Service Arm #5
- LUT model
... only three left. A new swing arm - Service Arm #5, commonly known as SII FWD - is now part of the neverending story.
Service arms #5 and #6
And here it is. It supplied the second stage with LOX and LH2, which together - as we know from our chemistry lessons - formed a highly explosive mixture, which we got to know under the affectionate name 'Oxyhydrogen'. Smoking was probably strictly forbidden even in 1969 when you wanted to enter the swing arm. Another example of how far ahead NASA was of its time.
The arm is also a perfect example of NASA engineers' talent for improvisation. The original concept - as outlined in the preliminary report - looked so different that you wouldn't recognize the swing arm there. Apparently the many hoses and cables were so much in the way that the arm was redesigned on the fly. So now you see the lighting in the front section moved to the outside, the interface to Saturn almost doubled in width, and the visible tube along the flank was originally on the other side.
Side 1/4 - Level 200-300
Also in the landing zone on the take-off tower side room has become rare, so the pipe was moved to the level below on the outside, which was solved shirt-sleeved with fancy suspensions below the access platform of the swing arm above. In comparison, the way the cable sausage was led around the main spar of the LUT is almost trivial.
Side 1/4 - Level 200-380
Here is the new degree of completion. You should look at the picture in full resolution - it gives a good impression of how gigantic the launch tower was. A more calm section follows with the two arm less levels 180 and 160, before the grand finale begins with the triple cluster of the last three missing swing arms. Well. It's time to finally get the project done.