Class J's - trackworthiness?

[nw-modeling-list at nwhs.org]

Wow, sort of a heated discussion.  I was surprised to see the comment on Wikipedia, and that is why I asked it here.  It is a fact that the J's drivers and counterbalance system were pushing the envelope of technology and material for the time. So it isn't really a stretch to think there could be some truth to the comment.  But, Gary is right, that track standards were different then.  Noticeably so.  But the basic question remains, were the J's pickier about track-work than other steamers?  Did they have lateral movement in the drivers?  Did other N&W engines, like the Y's, have it?  Y3's or Y6b's?  I'm guessing that didn't exist in the early 1900's when the Y's were coming into being.  

It's funny... even our models have lateral movement in the drivers to help with trackwork. 

Mike Rector

nw-modeling-list at nwhs.org wrote: All,
  
 You should know what wikipedia is.  Wikipedia is basically a web blog.  The content is all from users.  You can edit the entries.  If there are errors of fact a person can go in and change the entry.  There is also a disccusion board feature for each entry were editors discuss the content of that article.  So if someone has time to work on the article they should. 
  
 It is okay to challenge,
  
 John Rhodes

 
 On 10/2/06, nw-modeling-list at nwhs.org <nw-modeling-list at nwhs.org > wrote:    Far be it from me to challenge the accuracy and conciseness of Wikpedia and any information available on the internet






.. 
  
 In general in the steam days, tracks were configured for higher train speeds due to the passenger trains present.  Once the late 1950's came passenger trains were not run at the fast schedules previously.  A consequence of diesels was that the track could be re-elevated to suit the slower 'freight' type train speeds most common.  The shorter truck wheel base and the smaller diameter of the wheels, 40" inches mostly, meant that climbing the rail was less possible than a 70" or 80" driver on a steam locomotive. 
  
 Of course, the N&W used a compromised gauge and elevation to give the best passenger train speed and practical freight 'ride' conditions at slower speeds. 
  
 The dynamic 'pounding" of the steam drivers, no completely accurate balancing being possible, tends to push the rail and bed out of 'spec.' which meant that section crews were constantly adjusting the rail.  Smooth passenger ride was important too also forcing more maintenance.  Of course jointed rail needs constant re-tightening. 
  
 In general, steam locomotives perform better, that is maintain a higher tractive effort with rail that is close to optimum, than with poor track.  This affects the gross ton mile performance of all engines and trains and that is direct operating cost. 
  
 Changing over to a diesel fleet means that the MoW engineering can and has to adjust the rail to suit the operating characteristics of diesels.  With the drop-off of passenger traffic the upper end speeds are lower so track elevation was decreased from steam days.  Rail gauge limits could be changed (more or wider tolerances) as the longer frames of steam locomotives with the drivers were gone.  But, these lateral stiffness issues had been handled with blind drivers (no flanges) or lateral motion devices (axles shifting side to side a little).  However these measures were more for tight curvature than mainline running.  The reduced cost of track maintenance was one of the advantages of going to diesels. 
  
 So the short story is that rail/track and the locomotive and the train is a SYSTEM that has to be optimized through a number of engineering compromises to keep the tractive effort high, keep the cars on the rail and keep maintenance costs reasonable.  Running an excursion 611 on track optimized for freight-only diesels means that the J is running on non-optimum conditions.   
  
 "Picky" is an oversimplification and implies something "bad" when 'not designed for modern track conditions' would be more accurate.  Driving your Toyota Corolla at 200 mph will introduce into the system a whole series of aerodynamic effects that the car design cannot handle.  Does this make the car 'picky'? 
  
 Track engineering is a field of its own.  It was in the steam days and it still is today.
  
 Gary Rolih
 Cincinnati 
  
   
---------------------------------
 
 From:  nw-modeling-list-bounces at nwhs.org [mailto:nw-modeling-list-bounces at nwhs.org]  On Behalf Of nw-modeling-list at nwhs.org
Sent:  Sunday, October 01, 2006 12:53 PM
To: nw-modeling-list at nwhs.org 
Subject: Re: Class J's - trackworthiness?

  
  I'll take a shot at your question.  I read that N & W main line trackage was re-gauged after the steam era ended.  This would have reduced the spread on curves, no longer needed to suit the effective wheelbase of main line steam, such as the J.  The accidents cited in the story took place in the 80's and 90's; suggesting that the J's might not have been 'picky'; but that they were operating under 'borderline' conditions which did not exist 40 years earlier. 

   

  Jerry Crosson




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