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Dallas Trolley Turntable
https://www.rypn.org/forums/viewtopic.php?f=1&t=31550		 Page 1 of 2
Author:  softwerkslex [ Fri Jun 10, 2011 11:21 am ]
Post subject:  Dallas Trolley Turntable
Why is Dallas installing a turntable for its streetcars? It would seem an enormously expensive, not to mention inaccurate, recreation.

I can't identify a single precedent (excepting cable cars).
Author:  Bruce4501 [ Fri Jun 10, 2011 11:39 am ]
Post subject:  Re: Dallas Trolley Turntable
From the schedule on their site, it looks like they put quite a few miles on the cars daily and one would have to ASSUME it would be to equalize wheel wear as I did not see any other means of turning the cars from their map.
(just speculating)
Bruce
Author:  Erik Ledbetter [ Fri Jun 10, 2011 11:44 am ]
Post subject:  Re: Dallas Trolley Turntable
Would you accept non-US?

http://www.mashke.org/kievtram/pictures/showphoto.php?g=tram/t2/3&f=%2Fkievtram%2Fpictures%2Ftram%2Ft2%2Ft2-5046-28-196xxxxx-naberezhnoe-MUS.jpg&l=en&fd=parsefname
Author:  Andy Nold [ Fri Jun 10, 2011 11:54 am ]
Post subject:  Re: Dallas Trolley Turntable
They want to use the Toronto PCC cars on the system which, as you might know, are single ended cars. A turning loop or wye is being built on the downtown end of the line, but the street configuration of the uptown end and the high cost of real estate makes a turntable an ideal option.

Also, it will be a new focal point for the tourists. What do you mean about inaccurate recreation? MATA is not a museum. They are a transit authority that utilizes old cars. They owe no quarter to preservation and will do whatever is needed to keep the cars running and address comfort issues. Have you seen the air conditioning units on 3 of the cars?

The cars used to turn every trip with the loop on uptown end and the stub downtown, so wheel wear was not a problem. When they added the second stub at Citiplace, the automatic turning was lost, so turntable will help with that respect.
Author:  Dave [ Fri Jun 10, 2011 12:27 pm ]
Post subject:  Re: Dallas Trolley Turntable
While not a recreation of a Dallas site, I'd argue that the experience they offer - providing visitors with a practical useful streetcar system based on old school technology in a legitimate urban environment that really does move people around for other than recreational purposes - is actually a better form of preservation than a ride into nowhere for no reason on an old streetcar with nothing but fields, weeds and a pole barn as context. Remember, that stuff is just a means of preserving and recreating the experience. I'd rathert have less accurate stuff than a less accurate experience.

McKinney is a success story in many ways, and I heartily wish my city would choose it rather than a modern federally funded system that won't even get built for 30 years as a model.

dave
Author:  wesp [ Fri Jun 10, 2011 2:26 pm ]
Post subject:  Re: Dallas Trolley Turntable
There is a precedent from the Waterloo Cedar Falls & Northern interurban in Iowa.

Wesley

Photo source: Dave Mewhinney photo, Dave's Railpix.

Image
Author:  Gord M [ Fri Jun 10, 2011 3:42 pm ]
Post subject:  Re: Dallas Trolley Turntable
wesp wrote:
There is a precedent from the Waterloo Cedar Falls & Northern interurban in Iowa.

Wesley

Photo source: Dave Mewhinney photo, Dave's Railpix.

Image


And the Quebec Railway Light & Power in Quebec City, Canada. To be fair though, the WCF&N and QRL&P turntables were used by interurbans, not streetcars.

Gord
Author:  softwerkslex [ Fri Jun 10, 2011 5:42 pm ]
Post subject:  Re: Dallas Trolley Turntable
Note the news posting makes a side comment about how expensive streetcars are, in Dallas. I am not convinced this is the most cost effective turning idea, especially when future maintenance costs are included. That is also why I suspect turntables were not chosen for turning facilities on routes The examples posted here are for carbarns. I am aware for example that the Minneapolis barns had a least one turntable (although I believe it was inherited from the prior steam dummy).

Cute, fun, a tourist focal point, yes, but they really couldn't manage a city block loop?
Author:  Andy Nold [ Fri Jun 10, 2011 5:56 pm ]
Post subject:  Re: Dallas Trolley Turntable
They can spend their money however they choose.

What are these huge maintenance costs? I'm really trying to figure this out. I've never owned a turntable. What is involved? We've got a recycled SP/Texas Electric Bridge for the truss. We've got a center bearing and outrigger wheels from Irwin Car. The pit will be completely covered with a deck and equipment under cover. Stock AC motor with an incredible reduction ratio and a computer controller. The wire will not rotate with the table, the pole will have to be removed from the wire before starting. I'm really ignorant of these exhorbitant maintenance costs, so turntable owners please advise.

I'm not sure what fact or figure caused the author to note that streetcars are as expensive as heck. I think the MATA line has been very cost effective when compared to the DART LRV system or other modern equipped streetcar lines.

And yes, there is an issue with looping the track. The goal is to get passengers to the DART subway station and you've got a major freeway, one-way streets and some of the most expensive land in Dallas around the station. The idea works and it will be a good drawing card.

Ultimately the thing will be built regardless of your feelings. Should be operational before too long.
Author:  softwerkslex [ Fri Jun 10, 2011 7:50 pm ]
Post subject:  Re: Dallas Trolley Turntable
Please do not take offense at my observations on the Mckinney turntable. I am a long way away and haven't been to Dallas (and ridden this line) in over ten years. I do offer my observations for discussion and reflection. My fears would be that the turntable, although visually attractive, leads to higher costs and lower reliability which creates negative results for the streetcar line.

Turntables have a number of maintenance items: motors, gears, controls, etc., not to mention that they require the same inspections as bridges (see another recent thread on this topic). A typical turntable, say maybe Tennessee Valley, makes one revolution an hour, peak. This streetcar line has headways of 10-15 minutes, so this turntable is going to make 4 revolutions per hour, perhaps ten hours a day, 365 days a year. That is a much higher wear rate.

I can report accurately that the turntable at Powell and Market on the San Francisco cable system was/is very troublesome since the 1984 reconstruction. Numerous problems with rotational balance, friction, and wear have challenged supervisors over the years.

I satellite mapped the site and compared it to Baltimore Streetcar Museum's turning loop. It would appear to me that a turning loop could fit on the same site, maybe with some of the loop extending into the street.

Again, I just offer my thoughts, and obviously there are other issues of aesthetic design and street scape. Perhaps they have been planning this for a long time, as the article states they have owned this turntable bridge for 14 years. The turntable does also offer some attractive display and layover tracks.
Author:  Dave [ Fri Jun 10, 2011 10:12 pm ]
Post subject:  Re: Dallas Trolley Turntable
All that means is the work done in 1984 wasn't as good as the work done after the earthquake. Modernization isn't necessarily improvement. I've done my share of turntable work, and found that the lowest applicable and most robust tech is the best tech for these kind of applications.

dave
Author:  Joe Magruder [ Sat Jun 11, 2011 12:43 am ]
Post subject:  Re: Dallas Trolley Turntable
Am I correct in assuming that the street configuration is such that a Y wouldn't work? That was how Los Angeles and San Francisco (my limited experience) adapted to PCCs in many locations.
Author:  Zak Lybrand [ Sat Jun 11, 2011 4:46 am ]
Post subject:  Re: Dallas Trolley Turntable
Joe Magruder wrote:
Am I correct in assuming that the street configuration is such that a Y wouldn't work? That was how Los Angeles and San Francisco (my limited experience) adapted to PCCs in many locations.


MATA actually has a wye at the west end of the Cityplace leg. I've had to turn cars there before for maintenance reasons. The problem lies in, as Mr. Nold said earlier, that acquiring new land is expensive, and they aren't going to run the PCCs backwards for a quarter mile just to turn it on the wye in the middle of a busy intersection.

I, for one, am greatly excited to hear this. I was a conductor on the M-Line for a few years before I moved out of state for my current job, and I'd been hearing about the new extension and the turntable for years. From what I understand, right around the time I left in August of '10 was right about when the bids went out for the job, and when I visited Texas again in March of this year, they had actually started breaking ground. It's great to see this streetcar line I've grown up around expanding so much. I wish nothing but the best to the Landrums and all the others involved with MATA.
Author:  bbunge [ Sat Jun 11, 2011 8:02 am ]
Post subject:  Re: Dallas Trolley Turntable
Early Columbus, Ohio horsecar line:

http://www.columbusrailroads.com/hc-photos.htm

See bottom photo. Does that count? :-)

Bob
Author:  Mr. Ed [ Sat Jun 11, 2011 11:05 am ]
Post subject:  Re: Dallas Trolley Turntable
In the Philly and suburban areas, both PTC and Red Arrow (the forerunners to SEPTA) both used loops to turn the cars. But back then, these loops were at the ends of the line and there was nothing out there so land was cheap. So with this table being installed in a dense area, this was probably cheaper than a loop even factoring in the maintenance costs.

Later!
Mr. Ed
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