The past few weeks I've been busy working long nights for bridge and tunnel inspections. Our inspections were located in Revere, South Boston and Brookline and each had its own unique access requirements.
The Revere bridge spans over the Blue Line and was inspected using ladders since it was a short span consisting of prestressed concrete butted box beams in good condition. Using ladders allowed us more time for inspection since we did not have to wait for a hi-rail lift truck to be put on and driven to the bridge. We were able to get on track around 1am and finished just before they needed power back.
The South Boston bridge spans over the Red Line and MBCR commuter rail tracks and was inspected with ladders even though it was a larger span consisting of prestressed concrete butted box beams in good condition. We decided to use ladders since we could inspect the commuter rail portion starting at 10pm and finish before the MBTA would allow us access to the Red Line around 2am. There was also a small portion over a dirt road with no traffic at 1am. Working in all three sections could not be accomplished using a hi-rail lift since the truck would require traveling further south to be able to get onto the tracks.
The Brookline bridge spans over the Green Line near the Beaconsfield Station and was inspected with a 40 foot hi-lift since the bridge was wide and consisted of 57 rolled steel beams. We were able to get on right near the bridge just after 1am and finished the wide bridge just before power was needed back.