IMPROVEMENTS IN LOCOMOTIVE ENGINES
Year: 1873

page_text: PROVISIONAL SPECIFICATION left by Francis William Webb at the
Office of the Commissioners of Patents, with his Petition, on the
19th November 1873.
I, FRANCIS WILLIAM WEBB, of Crewe, in the County of Chester,
Mechanical Engineer, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN LOCOMOTIVE ENGINES," to be as follows:-
*My improvements relate to locomotives intended more particularly for
working in tunnels or underground railways, and their object is to more
effectually condense the steam and prevent the sulphurous vapours and
impure gases from escaping into the tunnels. This object has hitherto
been imperfectly accomplished by closing the blast pipe of the engine
and turning the steam into the water tank.
My Invention consists in surrounding the chimney (which may be
made double or cased) with a casing open at its lower end to the water
tank, and having a sliding or other valve at its upper end, which valve
can be opened or closed by hand, or by a small steam piston and cylinder,
or other means, brought into action by a tappet placed at the required
points on the railway where such operation is required, which tappet

page_text: will act upon a lever in connection with the valve of the cylinder of the
steam piston. When passing through a tunnel the valve at the top of
the casing of the chimney is closed and the "blast" is driven down upon
the water in the tank, and when the engine passes from the tunnel into
the open air the said valve is opened (by hand or the tappet above !
referred to), and the blast then causes an induced current down a funnel
at the opposite end of the tank to the chimney end, which current draws
out the vapour and cools the water in the tank.
In some cases I propose to use a pump to circulate the water in the
tank and force it up a pipe to the level of the top of the chimney 1
casing to descend through a pipe having numerous holes in a shower, so
as to more rapidly cool the water, and condense the steam, and wash the
gases from impurities; and I further arrange so that the water thus
circulated can be turned on and off by a lever or other mechanism in
connection with the rod that actuates the valve at the top of the 1
chimney casing; and I also arrange that when the water is shut off from
the chimney it may be turned on to descend in a shower down the said
funnel at the opposite end of the water tank.
Instead of causing the blast to pass into the tank, as above described,
it may be closed, and the steam may be made to pass to the tank in the 2
ordinary manner, in which case the valve at the top of the chimney
casing is not required or used, but the blast in this case when in use
will cause an induced current of air to pass down the funnel and will
thus empty the vapour from the tank and cool the water in it.
The tank may be made with a series of shallow trays, one above the 2
other, with spaces between, and the water from the shower may be made
to pass first on to the upper tray and then to the next lower, by which
arrangement a greater surface of cooling and condensing water will be
obtained.
I sometimes arrange the pump for circulating the water so that it can
be stopped, or started, or thrown in or out of gear by connection with
the mechanism that actuates the valve on the top of the chimney
casing.