it could be a mix.

 

one side the wall,

 

the other side, the skeleton frame.

 

this way there is no risk of getting the spiral drill crushed by the weight of the ship.

 

(once the drill separates the connection between the bottom earth to one above,

weight of the ship will descend on the drill)

 

 

but whichever is more effective as calculation........

 

 

i think it can work if there's simulation's done prior...........