Curious turbine assembly. II would think it would be way too small for a main power generator - perhaps an auxiliary pump? Looks too large for that. Maybe it's just way smaller than I thought it would be...

I was a marine engineer, and I know a lot about how dangerous these things can be. In 1989 an explosion caused by a fuel leak killed 4 friends of mine :(

However, I am still to this day in awe of power plant equipment - even after having built, rebuilt, and operated them for 10 years

My guess is that these would be the "steam drums" for the boilers. The "nipples" are actually strongbacks holding the access dorrs in place - the access doors being for umm...access.... for repairs, cleaning, etc.