Great replies and information. Of course, all quite different.
Don’t want to be ‘greedy’, but hope to see more. I am sure all readers/viewers here enjoy too.
So many years back, brand new F/E on the 707 (freighter as it were) had to operate the ‘hammer’ on a hammer start (JT3D’s) in the middle of the night with 2 newbie pilots - a/c ‘new’ to company. Learned about the start in classroom - ‘you can use a tool to open the start valve....’ Man, an eye opener for me......
Thanks to all and Happy Holidays.