1. Liquid Tanks: Storage tanks for liquid volume in liters.
  2. Liquid Transportation: Tanker ships and trucks that accept liquid volume.
  3. Production: Produce (e.g. gasoline) as a liquid volume instead of barrels.
  4. Filling Barrels: Mechanic for filling barrels from liquid volumes and back.
  5. Vehicles: Make gasoline transport vehicles to take in liquid volume, instead of barrels.