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 Post subject: Re: Tamper for the WW&F
PostPosted: Thu Nov 19, 2020 10:40 am 

Joined: Sun Apr 05, 2015 1:28 am
Posts: 441
Location: Ipswich, UK
Meghan wrote:
This is an enlargement up of a picture of the dual-gage crossing at Darby taken about four years ago. The B&O runs top to bottom with Philadelphia behind the photographer.
Meghan


Many thanks for posting that photo. I've "clunked" over that crossing on the SEPTA trolley a few times in the past 20 years on my visits to Philly and hadn't realised what the track arrangements are. I don't think you would get away with that arrangement in the UK!

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 Post subject: Re: Tamper for the WW&F
PostPosted: Thu Nov 19, 2020 4:15 pm 

Joined: Fri Mar 12, 2010 9:52 pm
Posts: 155
Location: Pittsburgh
Quote:
It is not a properly built crossing at all but looks like a jury rig made out of bits of left over rail (That's both the lawyer and the civil engineer speaking). Despite the guard rails there is inadequate flange support for the SEPTA cars and the flanges were striking the CSX running rails instead of just rolling over them. If you look closely the grooves in the running rails from the streetcar wheels are between the size of a quarter and a half-dollar.


The crossing in Meghan's photo is actually not the crossing that's there now. Darby OWLS Crossing Version 1 had some design details that simply were not up to the abuse of this location. Hence the severe grooving of the CSX running rails seen in her photo. Version 2, which has been in place since 2017, is reported as doing better, although I've not seen it personally. They also replaced the cheesy asphalt paving with precast concrete panels. I have a copy of the manufacturer's general assembly drawing for OWLS Version 2, but the file is too big to post here. However, I can assure all of you that neither it nor Version 1 is built from "bits of leftover rail".

Even with it's shortcomings, OWLS Version 1 lasted far longer than any previous diamond crossing at this location. A professional colleague (Ned knows him too) was B&O's Roadmaster for this Division back in the early 1960s, during which time he replaced the Darby Diamonds at least twice if not three times. He tried everything to make it last, including pouring several feet of concrete beneath the crossing. Nothing worked. Needless to say Max simply hates Darby.

One of the curious things about Darby is that the trolley line was there first, SEPTA's Route 11 dating back to the very earliest days of electric streetcars. The railroad didn't show up until over a decade later. Hence, CSX, not SEPTA, is responsible for the crossing's considerable maintenance expense. If the shoe was on the other foot, I'd not be surprised if SEPTA suddenly discovered they could live without the Darby Terminal that Phil mentioned in his earlier reply to this thread.

Congratulations to the WW&F for their mechanization of ballast tamping. Perhaps, fairness to them, we should shift all of this crossing discussion over into the other thread from about a month ago that was specifically about diamonds.

/s/ Larry
Lawrence G. Lovejoy, P.E.


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 Post subject: Re: Tamper for the WW&F
PostPosted: Thu Nov 19, 2020 4:30 pm 

Joined: Wed Jul 26, 2017 4:24 pm
Posts: 45
As a former CSX engineering employee on the former B&O east end I have some experience with it. The area experiences the weird phenomenon of high current induction from PEPCOs unbalanced delta three phase high voltage transmission lines. The rail experiences bad wear from current induced oxidation. Tons of money spent on this gambit from a railroad looking for money in the 70s. It helped pay for the east ends analog microwave long lines and the territory with high voltage had poleline converted to buried cable, some of which still is used today. But as part of an engineering expedition with the advanced engineering group show that fractures in the diamond were effected by induced current causing arcing and plasma damage under track movement. Also learned how rough Darby is and why all the local signal maintainers on that territory kept at least an improvised weapon on them


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 Post subject: Re: Tamper for the WW&F
PostPosted: Thu Nov 19, 2020 6:50 pm 

Joined: Fri Dec 22, 2017 6:47 pm
Posts: 564
Location: Philadelphia, PA
Larry is right. The Woodland Ave car started possibly before 1810 as an omnibus line on what was then Darby Road. The Philadelphia and Darby Railroad (horsecar) opened in 1858 and was electrified in 1894.

The B&O Philadelphia Branch opened in 1886, 28 years after the horsecar line.

Phil Mulligan


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 Post subject: Re: Tamper for the WW&F
PostPosted: Thu Nov 19, 2020 7:24 pm 

Joined: Fri Dec 22, 2017 6:47 pm
Posts: 564
Location: Philadelphia, PA
As to the electrical issues, could the power line be PECO (Philadelphia Electric) rather than PEPCO (Potomac Electric Power). I can see some of PECO's feed from the Conowingo Dam coming up the B&O to Philadelphia.

Phil Mulligan


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 Post subject: Re: Tamper for the WW&F
PostPosted: Thu Nov 19, 2020 11:58 pm 

Joined: Fri Mar 12, 2010 9:52 pm
Posts: 155
Location: Pittsburgh
Quote:
The rail experiences bad wear from current induced oxidation. .....

But as part of an engineering expedition with the advanced engineering group show that fractures in the diamond were effected by induced current causing arcing and plasma damage under track movement.


I'm skeptical those corrosion problems had anything to do with PECO, PEPCO or any other alternating current system. More likely they were due to 600 volt DC traction power negative return currents running through SEPTA's trolley tracks trying to find their way back home to the substation through Meghan's "bits of rail". CSX may not have installed traction bond cables around the many joints in this layout, resulting in the arcing and electrolytic corrosion observed.

However, the electrolytic corrosion may be a significant part of the reason Darby OWLS Version 1 didn't survive as long as hoped.

Back in the day, trolley companies such as SEPTA predecessor Philadelphia Transportation Company would install very heavy underground jumper cables which completely bypassed entire specialwork layouts, such as these diamonds. Those cables were provided specifically so negative return current wouldn't have to depend on the many individual rail joint bonds within the layout. I'd bet serious money that PTC installed such cables under the Darby Diamond crossing. Whether SEPTA has maintained those cables, including keeping them connected to the adjoining plain track, it another question entirely.

/s/ Larry
Lawrence G. Lovejoy, P.E.


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 Post subject: Re: Tamper for the WW&F
PostPosted: Fri Nov 20, 2020 12:14 am 

Joined: Fri Dec 22, 2017 6:47 pm
Posts: 564
Location: Philadelphia, PA
I know the guys who were in SEPTA Track and they would have known to run jumpers. However, the crossing was a CSX project. Did THEY know trolley tracks carry a heavy 600 vDC current? Did they ask SEPTA?

Streetcar-Main Line RR crossings are not at all common.

Phil Mulligan


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 Post subject: Re: Tamper for the WW&F
PostPosted: Fri Nov 20, 2020 12:38 am 

Joined: Sun Aug 22, 2004 1:51 pm
Posts: 9768
Location: Somewhere east of Prescott, AZ along the old Santa Fe "Prescott & Eastern"
EJ Berry wrote:
Streetcar-Main Line RR crossings are not at all common.


This has been frequently claimed to be the ONLY surviving one in the USA/North America. I know of no other claimants other than some disused siding around a shop or whatnot.


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 Post subject: Re: Tamper for the WW&F
PostPosted: Fri Nov 20, 2020 1:44 am 

Joined: Wed Jul 26, 2017 4:24 pm
Posts: 45
Larry Lovejoy wrote:
Quote:
The rail experiences bad wear from current induced oxidation. .....

But as part of an engineering expedition with the advanced engineering group show that fractures in the diamond were effected by induced current causing arcing and plasma damage under track movement.


I'm skeptical those corrosion problems had anything to do with PECO, PEPCO or any other alternating current system. More likely they were due to 600 volt DC traction power negative return currents running through SEPTA's trolley tracks trying to find their way back home to the substation through Meghan's "bits of rail". CSX may not have installed traction bond cables around the many joints in this layout, resulting in the arcing and electrolytic corrosion observed.

However, the electrolytic corrosion may be a significant part of the reason Darby OWLS Version 1 didn't survive as long as hoped.

Back in the day, trolley companies such as SEPTA predecessor Philadelphia Transportation Company would install very heavy underground jumper cables which completely bypassed entire specialwork layouts, such as these diamonds. Those cables were provided specifically so negative return current wouldn't have to depend on the many individual rail joint bonds within the layout. I'd bet serious money that PTC installed such cables under the Darby Diamond crossing. Whether SEPTA has maintained those cables, including keeping them connected to the adjoining plain track, it another question entirely.

/s/ Larry
Lawrence G. Lovejoy, P.E.



No I am referring to the PECO high voltage transmission lines that run parallel with the csxt philly sub from the siding down by chester to eas bridgeboard. It's a iirc a 138 kilovolt and it's three phases in an unbalanced delta. This leads to current induction in the rail. There are impedance bonds to help put this to ground but issues still happen including running an ac drill with a connection to the rail and a connection to ground. An arc flash event where the high voltage arc over to the radio code line antenna, and ball plasma erupted in a signal case. It's so power ful when working on an antenna pole located at 25 feet, while using an insulated bucket truck and wearing hot gloves and insulated boots, a 12 inch adjustable wrench could induce enough current to shoot an air arc over to the ground wire on the pole at a distance of 1 inch.

So all this coupled with the inherent mechanical issues of the diamond lead to weird failures.


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 Post subject: Re: Tamper for the WW&F
PostPosted: Fri Nov 20, 2020 1:46 am 

Joined: Wed Jul 26, 2017 4:24 pm
Posts: 45
EJ Berry wrote:
As to the electrical issues, could the power line be PECO (Philadelphia Electric) rather than PEPCO (Potomac Electric Power). I can see some of PECO's feed from the Conowingo Dam coming up the B&O to Philadelphia.

Phil Mulligan


Yes autocorrect got me again
It's PECO and the high voltage transmission lines go from chichester siding to eas bridgeboard


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 Post subject: Re: Tamper for the WW&F
PostPosted: Fri Nov 20, 2020 10:50 am 

Joined: Fri Aug 27, 2004 4:02 pm
Posts: 1371
Location: Back in NE Ohio
Well this turned into quite an education on how electric traction works and the problems associated with it.


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 Post subject: Re: Tamper for the WW&F
PostPosted: Fri Nov 20, 2020 1:15 pm 

Joined: Mon Aug 23, 2004 3:01 pm
Posts: 1565
Location: SouthEast Pennsylvania
EJ Berry wrote:
Streetcar-Main Line RR crossings are not at all common.
Alexander D. Mitchell IV wrote:
This has been frequently claimed to be the ONLY surviving one in the USA/North America. I know of no other claimants other than some disused siding around a shop or whatnot.
Alex, that's an old claim. CSXT has another crossing, where the railroad is very senior, on what they call, for insurance purposes, a Main Line. It's with the Tampa Electric Co. Line modern trolley in Florida. Amtrak also runs on CSXT there.


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 Post subject: Re: Tamper for the WW&F
PostPosted: Fri Nov 20, 2020 1:53 pm 

Joined: Sat Aug 12, 2006 1:02 am
Posts: 123
Location: Northern California
There is also a crossing of a Union Pacific freight spur by the relatively new San Francisco Muni T line at Third Street and Cargo Way in San Francisco.

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