Driver Wheels

'Cause the real RR did.

Chuck Sartor posted:

'Cause the real RR did.

I do realize that, Chuck, hence posting the question in the Real Train Forum...

there are pictures of this locomotive with all six Scullin drivers installed.  perhaps one got damaged and a replacement set of the older boxpok design were installed.  another clue to the locomotive shown later in its life would be the inclusion of an unshrouded tender.

Somewhat related, there are also plenty of pictures of PRR K4s's with a mix of spoked and Baldwin disc wheels so I would say it is very realistic actually.  I agree, you might not expect to see them this way, but it did happen and there is good supporting photographic evidence to support the practice.

Reasons... on the PRR locos, I've seen the Baldwin disc in the center and that might make sense considering the point of the disc was better balance and the center driver had the largest counterweight.  Now I have also seen K4's with a mix of early and later designed spoke wheels and I think that would just have been whats available for non scheduled shop repairs.

overlandflyer posted:

 perhaps one got damaged and a replacement set of the older boxpok design were installed.  

I read somewhere that the NYC had issues with cracking of the scullin disc drivers . As this occurred they were switched back to boxpoks.

There are numerous photos and videos  of mixed drivers that can be found online.

 Even the spoked set along with the plain j3a tender offered on the legacy ESE was prototypical.

T&P/AFT 610 had a like driver conversion.  Were all T&P 2-10-4 replaced?

Kelly Anderson posted:

WM #202 in Hagerstown also has a Box Pox main driver.  These conversions were more common that you might think. 

Conventional spokes are actually a pretty poor design to use on a driving wheel, being weak and prone to cracking.  The Box Pox or disc designs were actually engineered (not just drawn) and being hollow box sections were much stronger than the spoked wheel center they replaced.  Also, many older main drivers were not "cross counterbalanced" (an additional weight placed 90 degrees from the main counterweight to counteract the overhanging weight of the other main crankpin).  Adding that to the new wheel centers would make for a smoother running locomotive.

I think that is actually a Baldwin disc driver.  Boxpok wheels did not have a protruding flange around the holes like this one does.

Boxpok wheels:

Baldwin Disc wheels:

The back side of a driver casting. Pay close attention to the areas where counter balancing is located.

Something that I find interesting is that with all the talk about the superiority of the Boxpok (and other disc) drivers over the spoked drivers, that Norfolk & Western and Chesapeake & Ohio (except for the last group of J-3a 4-8-4's) only used spoked drivers.

Stuart

A Scullin ad just for comparison:

Stuart posted:

Something that I find interesting is that with all the talk about the superiority of the Boxpok (and other disc) drivers over the spoked drivers, that Norfolk & Western and Chesapeake & Ohio (except for the last group of J-3a 4-8-4's) only used spoked drivers.

not all locomotives were designed for the same purpose.  the positive effects of more exotic wheels were likely realized in high speed service to a greater extent.  with low speed heavy drags, the increased cost of replacing the wheels would probably not have contributed to any major savings in time out of service.

Kelly Anderson posted:

Stuart posted:

Something that I find interesting is that with all the talk about the superiority of the Boxpok (and other disc) drivers over the spoked drivers, that Norfolk & Western and Chesapeake & Ohio (except for the last group of J-3a 4-8-4's) only used spoked drivers.

Stuart 

Yep, I've been kind of curious about that as well.  My only thought regarding the N&W is that they wanted to make them in house to save money or due to "not invented here" syndrome. 

Or, what with the "Brazeitoriums" located at every major roundhouse they didn't have any concerns about cracked spokes and brazed them back together as part of the daily hostling routine...

Must be where the phrase "he can braze with a rosebud tip" came from??!!

I have never heard of broken spokes being any kind of problem on the N&W.

Apples55 posted:

I am hoping someone here can answer what might be a dumb question...

In the Lionel 2019 catalog, at least one of the NYC J3A engines is listed as having a mix of Boxpok and Disk drivers. As I remember, the same was true of some of the ESE Hudsons that were issued a few years ago. Is there some reason why they would mix the two types of wheels???

Thanks.

Post WWII with steam on the way out, keeping everything the same every time a steamer was shopped went out the window.  to get the engines back on the road they used what they had on hand for as cheaply as possible.

Didn't say that it didn't happen, just, that I have never heard of it it being a problem.

Well, I guess it wasn’t so dumb a question after all. Thanks for all the info and history.  My main takeaway from all of this would be that the mixed wheel types weren’t an initial design feature, but, as has been suggests above, changes were made throughout the life of the engine based on improved technology or what was expedient at the time. Personally, since I am not a rivet counter, I prefer my wheels consistent!!!

Thanks.

 Wait one second...

Doesn't having a preference at least qualify you for rivet counter jr? 

Apples55 posted:

Well, I guess it wasn’t so dumb a question after all. Thanks for all the info and history.  My main takeaway from all of this would be that the mixed wheel types weren’t an initial design feature, but, as has been suggests above, changes were made throughout the life of the engine based on improved technology or what was expedient at the time. Personally, since I am not a rivet counter, I prefer my wheels consistent!!!

Thanks.

 Just "toyin'" with you

And thanks for the in depth look at disk types folks.  The fine brand details for discs are what I never picked up.

  The overall look, the disc wins in general for me. (Maybe not against true spokes, but without air between spokes, discs win pretty easily)

Adriatic posted:

 Wait one second...

Doesn't having a preference at least qualify you for rivet counter jr? 

 

 I can safely assure you, Sir, without fear of contradiction, that there is not a single rivet counting bone in my body - I’ve checked