The Sun.
London, England, 1865-03-20 00:00:00

BAILWN

'ME NOE.

METROPOLITAN.

The system of signalling the trains on this com-
pany's line has now been in successful operation for
more than two years. Mr. J. Fowler, the engineer-
in-chief, Mr. J. M. Johnson, the resident engineer,
and Mr. M. Fenton., the general manager, have
testified as to the simplicity and efficiency of Mr.
C. E. Spagnoletti's telegraphic disc system for show-
ing and working the signals on the above line. This
is a most important matter for the public, as it•
proves that at least one fruitful source of accidents
from collisions on railways can be effectually pre-
vented by the adoption of this system of railway
telegraphy, which has been in operation on the
Metropolitan Railway since its opening on the 10th
of January, 1863, and by which every train on the
line has been telegraphed from station to station
without failure or any error, so far as the general
manager is aware of. This telegraph block system
enables any number of trains to be run in succession
on a railway with safety, and at the shortest pos-
sible intervals, the latter being dependent on
the distance between the stations and the time
occupied by the train in running from station
to station, because a train is not allowed to start
from a station to follow another train in advance
of it on the same line of rails until the latter has
actually left the next station, and so on from
station to station, keeping a clear space betweenthem
until the whole journey has been accomplished.
Signal-boxes are placed in or close to each station,
in which the telegraphic instruments are fixed for
signalling the trains on the up and down lines, there
being a separate instrument for each line. The
telegraphic instrument consists of a plain green
dial, having an oblong opening in it, behind which
are suspended two sliding discs of the same size as
the oblong opening. One of the discs is white, with
the following black letters upon it—" Line clear,"
and the other is a red disc, with the words " Train
on line" in white letters. These discs are worked
by direct action from the battery, and are so ar-
ranged that-when the instrument is not in use only
one half of each disc is seen through the oblong
aperture in the dial. The colours, white and red,
correspond with the signals and lights exhibited on
the line, the white representing all right and the
red danger.

The instrument is worked by two keys, one for
each disc, and labelled the same as the discs, so that
on pressing down the white key the white disc with

" Line clear" on it fills the aperture in the green
dial, and remains so until altered ; and on pressing
down the red key, the red disc with " Train on
line" takes the place of the white disc on the green
dial, so that the operator can make no mistake.
Either of the keys can be fastened so as to keep
either signal in its proper position as long as neces-
sary.

Those instruments are so constructed that which-
ever signal is given at the station, the same signal
will be shown at the station to which it is sent ;
and when a signal is given and the key fastened, it
cannot be reversed from the station to which it is
sent.

Another advantage of the instrument is that it
registers the gradual exhaustion of the battery, so
that the battery can be attended to before it be-
comes too weak to perform its work.

A single striking bell is worked in connexion with
this instrument, separately, or attached to the in-
strument, if the former, it has a key of its own ; if
the latter, on either of the keys of the instrument
being pressed down, the signal is shown with a
simultaneous stroke of the bell, so that, by having
a code of the number of the beats of the bell, a cor-
roboration is given to the signals shown by the
discs. This instrument can be worked on two sys-
tems—on that which is called the "permanent
block," showing whether the line is clear or blocked,
or on that which is called the " block system," asking
if the line is clear, and blocking only during the time
a train is on the section of line so worked. Any de-
fect in the instrument at either end, or to the line

wire, is immediately registered at both ends by the
discs, showing half red and half white in the aper-
ture on the green dial.

In accordance with the system of signalling be-
tween station and station, the operators, by means
of coloured levers arranged in the signal-box, also
work the outside ordinary signals on the line of rail-
way corresponding with the signals shown by the
instruments, at the same time altering the position

of the switches on the line to suit the safe working
of the traffic, so that no mistake can take place while

the signals are attended to. Trains have been worked
at intervals of four minutes, some at intervals of 71
minutes, and others at irregular periods, without
any mistake occurring. This system has been
adopted on several portions of the Great
Western Railway and on other railways, es-
.

_ .
pecially where tunnels exist, it being considered
the most certain and efficient system for that pur-

pose. Mr. Spagnoletti has also successfully adapted
his disc telegraph system to supply the place of bells
at the Great Western Hotel, Paddington, and other
large establishments.