We saw a compartment on the USS John Warner called a
Lockout trunks are used as an escape hatch for the crew
and to get SEALs off the ship.
During our recent tour of the USS John Warner
nuclear-powered submarine, we got a chance to see a small
compartment known as a “lockout trunk.”
“This is actually how we would get SEALs off the ship submerged,”
Senior Chief Mark Eichenlaub told Business Insider.
“So you would stick a platoon of SEALs in here, 14 guys … you
fill this chamber with water until you match the outer sea
pressure. Once the pressure in and outside the ship match, the
hatch will lift off open, and they can swim out of a fully filled
chamber into open ocean.”
Once the chamber is filled with water, matching the pressure
inside and out, “there’s an internal locking mechanism that would
open” the top hatch where SEALs swim out, Senior Chief Darryl
Wood told Business Insider.
The SEALs can then swim to retrieve what is known as a
special-forces operations box, which would be filled with weapons
and needed gear, from the tower.
In addition to getting SEALs off the ship, lockout trunks can be
used for the entire crew to escape in case the submarine is
This video gives a close-up look at the lockout