I didn’t know about the hammers not always working in slaughterhouses. That’s pretty bad. I always used a .22 LR to the brain on livestock and never failed to stun, hoist and bleed them immediately.
Its not so much of a problem with regular mechanical failure as much as it is does to do with being human. Cold, gore, fatigue, aim, smells, etc all add up. Its hard to keep employees on the kill floor. It seems to me that it would be so much easier, cleaner, and faster to use a guillotine type device but Im guessing that its considered a safety hazard to the humans working there or something (I don’t know).
We had a couple of big slaughter houses and a lot of little ones in the area. Many here have worn the scale mail apron and scabbard of a meat processor. If you were good at it and really wanted to be a butcher you could move to one of the little places that does custom processing and learn to make specialty things like Zungenwurst. Mostly its the job people up here used to do when we were between our regular employ for whatever reason instead of going on a government program. At least that’s the way it was up until the stigma of programs disappeared and the Mexicans were shipped in.