In this paper, it is proposed to describe the construction of the
tunnels extending eastward from the easterly extension of the Terminal
Station to the permanent shafts east of First Avenue.
They were located under 32d and 33d Streets from the station to Second
Avenue, and thence, curving to the left, passed under private property
and First Avenue to the shafts, as described in a preceding paper.
Typical cross-sections of the tunnels are shown on Plate XII.[B]
On May 29th, 1905, a contract was entered into with the United
Engineering and Contracting Company for the performance of this work.
This contract provided that work on each pair of tunnels should be
carried on from two shafts. The first, here referred to as the First
Avenue Shafts, were located just east of that avenue and directly over
the line of the tunnels; the other two, called the Intermediate Shafts,
were located on private property to the north of each pair of tunnels in
the blocks between Fourth and Madison Avenues. It was originally
intended to do all the work of construction from these four shafts.
Workings were started both east and west from the Intermediate Shafts,
and those to the west were to be continued to the Terminal Station.
After the change of plans, described in a previous paper, it was decided
to sink a third shaft on each line. These were known as the West Shafts,
and were located between Sixth and Seventh Avenues. Finally, it was
found necessary to build a portion of the tunnels on each line west of
Sixth Avenue in open cut. The locations of the shafts are shown on Plate
XIV.[C]
The First Avenue shafts were built by S. Pearson and Son, Inc., for the
joint use of the two contractors, as described in the paper on the
tunnels under the East River. While the shafts were being sunk, the
full-sized tunnels were excavated westward by the contractor for the
river tunnels for a distance of 50 ft., and top headings for 50 ft.
farther. By this means, injury to the caissons and to the contractor's
plant in the shafts by the subsequent work in the Cross-Town Tunnels was
avoided. The west half of the shaft was for the exclusive use of the
contractor for the Cross-Town Tunnels.