AN IMPROVEMENT IN BRIDGES FOR FACILITATING THE PASSAGE OF SHIPPING PROVISIONAL SPATIONP WITHOUT STOPPING THE CARRIAGE OR GENERAL TRAFFIC
Year: 1875

page_text: LETTERS PATENT to Frederic Barnett, Engineer, of 104, Queen
Victoria St., E.C., London, Middlesex, for the Invention of "AN
IMPROVEMENT IN BRIDGES FOR FACILITATING THE PASSAGE OF SHIPPING
PROVISIONAL SPECIFICATION left by the said Frederic Barnett at
the Office of the Commissioners of Patents, with his Petition, on
the 19th October 1875.
I, FREDERIC BARNETT, Engineer, of 104, Queen Victoria St., E.C.,
London, Middlesex, do hereby declare the nature of the said Inven-
tion for "AN IMPROVEMENT IN BRIDGES FOR FACILITATING THE PASSAGE OF
SHIPPING WITHOUT STOPPING THE CARRIAGE OR GENERAL TRAFFIC," to be as
follows:
-
Important rivers like the Thames flowing through densely populated
cities are undoubtedly ports, where great ships and steamers come and
go, bringing and fetching cargoes to and from the very heart of such

page_text: which will then within the enceinte be as in a dock or harbour. These
gate bridges will only be opened for such vessels as cannot pass under
the bridges. While these gate bridges are opened on one side of the
enceinte they will be closed on the opposite side, by which means all
the traffic can be diverted thereon, and so continue to pass without
interruption; then when those gate bridges are closed, the ships being
entered within the area of the oval, the gate bridges will be opened on
the opposite side, the traffic being previously diverted to the opposite
portion of the bridge, during which time the ships will pass up the river
or down, as it may happen, but during these operations the traffic on
one or the other side will always pass without interruption.
I reserve the right of form, size, height, length, material, or any
variations or modification I may find necessary in my constructions on
my improved principle.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Frederic Barnett in the Great Seal Patent Office
on the 18th April 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERIC
BARNETT, Engineer, of 104, Queen Victoria Street, E.C., London,
Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Nineteenth day of October, in the
year
of our Lord One thousand eight hundred and seventy-five, in the
thirty-ninth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Frederic Barnett, Her
special licence that I, the said Frederic Barnett, my executors,
administrators, and assigns, or such others as I, the said Frederic
Barnett, my executors, administrators, and assigns, should at any
timc agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "AN IMPROVEMENT IN BRIDGES FOR FACILITATING THE PASSAGE
OF SHIPPING WITHOUT STOPPING THE CARRIAGE OR GENERAL TRAPPIC," upon

page_text: my executors or administrators, by an instrument in writing under
my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Frederic Barnett, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement:-
-
Important rivers like the Thames flowing through rich and densely
populated cities are undoubted ports, especially those influenced by the
tide, and having abundant depth of water to enable great ships and
steamers to navigate them to a great extent, freighting cargoes to and
fro their very centres, loading and unloading their rich produce at the
wharves which without interval fringe their banks. These wharves from
their vast shipping commerce are of immense value. Were vessels
however prevented from coming alongside these wharves by the inter-
vention of ordinary bridges their business would inevitably be paralyzed,
and as a natural consequence loss and ruin would ensue. On the other
hand, a great evil exists in such cities as London, where for miles no
means exist to enable waggons, carriages, foot, and general traffic to
cross the river where there exists the greatest necessity, except by very
long and circuitous routes over the nearest bridges, by such means
causing loss of time, waste of horseflesh, and wear of vehicles, besides
the danger resulting from overcrowding where many great thoroughfares
merge into one comparatively narrow channel. When and where such
a state of things occur it evidently can only be relieved by additional
bridge accommodation, connecting the river banks in such parts of the
rivers where new communication becomes indespensable; but as the
noblest of our low level bridges have only sufficient headway at flood to
allow the passage beneath them of barges, river steamers, and similar
craft it becomes evident that such bridges a few miles east of London
Bridge, or any such bridges similarly situated on other rivers would be
impracticable, as they would bar the passage of large sailing ships or
steamers. In order to overcome this difficulty I have invented a low
level bridge, which completely remedies this inconvenience by permitting

page_text: general traffic of horses, carriages, or foot passengers, and to this effect
my improved bridge can be established in any part (for example say) of
the Thames.
,
From each bank (where the river is from six hundred to one thousand
two hundred feet wide, or thereabout) by single approches of about
one-third its width, extending inwardly towards the centre, I construct
my bridge either of stone, iron, or any other suitable material A to A¹,
and A to A at the ordinary clevation above the highest tides. To
span the remaining space between the approaches A, A', and A", A,
where those terminate, the road splits into two roads of the same width
and height B, B', by easy inclined angles outwardly extending A' to O,
and A" to C¹, till they meet the movable bridges F, F', at C, C₁, C, C,
the whole forming a sort of angular loop. In its largest diameter I
have on each side (for preference) two openings D, D¹, and D", D111
practically covered and united by the platforms F, F¹, turning on their
centres the platforms each covering two openings by one operation,
cover or uncover both at the same time on the one side of the loop.
These openings D, D¹, D", D, are sufficiently wide to permit the
largest ships that come up such rivers to pass through them as regards
their beam. In the largest diameter D¹ to D" there will be sufficient
length to accommodate the longest ships that navigate such rivers to
moor within the loop if necessary. From the central pier J, J,
extending the whole length of the width of the loop, there is a
platform H, H', uniting the two piers, which platform lies with the
axis of the river, dividing the loop into halves, at the same time being
provided with the means for mooring ships alongside if necessary.
On the extreme of the piers J, J', there will be capstans and signal
lights. There will be two other platforms I to I', and I" to I™ running
parrellel to the chief platform H, H'; these platforms in conjunction
keep the vessels straight on their road through the loop. The vessels
steering port will thus pass through the opposite sides of H, H¹, com-
pletely assured against the risk of collision.