The Portland daily press. [volume] (Portland, Me.) 1862-1921, 1891-11-04
THE TELEPHONE ooNpulrs
The way In Which the Wires Are pu.
Underground.

The New England Telenhone ora ro,o
graph company have begun the construction
Oh an underground system of conduIts which,
wnen completed, will enable it to plaza the
bulk OF Its wires In Portland underground.
The conduits. SO far as they are now being
laid, are OF the full capacity that will be
required for many years.
The trenches In Exchange and part of
Middle street have already been opened and
the conduit in Exchange street Is nearly
completed. This trench will contain IA
pipes. with capacity for 1880 wires.
In Exchange street the trench is excavated
about 81 feet wide and 81 feet deep. In this
trench, at the sides, boards are placed on
edge in order that the conduit may be on a
straight line and also to protect the conduit
against other people digging in the street.
Inc bottom of the trench is prepared to q
true grade,and then layer of concrete, three
inches thick, is spread ON the bottom be-
tween the boards. On this concrete five
pipes are laid and secured in position by
joints of neat cement When the cement has
hardened SO that the pipes cannot be easily
moved the spaces between them are filed
with concrete and layer of an inch OF more
OF concrete is placed on top of them, Upon
this bed another layer of five pipes is laid
and covered with concrete as before, and a
top layer of four pipes added covered with q
layer of three inches of concrete. On this
Will be placed two inch plank, to cover the
width of the conduit, and what is left of the
trench will be refilled with dirt, and the
paving replaced. Very little trouble has
been experienced with the paving settling
over the trenches. There will be man.
hole in front of the Office connected by an
archway with the basement of the building,
and another at Middle street 400 feet away.
These manholes will be seven feet deep and
five or six square. They will have iron
covers similar to the sewer manholes.
The cables, containing from one to two
hundred wires apiece, will be prepared to
reach from one manhole to another. These
cables come on reels and are drawn into the
pipes, from one manhole to another. The
method of drawing the cables into the pipes
is this: First set of rods, like jointed
fshing-rod, about fonr feet long, fastened to-
gether, are pushed into the pipe, and addi-
tional rods added, until the first rod comes
out at the second manhole. Then small
rope is fastened to the end of the first rod,
and the rods are pulled back until the end of
the rope appeares at the first manhole With
the small rope a heavy rope II inches in
diameter, Is drawn into the pipe, and then,
by means of this large rope the cables are
drawn into each pipe by power furnished by
from four to six men working on winch.
Unless the company meets with unfore-
seen obstacles they expect to complete the
work by November Goth.
The engineers of the company hBve pre-
pared map of the route on large scale
showing the car-tracks. curbstones, Portland
gas pipes and sewers, and the route for the
conduit has beeu laid out so as to interfere
as little as possible with existing street
pipes.
Mr.. d. A. Harrington, who has been en-
gagged Ia similar workin Boston and Spring
field. has charge of the work, and Mr.. Chas.
r. Dyer is the contractor.