Each old bridge comes down once its replacement carries traffic. The first is the old Sagamore, after traffic moves to the first new bridge in 2033. The Bourne comes later, once it has its construction money. Pieces of the old Sagamore will be saved and reused, some will go to a fish reef off the coast and most of the rest will be recycled. There’s no plan to keep a whole old bridge as a walking path or monument.
When demolition happens
- Old Sagamore: after all its traffic moves to the first new bridge. MassDOT expects that in 2033.
- Old Bourne: no date yet. The new Bourne does not have its construction money yet.
Each demolition takes several months.
How the old bridges come down
- Workers cut the steel into smaller sections.
- Cranes lift each section onto barges.
- Barges carry the pieces away from the canal to a scrap yard.
- The road bed and decking get broken up and removed in chunks.
- The piers (the concrete supports in the water) get demolished down to below the canal floor.
What happens to the materials
For the old Sagamore, MassDOT has said where the pieces go:
- Some stays at the bridge. Sections of the steel truss, granite from the piers and the granite sidewalk will be reused at the new bridge and along the new paths.
- Some goes to the public. MassDOT will offer pieces to towns, schools, history groups, art groups and the public.
- Some goes to sea. Concrete and granite from the old piers will go to a fish reef off the Massachusetts coast.
- The rest gets recycled where it can be. How much depends on how the bridge comes down and what shape the material is in.
- Lead and asbestos get handled and disposed of under the safety rules.
That comes from MassDOT’s answers to the Sagamore hearing questions. MassDOT has not said yet what happens to the old Bourne.
Why not save a whole old bridge as a walkway or monument?
- They’re in the way. The new bridges sit very close to the old ones, in space that needs to be cleared.
- Maintaining a closed-to-traffic bridge over a federal canal is expensive. Someone has to inspect it, paint it and repair it.
- No public agency or private group has stepped up to take ownership.
- The Cape Cod Canal already has paved paths along both sides for walkers and bikers.
When can people watch?
The Army Corps and MassDOT typically open public viewing areas during major construction. We’ll cover those when they’re announced.
Drone footage and time-lapse video will likely be common, both from the contractors and from local news outlets.
For project status and timeline, see the Project Tracker. For the longer story on the rebuild, see The Cape Cod Bridges Replacement, Explained.