Putting on the High Beams in Windsor
100-Ton Concrete Spans Ready to Be Placed in Interstate 91 Bridge Construction
Workers ready piers to be filled with concrete for the Interstate 91 southbound bridge spanning Route 44 in Windsor, Vt., on Sept. 5, 2013. The bridge is expected to be completed by mid-November. (Valley News - Sarah Priestap) Purchase photo reprints »
The Interstate 91 southbound bridge, in the midst of construction, is seen from Route 44 in Windsor, Vt., on Sept. 5, 2013. (Valley News - Sarah Priestap) Purchase photo reprints »
Windsor — Officials managing the bridge replacement on the southbound lanes of Interstate 91 over Route 44 in Windsor have a plan to minimize traffic delays in the coming month when massive concrete beams are moved into place.
The beams, measuring 159 feet in length and weighing nearly 100 tons apiece, will be placed on top of the new concrete piers, roughly 100 feet above Route 44. There are five beams for each span and the bridge has four spans.
“It is not complicated but coordination is the key,” said Erich Brown, project manager with the general contractor, Lane Construction, at a briefing Thursday morning at the site.
Brown said the first set of concrete beams are being hauled by truck from the New York manufacturer and will be staged north of the bridge on the southbound side when they arrive early next week. Beginning Wednesday, the beams will be moved onto the northbound lanes and then lifted by two cranes below the bridge to be set on the concrete piers. Brown said there will be a temporary slowdown of the traffic, called a “rolling roadblock,” while the beam is moved onto the bridge and grabbed by the cranes.
Once the beam is off the truck, the truck will immediately leave the bridge and regular traffic flow will resume. The work will be done between 7 a.m. and 5 p.m.
The $21 million project started in April, with the dismantling of the old bridge.
Elliot Bent with KSE Partners, a public relations firm working with Lane on the project, explained the concept of a rolling roadblock. Bent said when each beam is ready to be moved, pairs of Windsor County Sheriffs, on both the south and north lanes, will “pace” traffic at 20 miles per hour about three miles from the bridge. Ideally, when the traffic arrives at the bridge, the beam will have been moved and the truck will be out of the way.
However, if there is a delay, Brown said traffic could be halted, but for no more than 15 minutes.
“There will be an hour between beam settings,” Brown said, adding that they hope to do two or three beams on Wednesday and finish on Thursday but the work could also go faster.
“We could set them all in one day,” he said.
The following week the same procedure will be in effect for the next span, with the beam setting scheduled for Sept. 18 and 19. Also that week, Route 44 will be shut down because the second span is over the road. Setting of the beams on the third span is scheduled for Sept. 25th and 26th and the final span, October 2nd and 3rd.
“It is weather dependent,” Brown said. Weather related delays will force them to keep pushing back the dates of moving the beams, he said.
Brown also said there is a contingency plan to divert traffic off I-91 at exit 9 if for some reason they cannot lift a beam, causing an extended traffic stoppage of more than 15 minutes.
The current steel bridge, built as part of the original highway construction project in the late 1950s and early 1960s, has a life span of about 50 years. The new prestressed concrete of the new bridge has a life span of twice that. The concrete is more corrision resistant to salt and water than steel and requires less maintenance, Brown said.
Though the heavy rain in June and July caused some delays, officials said they will finish the work on schedule in mid-November.
“Trying to keep water out of the work area,” said Brandon Merkosky, project engineer with Lane when asked whether there were any unique challenges to the job. The Mill Brook, which snakes past the construction trailers and under a temporary bridge used as a staging area beneath 91, rose perilously close to flooding some of the work site during heavy rains, Merkosky said.
At Thursday’s meeting, Windsor Town Manager Tom Marsh said he has heard no complaints about the work or temporary road closures.
“They know the work has to be done and there has been plenty of notice,” Marsh said.
The northbound bridge will be replaced in 2014.
Patrick O’Grady can be reached at firstname.lastname@example.org.