From Engineering News-Record, November 2, 1939: “Timber bulkheads sealed the tubes’ mouths to make possible the 15-mi. voyage. afloat, the tubes were submerged 18 ft., with 5 ft., above the water. In plan, they measure 200 x 40 ft. Two stiffener ribs at the ends will connect the receiving cofferdam at the land ends of the subway.”

From Engineering News-Record, November 2, 1939: “Timber bulkheads sealed the tubes’ mouths to make possible the 15-mi. voyage. afloat, the tubes were submerged 18 ft., with 5 ft., above the water. In plan, they measure 200 x 40 ft. Two stiffener ribs at the ends will connect the receiving cofferdam at the land ends of the subway.”