The Portland daily press., 1895-11-16
MAKING A TIME TABLE.
How the Train Schedules Are Figured
Out.

1t Is Done With Colored Chalk and Pins
On a Blackboard, With String to
Represent the Train.
The operation of making up time
table is comparatively simple as pursued
by most roads AS rule, the passenger
Timetable is made up twice year. for
the summer and winter seasons. In the
general superintendent's room in the
Grand Central station OF New York, says
Tribune writer, there stands a huge
time board, which has made up great
many tables for the New York Central
and Hudson River railroad. 1t occupies
half one side Of the room and extends
from the floor to the ceiling. Upon, it
are ruled vertically "a heavy black lines
the space between each of which repre-
sents one hour. Between these are small
Ter black lines, which cut the hour into
spaces of i've minutes each, the quarter
hours being green and the half hours blue
From the bottom of the board, extending
upward, thu names of all the stations on
the line are printed along the side.
They are at varying intervals. CORES
pond1ng to the distance in miles between
each station From each station heavy
black line runs horizontally across the
board. When table is made up pin
is stuck in the interval at the bottom of
the board, representing the exact time az
which each train starts. Another rim is
placed at the interval representing the
time at which it will arrive A string is
then stretched from one pin to the other,
and represents the passage of the train.
The points at which the string intersects
the horizontal lines leading across the
board from the different stations repre-
sent the time at which it will pass each
station.
Trains running into New York are rep
resented by strings running from left to
right and those going out are shown from
right to left. Surprising it is desired to
start train from New York at clock,
a pin is placed at the O'Clock line at the
bottom of the board. and another ON the
O'Clock line opposite Albany. All the
horizontal lines cut by the string which
stretches from pin to pin will show the
time of arrival at each station on tho
route. The faster the train, the nearer to
vertical is the string, while the slower
it is, the greater angle will the st ring
make with the horizontal lines across the
board. When the trains are all placed on
the board, it presents perfect net WORK
of strings. Intricate as it appears,
finger can instantly be put upon the time
of arrival of train at any given station.
The movements of all trains are thus
shown for the whole "a hours. and any dis
crepancy is Immediately apparent, such
as trains running dangerously close to-
gether.
| This simplicity is only found on roads
with four or six tracks. Where there is
only a single track, the board is much
more complex. AS soon as the tables are
shown on the board, and everything is
seen to be all right, the results are print
ed in the timetables, and the board is
rarely used until another table is made
up Where there is only one track the
tiings are always kept on the board,
which is in constant use.
| Freight trains are not often run on
regular time. They are generally sent
out by the train dispatcher as soon as
they are made up and the road is clear.
Some freights are, however, run on regu-
lar time, while the Others, called extras,
have to get along when they can, side
tracking when they would be in the way
of passenger trains.
| All the calculations on the big time
board are made upon the assumption that
the train travels at uniform speed
throughout When the rate of travel is
not the same, owing to heavy grades or
the like allowances have to be made at
those points where the speed is lessened.
The use of the board is not necessary
when local trains are temporarily put on
or off. aud it is fully strung up only
twice a year.