Alien: Comparison between Giger's derelict and Chris Foss' spacecrafts

Leading from: 

Alien: Giger's derelict exterior
and 
Chris Foss' derelict

a) Comparison to Chris Foss' "lobster"
Perhaps since Giger didn't consider himself to be a designer of spacecrafts, he took inspiration from Chris Foss whose art he should have encountered before hand from from Alejandro Jodorowsky's Dune production. 

For Alien, Foss had created a derelict for the design that resembles a  cross between a lobster and a train 

If one compares it wth Giger's main design, work 374, it looks a lot as if the left half of Giger's ship is a biomechanised version of Foss' lobster like structure sticking out of the sand. 

It was as if Giger had taken Foss' design as a starting point and had given the thing another half with a hammer shaped tip . 

The fin to the left side of Foss' derelict on Giger's derelict becomes a bulbous protuberance .  

One side of Giger's derelict in comparison to Chris Foss' derelict ship. 
Foss image (right) from Charles Lippincott's collection.

b) Comparison to the 1973 cover of Voyage of the Space Beagle.
Giger was aware that usually, spacecrafts are designed with an axial symmetry, and Giger's design didn't conform to that which made it fairly unusual.

Interestingly Chris Foss had come up with an example of one with a non axial symmetry back in 1973 for the cover of Voyage of the Space Beagle, its engines point in three different directions and none directly aligned with the front.

Where the front of Foss' ship was  precisely supposed to be seems to be a question that will not be answered any time soon although it's certainly somewhere on the other side of the ship from the engines.

So something like this could have served as poetic license for Giger about where to take a spacecraft design and still consider it a space ship of sorts.

1973 cover of Voyage of the Space Beagle showing non-axial spacecraft design

Giger's non-axial derelict ship as seen from above.

Quote source

1. HR Giger: The Alien spacecraft, too, was not like … Usually, with us everything usually has axial symmetry, and with these Alien things it  wasn’t actually so clear  how it technically ... how this thing was supposed to work. ( Report from what Giger said for Alien Evolution)