The Portland daily press. [volume] (Portland, Me.) 1862-1921, 1893-11-25
MODERN LEG SAVERS.
An Interesting Account Of How the
Modern Elevators Work.


Ride on Them Daily-Onc Elevator WIFI
Garry 10000 Persons IL DaJ-Eow Some
of Them Are Operated by Water Power.
Five hundred Thousand men ride in the
elevators Of New Mark city every day OF
the year, and not one man of them in {,
hundred has more than the vaguest idea
how these shooting cars work. AS fol
the 100000 or so women who daily call
out cup" or 'down," the percentage who
know what makes the thing go'' would
be shockingly small.
To get some more precise ideas about
these vertical railways, the writer went
down the other day into subterranean
New York, into those wonderful modern
catacombs where engines throb and cleo
tricity takes its birth, under one of the
great down town buildings, which con
tains no less than 81 elevators, 81 for pas
Bengers, IS for freight.
A strange and unfamiliar region is this,
where giant wheels, belted to other
wheels, make the foundations tremble and
the air roar in ones ears.
s'Here, said the engineer, to whom all
this was as familiar as the schoolroom to
it's teacher, there are the boilers which
supply steam to work the elevator pumps
and to turn the dynamos. There are nine
of them, each IS feet long and feet in
diameter. They burn 1875 tons of coal a
week, winter and summer. The seasons
make very little difference: it is always
the same down here.
"Now come this way, and you will see
how this steam makes the pumps send
water up to the tanks at the top of the
building-5,000 gallons of it minute
Say they work at full pressure half the
time, or four hours day, that gives $780,
600 gallons pumped up about 200 feet,
which means nearly $40, ,000 foot
pounds of energy day to run the ele,
vators alone.
'sNot so bad is itP And the beauty of
it is that in doing this work we use the
water over and over again; pumped into
the tanks above, then discharged into the
big tank down here, then through the
pumps again and SO on until we change it
for cleanliness "
''And how does the water run through
the eleyators?"
II can make tina; plain to you in two
minutes. You SEQ each elevator has it's
water tank at the top Of the building and
its own hydraulic machine at the bottom,
and the two are connected by an inch
iron pipe. That pipe lets the water from
above into the foot cylinder of the by
draulic machine, and this water is kept by
the pumps ut pressure of 100 pounds to
the square inch.
consequently whenever the water
presses into the cylinder it drives this pis-
ton rod out to it's full length, 16 feet, with
the force of some scores of tons-the cal
culation is easy if you remember the for
mula. Now this piston rod in moving
pulls apart what you might call the two
blocks Of an enormous pulley, with five
wheels in each block.
"Here they are, see. And the wire rope
which runs around these pulley wheels
goes over wheel up under the roof, and
then down till it catches the top of the
elevator car. AS there are 10 wheels in
the two pulley blocks the end Of the rope
with the car attached travels 10 times as
far as the piston rod does, or 10 times 16
feet, which is the distance the elevator
travels up and down"
"What brings the piston back and the
elevator down?''
"The changing of this valve where the
iron pipe joins the cylinder. When the
valve is thrown one way, the water presses
into the cylinder, and up goes the ele-
vator; when the valve is thrown the other
way, the pressure on the piston Is relieved
and the water is discharged into the tank
over there, through these pipes. Then the
elevator comes down by it's own weight
and that-of the passengers.
The valve is worked by the elevator
boy when he pulls the cord either way,
and if he should forget to pull the cord
the valve would act automatically, just
as the valves in an engine do.
1.-THE wider the valve is opened, going
either way, the faster the car goes, up to
a certain point, where, whatever might
happen, even supposing the valve to burst
a separate attachment, consisting of an
independent cable, would stop the car by
the action of what we call the safety gov
ernor. There you have the whole thing
in a nutshell"
"And what if the wire rope which holds
the car should break"
1.-THE elevator would stop instantly, as
it would also if one of the four ropes-for
there are four, not one-should even
stretch. The car would stop because by
reason Of a simple device a series of
wedges would be thrown out and grip the
iron frame in which the elevator slides.
The heavier the load the harder the wedges
would hold"
In some elevators the big cylinder is
visible above the floor in a vertical instead
of a horizontal position, with the pulley
wheels scattered along at intervals on the
way up, as if to give the passengers food
for reflection.
In some again there is no water tank at
the top of the building, the requisite pres
sure being obtained by pumping COM
pressed air. These are details which con-
Germ the elevator men only, and not the
general public. 1t is Il splendid achieve
ment to have mastered the main point of
a single system.
One point which I found interesting is
the question of speed. How fast do these
elevators run? How many miles do they
cover day?
This merely depends upon the number
of pulley wheels you have attached to your
piston rod. With six, seven or ten pairs
Of pulley wheels, instead of five pairs, the
elevators just under consideration would
run SO, Ga or 100 feet farther for each
stroke of the piston than they do at pros
pnt