the lever,
forms a counterpoise to the weight of the central column A and the table
affixed to it. K is a rod which, at the bottom, is connected to the lever G,
and at top is jointed to a lever L by means of a cross pin M, which is passed
through a long slot N in the lever L. The pin M terminates at each end in
handles M, M', by which it may be laid hold of, so that the lever G, the
central column A, and the table affixed to the cap B may all, by the simple
application of the hand, be raised through a certain portion of the limits of
their range of action for the purposes to be presently described. The lever L
is jointed at its lower end to a fixed plate nearly on the level of the rails,
while the upper and free end terminates in a weighted handle O, which is
calculated, with the leverage obtained by the machine, to form a counter-
poise to the medium of the weights of an empty carriage when put upon the
table. The manner of using this table is as follows:-Supposing that the
carriage is upon the line of rail F, F, Figure 11, it is brought over the place

page_text: occupied by the table, which is supposed at that instant of time to be at its
lowest position; namely, with the top of the bars or rails C, C, flush with the
top of the line of rails F¹, F'. The attendant now takes hold of the handles
M', M', and presses them downward (which is easily accomplished with the
assistance of the counterpoise H¹; and by this action the central column is
raised up and brings the rails C, C, in contact with the axles of the carriage.
A catch P, which is attached to the lever L, is now brought down upon the
cross pin M, which secures it from again sliding up the slot N until it has
been released on the completion of the operation. The lever L is next laid
hold of by the attendant, and brought down to the position it is represented
as occupying by the red lines, which causes an additional rise of the table and
its load, and the wheels of the carriage to be taken thereby clear off the rails.
The table and carriage are now ready for being turned to the required
position over the line of rails F¹, F¹, which is again easily accomplished by
hand (the friction of the rubbing parts being comparatively small), and by a
reverse operation the carriage is lowered upon the rails and the table into its
original position, flush with the line of rails. R, R, are friction rollers fitted
upon the top of the hollow casing E to facilitate the horizontal movements of
the table. As, in consequence of the varying diameter of the carriage wheels,
the connecting rod K may not always be exactly of the length requisite to
bring the top of the bars of the table C, C, in contact with the lower sides of
the carriage axles at the precise moment when the catch P comes into play,
in order to provide against this contingency, there is attached to the upper
end of the rod K a sliding piece Y 13, by means of which, with the assistance
of the screw Z, the connecting rod may be elongated or slackened at pleasure.
One of the great advantages attending a turntable of the kind just described
is, that trains in passing over it do not touch it, and that it is consequently
spared much of the tear and wear to which other tables are exposed.
Another prominent advantage is, that as the table contained within the lines
of rail, it will turn carriages on railways where tables of the ordinary size,
such as tables of thirteen or fifteen or sixteen feet diameter could not be
used, owing to the contiguity of the rails; and consequent with this improved
table, six-wheeled engines and carriages may be turned with as much facility
as those with four wheels.
Thirdly, my Invention consists in constructing railway turntables in the
manner represented in Figure 14 and Figure 15 of the Drawings hereunto
annexed, the former being a vertical section, and the latter a plan, of the
apparatus. A is the rail platform; B, the framework; C, the central pivot
on which in this table the whole weight is thrown; D, D, D, D, the hori-

page_text: zontal antifriction rollers, which are attached to the rail platform by means
of pins on which they turn easily and roll against the curb E, which is turned
or bored of a cylindrical form at that part against which the rollers work;
F is a step or foot for the central pivot to work in, which is connected to
the curb by the tie rods G, G. The curb E and step F are both firmly
bedded on brickwork K, K, masonry, or any other suitable foundation. Or,
instead of constructing the table in the manner which has been so fare
described, the construction may be modified as represented in Figure. *
.
Figure 16 (a vertical section); and Figure 17, a plan. In these two
Figures one half of the rollers are, for the sake of illustration, shewn in a
horizontal position, and the other half in an oblique position; but it will
readily be understood, that in constructing a table of this description, it will
be necessary to have all the rollers arranged in the same way, either hori-
zontal or oblique. Here the rollers D, D, D, D, are attached to the curb by
means of pins on which they turn-freely. The platform or upper frame is
provided with a ring R, which is turned of a cylindrical form for the horizontal
rollers, and conical for the oblique rollers, at that part which works against
the rollers. The oblique rollers should also be conical. The angles of both
the ring and the rollers may be determined by the method ordinarily used for
setting out bevel gear, and which is well known. I would also recommend,
that in all cases the edges of the rollers should be slightly rounded. H is a
screw for adjusting the height of the table when the oblique rollers are used,
which should be screwed down until the whole of the weight is carried by the
centre pivot and the rollers act merely as guides. This adjusting screw may
in some cases be applied with the horizontal rollers, but in general this will
not be necessary. To prevent water, dirt, &c. from getting to the centre
pivot, I surround it and the step it works in by an inverted air-tight cup or
chamber I, the air in which prevents the water from rising in it above the
step F, even should the pit be full of water. The step or foot F is also
formed into a cup round the pivot large enough to contain as much oil as
would be required for a considerable length of time. In the table described
under this third head of my Specification the platform and framework are
supposed to be construction of the same materials as usual, but I propose also
to apply to it the same improved combination of wrought iron and cast iron
which has been specified under the first head of this Specification.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that the improvements in railway
turntables which I claim as constituting the said Invention are as follows:―

page_text: First, I claim the constructing of turntables of the materials and in the
manner set forth under the first head of this Specification; that is to say, in
so far as respects the combining of wrought iron and cast iron in the peculiar
manner herein-before described; the employment of antifriction spheres or
rollers so placed and adjusted that the roadway of the table shall not project
beyond the centres of such spheres or rollers; and the use of coupling screws
to hold together tighter or relax the tension bars, as before described.
Second, I claim the improved turntable or apparatus, described under the
second head of this Specification, for raising carriages, waggons, trucks, and
other vehicles from off the railway before being turned, and then turning
them while so raised, in the peculiar arrangement, combination, and adaptation
of parts of which the same consists, but without laying claim to any of the
parts thereof individually and separately considered. And,
Third, I claim the improved turntable, described under the third head of
this Specification, in the peculiar arrangement, construction, combination, and
adaptation of parts of which the same consists; that is to say, in so far as
regards the position given to the central pivot, and the arrangements for
throwing the whole of the weight upon it; the position in which the horizontal
or oblique antifriction rollers are placed, for the purpose of guiding the upper
part of the platform; the inverted air-tight cup for protecting the central
pivot and step from water, dirt, &c.; and the combination in the said table
of wrought iron and cast iron, as before described.
In witness whereof, I, the said Richard Madigan, have hereunto set my
hand and seal, this Second day of March, in the year of our Lord
One thousand eight hundred and forty night