login   |    register
Modeling in General: Advice on...
Need some general advice? Place it here.
Question about the wheels color on RR cars
Wolf-Leader
_VISITCOMMUNITY
New Hampshire, United States
Joined: June 06, 2002
KitMaker: 1,142 posts
6th Scale: 1 posts
Posted: Wednesday, August 01, 2018 - 01:20 PM UTC
I am working on a WWII German flatcar and would like to know the color of the wheels on RR cars.I know or think they are made of steel,that is an easy color to do.But the part of the wheel that is running on the rail,what color would that be?
Thank you.
retiredyank
#160
_VISITCOMMUNITY
Arkansas, United States
Joined: June 29, 2009
KitMaker: 11,364 posts
6th Scale: 0 posts
Posted: Wednesday, August 01, 2018 - 01:32 PM UTC
AFAIK military trains had black wheels, while civilian trains were red.
JPTRR
Staff MemberManaging Editor
RAILROAD MODELING
#051
_VISITCOMMUNITY
Tennessee, United States
Joined: December 21, 2002
KitMaker: 7,186 posts
6th Scale: 0 posts
Posted: Wednesday, August 01, 2018 - 01:52 PM UTC
Hi Jody,

Freight car wheels were usually either painted black or delivered in bare metal. They would quickly rust but railroaders have told me that the rust never gets to the point that it will destroy the thick steel wheel - except maybe in 200 years.

Eventually, those wheels are caked with dust, dirt, metal particulates, grease, oil, soot, and mud. They can take on the color of the terrain they roll through, and vary by season.

Here is a small feature I put together: Train Wheel and Truck Muck

JPTRR
Staff MemberManaging Editor
RAILROAD MODELING
#051
_VISITCOMMUNITY
Tennessee, United States
Joined: December 21, 2002
KitMaker: 7,186 posts
6th Scale: 0 posts
Posted: Wednesday, August 01, 2018 - 02:06 PM UTC
Where railcar wheels contact the rail (called a "Contact Patch") in more of an ellipse that flat on flat surfaces. Elasticity of the steel and wear patterns change over time. But a new wheel on a new rail will have a very small surface of contact, perhaps 5mm IIRC. (Here is a highly technical paper on railcar wheel-to-rail contact: The geometry of wheel-rail contact )

This is even better and easier to understand without a PhD:

Wheel‐Rail Interaction Fundamentals

But to answer your main question, where the Contact Patch is steel. Sometimes bright, sometimes dull due to impurities ground in, but a nice steel. I have replicated it with steel, but nowadays I use pencil lead.
JPTRR
Staff MemberManaging Editor
RAILROAD MODELING
#051
_VISITCOMMUNITY
Tennessee, United States
Joined: December 21, 2002
KitMaker: 7,186 posts
6th Scale: 0 posts
Posted: Wednesday, August 01, 2018 - 02:42 PM UTC
Jody, here's a great site: Railways of Germany

This thread is about weathering. Nothing really about wheels, but a start.

https://www.tapatalk.com/groups/germanrailfr/viewtopic.php?t=6892
Scarred
_VISITCOMMUNITY
Washington, United States
Joined: March 11, 2016
KitMaker: 781 posts
6th Scale: 0 posts
Posted: Wednesday, August 01, 2018 - 02:58 PM UTC
I don't know about the color of the wheels during WWII but the tread and inner edge of the flange can range in color from polished steel where they rub on the rail to shiny steel to just bare metal color depending on wear and tear and if the train has been sitting for a while the bare metal parts could have a rusty patina to them.
barkingdigger
Staff MemberAssociate Editor
ARMORAMA
#013
_VISITCOMMUNITY
England - East Anglia, United Kingdom
Joined: June 20, 2008
KitMaker: 3,243 posts
6th Scale: 0 posts
Posted: Thursday, August 02, 2018 - 08:51 AM UTC
Not positive about the Germans, but US practice at the time was to leave the wheels and axle unpainted so any cracks or imperfections could be more easily detected. They quickly developed a harmless thin layer of rust that would look a dark "earth" brown. But the axle-boxes of that period were grease-filled friction bearings that leaked like sieves, so the outer face would build up a layer of blackish-grey greasy crud, decorated with all manner of track dust. The contact surfaces (the outer rim and the flange) would rub themselves raw on the rails and be shiny polished steel when in use, but quickly bloomed with orange rust if left standing any length of time. Local weather conditions naturally affected the speed of polishing and rusting, of course!

Since wheelsets do get damaged and worn out, they get replaced. That means you might find a clean wheelset and an old greasy one in the same two-axle truck.
Wolf-Leader
_VISITCOMMUNITY
New Hampshire, United States
Joined: June 06, 2002
KitMaker: 1,142 posts
6th Scale: 1 posts
Posted: Thursday, August 02, 2018 - 01:22 PM UTC
Hey everyone!
Thank you very much for all the info given.