Southern Pacific P-8

[dpeterson3]

I finally found time to return to live steam after a few months of school ruling my life. I finally decided I would like to build a P-8 like 2467 or 2472. Does anyone know where I might be able to get the drawings for the P-8 class engines? I checked the SMU archives and didn't see it listed there. I thought they had most of the existing Baldwin drawings. I found drawings for the P-10 locos, so if need be I will get those. I also found some basic drawings of SP 2479 on SteamCad's website.

Thanks in Advance

[jessebanning]

Try Little Engines. I think teir 1.5 scale Pacific is a P-7 or P-8.

[kenrinc]

The Little Engines Pacific would be a good bet although I believe it represents a P4 as is. Could easily be "kitbashed" into a later model. Infact it would probably be the easiest route to a nice looking model. Roger Goldman has drawings for an SP P10 pacific. It's only a few drawings but it might be just what you need. http://www.livesteamlocomotives.com/id28.html

It really depends on how much experience you have and how you work. Some can't do anything without a drawing. Some only need an erection print or photo. In most cases the LE pacific would probably be the best answer. Good luck and keep us up to date!

You can also try the library at the California State RR museum.

Ken-

[Rwilliams]

The P-8 and P-10 locomotives are basically the same beast except for a few minor changes. The P-10 had a much nicer trailer truck alignment device with rockers rather than friction plates as The P-8 class. Some minor differences in the trailer truck frame as well. One will probably never find all the drawings for either class of locomotive but maybe enough of the important ones where the missing information could be gathered by visits to the #2472, #2467, or the #2479. All locomotives are restored or in restoration.

The P-4 had much larger drivers and the wrong number of spokes to make a good model of a P-8 or a P-10. The P4 was nothing more that a warmed over P-1. Only a few were built to meet the needs of the car ferry at Martinez. The weight of the locomotive had to stay within a certain tonnage so a bigger locomotive was out of the question. Answer was to soup up a few P-1 class Pacific's to meet the needs of the passenger traffic on the Oakland to Sacramento run until the big drawbridge could be design and built.

As for drivers, I believe Grant Carsen has some 73 inch 17 spoke drivers patterns that might work very well for your needs. He posts here often.

Robert

[Doug_Edwards]

Gents,

As Rwilliams noted, the P8 was nearly the same as the P9 and P10. The P8 was built without the booster, and the rear frame extention is about 15" shorter than the other two because of this. This pushed the cab farther forward on the P8 also. Other then this, the running gears and boilers are the same.

The P8 also was not built with feedwater heaters, they were added later.

The Little Engines pacific is an extended A6 Atlantic. The atlantic had larger drivers, and they were used on the LE P4 pacific. The two classes on the SP had a very high number of parts that were common to both engines. Both are said to be rebuilds, but that is more for accounting purposes than to reflect on the design of the engines. The rebuilt engines shared only a relative few parts with the engines they were built from. The boilers, drivers, lead trucks, domes and stack are the major parts reused. The frame and running gear with the exceptions of the drivers and lead trucks were all new. Both classes received larger cylinder bores. It is a pity that neither class had an example saved.

The Little engine drivers would be about an inch larger in diameter than what they should be for a model of a P8.

Regards,

Doug

[dpeterson3]

Thanks. I knew the P-8s and P-10s were cosmetically almost identical. I wasn't sure about under the boiler. I plan to try to cast my own drivers. I was talking to the foundry guys at my school about it at the end of last year (yes they can do small steel casts). I can do wood working so I will probably make the pattern myself.

You can also try the library at the California State RR museum.

I thought CSR only had LIMA drawings. Do they have Baldwin also?

[Doug_Edwards]

Thanks. I knew the P-8s and P-10s were cosmetically almost identical. I wasn't sure about under the boiler. I plan to try to cast my own drivers. I was talking to the foundry guys at my school about it at the end of last year (yes they can do small steel casts). I can do wood working so I will probably make the pattern myself.

You can also try the library at the California State RR museum.

I thought CSR only had LIMA drawings. Do they have Baldwin also?

The CRSM has a few SP drawings, not a lot, but may have just the one you need.

You might consider joining the Southern Pacific Historical and Technical Society. You might find some members that have drawings, but if not, you will find a few people still left that have a pretty deep knowledge of SP Steam.

Regards,

Doug

[dpeterson3]

So I was going to make my drive wheel pattern today to see about getting them cast when foundry day rolls around at school soon. I realized something, though. I have no idea how thick to make the spokes and I haven't had any classes yet that taught me how to calculate such quantities. How thick are spokes generally made on drive wheels (neglecting machining and shrink tolerences which I will add in when I make the pattern)?

[Pipescs]

While not a P-8 or P-10 this is a reduced quality print from the book "Southern Ps-4 Class Pacific Locomotive Drawings". It is the Main Driver Print showing what you are discribing.

May not be what you are looking for but if it is you can send me a PM with an Email address and I will send you the higher resolution scan.

[Doug_Edwards]

So I was going to make my drive wheel pattern today to see about getting them cast when foundry day rolls around at school soon. I realized something, though. I have no idea how thick to make the spokes and I haven't had any classes yet that taught me how to calculate such quantities. How thick are spokes generally made on drive wheels (neglecting machining and shrink tolerences which I will add in when I make the pattern)?

I would suggest that you get a copy of the driver print offered by Roger Goldmann listed previously, and make the pattern to scale off the print.

Btw, the scan offered by pipescs is a very good drawing in regards to details.

Regards,

Doug

[Pipescs]

I must also give Roger credit for helping me find the drawings

I am looking at doing a set of drawings for a 1.5 scale Southern Ps-4 with the thought of using his Baker Valve Gear and Cylinder Castings if possible. I had started with a set of low quality drawings when Roger was kind enough to take the time on the phone and recommend the book of drawings on the Ps-4

The book of drawings was published in 1973 and I was able to locate a copy on the net.

This is a low resolution of the Front and Rear Drivers

[dpeterson3]

Right after i posted last, the week went from enough time to work on trains to no time. Thanks for the diagram. I think the drivers should be close. My big problem is I have no feel for strengths of metals yet so I can not just decide on a good number like I can with wood. That picture is high enough resolution for me to read it no problem. Also, thanks for the link. I don't know why I was thinking GGRM when 2479 is not a GGRM engine.