@Timo
You can see an idea of lines where the old rail lines were on the flight deck when Kirk looks sorta that way when he boards the Enterprise in TMP.
http://movies.trekcore.com/gallery/albums/tmp2/tmphd0391.jpg
Which we see the lines (which are very thin) in TWOK:
http://movies.trekcore.com/gallery/albums/twokhd/twokhd0447.jpg
And a clearer view of the actual model taken as reference shots:
http://www.galileo2.net/gallery/displayimage.php?album=2&pid=98
You can think of it as ST version of the RAST system. It could be a line of tractor beams designed to grab tight the shuttle to either guide it in or or out of the flight deck.
You can see an idea of lines where the old rail lines were on the flight deck when Kirk looks sorta that way when he boards the Enterprise in TMP.
http://movies.trekcore.com/gallery/albums/tmp2/tmphd0391.jpg
Which we see the lines (which are very thin) in TWOK:
http://movies.trekcore.com/gallery/albums/twokhd/twokhd0447.jpg
And a clearer view of the actual model taken as reference shots:
http://www.galileo2.net/gallery/displayimage.php?album=2&pid=98
You can think of it as ST version of the RAST system. It could be a line of tractor beams designed to grab tight the shuttle to either guide it in or or out of the flight deck.

) to notice there had been pictures with the signs and now these have gone. Mytran, do you recall if "WARNING FIRE" was the big sign on the port side?


But hold on, something is odd.
I just wanted to figure out whether it's port or starboard side and looked again at the genuine b&w shuttlebay model shots from that other BBS thread - it appears that close-up shot is not from the original model but a (shorter) recreation of it.
(and not three or four observation deck windows as in TOS-R).