Construction of the Leonard P. Zakim Bunker Hill Bridge
A bridge between Charlestown and Boston
had been conceived as far back as the 18th century. The “High
Bridge” as its called today was a temporary bridge built to deal
with traffic and as a means of passing through the center of Boston.
It was built in 1952 as a short answer to the problem. Over time it
became clear that it was not built to last as the design led to many
car accidents and traffic jams. Many cars also received flat tires as
the road began to wear away. The “Big Dig” is the largest project of
its type in the nation. I say “is” instead of was because
even today it is not finished. It was started in 1987 and no estimate
came close to the billions of dollars and nearly two decades that have
already been put into it. Christian Menn, a famous Swiss architect was given the
job of design this bridge. He was given a lot of constraints though
as the bridge construction could not interfere with everyday life. The
High Bridge had to remain open, the Charles River had to remain navigable
and the Orange line on the “T” had to remain open. Obviously
this created some problems. However Menn was not about to let that stop
him. He was going to design the widest cable stayed bridge in the country.
The two towers which were shaped like upside down “Y’s”
were of different heights. The one at the North end was 322 feet above
water and at the South end was 295 feet above water. The bridge was
both concrete and steel in design with a network of 116 cables, the
longest of which is 500 feet. The towers were finished by the end of
1999. The main span of the bridge had 70 small diamond and
hexagonal holes cut out of it to let light pass onto the water below,
but in 2001 much of it had to be torn up due to the discovery that the
concrete hadn’t solidified properly with the steel. |