The daily worker. [volume] (Chicago, Ill.) 1924-1958, 1927-01-02
Article II.

stream acquires speed and power because 1t is
flowing down hill. It is gravity that makes it flow.
The sleeper the grade of the river bed the quicker
the flow. and the greater the power developed.
There all kinds of streams in nature, from the
slow lazy river hardly moving along its level drop
ping bare few inches in the mile to the rapid tor
%ent with its swift current and drop in level Of
several feet per mile; best Of all the waterfall, with
immediate drop of hundreds Of feet-power
ready-made for the asking.
The power Of the waterfall is of course the easi-
est to utilize. The station which houses the gene
Fators is located just below the falls Then all that
Is necessary is to bring the water from above the
Ills down thru pipe into the station where 1t viii
dash against the blades of the turbine wheels In
stead Of falling over the precipice Hike the rest Of
the stream, the water that enters the pipe falls thru
Che pipe The intake of the pipe is a short distances
above the falls and sufficiently below the surface Of
the river to insure that the pipe will always be fun
Since the water in the pipe falls thru the same
height as if it had gone the falls, its speed and
power when 1t arrives at the turbines are also the
same as If 1t had gone the falls. After the
water has passed thru the turbine pit it is of course
discharged into the river again.
The development of a waterfall for hydro-electrIc
power Is thus seen to be a comparatively simple and
Inexpensive engineering task Next to a waterfall
NE most advantageous power source is rapid river
with steep "gradient"-as the drop in water level
per mile length is called Here again the situation
b largely similar to that at the waterfall The tur
hines are located at the lower level and the intake
81 the pipe Is at the higher level Of course place
where the course of the river is straight for long
distance would not be favorable location for the
plant as the pipe might have to go back a great
distance TO reach point where the river level Is
sutlc1enty above the level at the station. But q
point where the river makes curve like loop or q
horseshoe is very favorable spot For the river
may have to go nifty miles around the curve while
the pipe mayebe laid across the neck of the curve
q distance of perhaps only five or ten miles; vet
the difference In level between the intake at the
beginning and the station at the end of the curve
will be considerable.
In all cases except the waterfall and the type of
river Just described dam must be built The pur-
pose OF the dam is to create artificial difference
In level also TO regulate the water flow dam
Is merely q stone wall built straight across the river
Is grounded deep in the river bed and rises from
twenty-five to several hundred feet above the river
level; It's ends set firmly against the steep banks
ON either side of the river valley The water COM
ing down stream and striking against the dam can
not get around II, under it thru it. 1t must pile
up behind until the level of the accumulated water
b as high as the dam. We can at see that the
backngup of the water will flood the whole coun-
Looking upstream from the top of the DAM every
thing below that level will be under water. The
difference in level between the surface of the reser
voir and the river below is available to drive the
turbines, and the reservoir to reguarze the
now and acts storage system for the seasons Of
low water.
We are now in position to understand why some
rivers are available for hydroelectric development
while others are not. We might summarize the pos.
Bbiliies follows 1. All waterfalls of sufficient
height and volume. 2. All locations on rivers
where the very steep gradient and other conditions
make power in sufficient quantities available with
out the construction of a dam. g. Locations on
rivers where dams be built
AS for these, only those locations can be consi-
dered where the river has sufficiently steep gradi-
ent and where the river bed is of material that will
give firm foundation for the dam. Furthermore
the river valley must not be wide at the chosen
point. If It were the dam might have to be miles
long before it could reach the hills which close
The valley each side of the river; and the DAM