The transportation system of the city of Boston comprises a combination
of both rapid transit and surface lines operated under a single fare
arrangement with transfer privileges permitting a continuous ride in one
general direction from one end to the other of the system. The elevated
lines and the Tremont St. Subway were originally built by the railway
company in 1901. Today the total transportation system includes more
than 500 miles of line of which 37 miles are subway and elevated tracks.
The population served in the district of more than 92 square miles is
considerably over a million people and the number of revenue passengers
carried, approximates 350,000,000 per year. Statistics are not available
as to the passengers carried on the Rapid Transit lines.
[Illustration: EXTERIOR OF MAIN POWER STATION AT SOUTH BOSTON]
The original elevated structure operated between Sullivan Sq.,
Charlestown, and Dudley Street, with two branches through the city, one
by subway under Tremont St. and the other by the way of Atlantic Ave.
and South Station. In 1908-9 the elevated structure was extended to the
present terminal at Forest Hills and the Washington St. Subway was
completed through the business part of the city. The Cambridge Subway
was placed in operation in 1912. Recent extensions include an elevated
line from Sullivan Square to Everett and reconstruction of the tunnel to
East Boston.
Since July 1, 1919, the system has been operated by the Board of
Trustees of the Commonwealth. Under the direction of this board are
included not only the details of operation and management, but also the
decisions as to fares to be charged independent of the State Department
of Public Utilities.
Under the direction of the present management a continuous program of
improvements has been inaugurated which has necessitated the re-routing
of trains to handle the traffic to the best advantage.
Briefly there are four main routes as follows:
Forest Hills-Everett (via tunnel) 8.59 miles
Forest Hills-Everett (via elev.) 9.35 miles
Harvard-Andrew 5.56 miles
No. Station West-Kenmore 2.87 miles
Bowdoin-Maverick Sq. 1.67 miles
The Forest Hills-Everett route is called the main line, and the
Harvard-Andrew route the Cambridge Subway. The Bowdoin-Maverick Square
line up to the present has been operating three-car trains with overhead
trolley, but new equipment consisting of steel cars is now on order and
the third rail is now being installed in the tunnel. The Lechmere
Sq.-Broadway line over East Cambridge Viaduct and Tremont St. Subway is
also considered a rapid transit route, although surface type cars are
used with overhead trolley. These cars are equipped for multiple unit
control and are operated in three-car trains.
[Illustration: 35,000-KW. TURBO-GENERATOR IN SOUTH BOSTON POWER STATION]
The rush hour trains on the main line include as high as eight cars,
which is the limit set by the length of the station platforms. The
signal system is entirely automatic and during rush hours the headway
varies from 2 to 3½ minutes on the main line. The maximum grades
encountered are 2 to 3 percent with a high percentage of heavy
curvature. By taking advantage of the transfer arrangements at
terminals, rides of 14 miles can be obtained for a single fare.
_Power Station Equipment_
The power system as originally installed included several engine-driven
direct-current plants suitably located for distributing 600 volts direct
to the trolley. With the extension of the system, however, an
alternating-current station was installed at South Boston, generating
25-cycle three-phase current for distribution at 13,200 volts to
synchronous converter substations. Alternating-current generating
equipment has also been installed at the Lincoln Station. The total
installed capacity of turbine stations is now 115,000 kw. while the
direct-current generating stations have practically all been
discontinued.
[Illustration: RAPID TRANSIT LINES—BOSTON ELEVATED RAILWAY]
[Illustration: EXTERIOR OF EGLESTON SQUARE SUBSTATION]
_Substations_
There are in operation for supplying power to both elevated and surface
lines a total of 12 synchronous converter substations having a total
rated capacity of 58,000 kw. The power consumption of the Rapid Transit
lines is somewhat less than half the total energy used.
_Distribution_
Direct current is distributed from the several substations at 600 volts
and is collected on the rapid transit systems from an 85-lb.
over-running third rail.
_Rolling Stock_
Altogether there are 420 cars in the rapid transit service, the older
cars weighing about 34 tons with seating capacity of 48 and the newer
type as used in the Cambridge Subway 43 tons each, arranged to seat 72
passengers. On account of the limiting clearances in the old subway the
Cambridge cars cannot be used on the main line. All cars are motor cars
and no attempt is made to use trailers. Each car is equipped with two
motors and multiple unit control.
[Illustration: LATEST TYPE OF STEEL MOTOR CAR USED IN CAMBRIDGE SUBWAY]
[Illustration: MAIN LINE TRAIN—BOSTON ELEVATED RAILWAY]
[Illustration: INTERIOR OF SUBSTATION EQUIPPED WITH 2000-KW. SYNCHRONOUS
CONVERTERS]
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