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PRR 5550 Update: Boiler Assembly
http://rypn.org/forums/viewtopic.php?f=1&t=45908
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Author:  Stationary Engineer [ Mon Sep 27, 2021 1:05 am ]
Post subject:  Re: PRR 5550 Update: Boiler Assembly

The original on-line article, that is not available anymore, was written by Eugene Huddleston. In the article, he mentions that the C&O requested the T-1 with a booster. To compare it to the C&O engines that were equipped with boosters. PRR did not comply with the request.

Author:  Great Western [ Mon Sep 27, 2021 6:58 am ]
Post subject:  Re: PRR 5550 Update: Boiler Assembly

Dave Stephenson wrote:
To all those who read the C&O magazine article on the T1's and commented at length - thank you!!! It made all the effort 16 years ago worthwhile. The much maligned T1 is finally getting its proper consideration.


Thank you for writing the article. The detail is amazing. That is one that needs to be re-read many times.
Not to put you on the spot, but it would be interesting to learn more about drawbar pull -- the measuring off, how it changes, what effects it, etc.

Author:  Faller? [ Wed Sep 29, 2021 8:21 am ]
Post subject:  Re: PRR 5550 Update: Boiler Assembly

Kelly Anderson wrote:
Richard Glueck wrote:
2) Pennsy built a slug of them, tinkered with the basics, made them as efficient as roller bearings can make a steam locomotive, then killed them off entirely without looking back. Not one was preserved. Everything about this design is intriguing.
3) Slippery as they were, today a microprocessor can address the issue faster than a human can recognize it. Here's a chance to fix what was wrong with the successor to the K4s Pacific, and that's saying a lot.
Several years ago one of the Kalmbach magazines had an insightful article regarding the short life and urban legends surronding the T1's. Also, Vernon Smith wrote about them in his book One Man's Locomotives. Among the things that I learned were:
1. While the production run of T1's was building, PRR upper management decided to dieselize all passenger trains ASAP. The VP of western lines then unsuccessfully tried to have them canceled before any more money was spent. Failing that, he tried to sell them off to other railroads, also before they were completed, also without success. All this is indicative to me of PRR's left hand not knowing what it's right hand was doing.
2. Regarding their short life, they were in no way dual purpose locomotives, so when PRR completed dieselizing the passenger trains, they were literally out of a job, not being suitable for a downgrade to freight work as other RR's big 4-8-4's were.
3. As other posters have mentioned, PRR threw crews on the T1's with no orientation whatsoever. The article went on to say that the lack of management orientation also extended to the shop forces. For an example, the K4's had two sanders to keep operating, while the T1's had eight (and due to their high strung nature needed all eight to be operable at all times), the inference being that engines were often sent out without all of the sanders working, resulting in excessive slipperiness. Also, the shops were not equipped with the precision tools needed to maintain the poppet valve gear.
4. I recall reading once a great line regarding the T1's, "How can you find fault with an engine that had the following written up on the daily inspection report?" "Engine rides rough at 125 MPH."

Author:  Dave Stephenson [ Thu Sep 30, 2021 7:34 am ]
Post subject:  Re: PRR 5550 Update: Boiler Assembly

GreatWestern - The N&W tests of the T1 had more detail on what you're looking for. See PRRT&HS The Keystone, Vol.42, No.2 (Summer 2009). Contains both C&O and N&W tests. Should still be available as a back issue

Faller - The Kalmbach publication with the T1 story was in Steam Glory 3 (Holiday 2012). I believe this may be the one you were thinking about.

Author:  PMC [ Sun Oct 10, 2021 6:35 pm ]
Post subject:  Re: PRR 5550 Update: Boiler Assembly

Animation of the valve gear: https://www.youtube.com/watch?v=4fELZGD0ED0

Author:  mjanssen [ Sun Oct 10, 2021 11:51 pm ]
Post subject:  Re: PRR 5550 Update: Boiler Assembly

PMC wrote:
Animation of the valve gear: https://www.youtube.com/watch?v=4fELZGD0ED0


Will be interesting to see if they look at cam ramp profiles and valve spring dynamics.

Author:  joe6167 [ Mon Oct 11, 2021 2:11 am ]
Post subject:  Re: PRR 5550 Update: Boiler Assembly

PMC wrote:
Animation of the valve gear: https://www.youtube.com/watch?v=4fELZGD0ED0


Wow... the quality of that "animation" is right at the border of being indistinguishable from real life.

Author:  PMC [ Thu Oct 14, 2021 5:32 pm ]
Post subject:  Re: PRR 5550 Update: Boiler Assembly

Found a description of the wheel slip control system design for 5550 in a comment the T1 group made on their Facebook page: https://fb.watch/8EmE5oNMmy/

"Pennsylvania Railroad T1 Steam Locomotive Trust... traction control is fairly simple and will be completely hidden. A simple electrically actuated butterfly valve is inline with the steam delivery pipes to the cylinders. If a slip is detected with a small sensor, the valve quickly shuts and then reopens. This stops the slip automatically. It is nearly impossible for an engineer to detect a slip at speed with a dual exhaust locomotive."

So no hydraulics. Would such an electrically operated device use some sort of solenoid? Tough environment for electrical equipment to function, in my uneducated opinion.

Author:  p51 [ Fri Oct 15, 2021 12:20 pm ]
Post subject:  Re: PRR 5550 Update: Boiler Assembly

joe6167 wrote:
PMC wrote:
Animation of the valve gear: https://www.youtube.com/watch?v=4fELZGD0ED0


Wow... the quality of that "animation" is right at the border of being indistinguishable from real life.
I agree.
Note the U-joints and exposed drive lines (for lack of the proper term for that part) running on the outside of the valve gear rear wheel. I’ve never really understood the poppet running gear and it sure looks kind of fragile like that. I wouldn’t have expected this to be something that could spin at speed in excess of 120 MPH, which many say the T-1s got up to.

Author:  Aarne H. Frobom [ Fri Oct 15, 2021 1:07 pm ]
Post subject:  Re: PRR 5550 Update: Boiler Assembly

I see that the slip-control system works beautifully in the animation! That is some artwork.

The valve drive shaft is probably running slower than the same hardware in a truck driveshaft and rear end at 70 mph, and with lighter loads.

Aarne Frobom
Universal City, Michigan

Author:  bbunge [ Fri Oct 15, 2021 3:19 pm ]
Post subject:  Re: PRR 5550 Update: Boiler Assembly

Notice they not only model the vertical motion of the drivers, but also the vertical motion of trailing truck axles, so apparently the entire system.

Now start to imagine if the engineers of the day were able to use these types of tools.

We've seen comments for decades along the lines of "what if modern design, modeling and manufacturing methods were used..." It would appear we are now watching this realtime.

Bob

Author:  CA1 [ Fri Oct 15, 2021 3:30 pm ]
Post subject:  Re: PRR 5550 Update: Boiler Assembly

There's probably more force on a traditional valve gear than the rotating shaft on the T1.

A rotating shaft would be stronger than you think, with probably less force on it than you think. Vs looking at the weight of for example the baker valve gear components on a NKP 2-8-4 flying around at 70 mph.

Author:  filmteknik [ Sat Oct 16, 2021 9:02 am ]
Post subject:  Re: PRR 5550 Update: Boiler Assembly

I wonder what the effect would have been on the divided drive engines to link the two units. Not sure how on the S1, Q2, or T1 but it would have been easy to try on the Q1 with the back pedaling 2nd unit. In fact it's surprising they didn't. That advantage along with the reduced rigid wheelbase might have made the disadvantages of the back pedaling design worth it.

Author:  whodom [ Sat Oct 16, 2021 12:42 pm ]
Post subject:  Re: PRR 5550 Update: Boiler Assembly

These French locomotives had internally coupled drivers. While it looks like a 2-4-6-2, it’s actually a 2-10-2. These were compound locomotives, so keeping the two sets of cylinders appropriately synchronized was advantageous for optimum efficiency. Note these engines also had rotary cam poppet valves.

Image

Author:  filmteknik [ Sat Oct 16, 2021 9:27 pm ]
Post subject:  Re: PRR 5550 Update: Boiler Assembly

Before applying various updates they need to duplicate the original and see what it can do in the hands of a skilled, careful engineer. Maybe it won’t need any fixes.

It’s great that there are places where it can run but the only true measure of success will be around 100 MPH. Can that be done anywhere besides the NEC?

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