Safety?

Eeeuh...
Well, as a matter of fact: this is not really safe but we do it for years already.
Our gasturbines have 31 thermocouples in the exhaust which are used for measurement and control of the exhaust temperature.
When a thermocouple is out of range an alarm is presented at our screens.
When two couples next to each other are faulty the unit trips automatically.
So we have to replace the defective couple as soon as possible.
We cannot stop at once so we plan to do these things at night or during the weekend.
So for the time we cannot stop we bypass the defective couple and use the measurement of a good one.
This is normally our job (the shift on duty).
When the couple is at the lower part it's no problem.
See this one from last year.
But: when it's at the upper part we have to be creative and have to climb on stepladders and crawl up.
We have to do something about this....