Engine-men and firemen, 5
Mechanics in iron, 4
Carpenters, 5
Blacksmiths and helpers, 4
Pump men, 1
Manual laborers, 39
--
Total in July, 58
On the first day of November there were employed at this point, in all,
81. Of this number, 40 were engaged out of the shaft, and 41 in the
shaft.
The above enumeration does not include the resident engineer and
time-keeper, stationed here in November.
The depth of Central Shaft, when completed, will be 1,037 feet from the
surface; its form is an ellipse, whose axes are 27 and 15 feet. On the
fifth day of May it had reached the depth of 300.5 feet. At this time
the hoisting apparatus was removed from the shaft, and the work of
excavation ceased. The new hoisting apparatus was fitted on the first
day of August, and the drilling commenced at midnight on that day.
Previous to the change in the hoisting apparatus, the monthly progress
had averaged about 18-1/2 feet per month. The advance in October and
November was 46 feet; the gain over the previous rate of progress is
attributable to the practice of simultaneous blasting.
On the first day of January, 1867, the shaft had been sunk 393 feet,
leaving for excavation 644 feet.
_Table showing the progress at Central Shaft from November 1, 1865, to
December 1, 1866._
========================================
DATE. | Distance | Progress.
| down. |
==================+==========+==========
Nov. 1, 1865, | 200.8 |
Dec. 1, 1865, | 220.1 | 19.3
Jan. 1, 1866, | 232.5 | 12.4
Feb. 1, 1866, | 250.7 | 18.2
Mar. 1, 1866, | 264.1 | 13.4
Apr. 1, 1866, | 280.9 | 16.8
May 1, 1866, | 297.1 | 16.2
May 5, 1866, | 300.5 | 3.4
June 1, 1866,[A] | 300.5 |
July 1, 1866,[A] | 300.5 |
Aug. 1, 1866,[A] | 300.5 |
Sept. 1, 1866, | 311.9 | 11.4
Oct. 1, 1866, | 331.1 | 19.2
Nov. 1, 1866, | 354.0 | 22.9
Dec. 1, 1866, | 377.0 | 23.1
========================================
[A] Work suspended to put in new hoisting apparatus.
The present hoisting apparatus is expected to be sufficient to finish
the shaft. It has two wire ropes, each 1,260 feet long. The time for a
round trip is seven minutes. The engine here is of 100 horse-power. The
blacksmith shop contains two forges. At the small machine shop the
repairs required here are made, as also some repairs for the West Shaft.
The Central Shaft, though designed to aid in ventilating the tunnel, was
intended also to accelerate its construction by affording to the process
of excavation four faces instead of two during some portion of the work;
and the former chairman of the commissioners expected by the aid of
machine-drilling, the shaft might be completed in one year from the time
such drilling should commence within it. In this anticipation, ten
vertical drilling machines were constructed to work in the shaft area
and a compressor with two cylinders was provided to furnish the power
for operating them. The want of drilling machines at the East End became
so urgent, that these vertical ones were changed to horizontals, and
used at that point, and the sinking of the shaft by hand-drilling still
continues. But if the experiments now in progress at the East End with
the new drilling machine shall demonstrate its superiority over hand
labor, the machine will doubtless be introduced into the shaft.