What wheels are appropiate for which era and what type of rolling-stock. I am modelling 1940-50 and logging. What are the ribs for, surely they don’t add that much strength to the castings.
Ribbed back wheels would still have been common in your era. Wheels are no longer cast, they are now forged. I believe the ribs were to dissipate stresses so the wheel would not crack.
The ribbs increased the surface area of the wheel to dissipate heat generated during braking. Cast wheels were less tolerant of excess heat than forged wheels.