The Derelict's Interior

leading from:
The Design Of The Derelict

To know the structure of the ship's interior would be a starting point to unravel the mysteries of the derelict, and this is a point that we can not have defined details about what's inside. It might be a decision between either following either Ridley Scott or Giger's representation of the way it was constructed to have an operational reality.

work 376b

We can break this down into two directions: 

i. Scott has stated that the spores are "on board the derelict" (Starlog Sept 79, p240 ) the silo thus becomes a chamber that is the cargo hold of the derelict. Also in reference to the character Kane being lowered into the chamber below Ridley emphasised that he is being lowered into what would be argued as being the hold of the ship.

1. Scott :"So he's being lowered in to the hold really, this would be argued as the hold of the ship". (Alien Thirtieth Anniversary Edition commentary )

ii. Giger has referred to the silo as being under the ship. It has never been defined, it possibly never made that much a difference to them at the time. 

But to follow Giger's viewpoint that the silo is below the ship, we might wish to take notice of what are possibly volcanic gases coming through the floor of the ground of the silo, as if the silo has decided to use this as a continuous heating system. 

work 376a

The derelict was designed to be separate from the rock of the planetoid while the silo design had always be viewed as built into the surface of the rock.

In the sketches by Giger of the entrance tunnel to the pilot's chamber (Giger's Alien, p33, images 376a-c, sketches for corridor) shows that he did not design it with the silo as the cargo hold, the gangway leading from the entrance portals remained at the base of the ship.

work 376c

However the final gangway in the movie was nothing more than a  man sized tunnel in comparison to the intended cavernous gangway, the alterations were made due to budget restrictions and Giger himself wasn't impressed with the final corridor

the final derelict entrance tunnel that's much smaller than Giger's intended entrance tunnel