IMPROVEMENTS IN BRIDGES
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I WILLIAM HENRY LINDSAY of 14 Wharf, South Paddington Basin in the
County of Middlesex Engineer do bereby declare the nature of my invention.
for "IMPROVEMENTS IN BRIDGES." to be as follows:-
This Invention has for its object improvements in bridges.
>
In the specification of a former Patent granted to me dated the 2nd day of Juno'
1882, No 2007 I described constructing the flooring of bridges and other structures,
of built up corrugated or trough plates in which the flat upper and under sides
of each trough were made thicker than the sloping sides. According to my
present invention I make the floor of a bridge from such plates with the
corrugations or troughs running lengthwise of the bridge, and I truss this floor
with tension bars extending in a parabolic curve beneath it and secured to it at
their ends, and also at intermediate intervals with diagonal struts inclined to one'
another, after the fashion of what is known as a Warren girder.
I provide also transverse connections at each point wherever two struts meet'
together below the floor to distribute the strains and also to prevent the floor from
spreading laterally Or in place of strengthening the floor with tension bars
forming a parabolic curve below. it as above described I make the bridge of a-
number of parallel Warren girders the lower members of which are parallel with
the floor whilst the upper members are formed each of one of the troughs which is
to form part of the floor and similarly I provide transverse tie bars below the
flooring wherever the struts of the Warren girders meet together below the bottoms
of the troughs, which form the upper members of the girders.
]

page_text: COMPLETE SPECIFICATION.
I, WILLIAM HENRY LINDSAY of 14 Wharf, South Paddington Basin in the
County of Middlesex, Engineer do hereby declare the nature of my invention
for "IMPROVEMENTS IN BRIDGES" and in what manner the same is to be performed
to be particularly described and ascertained in and by the following statement :-
This invention has for its object improvements in bridges.
In the specification of a former Patent granted to me dated the 2nd day of June
1882 N° 2607 I described constructing the flooring of bridges and other structures
of built up corrugated or trough plates in which the flat upper and under sides of
each trough were made thicker than the sloping sides. According to my present
invention I make the floor of a bridge from such plates with the corrugations or
troughs running lengthwise of the bridge and I truss this floor with tension bars
extending in a parabolic curve beneath it and secured to it at their ends and also at
intermediate intervals with diagonal struts inclined to one another after the fashion
of what is known as a Warren girder.
I provide also transverse connections at each point wherever two struts meet
together below the floor to distribute the strains and also to prevent the floor from
spreading laterally Or in place of strengthening the floor with tension bars
forming a parabolic curve below it as above described I make the bridge of a
number of parallel Warren girders the lower members of which are parallel with
the floor whilst the upper members are formed each of one of the troughs which is
to form part of the floor and similarly I provide transverse tie bars below the
flooring wherever the struts of the Warren girders meet together below tho bottoms
of the troughs which form the upper members of the girders.
In the Drawings hereunto annexed I have shewn examples of bridges constructed
as above described.
Figures 1 and 2 show a side elevation and cross section of a bridge in which the
built up corrugated or trough floor is trussed with diagonal struts and parabolic
tension bars below it.
Figures 4 and 5 shew a side elevation and cross section of a small road bridge
constructed in a similar manner. Figures 6, 7 and 8 show details of the construction
of parts of this bridge. Figures 9, 10, 11 and 12 shew a side elevation and cross
section of a railway bridge in which some of the troughs forming the floor also
form part of the upper members of a series of Warren girders with which the floor
is trussed. Figures 13, 14, 15 and 16 show a similar bridge in which the details of
construction are modified.
Figures 17, 18 and 19 show another similar bridge otherwise modified.
In Figures 1, 2 and 3 A is a deck or flooring of iron or steel constructed in
accordance with the specification of my former Patent; as is seen the corrugations
are made to run lengthwise of the bridge. B are transverse iron or steel beams of
an I section. C are struts of T iron or steel. D are tension or tie bars of iron or
steel which form the lower member of the girder-these are connected at the centre
of their length by the transverse bar E. The corrugated floor is bolted down at
intervals to the transverse Ț irons B as shewn at Figure 2. F, F are transverse

page_text: supporting beams carried on the tops of columns, the ends of the floor are
supported on the tops of the beams F.
In Figures 4, 5, 6, 7 and 8 A is the corrugated floor, B transverse beams below
it, C, C, diagonal struts between these beams and D the tension or tie bars. In
these bridges I also make each of the troughs below which the tie bars are placed
of deeper section or of both deeper and stouter section than the other troughs as
shewn in the cross sections.
In Figures 9 and 10 G—G—are a series of parallel girders each formed with its
lower member parallel with its upper member and each having a portion of its
upper member formed of one of the longitudinal troughs of which the floor is
formed. The way in which the bottom of the trough is secured to the other parts
forming the remainder of the upper member is clearly seen in the detail view of
these parts on a larger scale shewn at Figures 11 and 12. B B are transverse bars
tying together the series of girders at the top and forming supports for the portion
of the flooring which is between the girders. The troughs which form part of the
upper members of the girders may as described with reference to Figures 1 to 8 be
made of deeper or if preferred of both stouter and deeper section than the troughs
of which the remainder of the flooring is composed.
Figures 13, 14, 15 and 16. shew views of a similar bridge in which the details of
construction are somewhat modified.
Figures 17, 18 and 19 shew views of another form of bridge which differs only
from the above described bridges in that flat plates are interposed between the top
and bottom members of the girders instead of struts and tie bars,
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1. A bridge with the floor built up of corrugated or trough plates with the
corrugations running lengthwise of the bridge and trussed with tension bars
extending in a parabolic curve beneath it and secured to it at their ends and by
intermediate struts and with the troughs below which the tie bars are placed made
deeper or both stouter and deeper than the intermediate troughs substantially as
described.
2. A bridge with the floor built up of corrugated or trough plates with the
corrugations running lengthwise of the bridge and with the floor supported by a
series of Warren or like girders the lower members of which are parallel with
the floor and also with part of the upper member of each girder formed of or partly
of one of the troughs substantially as described.
3. The construction of bridges substantially as hereinbefore described and
illustrated by Figures 1 to 8.
4. The construction of bridges substantially as herein before described and
illustrated by Figures 9 to 19.