Escape trunk
escape system for submarines
An escape trunk is a small compartment on a submarine which provides a means for crew to escape from a downed submarine; it operates on a principle similar to an airlock, in that it allows the transfer of persons or objects between two areas of different pressure.
Principle of operation
The water pressure on the outer hatch is always greater than the air pressure inside the submarine, which prevents opening the hatch. Only when the pressure inside the escape chamber is equal to the sea pressure can the hatch be opened. Thus the compartment must be sealed off from the interior of the submarine and the pressure inside the chamber must be raised to sea pressure in order to make it possible to open the escape hatch.
Operation
The drain valve is opened to ensure any residual water is drained from the compartment, and the pressure between the interior of the submarine and the escape trunk is equalized.
The drain valve is closed, 6–8 people climb up through the lower hatch into the escape chamber, and the lower hatch is shut. Before climbing into the chamber, the escapees don a Steinke hood or Submarine Escape Immersion Equipment, which will provide an air supply during the ascent to the surface.
The seawater valve is opened to flood the chamber. As the chamber floods, the air in the chamber is compressed until its pressure is equal to the sea pressure. When the pressure in the chamber is equalized with the sea pressure, the flooding of the chamber will stop.
This brief starts where responsible research should: with the source description of “Escape trunk” as escape system for submarines. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the general reference register because the source frames it as escape system for submarines. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Feb 6, 2026. The linked authority identifier is Q5397104. None of the 0 selected statements returned an explicit reference.
Overview language is designed for orientation and should not be treated as a substitute for the evidence cited beneath it. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “Escape trunk”, its source revision and the description used here.
- Expand the search: follow Escape trunk primary sources, Escape trunk archive and Escape research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Escape trunk”?
- Which institution is responsible for the underlying evidence?
- Which cited source is closest to the event, object or claim?
Search terms from this dossier
This entry incorporates text from “Escape trunk” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.