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The two Blue Line power supplies

Jack Newsham asks:

Why do Blue Line tracks have both third rails and overhead power lines?

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Instead of choosing one system or the other when modernizing the rail, somebody probably figured they could do it on the cheap and do a half a$$ed job, and ended up causing more problems than they started out with.

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Different unions for surface and overhead power lines. They want you to vote No on Question One, keep raising the gas tax and don't kill the jobs.

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You do realize the decision to have two separate systems was made in the 1920s, right?

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Bush's NO Coolidge's fault! Damn that sly silent Cal!

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Does that make it more or less likely that the Wobblies are behind it?

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Until the mid-1950s, the Blue Line ran only between Maverick and Bowdoin, and it used only third rail.

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My department at the T has been trying for years to remove the catenary from Airport north and convert it to a third rail system. The residents always oppose it using the "safety" excuse. I guess in certain spots kids like to cross the tracks as a short cut.

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I guess in certain spots kids like to cross the tracks as a short circuit.

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in requiring EVERY FRIGGING THING THEY PROPOSE to be subject to the public review and "civic engagement" processes, they could actually make improvements like this.

And for those of you who disagree, give us one legitimate reason why the public has to be involved with a decision like this one. BTW, "because the T is a government entity" doesn't count.

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It's because of the icing during the winter that can occur since its so close to the ocean.

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Ice makes sense (I think) but the reason of being close to the ocean not as much...

I don't think it's close enough to get splashing/misting and the ocean generally has a warming effect during winter.

Unless it sometimes floods in Revere?

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Are not too far from the ocean themselves. Just look at Wonderland and Revere Beach Stations. You can smell the salt from the platform.

This is also why the blue line cars were in much worse shape than the Orange Line cars (aka Rust) even though the BL cars were a year or two older (1978-1979 vs 1980-1981)

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Mentions that the catenary came post-third rail due to fears of icing on open track. I can't verify though, the source is published material that I'm not going to buy. I would add though, that there's no difference between power generated from the third-rail or power from a pantograph.

The legacy of streetcars is not the catenary, but the narrow tunnels. Which is relevant if you consider the T's purchase of new red and orange trainsets - having to customize new vehicles to meet 100 year old infrastructure drives up the cost considerably.

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The T actually extended the third-rail from Maverick to Airport in the mid-80s with the intent of extending it to Wonderland. Ice was definitely not a concern (just look at the Red or Orange Line as examples). There are devices called third-rail heaters that help with this.

Shortly after installation, the third rail between Maverick and Airport was de-energized and the catenaries were put back in-service. This was because there was a spot where many folks used to illegally cross the tracks, and they didn't want to deal with political fallout of electrocuting someone. Apparently hitting someone with a train was less of a concern.

In all likelihood, the third-rail to Airport was put back in service when Airport Station was renovated.

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The T has variously given both the proximity of the ocean (ice, salt water, etc) and the potential for trespassers (much of the blue line is at-grade with residential all around, which you don't really find on the other lines) as reasons why overhead power is used east of Airport.

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More here and here. Basically the Orange Line as originally envisioned was to extend from 128 in Reading to 128 in Dedham (or at least near 128). The south side via West Roxbury but the north side has many grade crossings. The good citizens of Melrose didn't want the dirty subway, so that's why they have a commuter train every two hours midday, and why there is a third track along the Orange Line north of Community College: that was to run express service in the peak direction.

In any case, with all those grade crossings up there, the plan would have used overhead past Oak Grove, with a similar power switch on the fly (MetroNorth actually makes the third rail-pantograph switch at speed). The Hawker-Siddleys on the Orange Line are longer clones of the Blue Line cars and have reinforced roofs and mounts for the pans which, of course, have never been installed, and probably never will be.

(Off topic, but hopefully the new Orange Line order will go smoothly, like the new Blue Line cars, as opposed to most other T equipment orders.)

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Chicago has done it for many decades now, setting an example that Boston and other cities could follow.

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as well as those on the Long Island Railroad were granfathered in when the regs were changed. Public grade crossings with third rail are no longer permitted for new construction.

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It really doesn't matter. The voltage is exactly the same 600-volt DC if it comes off the 3rd rail or the roof. Green, Blue, Orange, Red, the historic Mattapan trolleys, the Silver tunnel, and the Cambridge trackless trolleys all run on the same voltage. Maverick-Wonderland gets maintained exactly like the D Line's overhead does; Bowdoin-Airport gets maintained exactly like Red's and Orange's third rail. If it weren't for tunnel/platform clearance differences you could run a Green Line train on the wires from Airport to Wonderland and it would work fine, run a Blue car on the Orange and Red third rail and it would work fine, and run a Blue car on the B Line's overhead and it would work fine. The cost difference for ordering a train with both power sources vs. third rail-only or pantograph-only is trivial and way less than the cost of re-installing it all.

Seashore Trolley Museum up in Maine, which has working examples of pretty much every subway car and trolley in Boston's history, takes its old Blue/Red/Orange cars out for a spin on trolley track by attaching a small trailer with a trolley pole on it and jumper cables hooked to the train's third rail shoes. That's how little it matters to the train itself where the power source comes from.

Ice buildup was the original reason for doing it when the line was extended from Maverick to Wonderland 1952-54. There were also a couple official pedestrian grade crossings for many years for getting to beachfronts, so it wasn't just illegal track crossings. Third rail heaters have gotten a lot better since then, so if the Wonderland extension were built today instead of 62 years ago they would've done it all- third rail. But there's nothing wasteful about having both.

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