Medium cargo hold
From Cantr II Wiki
This is a modestly sized area below decks for cargo storage that can be built aboard a ferry or raker.
The hold allows most machines the require a building to be constructed aboard the vessel.
The machines that can't be built have a special category.
Also see cabins and holds for a full list of extensions buildable on ships.
Construction
Object: Medium cargo hold
Days needed: 10
Raw materials needed: 8000 grams of wood
Objects: none
Tools needed: stone, bronze or regular hammer
Build/Repair Skill: Shipbuilding
Capacity
People: 5
Weight: 400000 grams