Every construction has a problem spot, and the one that keeps your LUT designer busy is Side 2. No plans, just schematics without dimensions.

Or, occasionally, plans of some detail, such as those for the expandable joints of the characteristic ECS (Environmental Control System) piping that occupy large parts of Side 2.

Well, you take what you get. And with the help of the exact height of the joints you can get a lot out of the fortunately very conscientiously drawn overviews.

ECS pipes at Side 2ECS pipes at Side 2

Courtesy of NASA

The gentle reader thus compares model with reality. Whoever finds an error may - no, not keep it, but report it. Immediately ;) What complicates matters even more is that the LUT was also work in progress.

ECS pipes at Side 2

ECS pipes at Side 2

As you can see, the initial ramp of the ECS tubes from the MLP edge up to level 30 looks rather improvised. Not only looks like, but it is. The original plans and the LUTs v1.0 first let the pipes run parallel to the surface of the MLP and then climb up at an angle to level 80 ...

LOX pipes at Side 3

Courtesy of NASA

...as you can see here. What finally led NASA engineers to turn their backs on this solution remains in the dark. I suppose it were room problems on deck, when you look at how much equipment there was until just before the launch.

But one riddle I could solve in the meantime: the 4 white beetles on the surface of the MLP were winches ;)

ECS pipes at Side 2

ECS pipes at Side 2

The hobby plumbers among you are getting wet eyes. And the skeletal appearance of the LUT is getting more and more figure. The 4 pipes to the right hand are the irrigation system of the LUT. And the thing is thirsty. The 16-inch pipe on the far right fills the sprinkler system, which provides cooling water during take-off, while 3000 °C are removed from the engines.