These trucks were part of a treasure trove my father picked up a year or so ago. He actually thought they full of junk only...but a term of purchase for an atlas he wanted. We were quite surprised to find a bunch of neat stuff in the box...and auctioned the "junk" to someone that was even happier than we were with the find. These buckey trucks are sprung and they are hinged in the middle like real ones. I know that these are a major pain in real life...my father has dealt with them under the 765's tender and the Birmingham shops replaced the 611's buckeye trucks with commonwealth trucks. They were under a Varney tender to an SP 4-8-2 that had been extremely well kitbashed from a Varney pacific.