ted; second, the reduction of the sewer in Eighth Avenue
from a 6-ft. to a 5-ft. circular conduit; and, third, assuming that the
sewage and drainage from the Terminal would be pumped directly to the
sewers in the avenues, the reduction of the sewers in 31st and 33d
Streets, from Seventh to Ninth Avenue, to 15-in. vitrified pipes, except
west of the Service Building in 31st Street, to accommodate which
section, a larger sewer was required. The sewer in 32d Street, from
Ninth to Eighth Avenue, of course, could be dispensed with in any
arrangement, as all the area tributary to it was to be excavated.

[Illustration:
Fig. 2.
PLAN SHOWING LAYOUT OF SEWER IN CATCHMENT AREA ABOUT TERMINAL STATION]

GAS AND WATER MAINS.

A rearrangement of the gas pipes in the three streets crossing the
Terminal site was necessary. These pipes were of two classes: trunk
mains and service mains. Fortunately, there were but two trunk mains
in the three streets, one a 20-in. in 31st Street from east of Seventh
Avenue to Ninth Avenue, the other a 16-in. in 32d Street from east of
Seventh Avenue to Eighth Avenue. The 20-in. main was relaid from Seventh
Avenue and 31st Street down Seventh Avenue to 30th Street and through
that street to Ninth Avenue. The 16-in. main was relaid from Seventh
Avenue and 32d Street north to 34th Street and through that street to
Eighth Avenue. The service mains in 32d Street were no longer required,
and were taken up and not replaced. The houses on 31st and 33d Streets
were provided with service by two 6-in. wrought-iron mains back of the
retaining walls in each street, that location being chosen to avoid
damage by gas drip to the water-proofing of the street bridges. As the
permanent structures under the avenues were not to approach the surface
nearer than 19 ft., only slight rearrangements, sufficient to permit the
new sewers and water lines to be laid, were necessary.

There were no large water mains to be cared for, in fact, those in the
streets were too small for ample fire protection, being only 6 in. in
diameter. The main in 32d Street was taken up and not replaced, and
those on 31st and 33d Streets were replaced by 12-in. pipes laid back
of the retaining walls. No changes were necessary in the mains in the
avenues, but, before approving the rearrangement for the streets, the
Department of Water Supply, Gas and Electricity added a 48-in. main in
Eighth Avenue to be laid as a part of this construction,