From: elw4@po.CWRU.Edu (Evan L. Werkema)
Newsgroups: rec.railroad
Subject: Re: Genesee & Wyoming Now in Oregon
Date: 28 Jan 1993 17:43:09 GMT
Organization: Case Western Reserve University, Cleveland, OH (USA)
Reply-To: elw4@po.CWRU.Edu (Evan L. Werkema)
NNTP-Posting-Host: thor.ins.cwru.edu


In a previous article, pratta@rpi.edu (Anthony Edward Prattico) says:
>In article <1993Jan28.002233.7516@gw.wmich.edu> 195ochs@gw.wmich.edu writes:
>
>>SD's are mostly used for more traction, since they have more traction
>>motors. GP's are lighter and are also typically used for highspeed trains
>>(intermodal, etc)
>>Here's some typical weights of locos from Chessie System and CSX
>>(sort of an approximate, since different class engines weighed differently)
>>
>>GP 7/9 250,000
>>SD 7/9 370,000 (these were ballasted to make them slightly heavier)
>>GP35   260,000
>>SD35   390,000
>>GP38   270,000
>>SD38   380,000
>>GP40   275,000
>>SD40   390,000
>>
>>and also some GE's to compare:
>>U30B   277,000
>>U30C   377,000
>>B30-7  277,000
>>C30-7  385,000 and 411,500 (they have 2 different weights listed)
>>B40-8  288,000
>>C40-8  395,000
>>
>>So you can clearly see that there is typically 120,000-140,000
>>pounds between a B and a C trucked engine. This is very crucial on branch
>>lines. Most branchlines will be restricted to a GP30, GP35 or GP38 or GP40
>>or GP7/9 on some RR's (CSX doesn't have any GP7/9's left, they usually use
>>GP30,GP38.GP39,GP40 GP16 (rebuilt GP7/9's) and U18B,U36B, and B30-7's
>>on the locals in Michigan. Mostly GP30's and GP40's since they have scads
>>of GP40's (and GP40-2's)
>
>True, but the real limit is the weight PER AXLE. Of all the engines above, the
>weight per axle of the six axle engines is EQUAL TO OR LESS THAN that of the
>four axle units. Many of the problems with branchlines stems from the sharper
>curves that cause problems with the six axle units, which have a much larger
>minimum radius. I don't know about the particular trackage in question, but I'd
>assume this is more likely the case, giving the lower axle loads of the six
>axle units. In your example of locals, I bet that there are many industries
>sharp curved sidings to be served, which would demand a four axle unit.

  I've heard of at least two cases where 4-axle locomotives have been used
in favor of 6-axle ones because 6-axle engines are "harder on track."  One
case was the early sale of the Monon C630's (or was is C628's?) in favor of
new, 4-axle locomotives that were easier on the track.  The other is the GBW,
who presently has 6 ex-FRV, ex-LS&I, nee-ATSF RSD15's sitting in Green Bay
which will probably never see service on the GBW (according to Trains magazine)
because "the Alcos' 6-axle trucks are too hard on GBW's track."
  I know GBW is a regional, and doesn't maintain its track to the standards
of Class 1's.  Do 6-axle trucks knock the rail out of alignment quicker?

-- 
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Newsgroups: rec.railroad