stood proud for 86 years in Marietta, Ohio, but took only a
split second to tumble into the Muskingum River at 9:30 a.m.
on April 27, 2000.
Accurate Arms copper clad linear shape charges with RDX explosive
cores, amounting to only 60 lbs. of explosives, the old Putnam
Street Bridge was blasted in 28 milliseconds.
was planned, supervised and engineered by NADC-member Eastern
States Wrecking Co. (ESWC) of Bristol, Pennsylvania with the
assistance of W.J. Castle Engineering, PC, PE, of Lumberton
removed the sidewalk planks, railing and their supports. The
concrete deck was then broken apart and removed. Because of
the 3-ton weight restrictions on the bridge, ESWC utilized lightweight
Keibler Thompson Corp. remote controlled demolition equipment
to perform the break out. The ESWC crew then installed rigging
cables with buoys to various sections of the bridge, prior to
the explosive demolition, so that retrieval of steel members
from the river could be accomplished without divers
the actual explosive demolition to one of the country's premier
structural blasting firms, NADC-member Demtech Inc. of Dubois,
Wyoming. Together, ESWC and Demtech formulated a blast plan
to meet the stringent requirements of local, state and federal
officials. NADC-member Protec Documentation Services of Rancocas,
New Jersey was then contracted to perform pre-blast structure
inspection and vibration monitoring. Protec spent three days
inspection approximately 80 structures situated near each bridge
abutment and later reported that all blast vibration levels
fell within acceptable limits and adjacent properties suffered
stationed in the Muskingum River to handle and transport the
steel. Using 80 ton Manitowoc 222 barge mounted crane, the steel
was lifted out of the river and moved to the riverbank where
it was processed for recycling.
Working under the direction of the U.S. Coast Guard, the navigating
channel of the river was cleared within 24 hours of the detonation.
was demolished to make way for the new 11.4 million Putnam Street
Bridge, which is currently being built by Kokosing Construction
Co. The west end of the new bridge was only 4 feet away from
the bridge being demolished and suffered no adverse effects
from the blast.