| In a previous article published in the August 11, 1917,
issue of the Electric Railway Journal an automatic flagman then
in use on the Pacific Electric Railway's lines was described, together
with some experiences in the developing of an electrically operated device
of this character. Since that time further improvements have been made.
The former magnetic type was designed so that the warning disk was elevated
above the magnetic control box, and when set in motion the movement of
the disk was in a horizontal direction. In the improved type the disk on
the apparatus hangs and swings downward when placed in operation.
This flagman has no motors or gears, but is controlled by two sets of magnets, which when energized pull an armature from one side to the other, causing the warning disk to swing and a gong to sound. |
AT LEFT, SUPERCEDED TYPE OF MAGNETIC-AUTOMATIC
FLAGMAN. AT RIGHT. LATEST IMPROVED TYPE OF
ATOMATIC FLAGMAN USED ON THE PACIFIC
ELECTRIC RAILWAY
| For operating and controlling the flagman a contactor
brush is placed on the trolley wire at a distance of approximately 1,500
ft. from the crossing protected. When the trolley wheels of an approaching
train or car engage this brush it closes a circuit between it and the trolley
wire and current is transmitted over the signal line to the relay signal.
The operation of this relay closes the local circuit to the bell and sets
the warning signal in motion. Another brush placed upon the trolley wire
beyond the crossing causes the bell to come to rest when the trolley wheel
of a passing car or train engages it. All lines are provided with intermediate
and second intermediate contactors, which operate the relay in case trains
are traveling close together, thereby preventing trains from crossing on
a dead signal. The line wire used is No. 12 weatherproof iron wire, which
was the same for the former magnetic type. The trunking and cable flow
used is No. 12 Kerite insulated wire.
The Pacific Electric Railway has 250 of these devices. |
For a downloadable and printable:
MS Office version of this page, click here.
Acrobat (.pdf) version, click here.
Electric Railway Journal 6/7/20
Thanks to Donald Duke for sending this in.
