Be a tossup between the railway spare gang lifting track and the meat packing plant. I guess the spare gang would win.
I'll never forget that first day, 8 hours of walking along the roadbed picking up old escutcheon plates and chucking them up into a gondola car. If you can imagine a big tough 18 year old nearly reduced to tears from the fatigue and pain, you can picture me that day. I think what saved me was that when they'd stripped the plates off the ties they'd left them close to the ties so I was able to hook an elbow into the ladder on the car and let the car drag me along.
A friend of mine would probably argue that the packing plant was worse. His first day he got the job of stripping leaf lard off the warm intestines. That is a really crappy job. I had the job one day but was smart enuf not to let myself puke in front of the rest of the gang.
JF