It is currently Thu Apr 18, 2019 12:50 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 41 posts ]  Go to page Previous  1, 2, 3
Author Message
 Post subject: Re: A bad day for SP #18
PostPosted: Fri Apr 12, 2019 1:57 pm 

Joined: Thu Feb 27, 2014 10:08 am
Posts: 449
Kelly and Mr. Knoob - thank you for the clarifications.


Offline
 Profile  
 
 Post subject: Re: A bad day for SP #18
PostPosted: Fri Apr 12, 2019 4:36 pm 

Joined: Sun Aug 22, 2004 7:19 am
Posts: 5630
Location: southeastern USA
Very interesting. I think it is unlikely the piston seized since she was apparently well broken in (i.e. showing signs of a lot of in service wear) so the piston wouldn't fit the bore so tightly as to bind without some large amount of foreign material gumming it up, which wouldn't be a sudden sort of thing. The rings would compress into their grooves when overheated providing even more room to freely vibrate while, as Earl says, the Johnson Bar would be doing a frantic dance. Others comment that the bore appears to be in unmangled condition - very good. It seems likely that the piston itself may have knocked a chunk of itself loose due to some hidden flaw combined with the intensity of working the heavy grades which got propelled towards the front, caught between the rod end or piston and head, and mayhem ensued. Since the engineer was quick on the draw about shutting off at the first sign of trouble he's experienced and savvy enough to have also stopped if the Johnson Bar had started thrashing him near the crotch, so the oil scenario doesn't (forgive the pun) seem to hold water.

_________________
Santayana: "He who does not remember the past is condemned to repeat it."
Corollary: "He who does is doomed to watch those who don't repeat it anyway."


Offline
 Profile  
 
 Post subject: Re: A bad day for SP #18
PostPosted: Fri Apr 12, 2019 4:38 pm 

Joined: Sun Aug 22, 2004 7:19 am
Posts: 5630
Location: southeastern USA
[quote="Kelly AndersonPRR #1223 never had bump marks on her left crosshead guide showing where the piston hits the head, so the first chance I had when the main rod was disconnected, I put some on. She has a 26" stroke, and the bump marks were 25-15/16" apart! quote]

The Standard Railroad of the World. Nice catch.

_________________
Santayana: "He who does not remember the past is condemned to repeat it."
Corollary: "He who does is doomed to watch those who don't repeat it anyway."


Offline
 Profile  
 
 Post subject: Re: A bad day for SP #18
PostPosted: Sat Apr 13, 2019 4:01 pm 

Joined: Sat Aug 25, 2007 12:45 am
Posts: 581
Scranton Yard wrote:
2. It has been mentioned that the consist was backed up so that the tender could be refilled at a creek. Was a regularly scheduled watering overlooked or was the locomotive consuming a lot more water than anticipatedd?
Neither - the Hermosa water tank was dry, so they siphoned water from Hermosa creek.


Offline
 Profile  
 
 Post subject: Re: A bad day for SP #18
PostPosted: Sat Apr 13, 2019 4:42 pm 

Joined: Wed Sep 25, 2013 12:36 am
Posts: 302
Location: Anchorage, Alaska
Quote:
I'm sure the D&S will have her back in service soon after they get the castings from the foundry.


Given the current technology, would using centrifugal cast or ductile iron be the quickest way to make the replacement piston and head?


Offline
 Profile  
 
 Post subject: Re: A bad day for SP #18
PostPosted: Sun Apr 14, 2019 7:08 am 

Joined: Sat Jan 21, 2012 10:03 pm
Posts: 152
Location: Pennsylvania
Video of the event.

http://trn.trains.com/news/news-wire/2019/04/video-southern-pacific-no-18-blows-a-cylinder-while-on-dsng-excursion


Offline
 Profile  
 
 Post subject: Re: A bad day for SP #18
PostPosted: Mon Apr 15, 2019 10:28 am 

Joined: Wed Jan 28, 2009 4:30 pm
Posts: 154
Robby Peartree wrote:
Kelly Anderson wrote:
Besides, lack of lubrication wouldn't cause the piston to shatter.

So if a lack of lubrication did not cause it what did. You seem to be saying valve oil is unessary.

Robby Peartree


It is well known that in vertically oriented pistons on marine applications running saturated steam no lubrication is supplied to the valve or piston. Superheat requires lubrication and intense oil removing procedures for condensate destined for boiler feed water.


Offline
 Profile  
 
 Post subject: Re: A bad day for SP #18
PostPosted: Mon Apr 15, 2019 12:33 pm 

Joined: Thu Oct 08, 2015 11:54 am
Posts: 473
Location: Orrville, OH
Since speculation is rampant, I'd guess at stress/fatigue cracking due either to an internal flaw in the casting that finally revealed itself, or the design of the piston. It'd be nice to know if the engineer had any warning - he did shut it down fast. If it broke without preceding symptoms, then I'd lean towards fatigue. But what do I know about steam... I'm a lowly diesel guy.

_________________
Eric Schlentner
ORHS Car Knocker & Gandy Dancer
http://www.orrvillerailroad.com


Offline
 Profile  
 
 Post subject: Re: A bad day for SP #18
PostPosted: Mon Apr 15, 2019 8:04 pm 

Joined: Wed Aug 25, 2004 11:16 am
Posts: 629
CCDW wrote:
Robby Peartree wrote:
Kelly Anderson wrote:
Besides, lack of lubrication wouldn't cause the piston to shatter.

So if a lack of lubrication did not cause it what did. You seem to be saying valve oil is unessary.

Robby Peartree


It is well known that in vertically oriented pistons on marine applications running saturated steam no lubrication is supplied to the valve or piston. Superheat requires lubrication and intense oil removing procedures for condensate destined for boiler feed water.



True but then in a vertical motion the condensing water would evenly spread over the ring to lubricate it. With horizontal the water would not reach the top as easily.

Robby Peartree


Offline
 Profile  
 
 Post subject: Re: A bad day for SP #18
PostPosted: Mon Apr 15, 2019 9:47 pm 

Joined: Thu Apr 12, 2007 8:09 pm
Posts: 382
What would the advantage be to getting new parts cast, vs. just getting them CNC'ed and milled?


Offline
 Profile  
 
 Post subject: Re: A bad day for SP #18
PostPosted: Mon Apr 15, 2019 11:07 pm 

Joined: Sun Aug 22, 2004 7:19 am
Posts: 5630
Location: southeastern USA
If there's an advantage it isn't going to be production by removing everything from a billet that doesn't look like a piston or casting something limited to what does, but in doing a better piston than Baldwin put in it - multiple rings in a better designed spider or a built - up variety - there's a lot to be learned from what happened after the 1920s in locomotive technology. If I were convinced it was a lubrication failure, I'd also want to add supplemental force fed mechanical lubrication too..... just sayin'.

_________________
Santayana: "He who does not remember the past is condemned to repeat it."
Corollary: "He who does is doomed to watch those who don't repeat it anyway."


Offline
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 41 posts ]  Go to page Previous  1, 2, 3

All times are UTC - 5 hours [ DST ]


 Who is online

Users browsing this forum: 6-18003, Google [Bot], Rader Sidetrack and 34 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to: