cb@mitre-bedford.ARPA (Christopher Byrnes) (01/09/86)
I believe that the MBTA's Blue Line uses both third rail (in the tunnel under Boston Harbor) and overhead wire for power. As I recall, the reason for this is due to a combination of factors. The Boston Harbor tunnel was originally built for streetcars, so its small size prevents putting a full overhead in the tunnel. The above ground section of the Blue Line in East Boston and Revere runs close to the shoreline, so winter iceing problems forces the need to switch from third rail to overhead. It sounds complicated, but it seems to have worked for the last 30 years. Christopher Byrnes The MITRE Corporation Burlington Road M. S. A425 Bedford, Mass. 01730 cb@Mitre-Bedford.ARPA ...decvax!linus!bccvax!cb.UUCP
dennis@CSNET-SH.ARPA (Dennis Rockwell) (01/10/86)
From: Christopher Byrnes <cb@mitre-bedford.ARPA> Date: 09 Jan 86 08:28:54 EST (Thu) Subject: Re: combination of third rail and overhead power I believe that the MBTA's Blue Line uses both third rail (in the tunnel under Boston Harbor) and overhead wire for power. Thanks! I've been wondering why the switch was made. The four stations in downtown Boston are third rail, the switch is made at Maverick (in East Boston, on the other side of the harbor), and the rest of the line north and eastward (past the airport, the beach, and the racetrack) runs under wire. Also, Boston's Green Line is essentially a buried (in the denser portions of the city) streetcar line, now running a few PCC cars (trolley poles) as well as Boeing LRVs (half-pantographs), the same cars used in parts of San Francisco. There is an LRV in the shops with trolley poles that was used for evaluation. The other two rapid transit lines (Red and Orange) use third rail exclusively. Red, Orange, and Blue lines all use reasonably normal-looking subway cars, although all three are different (the Red Line uses two different types itself). For those interested in arcana, an MBTA employee has restored an old (wooden!) streetcar and occasionally runs it around the Green Line for fantrips. He told me that he sometimes runs it on old street trackage, using one wire from the trackless trolley overhead! Dennis
edg@micropro.UUCP (Ed Greenberg) (01/13/86)
In article <1434@brl-tgr.ARPA> dennis@CSNET-SH.ARPA (Dennis Rockwell) writes: >.... There is an LRV in the shops with trolley poles that was used >for evaluation. >Dennis The book "Inside MUNI" by John McKane and Anthony Perles carries two interesting pictures from the early days of the Boeing LRV's. Page 47 carries a picture of "TWO PILOT LRV's nos. 1220 & 1221, arrived in October 1977 and ran under existing overhead wires with trolley poles to test components of the cars" Sure enough, there it is, trolley poles and all. Page 62 carries a picture of "MUNI REPAIR CAR. #1088, one of the 1948 double-end PCC's ... was a testbed for the pantographs to be used on the Boeing-Vertol LRV's and was the first electric car to operate in the Muni Metro under Market St." Indeed, two trolley poles (at each end) and a half-pantograph in the center. T'is amazing what a car-shop can do if told to do so. :-) -e -- Ed Greenberg | {hplabs,glacier}!well!micropro!edg MicroPro International Corp. | {ucbvax,decwrl}!dual!micropro!edg San Rafael, California | {lll-crg,ptsfa}!micropro!edg