Trains.com

What's the deal with Cab replacements

2918 views
19 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    December 2006
  • 1,879 posts
What's the deal with Cab replacements
Posted by YoHo1975 on Friday, August 2, 2024 12:28 AM

So the DC to AC thread got me thinking.

I know when CSX(I think) rebuilt a bunch of their SD40s they put new cabs on that were NOT stock that were supposed to be more crash worthy than the original EMDs. And of course sometimes the metal is just beyond salvage, but in the general sense it seems that all the big rebuild programs are seeing complete cab replacements. Why is that?

What is the purpose of replacing the cab on those Dash 9 to ACs for instance?

Can't you just pull out the desk, sandblast everything and put a control stand in? 

I've heard in some cases there is additional reinforcement in the nose. is that the case? it's just easier to swap the cab than it is to get in with a welder and upgrade bracing?

It all just seems like added cost to little benefit from this ignorant foamer. 

I could see it if say non-isolated thunder cab EMDs came in and they got Isolated cabs or something like that, but my gut feeling is that sheet metal is sheet metal.

Or could you pull the cab off, put a new one on and rebuild the original cab for the next unit.  

 

  • Member since
    September 2010
  • From: East Coast
  • 1,199 posts
Posted by D.Carleton on Friday, August 2, 2024 7:03 PM

Fair question. Crashworthiness is a factor. But also keep this in mind: I was assigned to a shop to integrate new locomotives into a fleet. Whilst I was there the management was junking all manner of test and machining tools. The mindset: replace not repair components. So what's the expense of stripping out a cab (pipefitter and electrician), sandblasting the rust (body), patching the holes (tin-knocker), prep and paint (body), install not the stuff taken out but new stuff including PTC (pipefitter and electrician) OR cut off the cab and install a new one.

Editor Emeritus, This Week at Amtrak

BDA
  • Member since
    April 2018
  • 95 posts
Posted by BDA on Wednesday, August 7, 2024 5:56 PM

I was under the impression that fitting new modern cab gives a locomotive a complete module fitted with all current and available components .

It could start with cab isolation and include all modern equipment ie brake controllers and all forms of electronics . This removes the need to retro fit anything and everything should be available from parts suppliers .

I'm not sure if it's well known but all kinds of parts from the Dash 9 era are no longer available and second hand bits are drying up fast . 

Over here there is a smallish fleet of units are being sidelined because they are SD60DC based with 30CDW brakes and it's not thought to be cost effective to update them with electronic air brakes and ECP . More current ACs do the job as well or better and have all the currently required fruit .  

  • Member since
    September 2010
  • From: East Coast
  • 1,199 posts
Posted by D.Carleton on Thursday, August 8, 2024 12:09 AM

BDA
I was under the impression that fitting new modern cab gives a locomotive a complete module fitted with all current and available components.

When you have complete cabs being built assembly line style and significant orders for DC-to-AC rebuilds then cab replacement makes more financial sense.

Editor Emeritus, This Week at Amtrak

  • Member since
    December 2006
  • 1,879 posts
Posted by YoHo1975 on Tuesday, August 13, 2024 12:59 AM

It still feels like the rebuilder could take in the old cabs and rebuild them in many cases.

For spartan cabs, it's not as if those cabinets haven't been rebuilt before. pre-dash2 units to dash 2 standards, then to computer controlled. Upgraded brakes and control features. 

  • Member since
    September 2010
  • From: East Coast
  • 1,199 posts
Posted by D.Carleton on Saturday, August 17, 2024 9:01 AM

YoHo1975
It still feels like the rebuilder could take in the old cabs and rebuild them in many cases.

I'd be willing to bet real money they are throwing away perfectly salvageable cabs. But that would require triage and someone to judge on a case by case basis what is and what is not worth saving. Bluntly, we are still in a war on the crafts and no one in the C-suite wants to pay more for craft work than what they think is necessary. So, as long as they can justify the scrap then this will continue.

Editor Emeritus, This Week at Amtrak

  • Member since
    January 2002
  • From: Canterlot
  • 9,575 posts
Posted by zugmann on Saturday, August 17, 2024 5:31 PM

I'd wager msot of those cabs are in worse shape than you think. 

It's been fun.  But it isn't much fun anymore.   Signing off for now. 


  

The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any

  • Member since
    September 2010
  • From: East Coast
  • 1,199 posts
Posted by D.Carleton on Sunday, August 18, 2024 8:26 AM

zugmann
I'd wager msot of those cabs are in worse shape than you think.

My railroad career started out in mechanical on shortlines. 'Nuff said?

Editor Emeritus, This Week at Amtrak

  • Member since
    January 2002
  • From: Canterlot
  • 9,575 posts
Posted by zugmann on Sunday, August 18, 2024 5:34 PM

nevermind.  

It's been fun.  But it isn't much fun anymore.   Signing off for now. 


  

The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any

  • Member since
    March 2016
  • From: Burbank IL (near Clearing)
  • 13,540 posts
Posted by CSSHEGEWISCH on Monday, August 19, 2024 1:56 PM

I would think that it would be less expensive in the long run to just scrap the old cabs and replace all of them with a standardized design and layout.  The operating crews would know where everything is located which would make their job a bit easier and shop crews would know where all the parts are located, lessening down time.

The daily commute is part of everyday life but I get two rides a day out of it. Paul
  • Member since
    November 2008
  • 1,881 posts
Posted by Leo_Ames on Monday, August 19, 2024 7:18 PM

It took over 30 years after the first GP7 was built for 1st generation Geeps to start getting new cabs, over 10 years after rebuild programs were born for them. I wonder if what appears to be serviceable cabs that are still fine are getting dumped not because they're basket cases, but because of the fear that they might start showing their age in 5-10 years on locomotives that I assume they're aiming for at least 20 more years of service out of at a minimum?

Edit: Forgot about Santa Fe's Topeka cabs, but it seems like the end of the 70's is when other roads started doing more than just chop nosing the short hood when a 1st gen Geep was rebuilt.

  • Member since
    December 2006
  • 1,879 posts
Posted by YoHo1975 on Tuesday, August 20, 2024 12:50 AM

Leo_Ames

It took over 30 years after the first GP7 was built for 1st generation Geeps to start getting new cabs, over 10 years after rebuild programs were born for them. I wonder if what appears to be serviceable cabs that are still fine are getting dumped not because they're basket cases, but because of the fear that they might start showing their age in 5-10 years on locomotives that I assume they're aiming for at least 20 more years of service out of at a minimum?

Edit: Forgot about Santa Fe's Topeka cabs, but it seems like the end of the 70's is when other roads started doing more than just chop nosing the short hood when a 1st gen Geep was rebuilt.

 

 

The Topeka cabs at least undeniably show some advantage.

 

These cabs are just plate steel. Any welder worth his union card should be able to fix anything wrong with them Oh, is this mount for the desktop in the way of the placement of the traditional control stand, let me fix that for you. 

 

Like I said, I can see pulling cabs off, refurbishing them elsewhere and then in the meantime one already done is installed, but buying new steel, even if recylced and starting from scratch just seems odd on the face of it. 

 

If nothing else, you're subject to the fluctuation of the price of steel whereas an existing cab, the Steel's been paid for already. 

  • Member since
    January 2012
  • 36 posts
Posted by Greasemonkey on Tuesday, August 20, 2024 1:39 AM

Keep in mind....steel bends and twists.  After many years of service, nothing is going to be as straight and true as it was when it was new.  That makes retrofitting and rebuilding a much more onerous process.  Simply starting from a brand new cab, would simplify and speed things up.  Time is money, and having to strip and rebuild something to as new condition and current standards takes a bit more time, money and effort than I think you realize.

  • Member since
    May 2003
  • From: US
  • 25,292 posts
Posted by BaltACD on Tuesday, August 20, 2024 9:42 AM

YoHo1975
...

If nothing else, you're subject to the fluctuation of the price of steel whereas an existing cab, the Steel's been paid for already. 

And the depreciation has already been applied to the books.

Never too old to have a happy childhood!

              

  • Member since
    September 2010
  • From: East Coast
  • 1,199 posts
Posted by D.Carleton on Tuesday, August 20, 2024 10:30 AM

I would add that everything ahead of the alternator is getting replaced on a Dash-9 (or AC4400) to AC44C6M rebuild. Ergo, replacing all of this as a unit probably makes more sense modification wise. 

Editor Emeritus, This Week at Amtrak

  • Member since
    December 2006
  • 1,879 posts
Posted by YoHo1975 on Tuesday, August 20, 2024 11:13 AM

Greasemonkey

Keep in mind....steel bends and twists.  After many years of service, nothing is going to be as straight and true as it was when it was new.  That makes retrofitting and rebuilding a much more onerous process.  Simply starting from a brand new cab, would simplify and speed things up.  Time is money, and having to strip and rebuild something to as new condition and current standards takes a bit more time, money and effort than I think you realize.

 

 

But retrofitting and rebuilding cabs used to be the norm. And I would think that steel fatigue would only have been worse in those units. 

  • Member since
    December 2006
  • 1,879 posts
Posted by YoHo1975 on Tuesday, August 20, 2024 11:16 AM

D.Carleton

I would add that everything ahead of the alternator is getting replaced on a Dash-9 (or AC4400) to AC44C6M rebuild. Ergo, replacing all of this as a unit probably makes more sense modification wise. 

 

 

But the Cabs aren't part of a "unit" in this case, they are bolted on Separately .

 

 

 

Anyway, I feel like I'm just arguing against everyone now. While I think it is entirely possible that the railroads/builders DO NOT have particularly good reasons to do what they do every time.

I'm also not trying to suggest they MUST be doing something wrong. There's just something in this process that elludes me.

Like, maybe there's an OpEx vs. CapEx style of difference here where it's not cheaper to buy a new cab, but the accounting makes it easier.

 

The kind of answer that anyone in a buisness that makes things gets, but the Engineers really dislike. 

  • Member since
    September 2010
  • From: East Coast
  • 1,199 posts
Posted by D.Carleton on Tuesday, August 20, 2024 12:11 PM

YoHo1975
Anyway, I feel like I'm just arguing against everyone now.

No arguing here. Just a group thought exercise. We all have different vantage points and we express our thoughts from said positions.

Editor Emeritus, This Week at Amtrak

  • Member since
    January 2012
  • 36 posts
Posted by Greasemonkey on Friday, August 30, 2024 6:10 PM

YoHo1975

But retrofitting and rebuilding cabs used to be the norm. And I would think that steel fatigue would only have been worse in those units. 

 

 

Possibly, but labour costs have gone up considerably over time.

  • Member since
    May 2003
  • From: US
  • 25,292 posts
Posted by BaltACD on Friday, August 30, 2024 7:05 PM

Greasemonkey
 
YoHo1975

But retrofitting and rebuilding cabs used to be the norm. And I would think that steel fatigue would only have been worse in those units.  

Possibly, but labour costs have gone up considerably over time.

Fully expect the tax aspects of the 'rebuild' are guiding what parts are reused and what parts aren't.

Back in the steam days, in many cases, the only thing that was actually 'rebuilt' was the engine number - everything else was hardware that was new to the engine number.

Never too old to have a happy childhood!

              

Join our Community!

Our community is FREE to join. To participate you must either login or register for an account.

Search the Community

Newsletter Sign-Up

By signing up you may also receive occasional reader surveys and special offers from Trains magazine.Please view our privacy policy