The daily morning journal and courier. [volume] (New Haven, Conn.) 1894-1907, 1897-02-11
B0ST0N'S FAMOUS SUBWAY
CHIEF EN6INEER oARSON Tells
NOW 1T rs TRUCTED.

Lecture Before Engineers Club-Features
of the Engineering Work on the subway
-Subways in other Cities.
An exceedingly interesting and valu-
able lecture was given last evening in
North Sheffield hall by Howard A. Car
son, member of the American Society
of Civil Engineers and chief engineer
of the famous Boston subway. The
lecture was given under the auspices
of the Engineers club and was largely
attended by citizens as well as stu
dents.
Professor Dubois introduced Mr.. Car
son, who spoke on "Subways in Bos-
ton, London and Elsewhere" The lee
ture was Illustrated by stereopticon
views of the Boston subway and also
of some of the European subways
which Mr.. Carson has visited
The lecturer at the commencement
explained why the Boston subway was
built. "The population of Boston 100
years ago was less than $4,000; 100 years
ago about $4,000; In 1880, in the remem-
brance of many, about $4,000. while to-
day the city has about 100000. The
population of Boston doubles in about
| thirty-five years.
1.-THE use of the streets for travel in
creases faster in proportion than the
population Of the city. In 1896 1857, 100000
persons were carried by the street rail-
ways. While the population doubles
only in twenty-five years travel on the
street railways doubles In about ten
years.
| "The streets are no wider now than
| they were one hundred years ago, and
| they are not able to do the work they
are needed to do. If streets can't do
| the work required of them the natural
| thing to do is to build them wider or
| make new streets, but the cost is too
great for this, costing perhaps 500 a
foot. If you can't build or broaden the
| old streets you must do the way a per
son does when, q house Is oyercroWded
and has not land to build newly add
| ing stories to the old. In the case OF
street you have to decide between an
elevatedway or a subway.
1.-THE mere cost Of erecting an elevat-
| ed road Is only about one-half or one
third of that of subway, but the dam
age which has to be paid to adjacent
property owners makes the cost of the
| two systems about the same. AS to the
convenience and comfort of the two
methods, different persons are likely TO
hold different views"
Mr.. Carson then explained an elevat-
ed road which is being constructed In
Germany, where the cars are suspended
| from the track instead of running on
| the rails.
THE Boston subway is being built
under some of the most Travelled streets
of the city. For most Of the distance it
is to have two tracks, but at points
there are four tracks where the cars
can run back without running to the
end of the line At the northern tern1i-
nus there is an incline where the cars
/; can come to the surface. Stations Tor
passengers are placed at convenient
distances, usually one in about l,0oo
! feet.
1.-THE retaining walls of the subway
are of granite and concrete, mostly OF
concrete There are two forms of con-
struction employed in the roof, one
made of steel and concrete and the 9TH
| er the brick arch.
1.-THE subway is about twentyfour
feet in width at the incline, where there
are two tracks, and about sixteen feet
| high. In the middle Of the subway is a
drain. the side walls of which are of
brick with open joints, so that the wa
ter can easily find its way into 1t, and
the top is covered over with flags cas-
| ily removed if the drain needs inspec-
| ton or repair.
| Eat the passenger stations there are
| two stairways, each fifteen feet in
width 1t was not intended at first to
use elevators at all, but it may be
thought desirable to adopt them at
some stations later on.
| I'm the work of construction many
pipes were encountered which had to
be removed or passed under The work
| is being so performed as to cause the
least possible hindrance to travel on
| the streets. In the daytime one-third
| of the street is occupied for the plant
and material used for the work, and
| the other two-thirds is left for travel.
| At night about two-thirds of the street
| is occupied in the work.
Bridges are built over the excava-
lions on level with the street, so that
one passing over them will hardly no.
! tice the fact. The work is done by
what is known as the slice method, by
which ten or a dozen sections are being
| excavated at the same time, no two be-
| ing adjoining.
'"There are eight fans placed at ap-
propriate intervals to ventilate the tun-
mel, each fan being seven feet in diam
eter. 1t was feared by some that the
4 excavations would weaken the founda-
tons of some of the high buildings, but
| the work has so far advanced now that
there is seen to be no danger"
| Mr.. Carson closed his lecture with a
rapid description of subways in Buda-
pest, Paris, London and Glasgow, and
also a description of the use of the
shield in tunnelling.
1