#S. Number of shifts covered by observations.
#Hrs Average number of hours worked per shift.
D/Hr Average depth drilled per hour per drill.
D/Yd Average depth drilled per yard.
Hack. Hackensack
Whk. Weehawken
CS Central Shaft
----------------+-----------+----+-----------+------+------+------
Method. | Date. | #S | Place. | #Hrs | D/Hr | D/Yd
----------------+-----------+----+-----------+------+------+------
{| Aug. '06 | 44 | Hack., N. | 5.69 | 2.78 | 10.1
{| Sept. '06 | 38 | " N. | 5.80 | 3.77 | 11.1
No. 1-- {| Aug. '06 | 43 | " S. | 5.60 | 2.89 | 9.1
4-drill {| Sept. '06 | 36 | " S. | 6.18 | 2.65 | 8.7
{| Jan. '07 | 16 | CS E. N. | 5.99 | 2.99 | 8.2
{| Jan. '07 | 20 | " S. | 6.05 | 2.9 | 7.1
{| Apr. '07 | 48 | CS W. N. | 4.92 | 3.3 | 6.7
{| Apr. '07 | 48 | " S. | 5.00 | 3.2 | 7.7
| | | | | |
{| Dec. '06 | 54 | Whk., N. | 4.95 | 2.16 | 4.52
Nos. 2 and 3-- {| Dec. '06 | 54 | " S. | 5.23 | 2.14 | 4.54
5-drill {| Dec. '06 | 52 | Hack., N. | 5.03 | 2.2 | 5.77
{| Dec. '06 | 54 | " S. | 5.90 | 1.82 | 5.67
| | | | | |
No. 4-- {| June '07 | 56 | Whk., N. | 4.77 | 2.55 | 4.23
7-drill {| June '07 | 58 | " S. | 4.82 | 2.26 | 3.88
| | | | | |
8-drill {| May '07 | 60 | Hack., N. | 4.67 | 2.44 | 5.00
{| May '07 | 60 | " S. | 4.54 | 2.57 | 4.80
----------------+-----------+----+-----------+------+------+------