Talk:Pennsylvania Railroad class P5

Expanding this article

I have ordered the PRRTHS's book "The Pennsy's P5 Electrics" to expand this article properly. Matthew Brown (Morven) (T:C) 15:19, 29 August 2008 (UTC)

Removed unsource paragraph

I removed the following:

Because there was no reciprocating load on the axles of an electric locomotive, the P5 was originally built with an unprecedented load of 82,500 pounds on each driving axle. With the completion of the electrification to New York, the standard schedule for North Philadelphia to Newark was cut. Not long after this problems were observed with maintaining gauge on some curves. The speeds were reduced, but then the P5 axles began to break. They were replaced with a larger radius fillet on the outboard extension of the axle, and the equalization was changed to reduce the driving axle loading to 75,000 lbs. The axle loading of the GG1 which replaced then in high speed service was less than 55,000 lbs.**

because it is not sourced and I cannot presently find any collaboration for most of its claims. I suspect it's largely correct but lacking sourcing it should be left out until it can be properly sourced.

In addition, I find the two stars at the end of the paragraph troublesome; they suggest that a footnote was supposed to be referenced, which makes me wonder if this was lifted from some other online site complete with footnote reference. Matthew Brown (Morven) (T:C) 08:10, 30 August 2008 (UTC)

I have acquired the PRRTHS book on the P5s which I'm going to use to source this article better. More news soon. Matthew Brown (Morven) (T:C) 15:53, 9 December 2008 (UTC)

Power of P5b

Note, that the power indication in the article was given with 5,350 hp (3,990 kW) for the P5b, which is obviously wrong because the installed power of the locomotive was only 4 × 375 + 6 × 625 = 5,250 hp (3,910 kW). The wrong number comes from the cited book of Alvin F. Staufer, which actually - even if I really like it, contains some more errors. Therefore I removed the source of Alvin Staufer and put the PRR drawings as source there.--Pechristener (talk) 15:48, 15 January 2018 (UTC)

Just so you understand, I wasn't trying to be awkward. The truth is that figures for horsepower can get very confusing, and fast. The truth is that locomotives have many levels of horsepower, depending on whether it is a continuous rating, a one-hour rating or a short term rating (5 or 15 minutes etc.) Also the installed motor power, does not easily translate into the generally accepted definition of horsepower, which is the power at the rail. In other words the power available at the railhead to pull coaches/wagons etc. is not the same as the sums of the power of the motors, because of losses and also gearing. Gear ratio in particular can change the available pulling power, for identical locomotives with the same motors. A lower gearing will give more pull for freight, but at the price of a lower top speed. Conversely, a higher gear ratio will allow you to pull a lighter load, but at a faster top speed. I would agree that Staufer needs to be clearer, but as it's a published work (and a great read at that), there's little to be done, other than find other sources to either validate or contradict the quoted power. - Morphenniel (talk) 16:26, 15 January 2018 (UTC)

Thanks for the explanation, but its actually not necessary since I'm a railroad engineer building and testing electric locomotives. From the context in A. Staufer's book, it is quite clear that he talks about the installed power because he writes about a xyz hp motor. This typically refers to the shaft power rating of the motor and does not include any gear losses etc further downstream in the traction chain. The contradiction of the power rating is already in the book itself, since the figure for the total power is above the figure of the installed power. So there is no way, that Staufer talks about power on the rail head, since that figure can only be lower than the installed power due to the losses as you explained before. Note that he gives too different ratings: one is 5350 hp on p. 267 and another is 5310 hp on p. 269. Both are above the installed power.--Pechristener (talk) 10:47, 16 January 2018 (UTC)

Accident leading to modified design

Would the accident that was the reason for the modified redesign possibly be the one described in this Brookly Daily Eagle article? It seems to match up with the build dates and general description presented here. The person who clipped the article put "GG1 206" in the notes perhaps indicating that #206 was one of two locomotives involved. Slambo (Speak) 15:56, 1 January 2019 (UTC)