e 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.

CONTRACTOR'S PLANT.

The method of handling the work adopted by the contractor was, broadly
speaking, as follows: Excavation was usually carried on by modifications
of the top-heading and bench method, the bench being carried as close to
the face as possible in order to allow the muck from the heading to be
blasted over the bench into the full section. The spoil was loaded into
3-yd. buckets (designed by the contractor and hereinafter described), by
steam shovels operated by compressed air, and hauled to the shafts by
electric locomotives. Electrically-operated telphers, suspended from a
timber trestle, hoisted the buckets, and, traveling on a mono-rail
track, deposited them on wagons for transportation to the dock. Arriving
at the dock, the buckets were lifted by electrically-operated stiff-leg
derricks and their contents deposited on scows for final disposal. The
spoil was thus transported from the heading to the scow without breaking
bulk.

When concreting was in progress, the spoil buckets were returned to the
shafts loaded with sand and stone. The concrete materials were deposited
in storage bins placed in the shafts, from which they were fed to the
mixers located at the foot of the shaft about on a level with the crown
of the tunnels. The concrete was transported to the forms in side-dump,
steel, concrete cars, hauled by the electric locomotives.

Electrical power was adopted largely on account of the restricted area
at the shaft sites, where a steam plant would have occupied