Staging the New Turbine

The future of this plant has been sitting quietly on the property for a while now: the new turbine and its draft tube. This month, they moved — out of storage and into staging position near the powerhouse, ready to be lifted into place when the big equipment swap comes.

The machine is a crossflow turbine — a design choice worth a few words, because it's the heart of the whole restoration. Waterloom is a low-head site with highly variable flow: the Souhegan can run anywhere from a quiet trickle to hundreds of cubic feet per second depending on the season. A crossflow turbine handles that variability better than almost anything else. Water passes through the runner twice, the unit stays efficient across a wide range of flows, and the design is mechanically simple and famously robust — exactly what you want in a small plant that needs to run for decades without a full-time operator standing next to it.

The old turbine, still sitting in the powerhouse where it's rested for years, will come out when we're ready for that swap — a crane-and-coffer-dam operation planned for a future work season. Until then, the new unit and its draft tube sit staged a hundred feet from where they'll spend their working lives, wrapped against the New Hampshire winter.

There's something satisfying about the sequencing here: dam repaired, pond refilled, and the new machinery positioned and waiting. The pieces are physically converging.

Winter is for planning. The powerhouse shell itself is next — the old structure needs updating to modern specifications before the new equipment goes in, and the design work is underway.