The South Loren Railway is a railroad that used to operate switching and rural trackage in the Boston area (lines running south from the vicinity of South Station) but now only operates a line from the PV&T’s Boston main to the P&W’s Worcester to Providence main @ Woonsocket, Rhode Island (plus – via owning the Old Colony Railway – a moderately dense network of lines in SE Mass & Cape Cod.)
It was formed in 1891 as a joint venture between the Boston and Maine, the New York, New Haven and Hartford, and the Parsons Vale and Termite to operate switching trackage around Boston. In 1906, it was electrified @ 600VDC with a mixture of third rail & overhead wire, and in 1930 the third rail was extended into rural Mass when the New Haven transferred control of their minimally trafficked Woonsocket to Needham branch.
In 1950, the PV&T bought out the other owners, in 1958 reelectrified the system (and removed the third rail) at 3000VDC to match the PV&T’s tension, and reached its largest size when it purchased the Boston and Albany’s Milford Branch in 1965.
It operated as a 100% electrified 3000VDC line for about 40 years, but then Amtrak extended the NE Corridor electrification from New Haven to Boston, cutting off the Quincy branch in the process. As a result, that line was de-electified and a class DL16 diesel was brought in to service the (few) remaining customers.
The P&W had been negotiating with Amtrak & the MBTA for overhead
rights on the NE Corridor between Attleboro and Boston, so the SLR
started planning to reenergize their overhead at 25kvac so they
could reconnect the Quincy branch and make it possible for P&W
traffic to get off the NE Corridor and over to the SLR/B&ACSX’s
Harvard Yard.
In 2015, the SLR rebuilt (and relectrified, but at 25kvac) most of their (abandoned since 1965, but the rails were still in the street) Boston Harbor branch to connect to Massport’s Conley container terminal, but that didn’t stem the slow drain of customers along the rest of the Quincy Branch, and by 2019 the last customer quit shipping by rail and the branch was abandoned.
But that hadn’t stopped the rest of the plans to re-electrify the SLR at 25kvac; when Amtrak and the MBTA wanted to remove the South Station power-delivery interlocking that was being used to power the K3 motors on the Alouette the PV&T & SLR agreed and stepped up the pace of the reelectrification; The SLR had already reelectrified their ex-New Haven branch from Needham Junction to Woonsocket, leaving only the Boston-Needham & Needham-Waltham sections of the line (the old line to from Boston to Mattapan had gone out of service several years earlier, leaving Needham-Boston & Needham-Waltham as the SLR’s remaining 3000VDC lines), so those were switched to 25kvac in 2020, at the same time as the PV&T re-electrified Lowell-Boston at 25kvac.
At about the same time as traffic on the Quincy branch vanished Iowa Pacific Holdings failed, the SLR picked the Massachusetts Coastal Railroad out of receivership, renamed it to the Old Colony Railway, and started to slowly electrify it at 25kvac.
All-time SLR locomotive roster
| No. | Type | Builder | Built | Disposition |
|---|---|---|---|---|
| 1 | class B shay | Lima | 1895 | retired 1950 |
| 2-3 | class B shay | Lima | 1895 | retired 1909 |
| 10-11 | class B climax | Climax | 1899 | retired 1937 |
| 101 | box motor | Brill | 1899 | retired 1948 |
| 100 | box motor | Brill | 1899 | To Seashore Trolley Museum 1958 |
| 102 | box motor | Brill | 1899 | retired 1948 |
| 103-109 | box motor | Brill | 1904 | Retired 1932 |
| 1000 | B-B boxcab | ALCO&GE | 1915 | to PV&T #309, rebuilt @ 3000VDC |
| 1001-1005 | B-B boxcab | ALCO&GE | 1915 | retired 1958 |
| 1100-1103 | B-B steeplecab | B-W | 1922 | retired 1958 |
| 320-327 | E10B | GE | 1956 | in service Dec 31, 1957, last units retired 2020 |
| 442 | DL10 | MLW | 1966 | Conley Massport switcher 2001-2019 |
| 661-665 | Jm | Portland | 1988 | assigned to the SLR in 2015 after the Boston Harbor/Conley Massport elecrification |
| 801-802 | M | Portland | 2000 | assigned to the SLR after Needham Junction to Woonsocket was re-electrified at 25kvac |
| 833 | DL28 | ILW | 2000 | Conley Massport switcher 2020-2024 (leased from the Central Vermont Railway) |
| 1619 | DL48 | ILW | 2024 | Conley Massport switcher |