100th Anniversary Main Line Electrification to Paoli

Wire train

NorthPennLimited wrote:Still waiting for the experts / historians to weigh in. But this is an interesting topic (to me).

According to " the Internet" (if you read it on the Internet, it has to be true, right?) the power comes from Safe Harbor Dam up in the Susquehanna River. The power comes out at 25Hz. Not sure about 100 years ago. Seems the dam came online nearly 16 years to the day after the PRR electrified the Paoli Line.

Safe Harbor is one of several sources that powered the PRR's traction power network. Between 1914 and 1928 the Paoli and Hill West lines were fed from PECOs Schuylkill Power Station located adjacent to the Arsenal branch. The plant provided 18MW of 25Hz capacity to the Arsenal substation which stepped up the 13.2Kv feed to 44Kv for distribution between Philadelphia and Paoli/CHW.

In 1928 the Lamokin converter plant came online for Wilmington and West Chester service followed by the large Port Richmond plant in 1933, which powered the bulk of the eastern network. Safe Harbor only came online for railroad power in 1938 with the Low Grade and Harrisburg lines were wired. Today the whole system operates like any other power grid except that the Paoli section had the oddball 44Kv feeders removed around 1960 as freight traffic on the Main Line fell. The 20 mile segment is now fed from the ends via the 1938 Paoli Substation and the 1930 Zoo Substation. Bryn Mawr substation has catenary section breakers only and possibly some mechanism to tie the 4-main line catenary lines together so they can act as mutual feeders since the gap between substations is twice as long as it normally is...or at least that is how it was explained to me.

NorthPennLimited wrote: This is a tough subject to research online.

Not if you know where to look.

tgolanos wrote:The PRR electrified early, but the RDG waited until sometime in the early 1930's to begin putting wires up. It begs the question, was the Reading behind in the times or were they waiting to see how the PRR's experiment went before doing it themselves?

I've sometimes wondered whether the Reading also looked at the DL&W electrification which was happening at about the same time, and whether they considered 3000 DC before deciding on the same as the PRR. I believe that if they'd chosen 3000 DC we wouldn't have the Center City Commuter Connection today.

ExCon90 wrote:I've sometimes wondered whether the Reading also looked at the DL&W electrification which was happening at about the same time, and whether they considered 3000 DC before deciding on the same as the PRR. I believe that if they'd chosen 3000 DC we wouldn't have the Center City Commuter Connection today.

Then there probably would have been an AC conversion project just as NJT did in 1984.

But they would then have had to deal with the entire RDG fleet being unusable and needing to be replaced in its entirety with new AC equipment. I have to question whether the resulting cost would have torpedoed the whole project.

ExCon90 wrote:But they would then have had to deal with the entire RDG fleet being unusable and needing to be replaced in its entirety with new AC equipment. I have to question whether the resulting cost would have torpedoed the whole project.

By [the opening of the Center City Tunnel] 1984, the RDG Blueliners were nearing the end. They did reach 1990, at the age of 59. Had RDG used DC, the Blueliners would have probably been replaced even earlier, possibly with additional Silverliner IVs on order.

ExCon90 wrote:But they would then have had to deal with the entire RDG fleet being unusable and needing to be replaced in its entirety with new AC equipment. I have to question whether the resulting cost would have torpedoed the whole project.

I'm with you on this. Philly would have 2 separate systems today if the RDG and the PRR had vastly different electrification.

Back to Paoli - I've only ever ridden the Main Line once and I don't know as much about the PRR as I do the RDG. Always happy to learn something off this board.

ExCon90 wrote: I've sometimes wondered whether the Reading also looked at the DL&W electrification which was happening at about the same time, and whether they considered 3000 DC before deciding on the same as the PRR. I believe that if they'd chosen 3000 DC we wouldn't have the Center City Commuter Connection today.

Reading had plans to electrify to Jersey City that the depression ultimately quashed. That long distance thinking put them into the AC camp. Also wasn't Thomas Edison still bouncing around North Jersey? I think he may have influenced the DL&W somewhat.

tgolanos wrote: I'm with you on this. Philly would have 2 separate systems today if the RDG and the PRR had vastly different electrification.

ExCon90 wrote:I've sometimes wondered whether the Reading also looked at the DL&W electrification which was happening at about the same time, and whether they considered 3000 DC before deciding on the same as the PRR. I believe that if they'd chosen 3000 DC we wouldn't have the Center City Commuter Connection today.

We probably would have ended up with DC versions of what is used on the Metro North New Haven Line (third rail in the tunnel, overhead catenary outside the tunnel.)

Jersey_Mike wrote:Also wasn't Thomas Edison still bouncing around North Jersey? I think he may have influenced the DL&W somewhat.

Yes. He operated the first electric train out of Hoboken Terminal to Montclair. Edison was a proponent of DC power. [sarcasm]I wonder if Tesla was on the first train out of Broad Street Station to Paoli?[/sarcasm]

In addition, I recall reading somewhere that the PRR orignally experimented with trolley wire on a short stretch of track in Long Island before stringing up the wire to Paoli. I need to do research on my own time for this one.

Also significant was that the Lackawanna equipment (including cars and electrical system) was supplied by GE (rolling stock a GE/Pullman joint venture). General Electric was Edison's company, dating to 1878.

When I referred to the entire RDG fleet I was including the Silverliners II and IV, which would all have been delivered with DC only; I assume retrofitting them (particularly the IIs) for AC would have been prohibitive.
The PRR did electrify a line from Camden to Millville, in South Jersey, at 600v DC (using trolley poles), in 1906, partly to evaluate its practicality, but was more impressed by the New Haven's experience with 11kv 25Hz.

R3 Passenger wrote:...I recall reading somewhere that the PRR orignally experimented with trolley wire on a short stretch of track in Long Island before stringing up the wire to Paoli.

Michael Froio, on his wordpress web pages, has a concise story of the PRR's early dabblings with DC and trolley wire on the Burlington and Mt. Holly, the West Jersey & Seashore, and the Dillsburg Branch.

Jersey_Mike wrote:Also wasn't Thomas Edison still bouncing around North Jersey? I think he may have influenced the DL&W somewhat.

You could say that. He was motorman on the inaugural train. There's a pic somewhere, perhaps in the Middleton book.

the Mike Froio website is pretty detailed.

The PRR blueprint is amazing. I would have never guessed those 80' catenary towers are only sunk into 9' concrete footings.

What is the advantage of the 132 Kv Pirelli Cable? It was solid copper with an oil filled core?

(1) How do you connect 2 pieces of oil core wire?

(2) What properties do oil serve within a wire core to help conductivity?

NorthPennLimited wrote:the Mike Froio website is pretty detailed.

The PRR blueprint is amazing. I would have never guessed those 80' catenary towers are only sunk into 9' concrete footings.

What is the advantage of the 132 Kv Pirelli Cable? It was solid copper with an oil filled core?

(1) How do you connect 2 pieces of oil core wire?

(2) What properties do oil serve within a wire core to help conductivity?

The Pirelli Cable in the drawing was most likely for an underground/underwater/in tunnel transmission line, not what was used in the catenary towers. Pirelli was the manufacturer, the same Pirelli that makes tires. I believe they sold off their cable arm about ten years ago.

Oil is primarily used in paper and lead insulated transmission wires to help with insulation by ensuring no air voids within the cable that can be caused by expansion/contraction and loading cycles. Air voids in time reduce insulation - which leads to line failure. Connecting two pieces is more involved as a certain amount of oil pressure has to be present once installed.

All of the oil filled transmission lines that I came across were like the Okonite cables in the drawing, not the Pirelli with a center core of oil. I would assume this could have been for cooling(?).