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 Post subject: SF Muni wire configuration and maintenance
PostPosted: Sat Nov 18, 2017 9:58 am 

Joined: Thu Apr 14, 2005 9:34 pm
Posts: 1895
Location: Copenhagen, Denmark
Just curious, does San Francisco MUNI still maintain their wire for pole operation throughout? I imagine at some point they will have to stop doing this, or justify the expense.

Prompted by news item of their latest modern LRV fleet.

http://trn.trains.com/news/news-wire/2017/11/17-siemens-san-francisco

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 Post subject: Re: SF Muni wire configuration and maintenance
PostPosted: Sun Nov 19, 2017 10:56 am 

Joined: Mon Aug 23, 2004 3:01 pm
Posts: 1440
Location: SouthEast Pennsylvania
Does Muni maintain the overheads wire, or is it the responsibility of the municipal power company, who sells electricity at the top of the trolley pole or pan?


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 Post subject: Re: SF Muni wire configuration and maintenance
PostPosted: Sun Nov 19, 2017 1:25 pm 

Joined: Mon Aug 23, 2004 12:59 pm
Posts: 525
San Francisco generates a lot of hydroelectric power through the Hetch Hetchy Project, which transmits it to the city for municipal facilities including Muni.

I'm pretty sure that Muni gets the high-voltage AC at their substations and handles the distribution of the DC power through the trolley system itself. That would include overhead and underground DC feeders as needed.

The Western Railway Museum owns Muni 0305, which is a Marmon Transmotive diesel-powered car designed and built to service the trolley system in the subway under Market Street. It is still painted in its Muni paint job, and is very useful as our shop switcher.


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 Post subject: Re: SF Muni wire configuration and maintenance
PostPosted: Sun Nov 19, 2017 2:01 pm 

Joined: Mon Aug 23, 2004 12:29 pm
Posts: 88
Location: San Francisco, CA.
Good Morning,

I cannot see what the "trains" article has to say, so it is difficult to answer this question directly.
However I can say, years back there was talk of putting pantographs on the older cars, but then realized mixedwith the running wire on Market Street with all the trolley buses would be a huge undertaking. The metro main lines are all pole compatible (except the N line), Twin Peaks Tunnel and the Subway to the east portal along the Embarcadero.

Cheers,
Karl J.


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 Post subject: Re: SF Muni wire configuration and maintenance
PostPosted: Sun Nov 19, 2017 2:06 pm 

Joined: Mon Sep 06, 2010 10:51 pm
Posts: 82
softwerkslex wrote:
Just curious, does San Francisco MUNI still maintain their wire for pole operation throughout? I imagine at some point they will have to stop doing this, or justify the expense.

Prompted by news item of their latest modern LRV fleet.

http://trn.trains.com/news/news-wire/2017/11/17-siemens-san-francisco


Toronto is well along in a program to equip the system for pan operation. All contact wire is being changed to 4/0 grooved and for the time being, will accommodate pans and poles. The primary reason for doing this is the current draw of the new 92' long, low floor cars which when run on a high rate would push the limit of the current carrying capacity of a J-6 shoe carbon. The J-6 shoes on all cars were changed a few years ago to a design which matched to old harp but provided a wider carbon with a reduced concave radius providing more contact area.

My understanding at this point is that the whole system will be pans in a few years. All low floor cars have pans and poles but are using poles most of time.


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 Post subject: Re: SF Muni wire configuration and maintenance
PostPosted: Fri Dec 01, 2017 5:32 pm 

Joined: Thu Nov 22, 2007 5:46 am
Posts: 2455
Location: S.F. Bay Area
softwerkslex wrote:
Just curious, does San Francisco MUNI still maintain their wire for pole operation throughout? I imagine at some point they will have to stop doing this, or justify the expense.

What expense?

Making wire friendly to pole&pan isn't about *more*... it's about *different*. You're not buying X and Y, you're buying X instead of Y.

You know those U-hangers that put the crosswires at the same height as the trolley wire? You don't use those with pans, they will strike. You either flip them over (inverting their benefit and making the hanger prone to rocking), or use flat bars with less trouble, or ideally wider versions of same.

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With switches and diamonds, you use a trolley frog that is correctly ramped for pans instead of one that is not, or an extra wire that carries pans under the frogworks as you would for a section insulator... or on rarely used non-revenue track, you just put out a bulletin order saying "no frog, expect to dewire". Any trolley operator worth his salt will be watching for that anyway, if he knows he's in little-poled track.


You can even do trolley bus (although San Francisco does not), you just shove the return wire a couple feet over. Now the bus can't swerve quite as far left (but would rarely need to since LRV track is usually in the inner lanes) -- and will be prone to losing one pole before the other since the poles are no longer parallel. Modern battery buses and powercatchers which yank both poles down on any dewirement make this a non-issue.


JimBoylan wrote:
Does Muni maintain the overheads wire, or is it the responsibility of the municipal power company, who sells electricity at the top of the trolley pole or pan?

Municipal power company.... that's a low blow...

Federal law requires San Francisco to have a municipal power company and directly serve its citizens. No one is to profit from electricity sales in the City. This was part of the deal when the Feds subsidized the Hetch Hetchy dam project, where much of that electricity comes from.

Never happened. PG&E is the "municipal" power company. 100 attempts have been made to nationalize power distribution in the City... all of them shot down, usually by crafty PG&E lobbyists and campaigners. Ratepayers in the City are rather bitter about that...

Muni maintains their own wire and has a substantial force to do so.


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 Post subject: Re: SF Muni wire configuration and maintenance
PostPosted: Sat Dec 02, 2017 3:02 am 

Joined: Wed Oct 22, 2008 8:18 pm
Posts: 2095
I would presume since the new cars are pans that they would understand the overhead requirements and do that and make the proper financial means to do that.

Depending on who owns the power company and the rail line may say who maintains the wires aka Samuel Insull of the 3 interurban lines, but techically the rail line is responsible for the wire work. But you know business, you could contract that out.


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 Post subject: Re: SF Muni wire configuration and maintenance
PostPosted: Sat Dec 02, 2017 11:58 am 

Joined: Sun Aug 22, 2004 8:51 pm
Posts: 1488
Location: Southern California
Several decades ago (and maybe still) the maintenance of the SP Muni overhead wire was assigned to the Hetch Hetchy power department of the City and County of San Francisco. This was told to me by a now deceased railfan who worked in maintenance/contrustion of the SF Muni overhead wire.

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