The Michigan Technic Volume 21

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908 Excerpt: ...The work was sublet for construction in four sections by the general contractor. The river tunnel section was let to the New York Tunnel Company about the end of the year. ROUTE. The route of the river tunnel section as contracted for, begins at a point at the east side of Battery Park opposite Pearl Street, curving to the south and east through Battery Park, passng the bulkhead line on the river tangent at the foot of Whitehall St., continuing under the East River to the Brooklyn side, thence curving east to take the direction of Joralemon St., and ends at Clinton Street. After construction began a deviation in the line of 4 to the south was made near the Manhattan side to allow for passing under the Brooklyn slip instead of under Pier No. 17 to the north as originally planned. GRADE. The grade is 3.1% downward on each side of the river, execpt for a short distance near the middle, where a 0.5% grade upward toward Brooklyn was later introduced. This portion is joined to the steeper grades on each side by vertical curves of 10,000 ft. radius. The tunnel is everywhere below water level, except for about 700 feet at the east or Brooklyn end. The lowest point reached by the tunnel is 94 feet below mean high water. GENERAL DESCRIPTION. The tunnel consists of two circular single track tubes of the usual cast iron ring construction. They are 15'-6" internal diameter, and run side by side 28 feet apart on centers, except under Joralemon Street, where this distance is decreased to 26 feet. The tubes are lined throughout with concrete, and are grouted externally. MATERIAL. The material on the Manhattan side from the shaft east to the lowest point of the tunnel, a distance of about 2,700 feet, consisted almost entirely of rock. About half way from the low point ...