My understanding is that the stacks were built with a tower of scaffolding on the inside. So it may have been too inconvenient for them to add a ladder on the outside, while the heat on the inside meant it wouldn't have lasted?
There's anothing video of him setting up the ladder on a stack: https://youtube.com/watch?v=Keq-Lig-z74 while definitely sketchy it doesn't seem nearly as bad as the process to make the platforms, which he has to repeat over and over while knocking it down. So in that respect I'm not sure it would've saved him much time overall.
> There's anothing video of him setting up the ladder on a stack: https://youtube.com/watch?v=Keq-Lig-z74
At 16:20 in that video, it shows the camera crew in a cherry picker filming at the same height as him. Ive always thought that Freds chimney days were pre technology like this. but why would he not just put the scaffold platform up in a cherry picker to start with instead of spending days fixing a gazillion ladders to the side of a chimney?
The very end of the video shows the Cherry picker and the size of it. I'd guess it wasn't normally used because of cost and possible limitations on weight carried.
Fred was creating the platform with 3-4 guys and basic tools. Probably a lot cheaper than hiring a specialised Cherry Picker for a day or two.