Safety cages on Ladders: When did they become required by law?

[IronBeltKen]

I am assembling a Walthers Concrete Coaling Tower kit and I can't help but notice that the ladders do not have safety cages on them. I'm modeling the late Sixties-early Seventies period, when steam power was no longer used, but many of these concrete towers were still left standing. I know that back in the steam days, safety wasn't as strongly emphasized as it is in modern times. But I would have thought safety cages were a basic item on the ladders of every tall post-WWII structure.

What I'm really trying to figure out is: Can I use the Walthers coal tower kit "as-is" for an abandoned structure in my 1:87 diesel-era loco terminal without it looking unbelievable?

 

[Sirfoldalot]

Would appear to have become required after 1971?

See answer to question 2&3:
https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=22435

 

[photoman475]

As an abandoned structure, you can leave the ladders off completely if you'd like. I've also seen abandoned structures where the ladder was partially torched off at some height above the first floor equivalent to make it harder to get to.

 

[IronBeltKen]

Sherrel - Excellent link! I believe that totally explains why I've never seen a coaling tower with safety-caged ladders.

... I've also seen abandoned structures where the ladder was partially torched off at some height above the first floor equivalent to make it harder to get to.

Yeah, I was thinking about doing that too. First I'd like to apply some type of rust streaks, to indicate that the ladders at one time did reach all the way to the ground.

Thank you both for your input!