If you have been hearing a deep, slow banging near the Sagamore Bridge since the spring, that is the new bridge starting.
MassDOT began driving test piles into the ground on Tuesday, May 5. The work is called foundation load testing. MassDOT scheduled it for two to three months of intermittent work, on weekdays, roughly 7 a.m. to 4 or 5 p.m.
Nobody pretended it would be quiet. The project’s director put it plainly at the time: there is no way to bang a pile 90 feet into the ground without making a lot of noise.
What the crews are actually doing
A pile is a long steel column. A hammer drives it into the ground, over and over, until it will not go deeper. These are going down 75 to 90 feet.
Then engineers pull on them, push on them and lean on them. They run a vertical load test, a tension test and a lateral test. All three measure the same thing from different angles: how much the ground here will actually hold.
They are testing three kinds of pile. H-piles, which look like an I-beam. And round steel pipe piles, in two versions, one with a closed end and one open.
This is not building the bridge. It is finding out what the dirt can take, so the people designing the foundations know which kind of pile to specify and how deep to send it.
Where it is happening
Four spots near the Sagamore. Two north of the canal and two south of it.
The loud one is on the southeast side, next to the old Christmas Tree Shops.
Worth knowing if you live there: the new bridge does not go where the testing is. It gets built on the west side. Crews are testing here because the ground is similar, not because this is the spot.
Look for signs reading “Work in Progress, Early Work for the New Sagamore Bridge.”
Is it over?
Two to three months from May 5 runs out somewhere between early July and early August. MassDOT has not announced that the load testing is finished.
The quieter half of the job runs longer. Drilling the shafts makes far less noise than driving piles, and MassDOT said that part would go on for several months.
There is also separate work that never stopped: crews taking soil samples along the highways and on Army Corps land, north and south of the Sagamore, with some brush clearing alongside it. Same purpose. Nobody designs what holds up a bridge without knowing what is underground first.
Did it change your drive?
No. MassDOT said the foundation testing would not affect traffic, and no lane closures were announced for it. Both bridges have been running normally the whole time.
What changed was the noise, which is a real thing if you live near it and a surprise if you booked a week by the canal.
Why now, when the bridge is years off?
Because the ground work has to come first.
The company that will build the new Sagamore has not been picked. MassDOT expects to award that contract in late 2027, and real construction follows in late 2027 or early 2028. But the design has to be finished before anyone can bid on it properly, and the foundation design depends on what these tests found.
MassDOT calls this early work. It is the first of it anybody could hear from the yard, about eighteen months ahead of the real thing.
The short version
The banging started May 5 and was scheduled to run two to three months. Crews drove test piles 75 to 90 feet down at four spots near the Sagamore to find out what the ground will hold. It never touched traffic. The quieter drilling runs longer, and the real construction is still years out.