DIVE-IN:                       
The CoastX Blog

On a dark September night in 1939, steam-driven locomotive 3666 billowed smoke as she slowly pulled a routine passenger train northbound over the Piscataqua River atop a damaged, poorly maintained wooden trestle bridge where the present-day Sarah Long Bridge now stands. Without warning, the strained wooden pilings gave way, plunging Locomotive 3666 and two train cars into the rushing tidewater. Two crewmembers perished. Miraculously, no passengers were in the forward cars and all were rescued from the back of the train, which remained on the bridge. To this day, below busy car and boat traffic, Locomotive 3666 still rests on the murky bottom next to the bridge.

That’s the story anyway. There were rumors the train was removed during bridge construction, relocated, or simply rusted away. CoastX twice tried to locate it, but conditions proved difficult with limited visibility, strong currents, and proximity to the bridge. Determined to solve the mystery, CoastX cofounders Jim Case and Matt Scheuer planned a carefully timed dive mission between tides. Scanning the area with sonar, they noted several anomalies and anchored on the most promising one.

Descending through the dark, murky water, the outline slowly emerged—there it was! The locomotive, encrusted with mussels, sponges, and sea stars, lay on its side in 45 feet of water. The heavy iron boiler, wheels, and side rods were still plainly identifiable 86 years later. Jim’s 360° camera captured video and data to create a 3D photogrammetry scan, while the vibrant mussel bed ecosystem covering the wreck showed how life had reclaimed the site. After about 30 minutes, the tide began to change and it was time to ascend—a successful dive.

Now that we know exactly where to find Locomotive 3666 and how to time the slack tide needed to reach it, we hope to explore the site next year by ROV with CoastX students.