How does spaceship integrity stress work?
You have an integrity stress limit based on your tech. With just spaceship tech you have a limit of 300. Spaceship Integrity research increases it by 100 per tech up to a max 1000. Factory Spaceship research increases it by 500 per tech with no limit.
Integrity stress is calculated in 2 parts, whichever value is higher determines the actual stress.
Part A is based the size and structure of the ship: Each spaceship tile with a spaceship wall takes 0.5 integrity, each spaceship tile without a wall takes 1 integrity.
Part B is based on cargo capacity: Each item slot of a chest or similar container takes 0.5 integrity, each 1k of fluid capacity takes 1 integrity (except booster tanks which are 1 integrity per 4k and vanilla tanks which are 1 integrity per 2k). If a tank contains steam it costs double (2 integrity each 1k capacity with the same exceptions).
The ship has 60 tiles with walls, and 160 tiles without walls. The integrity stress is 30 + 160 = 190 from size.
The ship has 10 containers with 48 slots each. The integrity stress is 10 * 48 / 2 = 240 from cargo.
The total stress is 240 because 240 is higher than 190.
If 2 containers are removed for a total of 8 containers the stress would drop to 192.
If 2 more containers are removed for a total of 6 containers the stress from containers would drop to 144, but the total stress would be 190 from the spaceship size.