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Building the Callahan Tunnel

March 23, 1961: The steel ribs of the Lieutenant William F. Callahan Jr. tunnel stretch as far as the eye can see under Boston Harbor from East Boston to Boston. The 14,500 tons of special structural steel used to fabricate the basic lining of the tube came via rail to East Boston from Youngstown, Ohio. The massive corrugated series of curved steel plates when bolted together form “rings.” In the case of the new tunnel, concrete forms the secondary lining inside the rings. A total of 1,813 rings, each composed of 11 segments, are locked tightly into place.

Globe file photo

March 23, 1961: The steel ribs of the Lieutenant William F. Callahan Jr. tunnel stretch as far as the eye can see under Boston Harbor from East Boston to Boston. The 14,500 tons of special structural steel used to fabricate the basic lining of the tube came via rail to East Boston from Youngstown, Ohio. The massive corrugated series of curved steel plates when bolted together form “rings.” In the case of the new tunnel, concrete forms the secondary lining inside the rings. A total of 1,813 rings, each composed of 11 segments, are locked tightly into place.

Recent transplants to Boston could be forgiven for thinking we have but one harbor tunnel connecting downtown with East Boston. The twinned Sumner and Callahan tunnels, after all, begin and end in the same place on both sides of the harbor, a single entity for the casual observer. They were in fact built decades apart, the Sumner in 1934, and the Callahan in 1961. With increasing volume, a single tunnel with traffic moving on one lane in each direction proved dangerous and inadequate, and the Turnpike Authority opened the Callahan on Nov. 11, 1961. Workers toiled 24 hours a day, six days a week crafting 14,500 tons of steel into the nearly mile-long tunnel. - Lane Turner and Lisa Tuite.

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