Some carpenter years ago thought that two nails would be enough to hold the stairs up. They did, for a decade or two, but they would eventually fail when the stringer began to split around the nails.
The stairs did not collapse, no one was hurt. On the other hand they had sunk about an inch and felt decidedly unstable underfoot. Another weekend project!
Remove the old nails to free everything up. Use the 3.5 ton floor jack to push the stairs back into place. An aluminum plate and wood glue to splice together the split stringer. Quite a few new bolts, not nails, to hold everything together. A bit of 3/8″ threaded rod on the other stringer to secure it to a joist. I think everything is secure, solid underfoot again. I just need a little paint to cover over the new work.
It has been broken for two days. The contractor is here to fix it, but this is the day Olivier and I need to get a job done in AO. It would have to be the Keck 2 elevator, not the Keck 1 elevator. Which telescope are we working in today? Keck 2 of course.
This will mean climbing the stairs to the Nasmyth deck, all five flights of stairs. Five flights does not sound too bad, until you remember that the bottom of these particular stairs start at 13,600ft above sea level. Climbing these stairs is guaranteed to get your heart pumping and remind you of the consequences of every one of those 13,600ft.
The job? Re-installing one of the mirrors in the rotator that was re-aluminized earlier in the week. A delicate, fiddly job that would take much of the day. There will, of course, be missing parts, needed tools, or other small things that we will have to get during the course of the job. Things that are at the bottom of those stairs.
Every trip up and down would be planned, this is not the time to remember that you also needed an #8-32 nut, after the climb. No forgotten items, everything thought through twice. We got the job done, a critical bit of optics safely secured back in the mount and correctly aligned.
In the end I only had to climb the stairs five times through the day.