So here we have the secondary engine room located in the aft part of the saucer just ahead of the impulse engines (which are actually massive anti-grav generators). I can't really explain what everything in the room does, but we do have a central control panel and up against the back wall (or the forward bulkhead of the impulse engine housing) we also have a bank of monitor displays where anything can be called up in detail either as a schematic, status readout or actual visual display of what you might want to see. To reach the upper walkway you can enter either from the Deck 5 access ports or climb the ladders located on both sides of the engine room. Access corridors also go back around the sides of the impulse housing. So if everything is shut down it is possible to actually access the interior of the impulse housing. What are the units on the floor? I haven't figured that out, but I thought it looked interesting and somewhat evoked what we saw in TOS' engine room.