IMPROVEMENTS IN THE CONSTRUCTION OF FLOORINGS FOR BRIDGES "
Year: 1882

page_text: LETTERS PATENT to William Henry Lindsay of 14 Wharf South Paddington
'
Basin in the County of Middlesex for an invention of "IMPROVEMENTS IN
THE CONSTRUCTION OF FLOORINGS FOR BRIDGES
"
PROVISIONAL SPECIFICATION left by the said William Henry Lindsay
at the Office of the Commissioners of Patents on the 2nd June 1882.
WILLIAM HENRY LINDSAY of 14 Wharf South Paddington Basin in the
County of Middlesex "IMPROVEMENTS IN THE CONSTRUCTION OF FLOORINGS FOR
BRIDGES
"
Heretofore it has been proposed to construct the deckings or floorings for bridges
of plates of iron each having in them numerous curved corrugations which are to
be at right angles to the length of the bridge. By my improvements I am able to
form a flooring cheaper lighter and stronger than by the above mode.
I make the decking or flooring of alternate V and inverted V troughs connected
the one to the other as hereinafter described and with the apex both of the V and
inverted V troughs formed of flat horizontal plates to serve respectively as a
bearing for the roadway and to rest upon the girders or supports. The flat plates
I tie together by plates inclined at an angle say of about 60° from the horizontal
these form the sloping sides of the trough-the flat plates may be flanged along
their side edges to corresponding angles to allow of their being rivetted to the top
and bottom edges of the inclined plates. In this case the flanges of the top plates
are made to incline downwards and the flanges of the bottom plates upwards and
the inclined side plates are placed against the outside of both flanges. Or the top
and bottom plates might be flat unflanged plates and be secured by angle iron
corner pieces to the inclined plates In either case the top and bottom plates may
be of stouter metal than the sloping connecting plates so that greater strength may
be obtained for the same weight of metal used. Also by making the sides of the
Price B71

page_text: troughs to slope as above described the troughs will extend over a greater space
than if they were vertical and the cost of covering over a given space will be less
than if vertical sided troughs were used.
The alternate V and inverted V troughs connected one to the other as above
described form a continuous roadway with horizontal flat bearing surfaces at the
top for the roadway to rest upon and with other flat surfaces at the bottom to rest
upon the girders or supports.
Floorings constructed as above described are especially applicable for girder
railway bridges. In this case the sleepers for carrying the rails would be placed on
to the upper flat plates of the decking or flooring.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Henry Lindsay in the Great Seal Patent Office on the
2nd December 1882.
WILLIAM HENRY LINDSAY of 14 Wharf South Paddington Basin in the
County of Middlesex "IMPROVEMENTS IN THE CONSTRUCTION OF FLOORINGS FOR
BRIDGES
"
Heretofore it has been proposed to construct the deckings or floorings for bridges
of plates of iron each having in them numerous curved corrugations which are to
be at right angles to the length of the bridge. By my improvements I am able to
form a flooring cheaper lighter and stronger than by the above mode.
I make the decking or flooring of alternate V and inverted V troughs connected
the one to the other as herein-after described and with the apex both of the V and
inverted V troughs formed of flat horizontal plates to serve respectively as a
bearing for the roadway and to rest upon the girders or supports. The flat plates
I tie together by plates inclined say at an angle of about 60° from the horizontal
these form the sloping sides of the troughs and I make the top, and bottom plates
of stouter metal than the sloping connecting plates so that greater strength may
be obtained for the same weight of metal used.
Figures 1. 2. 3 and 4 shew half size different sections of which each flute com-
posing my new flooring or decking may be formed. Figure 5 is a perspective view
of a number of such flutes joined together to make up part of a decking or flooring.
Figures 6 and 7 shew two ways in which the deckings or floorings may be carried
by the main girders, these two views are only shewn as examples of the ways in
which the decking or flooring may be carried-other suitable arrangements might
however be adopted for the purpose.
The new decking or flooring is intended to supersede or take the place of the
usual cross girders rail bearers and planks with the advantage of producing a.
waterproof floor.
In Figures 1. 2. 3 and 4 the channel irons forming the top and bottom members
of the flutes are shewn of different profiles in the different figures but in each of
them the flat plates forming the top and bottom of the flutes are of solid metal of
greater thickness than the sloping side plates which form the sides of the flutes.
The section that I prefer is that shewn at Figure 1 in which the top and bottom
channel irons are made with their sloping sides of sufficient depth to allow of their
overlapping one another and of their being rivetted together this gives the
strongest form for the least weight of metal.
In Figure 2 the sides of one channel iron are shewn to be deeper than the
other.
In Figure 3 the sides of both channel irons are comparatively shallow and they
are connected by inclined web plates rivetted to them. In Figure 4 is shown a
modification of this construction.
The cross sections of girders Figures 6 and 7 shew two ways in which the
improved floor may be carried. When the ends of the plates rest directly on the
angle irons of the lower flange of main girder as shown in Figure 6 they are
secured by the same rivets which would otherwise only secure the angle irons to
the flange plates. It is therefore necessary that the pitch of the flutes composing
the floor should be made to a multiple of the pitch of the rivets, in order that
their general run shall in nowise be disturbed; this arrangement is shown by the
dotted lines in the perspective. plan Figure 5. When however the headway is not
cramped or limited the method of junction shown in Figure 7 should be adopted

page_text: when an extra strong angle iron is shown attached to the main girder forming an
upper smooth surface on which the new floor can be rivetted indiscriminately without
regard to the pitch of the rivets in the main girders.
By constructing a floor in the manner described an increase of strength is
obtained over a floor composed of an uniform thickness of corrugated plate. The
increase being as much is some cases as 30 per cent with no increase in weight
of iron.
This advantage is obtained by arranging that the greatest sectional area shall be
a maximum distance from the neutral axis.
Another practical advantage in the new floor is the utilization of trade sections
and scantlings of rolled iron to be obtained from any manufactures of rolled
sections of iron. The use of these trade sections rivetted or secured together by
bolts to form the desired floor reduces its manufacture to the class of simple girder
work, and also brings down the labor to a minimum viz: a single row of rivets
and producing a strong floor of greatest resistance, stronger as above stated than
the ordinary corrugated floor and thereby dispensing with the apparatus and
machinery necessary for producing such corrugated floors.
It should be quite understood that the depths of the floor shown at 8 and 9 inches
on the drawing can be increased or decreased to fit the requirements of leverage
and weight to be supported; also the widths of flutes and all scantlings may be
more or less as circumstances require.
Having thus described the nature of my Invention and the manner of performing
the same I would have it understood that I claim the construction of floorings for
bridges substantially as herein before described and illustrated in the drawing
annexed.
In witness whereof I the said William Henry Lindsay have hereunto set
my hand and seal this Second day of December in the year of our Lord
One thousand eight hundred and eighty two.
W. H. LINDSAY (L.S.)