Photo: The Wood Worsted Mill, 2011. Emw, CC BY-SA 3.0, via Wikimedia Commons.

Stand at the corner of Union and Merrimack Streets and you're standing between two giants: the Wood Mill on one side, the Ayer Mill on the other. What you can't see is what ran beneath your feet.

The Ayer Mill was built in 1909 across Union Street from the Wood Mill, and the two were connected by an underground tunnel. It makes sense once you know how they worked. The Ayer Mill existed to spin and dye yarn for the American Woolen Company; the Wood Mill was built to run the full worsted process, from raw wool to finished fabric. Two buildings, one company, and a street in the way.

The tunnel wasn't the only connection. On the river side, the Wood Mill once had three more sections, labeled A, B and C, standing across a railroad spur. Covered bridges linked them to the main building over the tracks. Those sections are gone now, but on the river-facing wall you can still see a few bricked-up bays where the bridges once met the mill. Trains ran along Merrimack Street too, and the Union Street Bridge, known locally as the Duck Bridge, carried traffic over the river right beside it all.

If you worked in either mill, or your parents or grandparents did, and you remember the tunnel, we want to hear about it. Call 978.645.6260.

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