The North Cambridge - Harvard Square - Belmont abd Watertown lines wehnt diesel-bus, with special mufflers to drastically breduce pollution in the Harvardc Square bus tunnels and stations, 13 March 2022. The dual-mode Silver Line roues, using overhead wire in Silverlivne-way tunnel to South Station saw the first battery-hybrid bus as early as the year 2019, and replacement of dual-mode TT-diesel buses by battery-hybrids in 2022, with the last, TT-diesel 1132, making its last run 1 July 2023.
The first TTs inb service ran Harvard Square - Lechmere 11 April 12936. The Boston -area TT system saw its maximum in 1953.
Information from Boston Street Railway Association’s Roll Sign, Nov. - Dec. 2023 issue, just received.
When I went to look at Harvard in 1974, I was delighted to see the ancient green trolleybuses coming out of the tunnel under Harvard Square. They did not have ‘headlights’ so much as a couple of (fairly dim) light bulbs standing up in sockets in not-very-reflective reflectors.
During the time I was watching, I saw two ‘dewirements’ requiring the operator to get out and put the poles back. One was as the result of a fairly amazing understeer slide on the curve going into the tunnel…
The ‘correct’ solution was probably always parallel hybrids once the battery technology and supply became sufficiently advanced. There is a case to be made for short overhead supply where ‘wayside storage’ for heavy regenerative braking is practical, in addition to periodic overhead recharging at stops – but absent some fairly careful robotics I can’t imagine that working well with double trolley poles.
I hadn’t realized that! The South Boston Piers Transitway (the original name for the electrified tunnel part of the Silver Line) was only opened in 2004, so the overhead wire lasted less than 20 years in service.
I rode that line once, just for fun, when it opened. Unfortunately the tunnel to South Station doesn’t line up directly with the Ted Williams tunnel to the airport, even though they were both built as part of the Big Dig project. It’s a pretty circuitous route to get into and out of the Transitway tunnel (see https://commons.wikimedia.org/wiki/File:MBTA_Silver_Line_geographic_map.svg). Also unfortunately, the extension of the tunnel from South (Red Line) to Boylston (Green Line) never happened, just like the North / South Rail Link, the Blue Line / Red Line connection, and basically all the other little “astronomically expensive last mile” projects that would have made the transit network more cohesive and efficient.
