Beverly Draw Bridge Modernization Project Advances

The General Manager has announced that the T’s Board of Directors has authorized the expenditure of up to $1,600,000 for a new hydraulic system and other upgrades for the Beverly Draw Bridge on the Newburyport/Rockport Commuter Rail Line.

The main span, originally built in 1886, is a navigational channel swing bridge with a symmetrical swing span consisting of four girders with an open deck and timber ties. The MBTA is required to open this bridge within ten minutes of a request from a marine vessel in adherence to federal regulations. The U.S. Coast Guard closely monitors bridge activity and strictly enforces non-compliance with significant penalties.

On December 21, 2007, a barge operating in the northern-most Danvers River navigational channel struck the swing span of the bridge while it was in the “open position”. The rear of the barge collided with the northeast corner of the east most outside girder of the swing span. A non-MBTA contractor was operating the barge as part of the Danvers River dredging project upriver from Beverly Draw.
The MBTA immediately notified its engineering consultant, HNTB, and requested the bridge engineers who had participated in the recently completed bridge inspection and recommendation report to inspect the bridge to determine structural damage resulting from the barge collision.

Damage was noted to the exterior turnbuckle that is associated with the linkage for the northeast wedge assembly that “seats” the bridge into the closed position. The force of the barge collision sheared the northeast wedge turnbuckle on the interior side of the east girder and distorted the exterior wedge turnbuckle. As a result of the barge collision, the swing span was not able to return to a closed position under its own power.

MBCR maintenance crews installed a replacement wedge guide/linkage assembly, restoring the bridge to full operation.

Immediately following the barge impact event, HNTB was authorized by the MBTA to prepare final engineering design and construction documents for a new wedge drive hydraulic system installation. The new hydraulic system upgrades the swing span’s mechanical system from the existing “gear driven” system to a more reliable hydraulic system.

The MBTA Board’s approval allows the MBCR to solicit bids and retain a General Contractor to utilize the HNTB final engineering design and construction documents to install a new wedge drive hydraulic system and associated upgrades.

The General Manager said this project will significantly extend and preserve the life of the bridge’s infrastructure and improve service reliability for thousands of daily customers.