Year: 1896

page_text: Date of Application, 27th Apr., 1898
Complete Specification Left, 25th Jan, 1897-Accepted, 27th Apr., 1897
This is similar to the pilot tickets now in use, which are worded to the following
effect :-
'It authorizes the driver after seeiug the pilot tablet for the section, to proceed
from such a station, to such a station; is only available in one direction, and for
one journey.
SEORET WORD.
This is a word printed on a card and put into a strong envelope which is securely
fastened, and no one is to know what the word is except those who make up the">
envelupes, which should be done at the head office of the railway.
The "secret word" and "pilot tablet" to be kept under lock and key; the
"secret word" in the compartment marked "Secret Word," and the pilot tablet in,
the one marked "Pilot Tablet."

page_text: The "pilot tablet tickets" to be kept in the drawer, together with a supply of
new panes of glass for the windows, and instruction book, and such like.
The compartment marked "Reserve Tablot or Staff" to be used for keeping a
reserve "tablet" or "electric staff" in. The tablet or staff, as the case may be, to
be supplied by the compauies themselves, either by having extra ones made or
taking one out of the tablet instrument, or electric staff apparatus, from which one
could well be spared.
As before stated there are two keys to each door, one key of each door is
for the use of signalman and the other one is to be kept by the lineman of the
district.
The signalman's keys to be placed inside the compartment they relate to, and
the compartments to be locked by the lineman with his own keys.
The signalman, to gain admittance to the "secret word compartment, must
break the glass of same, and to the other two lock-up compartments, by breaking
their respective glass windows to obtain the keys.
Each station to have an apparatus as above for each section. The "secret word"
at one end of each section to be the same ns the "secret word" at the other end of
the same section, each section to have a different "secret word."
The "secret words" must be supplied to the linemen from the bead cffice done
up in the following manner :--A piece of card twice as long as it is wide; the
"secret word" printed twice on the card, once on each end. This card to be
placed in an envelope which must be securely fastened in the ordinary way, two
fines to be drawn across the middle of envelope about a quarter of an inch apart;
the card and envelope to be stiched through together along each of these lines, or
fastened together along these lines in some other secure way.
The lineman when a box requires a fresh "secret word." (as explained in
instructions) must write the names of the two stations, between which they are
available, on each end of envelope, then out the envelope (and card) across between
the two lines, which will devide the packet in two, and insure that the "socret
word" in each. half is identical one with the other; one half to be put in the box
at one end of the section and the other half in the box at the other end of the
Bection.
The box to be made in two sizes, one as described herein to be used on lines
where they have the "Electric Staff"; and a much smaller size for those railways
where the "Tablet' system 18 worked,
The apparatus to be worked as per instructions relative to same.
The principle of the apparatus is to have a reserve tablet (or electric staff, as the
case may be), a "Secret Word" arrangement, and a pilot tablet, all three under lock
and key, so that the signalman cannot get at either without first breaking the glass;
and it is impossible for him to do this without the knowledge of the lineman, as
although he may put in a new pane of glass and put things back as they were he
ennnot lock the box when his key is iuside.
USE OF "SECRET WORD."
According to the old way, when a failure occurs in the "Tablet or Staff"
working, between any pair of statione, a pilotmau has to proceed from one end of
the section to the other, (that is from one of the stations to the other) to arrange
Pilt working all traffic being delayed while this is being done, which usually
takes about one hour.
Now a message seut by telegraph or telephone instead of being conveyed by a
man, would answer the same purpose, and without the delay which would be caused
by the man making the journey, if some safe way was adopted to ensure the
following three points, riz. :-
1st. That the message is really sent.
2nd. That it is really received at the station it was intended foi.

page_text: To show how the "Secret Word" arrangement will do this, we will call several
stations by letters as follows:-
and
If for instance a failure occurs at Section B & C, and the next train is running
in the direction from E to A. Station B will ascertain what the "secret word" is
for Section B & C by breaking the glass of the Secret Word compartment of that
section (at Station B); he will then send a properly worded message (ns per copy
shewn in instructions) authorizing Station C to start Pilot Tablet working. He
will also state in the message what the "secret word". is, which in this case
would be "Horse."
When the train arrives at Station the driver must be informed of the
circumstances, and to prove that the message is genuine, he, the driver (and no one
else) must break the glass of "Secret Word compartment at Station C and
compare the "word" with the "word" on the message received from Station B,
and if they are the same this will prove to the driver that the message is genuine,
and that it is quite safe for him to proceed under Pilot Tablet working, (as per
instructions).
It will therefore be the driver of the train that is required to start Pilot Tablet
working that really establishes Pilot Tablet working, and it will therefore be
natural that he will fully satisfy himself as to the correctness of the message, for
if he did not do so he would be risking his own life.
From the preceeding, it will be clearly seen that should the message ever be
received at the wrong station, or should it be received at tho right station but as
coming from a station different to what it really started from, the "secret word
received in the message would not correspond with the word the driver would
obtain, from the Secret Word compartment at the station from which he would-be
required to start Pilot Tablet working, and he would therefore refuse to proceed.
And of course if no message had been sent, the station wishing the driver to start
Pilot Tablet working could not inform the driver what the secret word was, as
they would not know themselves, therefore the "Secret Word" arrangement also
proves that the message was really sent.
Dated this 25th day of April 1896.
JOHN WALTER MITCHERD.
Improvements in Means for Working Single Line Railways during
Failure of Tablet or Electrio Staff Working.
JOHN WALTER MITCHERD Penrhyndeudraeth Station Merionethshire Booking
Clerk 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:-
This apparatus consists of a wooden box a pilot tablet and a set of pilot tablet
tickets and secret word arrangement as herein described viz.--

page_text: WOODEN Box.
22 inches long, 10 inches high, 7 inches wide (back to front) lower part
to consist of an ordinary drawer 2 inches deep, 12 inches long. The other
part of box to consist of 3 compartments or cupboards side by side, equal sizes.
First one left side to have a door with lock and two keys (duplicate) also to have
a glass window in the door. The other two compartments will be served by one
door only, that is, the other door will cover in the other two compartments. Thero
will be two windows in this door, one opposite each compartment. This door will
also have a lock and two keys (duplicate). The size of the windows to be about
4 inches by 2 inches.
The left baud compartiment is marked "Rezerve Tablet" or "Reserve Staff"
(as the case may be). The middle compartment is marked "Scoret Word." The
right hand compartiment is marked "Pilot Tablet." There is no putty used about
the windows and they are so arranged that when the doors are open, the glass can
be drawn out at the top or of course put in at the top, but when the doors are
closed the top of the box will prevent the glass from being withdrawn. The keys
of both doors must not be alike, so that they will not fit the door they do not
holong to.
section to proceed from such a station to such a station and is only available in one
direction and for one journey.
"SECRET WORD."
This is a word printed on a card and put into a strong envelope which is
securely fastened, and no one is to know what the word is, except those who make
up the envelopes which should be done at the head office of the railway.
The secret word and pilot tablet to bo kept under look and key. The
secret word in the compartment marked Secret Word and the Pilot Tablet
in the one marked Pilot Tablet. Pilot tablet tickets to be kept in a drawer
together with a supply of new panes of glass for the windows, instruction book
and such like.
The compartment marked Reserve Tablet or Staff to be used for keeping a
reserve tablet or electric staff in. The tablet or staff as the case may be to be
supplied by the companies themselves either by having extra ones made or taking
one out of the tablet instrument or electric staff apparatus, from which one could
well be spared. As before stated there are two keys to each door, one key of each
door is for the use of the signalman and the other key is to be kept by the lineman
of the district. The sigualman's keys to be placed inside the compartment they
relate to and the compartments to be locked by the lineman with his own keys.
The signalmen to gain admittance to the Secret Word compartment must break
the glass of same, and to the other two lock up compartments by breaking their
respective glass windows to obtain the keys.
Each station to have an apparatus as above for each section, the secret
word at oue end of each section to be the same, as the secret word at the other
end of the same section. Each section to have a different secret word. The
secret words must be supplied to the lineman from the head office done up in the

page_text: If for instance a failure occurs at Section B & C. and the next train is running
in the direction from E to A Station B will ascertain what the secret word is for
Section B and C, by breaking the glass of the Secret Word compartment of that
section (at Station B) he will then send a properly worded message as per copy
shewn in instructions, authorizing Station C. to start Pilot Tablet working, he will
also state in the message what the secret word is which in this case would be
"Horse." When the train arrives at Station C. the driver must be informed of
the circumstances and to prove that the message is genuine he the driver (and no
one else) must break the glass of Secret Word compartment at Station C. and
compare the word with the word on the message received from Station B and if
they are the same this will prove to the driver that the message is genuine and
that it is quite safe for him to proceed under Pilot Tablet working (as per
instructions).
From the preceding it will be clearly seen that should a message bu over received
at the wrong station or should it be received at the right station but as coming from

page_text: station different to what it really started from the secret word recoivod in the
message will not correspond with the word the driver would obtain from the Secret
Word compartment at the station from which he would be required to start Pilot
Tablet working and be would therefore refuse to proceed and of course if no
message had been sent, the station wishing the driver to start Pilot Tablet
working could not inform the driver what the secret word was, as thoy would not
know themselves, therefore the Secret Word arrangement also proves that the
message was really sent.
The secret word and pilot tablet are to be used in cases of failures caused
otherwise than by a damaged tablet or staff.
In cases of failures caused by a damaged tablet or staff the traffic to be carried
on. by means of the reserve tablet or staff like this-Signalman breaks glass of
reserve compartment takes out key unlock compartment takes out reserve tablet or
staff puts in damaged one, puts in new pane of glass in window, shuts and locks
door. The reserve tablet or staff to act in place of the damaged one until the
latter one is repaired.
The lineman will come and send damaged one for repairs and when it is returned
repaired be will place it in its proper place and restore the reserve tablet or staff
to the reserve compartment.
When a signalman breaks the glass of a compartment it is inmaterial whether
he takes out the tablet or staff through the window or by means of the door.
As previously explained the glass in the window can only be taken out (whole)
or put in when the doors are open. It is therefore impossible for a signalman to
tamper with contents of compartment) for although he is supplied with a stock of
glasses, nevertheless, if he breaks a window he cannot put in a new pane and put
things back as they were before, without the lineman detecting it, for if he puts a
new pane in, shuts door and locks it, he cannot then put his key inside the window,
or on the other haud should he shut door and lock it and put key inside through
broken window he could not then put a new pane of glass in, as this can only be
done while the door is open.
When a failure occurs and the official message is sent and the driver is satisfied
the message is genuine by comparing the secret words as previously explained, he
(the driver) will then release the pilot tablet by breaking the glass of that
compartment to obtain the key and will hand the pilot tablet to the signalman and
Pilot Tablet working will be established, the pilot tablet and pilot tablet tickets,
being used in the same way as a pilotman and his tickets are used.
Ordinary working will be restored by the lineman in this way, we will call the
two stations A and B and suppose the pilot tablet was released at Station A. The
lineman when the fault is rectified will proceed to B. (if not already there) take
Possession of the pilot tablet when it arrives (if it is not already there) also take an
ordinary tablet (or staff) out of the instrument in ordinary way, proceed on engine
of next train to it taking the tablet (or staff) and pilot tablet with him; when he
gets there, place the tablet (or staff) in instrument in ordinary ways, place the
pilot tablet back in its own compartiment, put in fresh (different) secret word, in
the Secret Word compartment (having) put half the packet in at B before he left
there) put new glasses in and sigualmans key inside and lock the box with his own
key, ordinary working will then be resumed.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what ]
claim is:-
1st. A box or apparatus containing a drawer at the bottom for ordinary use not
locked, and in the body of the apparatus, three compartiments or cupboards, the
first one labelled "Reserved Tablet" (or Staff as the caso may be) the second
compartment labelled "Secret Word" and the third labelled "Pilot Tablet." A
door with a glass window will enclose the first compartment, and another door with
two glass windows, will enclose the other two compartments each glass window to

page_text: be opposite each compartment each of the glass windows to be so constructed that the
glass of each can be lifted up and taken out or put in at the top of the windows when
the doors are open, but which cannot be done when the doors are shut, like top of
the box preventing it. Eaoh door to be locked and have duplicate keys to each
lock, but both locks to be different from each other so that the keys of the one will
not fit the other.
2nd. A pilot tablet. This is an oblong piece of wood or metal and bears the
word "Pilot Tablet" and the names of the two stations between which it is
available.
3rd. A supply of pilot tablet tickets as described herein which are similar to the
pilotinans tickets now in use.
4th. A Secret Word arrangement which is a secret word printed upon a card and
put into an envelope in the manner previously explained.
5th. The pilot tablet will be kept in the compartment labelled Pilot Tablet.
The envelope containing the secret word will be kept in the compartment labelled
"Secret Word." In the compartment labelled Reserve Tablet or (Staff) will be
kept a reserve tablet (or staff) which must be supplied by the companies themselves
as I do not supply these but only provide a compartment to keep them in.
6th. By the use of my invention a reserve tablet (or staff) is always ready for use
in case of an ordinary one getting damaged.
7th. In cases of failure caused otherwise than by a damaged tablet or (staff)
traffic can be carried on by means of my pilot tablet and tickets instead of a
pilotman and his tickets. The message authorizing the release of the pilot tablet.
being safe guarded by my Secret Word arrangement.
Dated this 23rd day of January 1897.
JOHN WALTER MITCHERD.