Transactions of the American Society of Civil Engineers, vol. LXVIII, Sept. 1910 / The Bergen Hill Tunnels. Paper No. 1154

by F. Lavis

CROSS-SECTION

LONGITUDINAL SECTION

PLAN

Drilling Method No. 1: Small heading, 60 to 80 ft. long. Twocolumns used in heading, with two drills on each. Drills on sub-benchand main bench mounted on tripods.

	Per Round				Per Cubic Yard		Per linear Foot of Tunnel
	Total Depth Drilled	No. of Cubic Yards	Pounds of Dynamite	Adv.	Linear Feet Drilled	Pounds of Dynamite	Cu. Yd.	Linear Feet Drilled	Pounds of Dynamite
Heading	140-155	18-21.6	93-131	5-6	8-9	5-6	3.6	29.-32	18-22
Bench	110-120	53-60	76-97	3½-4	2	1.4-1.6	15.4	30.-31	21.5-24.6
Total							19	59.63	39.5-46.6
Per cubic yard, whole tunnel section								3 to 33	2.1-2.5

Blasting Notes:		Number of Sticks
Heading:	First Round: 6 sticks, 60% in each cut hole, cut generallyblasted twice	36 to 72
	Second Round: 3 side holes each side, 5 sticks, 40%ea.	30
	Third Round: Rest of side holes and dry holes, 5 sticks, 40%each	40
	Stub holes, say	5 to 15
	Total Sticks	111 to 157
	Total Pounds	93 to 131
Sub‑bench:	4 widening holes; 2 to 3 sticks, each, 40%	10 to 12
	6 down holes; 5 to 7 sticks, each, 40%	30 to 42
Bench:	6 holes; 6 to 8 sticks each, 40%	36 to 48
	Taking up bottom, average, say	15
	Total Sticks	91 to 117
	TotalPounds	76 to 97

[Fig. 2.]

CROSS-SECTION