Airplane View... Looking toward
San Francisco, Showing Entrance
to Tunnel
HE Yerba Buena Anchorage, on the westerly shore of
Yerba Buena Island, anchors the cables on the east end of
the twin suspension bridges which comprise the West Bay
Crossing of the San Francisco-Oakland Bay Bridge. Two
163-foot concrete tunnels have been excavated in the rock of
the island, into which are sunk eyebar chains to which eye-
bars are attached in turn. Cable strands are looped around
these eyebars and anchored. Two cable bents imbedded in
concrete support the cables just immediately before they
begin their downward way to the anchorage. The entire
structure, when completed, will be 154 feet x 191 feet in size.
The double-deck tunnel is the largest bore vehicular tun-
nel in existence.
PICTURE NO. 10-B PUB. BY J. C. BARDELL SAN FRANCISCO, CALIFORNIA
