The New York Subway

asonry, almost without a break along the entire subway construction, has made it unnecessary to provide an extensive sy

h as by leakage through a cable manhole cover or by the breaking of an adjacent water pipe, or the li

e of the adjacent sewer, the carrying of the water away has been easy to acco

, at each depression where water is liable to collect, a well, or sump pit, has been constructed just outside the shell of the tunnel. The bottom

is necessary to maintain pumping devices, it has not been possible to employ a uniform design of pumping equipmen

pump employed, as the employment of com

t is necessary to maintain a pumpi

e lowest point o

ersection of Elm

h Street in the M

rsection of 46th S

ection of 116th Stre

section of 142d Str

ection of 147th Stre

144th Street in Ha

center of the Ha

section of Gerard Av

pumping plants are maintained, it is necessary t

el constructed under the Subway

e sub-subway at 42d

tal of the Lenox Avenue e

e southerly end of t

e northerly end of t

portal at Bergen Ave

ump wells which are not easily accessible, and the air lift was selected for the reason that no moving parts are conveyed in the air-lift construction other than the movable ball float and valve which control the device. The air lift consists of concentric piping

perated ejectors have been employed, for the reason that the conditions di

ing pumps will be employed. These pumps will be placed in readily accessible locations, where air lif

scends from the portal, it was considered best to employ large submerged centrifugal pumps, operated by reciprocating air engines. Also for the portal, at Loc

r line which supplies air to the switch and signal system, but break-down connections will be

pumps, within the immediate locality of each compressor plant. For the more remote pumps, air will be supplied by smaller air compressors located within