Empty (tare) weight of 611's Auxiliary Tender?

[NW Mailing List]

Based on the information from Ken, below, and Dave Stephenson in his  
response, I calculate that the auxiliary tender required about 370 drawbar  
horsepower to be kept moving at 26 mph on the 1.34% grade.  This includes  the 
following assumptions:
- The "Modified Davis" train resistance formula gives a reasonable answer  
(it's sort of the "industry standard", so that should be safe...)
- The Auxiliary Tender was still full
- The measurement was on tangent track (this assumption is mandatory since  
I had no information regarding specific location with respect to a curve) 
OR the  quoted grade was compensated.
- Yes, of course I added grade resistance to the rolling resistance.
 
Added to the 4400 DBHP the NS Research Car is quoted as having measured,  
this compares favorably with the slightly over 4500 DBHP  in the  N&W curve 
reproduced in Col. Jeffries' book, and is just about on (as  close as you can 
read the curve) the curve Classic Trains published (on-line) in  
conjunction with their special issue on 4-8-4s.
 
Several relevant conclusions, in no particular order:
- There have for years been "whispered" thoughts that the N&W's  published 
capabilities for the J were...um...conservative.
- Spencer did a super job!
- "The Old Girl" hasn't lost a step!
 
Thanks to Ken and Dave for their assistance!
 
Dave Phelps
 
 
In a message dated 7/8/2015 1:41:37 P.M. Eastern Daylight Time,  
nw-mailing-list at nwhs.org writes:

Dave  


The best I can do is off NS' diagram sheet for the 250001 and 250002,  last 
updated was 1-22-1991, which states an average light weight of 143,650  
pounds.


Ken Miller


On Jul 8, 2015, at 10:31 AM, NW Mailing List via NW-Mailing-List  wrote:



Could some kind soul please provide the empty (tare) weight of 611's  
current auxiliary tender?
 
I need the information to complete the input data to calculate, using  the 
modified Davis train resistance formula, how much the addition of the  
auxiliary tender impacts the drawbar horsepower measurements reported from  the 
NS Research Car during the recent excursions.  Then, a valid  comparison can 
be made with the N&W curve reproduced in Col.  Jeffries' book, and the curve 
Classic Trains published (on-line) in  conjunction with their special issue 
on 4-8-4s.
 
Thanks in advance,
 
Dave  Phelps

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