Improvements in Bridges and similar Structures.
Year: 1889

page_text: Date of Application, 25th Oct., 1889-Accepted, 1st Feb., 1890
COMPLETE SPECIFICATION.
[Communicated from abroad by EMILIEN THOMAS, of Raismes, in the Republic of
France, Engineer.]
Improvements in Bridges and similar Structures.
I. HENRY HARRIS LAKE, of the firm of Haseltine Lake & Co., Patent Agents,
Southampton Buildings in the County of Middlesex 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 stateinent :-
My invention has for its object to build bridges and similar structures in such a
manner that they can be easily transported and mounted or dismounted with the
greatest rapidity."
The invention consists in the employment and combination of steel or iron tubes
which are joined to each other by a special coupling so as to form all the main parts
of the structure which is to be built.
These iron or steel tubes are externally screw-threaded in inverse directions at their
two extremities so that they can be introduced into internally screw-threaded sockets
or sleeves serving to connect the said tubes one by one, according to the length of
the structure. The said sockets are provided with lugs or eyes cast or wrought in
one piece with the body of the same. These lugs or eyes are designed to receive
the articulated fixed extremities of the tubes forming the uprights and the cross
pieces connecting and consolidating the main pieces forming the girders of the
bridge and also the main pieces forming the piers.
The conditions which, for practical purposes, must be fulfilled by the dismountable
bridges so that they can be used by armies, for earth work and the like, portable
narrow-gauge railways, agricultural and many other industrial purposes where bridges
are necessary are as follows :-
1st. They must be light and strong.
2nd. Their parts must be employed which are capable of withstanding the defor-
mations produced in their transport and handling.
3rd. They must be able to be easily transported and handled by men.
4th. Simplicity must be ensured and the number of parts forming a bay must
be few.
5th. Rapidity and facility of the mounting, dismounting and packing must be
obtainable.
6th. It must be possible to augment the span of the bays without great changes.
7th. It is necessary that the elements composing the horizontal bays can be used in
the construction of piers of variable heights.
All these conditions are fulfilled by the bridges having girders of iron or steel
tubes as constructed according to the aforesaid invention.
These improved bridges may be any span and size. I will however, in order to
ender the principal features of my said invention better understood, proceed to
describe by way of example a bridge of steel having two bays, each 10 metres in
ength, with a pier of equal height, for enabling the passage, on a railway where
he rails are 0-60 m. apart, of locomotives or trucks the axles of which are at a
listance of 150 m. each being charged with a load of three tons.
Girders. Each of the girders, which are 2.750 m. apart from centre to centre is
omposed
1st. Of two horizontal main pieces made of tubes having an exterior diameter
f 0-100 m. and a thickness determined according to the loads to be supported.
These tubes are two m. in length. They are externally provided with right handed
crew threads at one extremity, and with left-handed screw-threads at the other
xtremity. Two by two are connected by a socket B having a right-handed interna

page_text: screw thread on one side and a left handed internal screw thread on the other. By
turning this socket, into which two of the above-mentioned tubes have been inserted,
the connection is readily effected. The same is done with two double tubes until the
proper length of the said main parts is obtained which in the present example is 10 m.
from centre to centre of the extreme nuts or sockets.
2nd. At distances of two metres are articulated upon these nuts or sockets provided
with lugs hollow uprights having an external diameter of 0.60 m. and a thickness
determined by the resistance which uprights thus connect vertically the two paralle!
main pieces that are 1 m. apart from centre to centre.
3rd. At distances of one metre upon the same nuts or sockets, and upon the
sockets of the hinges c, surrounding the aforesaid main parts are also articulated
inclined bars or cross pieces consisting of hollow tubes having a determined
thickness.
The entirety of the two main parts uprights and inclined bars or cross bars consti-
tutes a girder which can be easily and rapidly mounted and dismounted.
In practice I have found that it is preferable to employ for the support of the tubes
from distance to distance sockets having hinges and formed of two parts which when
they are connected present an annular section and which are placed on either side
upon the tubes by means of a ring. These sockets alternate with the sockets or nuts
for carrying the cross bars. It is understood that this modification of my invention
does not in any way affect its character, and one or the other of the said arrangements
can be employed without departing from the nature of my invention.
In the accompanying drawings I have shown the application of my bridge with two
kinds of sockets.
The transport and handling of the parts can also be effected by manual labour in
yards for the cases containing a girder can be easily carried.
For greater spans than 10 m. up to the length of 16 m. it will be sufficient to
employ tubes of greater thickness, the original external diameter and its external
screw-thread being retained, for all the accessory parts, such as nuts, axes, hinges,
and the like, which, are of a small weight, are calculated for spans of 16 m. For
still greater bays the girders are made of a greater height but the arrangements
of the parts and their dimensions will be altered according to the resistance.
Superstructure. The superstructure is formed of rivetted girders of steel, placed
at a distance of 2 m. from each other and secured to the nuts or sockets of the
lower main piece by bolts permanently retained in the said nuts. This arrangement
enables the mounting to be rapidly effected, because only the nuts will have to be
tightened upon the fixed shafts of the aforesaid bolts. Joists of rolled steel of 2 m.
and 4 m. in length and placed at a distance of say 0-600 m. from the rails are
fixed upon the cross-bars by means of corbels which, being adapted to pivot
upon their axis and driven home by means of a hammer will tighten the lower
part of the joists upon the cross-bars. The mounting and dismounting can thus
be effected with rapidity.
Upon these joists and two wooden planks is fixed a flooring for the railway.
To the exterior of the girders and upon the nuts of the lower main parts are
fixed, by the same bolts which secure the cross bars at distances of 2 m. consoles
of sheet iron and steel pieces of angular section which serve on the one hand as
abutments for the bolted counterfort, and on the other hand for the nuts of the
upper main parts which they prevent warping when under compression. A tri-
angular tracery formed of steel pieces of angular section, and fixed to the upper
part of the cross-bars, connects the girders horizontally and ensures the warping.
For expedition and transport two and two of these angular pieces are superposed
in order to prevent any deformation in the handling.
Support. The supporting plates made of wrought iron, cast iron or steel, which
are at the extremities of the girders, are placed below the sockets or nuts at the
ends of the aforesaid lower main pieces. They carry a socket B whose object
will hereinafter be described, and they are combined with a sheet iron plate
designed to distribute the total charge of a support upon a sufficiently large

page_text: surface. Two pressing screws are employed for fixing the supporting parts upon
the nuts with which they remain firmly connected.
Pier. The pier is composed of parts which are similar to those above described. In
short it is a bay placed vertically and modified as follows:
In the longitudinal direction of the bridge the two girders, which are 2.750 m.,
apart, form two vertical main parts, the upper extremities of which are fitted into
the tubes herein before mentioned. In the transverse direction these two main parts
are connected horizontally at distances of 4 m. and on each side by cross-bars which
are similar to those of the bays where they are placed 2 m. apart.
At the interior of the main-parts, at distances of 4 m. are fixed the consoles which
in the horizontal bays are placed at the exterior. These consoles and cross bars
serve for the vertical attachment of braces which are similar to those already
described. In this manner the aforesaid two mainparts which are supported at
distances of 2 m. can resist the deflection which the load of the bridge tends to
produce.
By adding, or dispensing with tubes the height of the piers can be augmented or
diminished.
From the foregoing statements follows that all the above-mentioned conditions are
fulfilled.
In the accompanying drawings,
Figure 1 is an elevation showing the general arrangement of a bridge of 20 m.
in length constructed in accordance with the present invention.
Figure 2 is a transverse section on the line xa showing a pier.
Figure 3 is a plan of the same.
Figure 4 is a view to an enlarged scale of a girder made of the tubes A connected
by means of internally screw-threaded sockets or nuts B, (B' is the socket of the pier)
Care hinged sockets.
The uprights are shown at D, and the cross bars at E. F designates the counter-
forts, and G the joint of the pier and tubes A. A.
Figure 5 is a transverse section of the improved bridge, showing the profile of the
screw pieces and of an upright.
Figure 6 shows a plan of a girder with the summers.
Figure 7 shows an enlarged view of an upright which is fixed in the socket H con-
nected with one of the lugs I on an internally screw threaded socket B. This
arrangement is at the lower and upper extremities of the tube.
Upon one side of the upper socket-piece is fixed the extremity of the counter-
fort F the latter being supported with its lower part upon the console J fixed by
bolts to the outside of the lower sleeve B holding one of the extremities of the
upright D. Upon the inner side of the lower socket is fixed a summer K. It is to
be observed that the sockets B which carry the uprights and summers are provided
with projections L forming feet and supporting the extremities of the summer K and
console J carrying the counterfort F. The same projections L are provided on the
body of the sockets B supporting the upright D and they are designed to serve as
buttresses at the upper extremity of the counterfort F. The projections on the
sockets, by supporting the parts K J and F prevent the shearing of the bolts 1, 1,
by means of which they are fixed.
Figure 12 is a section on the line A, B of Figure 7, showing the connection of the
tubes A A in the socket B, and also the mode of fixing the console J of the upright D
and cross-piece E, these two parts being fixed in sockets Hand H. The former
socket His provided with a forked part, whilst the second has only a single arm to
receive the bolt for the connection with the lugs I. These sockets are internally
screw-threaded and secured by pins to the tubes D and E, as shown in section in
Figure 7.
Figure 13 shows the connection between a socket H' and a lug I on a socket B.
Figures 8 and 9 represent to a larger scale a front and side elevation of the arrange-
ment of a socket Cupon a tube, this socket having a hinge at c and lugs at N, N.
Each of these sockets as above stated, is formed of two parts d, d connected by a

page_text: binge c. It is of the same section as that of the tube so that when put in its place it
encloses the entire circumference of the tube, its two extremities N N being closed
upon each other to form lugs I which fulfil partly the same purposes as those on the
sockets B above described. This socket is firmly held upon the middle part of the
tubes A by two rings or collars 0 0 welded or shrunk upon the body of the tubes.
Figures 10 and 11 show the front and side view of a socket B employed for the
extremities of the bridge and performing the same part as the other sockets & besides
that of carrying the bridge being mounted upon a bed-plate P by means of a counter
plate P having projections so to provide for a little play which can be regulated by
means of pressing screws q, q.
It will thus be seen that my above-described invention consists in the construction
of bridges having girders of iron or steel tubes so that they can be dismounted and
transformed into piers. According to the purposes for which the improved bridges
are to be used, the arrangement and construction of the whole and of the details can
be modified without departing from the nature of the said invention.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, as communicated to me by
my foreign correspondent I declare that what I claim is :-
First. The construction of bridges and similar structures, characterized by the
employment and the combination of iron or steel tubes which are connected with each
other, substantially as above described and shown in the accompanying drawings.
Second. In bridges and similar structures having girders made of iron or steel tubes,
the employment of tubes of any length, strength and diameter, which are screw-
threaded at their extremities for the purpose of connecting them by means of sockets
so as to obtain a definite length forming the main pieces, girders and piers of the
bridge substantially as above described and shown in the accompanying drawings.
Third. In bridges and similar structures of the kind above specified the employment
of tubes which are screw-threaded at their extremities, for forming the uprights and
the cross-pieces of the bridge substantially as described and shown in the accompanying
drawings.
Fourth. In bridges and similar structures the employment of intermediate sockets
designed to receive the cross-pieces the said sockets being formed of two parts joined
together by hinges and provided with lugs for receiving the extremities of the cross-
pieces substantially as described and shown in the accompanying drawings.
Dated this 25th day of October 1889.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.