Railway Preservation News
https://www.rypn.org/forums/

4960 test run!
https://www.rypn.org/forums/viewtopic.php?f=1&t=32870		 Page 1 of 1
Author:  jasonsobczynski [ Sat Feb 11, 2012 10:09 pm ]
Post subject:  4960 test run!
Here is the link: http://www.youtube.com/watch?v=VTkKMlLc ... e=youtu.be

Glad it's again operating but what about the 29? 29 still has 5 years or so remaining on the 1472 yet has not run since 2008, 4960 just had to go through the 1472 inspection. Just wonder why the 29 is not utilized and instead is allowed to rust away (partly because if salting agents crammed into the running/drive gear as it plays snow fence during the winter months) at the depot.

Also, has the stack been replaced with one custom built for the lempor? Looks much better without the"double chin".

Cheers, Jason
Author:  Zak Lybrand [ Sun Feb 12, 2012 12:55 am ]
Post subject:  Re: 4960 test run!
Here's a direct quote in response to a similar question that the Locomotive Manager for GCR, Eric Hadder, posted on Facebook:

"Christopher, there are currently no plans to put 29 back in service. With our reduced operating schedule, there is no reason to maintain 2 locomotives. However, 29 is not 'retired', and could be brought back on line in the future if there are any changes to the operating policy."

Having worked with Eric, I can safely say that he is definitely clued in enough to have a correct answer.

Also, from what I've noticed, 4960 has sort of become the "flagship" for GCR. As such, it appears that they would rather maintain it rather than set it aside for quite some time and bring back 29. I also remember hearing somebody say that 29 has some sort of boiler issue, or something with the tubes, but I am not positive about the truth behind that.
Author:  jasonsobczynski [ Sun Feb 12, 2012 1:25 am ]
Post subject:  Re: 4960 test run!
I don't understand why tey would rather it just sit there. I am involved with a railroad that made an offer on the 29 for $750,000 to Zanterra. They said there is no interest in parting with it regardless of offer amount.

A shame in my book...... But at least the 60 is sill getting attention!

Cheers, Jason
Author:  whodom [ Sun Feb 12, 2012 10:15 am ]
Post subject:  Re: 4960 test run!
This is very good news.

Jason, that's definitely a new stack on 4960. Compare the 3/4 shots in the video with the photo at the top of this page:

http://www.thetrain.com/grand-canyon-ra ... -7275.html

The new stack is definitely a cosmetic improvement.

On a related subject, I've read recently that the Lempor on the 29 showed a larger improvement than the one on 4960. This is apparently because the exhaust steam passages in the 4960 are significantly more restrictive than those in the 29 so that more of the energy in 4960's exhaust is expended before it ever gets to the stack. Nonetheless, both Lempors were a significant improvement over the original exhaust systems.
Author:  jasonsobczynski [ Sun Feb 12, 2012 2:51 pm ]
Post subject:  Re: 4960 test run!
That's correct, undersized exhaust passages are one of many deficiencies found in baldwin built products. The addition of the nanku (or however it's spelled) feed water system and the consumption of about 20% of the exhaust steam helped the situation.
When the system was first added there was question as to whether or not the lempor would have to be re-engineered as the volume of exhaust steam would decrease and it was originally engineered for full volume. Perhaps?

Cheers, Jason
Author:  Robby Peartree [ Sun Feb 12, 2012 5:06 pm ]
Post subject:  Re: 4960 test run!
It should be noted that GCR 4960 did not have the same type of exhaust nozzle as GCR 29 to start with. 4960 was fitted with a star nozzle during the rebuild in the late 1990s. With the better drafting equipment in 4960 than 29 one would have expected a smaller improvement. While the casting has less proportional space to allow the steam to flow than 29 it was and is not the only difference between the two locomotives. Blaming this on the builder seems to take the obvious difference between the two locomotives and not go into why this difference exists.

For the record, 4960’s factor of adhesion does not lend itself well to the branch particularly when working the yard at the Grand Canyon. I have had GCR 18 take 10 cars and a dead B unit to a stall on a 3 percent grade without slipping and 4960 would not have come even come close to that performance. Increasing 4960 tractive effort output will only make that part of the operation trickier

Respectfully
Robby Peartree
Author:  jasonsobczynski [ Sun Feb 12, 2012 7:02 pm ]
Post subject:  Re: 4960 test run!
Robby,

This is an inherent issue with baldwin locomotives. On most baldwin's as the exhaust passage makes the 90 degree turn up the cross section is greatly reduced compared to other builders and identically sized power. The 29's cross section at the bottom of the exhaust stand is larger than the 60's.
The difference in pulling power its the result of much weight having been taken off the drivers and distributed onto the lead and trailing truck coupled with the use of DHT tires. They provide a longer wear life but there is a reason the railroads used class B and C (non HT).

That"star nozzle" was cast from rather new patterns marked 1361, not sure if it was loaned or purchased....

Cheers, Jason
Author:  whodom [ Sun Feb 12, 2012 7:28 pm ]
Post subject:  Re: 4960 test run!
Robby Peartree wrote:
It should be noted that GCR 4960 did not have the same type of exhaust nozzle as GCR 29 to start with. 4960 was fitted with a star nozzle during the rebuild in the late 1990s. With the better drafting equipment in 4960 than 29 one would have expected a smaller improvement.


Robbie- Thanks for the info about the exhaust nozzle. I knew this but had forgotten it. From all indications, any division of the exhaust steam jet is superior to a single round nozzle and the "star" type seems to be fairly effective. It makes sense a Lempor would be less of an improvement over a star nozzle exhaust than a completely conventional one.

Jason- It's interesting to read that this exhaust passage issue seems to be common to many (all?) Baldwin locomotives. I imagine it would be difficult to do much about it aside from hand-porting the passages as far as possible.
Author:  jasonsobczynski [ Sun Feb 12, 2012 9:40 pm ]
Post subject:  Re: 4960 test run!
Hugh,

You are correct, and some of the baldwin power there is enough material to mill out the opening. This was actually going to be investigated on the 60 prior to the feed water system coming about. The exceptions to my original statement are 1) locomotives built to a railroads specification/design which provided for larger cross sections 2) refined super power design.


Cheers, Jason
Author:  Nigel Anthony Hewer Day [ Mon Feb 13, 2012 1:28 am ]
Post subject:  Re: 4960 test run!
I did 29 first and yes the passages are a little easyier on that one. It was not posible to fit the lempor in the exsisting stack so we simply did a new stack. Although I dont have the direct figures its probable that 29 had a greater reduction in back pressure. It was 29 I was called in to do, not origonaly 4960.

I had finished the design work by the afternoon and ahad time to spare before going back to NH. Sam asked me to look at 4960 which we did. Its true the steam passages are less forgiving on this one. The star nozzle has great friction and little mixing. The flue was also more out of proportion to 29. It was the origonal intention to go back and design a twin Lempor which never happened which is why it was fitted inside the origonal stack. I also made some slight changes compered with 29 in proportions which is why the loco is the better of the two.

These locos pushed the upper limmits of exhaust pipe work and hight restrictions for such large locos and larger locos would have to have much further work to make Lempors viable. The whole two locos lempors where designed in 48 hours.

I have not seen the new stack for 4960 but would say it has to be an improvement for a number of reasons.

I can not coment on the efect of the feed water heaters as I did not do them.

For the ultimate steam fix the sound of 4960 working hard into the canyon can not be betten and I hope one day I can hear more of it.
Author:  Les Beckman [ Mon Feb 13, 2012 12:19 pm ]
Post subject:  Re: 4960 test run!
Nigel -

I can't attest to the sound of 4960 in the canyon, but we rode behind 29 a few years ago. The train was long that day (a conductor told us if there had been one more car added, there would have been a diesel helper). Anyway, the 29 was "down on her knees" working through the canyon, and the sound was quite impressive! The 4960 was on the train the next day but we had other vacation committments so were only able to catch her departure from Williams.

Les
Author:  whodom [ Mon Feb 13, 2012 12:22 pm ]
Post subject:  Re: 4960 test run!
Here's a comparison of the old (left) and new (right) stacks.

Image

Photo on the left is from the GCRY's webpage; photo on the right is a screen cap from the video linked at the top of this thread.

It's definitely a cosmetic improvement, but it appears to be the same dimensions as the orginal "liner" that Nigel designed. Their Facebook page has quite a few detail photos of the inside of the smokebox with clear shots of the Lempor nozzles. The removal of the original stack with liner is shown in one of the photos.
Author:  hadder [ Mon Feb 13, 2012 12:55 pm ]
Post subject:  Re: 4960 test run!
Hugh is correct. Because of the stack modifications over the years, we needed a cutting torch to remove the stack in order to facilitate removal of the superheaters.

Instead of welding it back as it was, we decided to make a few modifications. The old stack (outer sleeve) was removed entirely, and the inner lempor liner was fastened directly to the flange that bolts to the top of the smokebox. So while the appearance is much cleaner looking, the functionality has remained unchanged.

Eric
Author:  Robby Peartree [ Tue Feb 14, 2012 2:03 am ]
Post subject:  Re: 4960 test run!
Eric,

I want to say publicly congrats on the successful inspection. Hopefully by the time you read this, the centennial run to the Canyon will have also been a success.

Robby Peartree
Author:  Nigel Anthony Hewer Day [ Tue Feb 14, 2012 4:14 am ]
Post subject:  Re: 4960 test run!
Thanks Hugh for posting the pictures. It looks good, Good luck for the run.
Page 1 of 1 All times are UTC - 5 hours [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/