Ribbed back vs flat back wheels

Ive been buying up lots of metal wheels on ebay. Just curious as to what the difference is between ribbed and flat back wheels? how did they come about? what was the purpose of each?

I don’t know exactly, but I remember reading somewhere that the ribbed backs were originally developed because they allowed the manufacturer to use less metal to make the wheel, thus saving weight and money. The ribbed backs went out of favor because many of them developed cracks and stuff leading to structural failure. This was because of the higher stress areas around the ribs. As a result, all newer wheels were mandated to be made solid to avoid this type of failure. The switch to solid-backed wheels happened sometime in the early 20th century, I think.

Oh, thanks for the info. I guess its not too prototypical to be running ribbed backs on my railbox cars then…[:I]

JPM–you’d want to use flat-back wheels on all of your modern cars. Ribbed-back wheels started being discontinued during the 1940’s, I believe. I have a lot of ribbed-back wheels on my rolling stock, but then I’m modeling the 1940’s so it’s fairly accurate. But if you’ve got a lot of ribbed-back wheels on your Railbox cars, I wouldn’t worry too much about it–theyr’e not really that obtrusive, unless you run into one of those ‘rivet-counters’ without a sense of humor.
Tom