Improvements in the Construction of Flooring for Bridges and other Purposes.
Year: 1889

page_text: Date of Application, 18th Dec., 1889)
Complete Specification Left, 6th Mar., 1890-Accepted, 19th Apr., 1890
PROVISIONAL SPECIFICATION.
Improvements in the Construction of Flooring for Bridges
and other Purposes.
FITZHERBERT WRIGHT and THOMAS GILLOTT both of Butterley Iron Works near
Alfreton in the County of Derby, Engineers, do hereby declare the nature of this
nvention to be as follows:-
Our invention has for its object improvements in the construction of what is known
as trough flooring to be made from malleable iron or steel bars and plates for bridge
and warehouse platforms and other purposes.
no variation
in
Hitherto these floors have generally been formed of hent plates or specially
rolled channels and other sections, which admit of little or
dimensions without involving the provision of rolls or dies to suit each individual
section, or increased expense in manufacture.
In the present invention, bars of Z section, such as are produced in the ordinary
course of manufacture for ship-building and other purposes, are bent in dies or rolls
so as to give a flat reversed curvature to the webs of the Z bars whilst maintaining
the upper and lower flanges parallel to each other. To each flange of a succession
of bars curved as described and placed in reverse directions, that is with two
flanges in the same plane facing each other, are rivetted horizontal plates so that a
succession of troughs are formed of the same or varying widths having flat
bottoms and curved sides. For railway bridges it is often convenient for the
troughs to be wider where transverse sleepers have to be placed, so as to afford
room for packing ballast under the sleepers without unduly increasing the depth of
the ballast on the floor; and for such bridges the troughs may be alternately wide
and narrow if a sleeper has to be placed in each alternate trough. Or the plates
joining the upper flanges of the Z bars may be narrower than those uniting the lower
flanges and the strength of the upper and lower members of the floor may be
equalized by varying the thicknesses of the plates, thus allowing a sleeper to be placed
in each trough when the span of the flooring is so great as to require deep and wide
troughs.
All these varieties may be produced from ordinary trade sections; but it is obvious
that where a large area of flooring is required that the Z bars may be rolled to the
required section so as not to require subsequent setting in rolls or dies after inanu-
facture in the rolling mills. The curved sides of the troughs when so formed
offer considerable facilities (compared with the straight sides hitherto used,) for
packing ballast under sleepers, when used for railway bridges as described.
Dated this Seventeenth day of December 1889.
COMPLETE SPECIFICATION.
Improvements in the Construction of Flooring for Bridges
and other Purposes.
FITZHERBERT WRIGHT and THOMAS GILLOTT both of Butterley Iron Works near
Alfreton in the county of Derby, Engineers, 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 :-
Our invention has for its object improvements in the construction of what is
known as trough flooring to be made from malleable iron or steel bars and plates for
Hitherto these floors have
bridge and warehouse platforms and other purposes.

page_text: generamy been formed of bent plates or specially rolled channels and other section
which admit of little or no variation in dimensions without involving the provision
of rolls or dies to suit each individual section, or increased expense in manufacture.
In the present invention bars of Z section such as are produced in the ordinary
course of manufacture for shipbuilding and other purposes are bent in dies or roll
so as to give a flat reversed curvature to the webs of the Z bars whilst maintaining
the
upper and lower flanges parallel to each other.
To each flange of a succession of Zbars curved as described and placed in
reverse directions, that is with two flanges in the same plane facing each other, are
rivetted horizontal plates so that a succession of troughs are formed of the same or
varying widths having flat bottoms and curved sides. For railway bridges it is often
.convenient for the troughs to be wider where transverse sleepers have to be placed,
so as to afford room for packing ballast under the sleepers without unduly increasing
the depth of the ballast on the floor; and for such bridges the troughs may he
alternately wide and narrow if a sleeper has to be placed in each alternate trough.
Or the plates joining the upper flanges of the Z bars may be narrower than those
uniting the lower flanges and the strength of the upper and lower members of the
floor may be equalized by varying the thicknesses of the plates, thus allowing a
sleeper to be placed in each trough when the span of the flooring is so great as to
- require deep and wide troughs.
All these varieties may be produced from ordinary trade sections; but it is obvious
that the Z bars may be rolled to the required section so as not to require subsequent
setting in rolls or dies after manufacture in the rolling mill.
The curved sides of the troughs when so formed offer considerable facilities,
compared with the straight sides hitherto used, for packing ballast under sleepers
when used for railway bridges as described.
In order that our invention may be clearly understood and applied we herewith
annex two sheets of drawings.
On Sheet I, figure 1, is shewn an ordinary Z bar, such as are regularly
produced in iron or steel for other purposes; and we take these bars and form
them into the shape shewn by Figure 2, either by passing through suitable rolls, or
subjecting them when hot or cold to hydraulic, steam or other pressure between dies
of the required shape; but as before stated these bars may be specially rolled to the
section shewn by Figure 2 when for commercial reasons it is more economical to
prepare suitable rolls for the rolling mill, than to roll to the shape shewn by Figure 1
and subsequently form them as shewn by Figure 2.
Figure is a cross section of our improved floor as applied to an ordinary
road bridge, this section being taken at right angles to the span of the floor. We
take the bars, Z, of the shape shewn by Figure 2, and place a number of them in
succession with the upper and lower flanges turned towards each other, and unite
these flanges by plates P; and rivet the bars Z, and plates P together, as shewn by
Figure 3.
In small bridges the troughs may run from one abutment of the bridge to the
other abutment, or piers, in which case the line of the troughs will be parallel to
the line of the road they carry. For larger bridges carried by main girders, the
flooring would span the transverse distance between such girders, and the line of the
troughs would be at right angles to the line of the road.
When the improved trough floor is applied to railway bridges, and the headway
is limited, the troughs may run at right angles to the road and be carried at the sides
of the bridge by main girders, and the troughs be so formed to allow sleepers carrying
the rails to be placed in the troughs, and the maximum headway secured. This is
shewn by Sheet II, Figure 4 in which the troughs on the upper surface are made
wider for the reception of the sleepers, and the upper and narrower horizontal
plates P, uniting the bars Z, are made thicker than the lower and wider plates P2, so
that the strength of the upper and lower members of the floor is equalized.
Figure 5 on Sheet II shews a similar trough floor to that shewn by Figure 4 but
with the upper and lower plates P of the same dimensions instead of being alternately

page_text: wide and narrow; this construction being preferred for the purposes of an ordinary
turnpike road, or for railway bridges where the line of the troughs run in the
direction of the railway.
It will be evident from an inspection of Figure 4 that the curved sides of the
troughs afford considerable facilities for packing ballast under the sleepers, compared
with those afforded by straight inclined sides as hitherto used.
Also that, by simply varying the widths of the top or bottom plates, the pitch of
the troughs may be varied to suit the girders to which they are attached, or the
sleepers that may be placed in the troughs; or in the case of roadway bridges, wider
troughs may be provided for the reception of pipes or sewers and still allow the
same Zbars to be used throughout so that for all the necessary variations in widths
of troughs no additional dies or rolls are required in the manufacture of this
flooring.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is:
The method of constructing the flooring of bridges, platforms, or buildings, by
means of plates and curved Zhars of iron or steel as described.
Dated this Fifth day of March One thousand