Right. The archive map shows the proposal, not the built line. Nice job on the map you made anyway, glad to see there's a level of interest for this stuff. After googling the wrong keywords and poring over old maps on mapjunction to no avail, I was totally flummoxed and I can't tell you all how satisfied I was to, totally serendipitously, glance at my grandparents' map on my wall (which is the same as the map below) to trace my kayak route and see the ROW staring at me right there!The map is from 1849, so would predate the actual line.
If you follow the terrain line, it ends in a road called "Medway Branch" where the Norfolk Highway Department is now located. So I would agree with all above that the Electrical Row houses the former branch from about just east of the Norfolk Arena to the Medway Water Department.
I wouldn't be so quick to bet his left gonad. Per Historic Aerials, it appears that that circular parcel wasn't there until after 2016. Open Railway Map shows the branch, but it only shows the ROW until the river, but it is not unusual for old ROWs on that map to be incomplete.I would bet Cornelius Vanderbilt's left nut that the weird circular parcel off Village St. amid the power lines was the RR roundhouse. It measures out big as roundhouses go, and seems a bit oversize for such a podunk branchline. But if that's inclusive of the surrounding property buffer being circular too and not just the structure itself, it fits like a glove. Moreover, while it's close to the end of the line the actual end of the line was where Sanford Mills was located...with the mill having the most direct access to the Charles water supply. The RR thus seemed to choose the nearest abutting touch to the Charles from the occupied end-of-line for the roundhouse, which would've been pumping large amounts of river water for the locomotive boilers.
Holy sh** Ive been looking for something even remotely close to this for years. That railway map is incredible!