Word.ws English Dictionary

porous portal

porous portal noun: a type of extended and perforated tunnel portal on high-speed railways, designed to reduce the build-up of pressure when a train enters a tunnel at high speed.

Noun

porous portal (plural porous portals)

  1. A type of extended and perforated tunnel portal on high-speed railways, designed to reduce the build-up of pressure when a train enters a tunnel at high speed.
    • The Down line portal will measure 220 metres in length, while the Up line portal will be 135 metres long. Known as 'porous portals', they will (as the name suggests) be punctuated with holes. These holes or vents slow the build-up of pressure created by trains within the tunnels. The resulting...2024 March 20, Chris Howe, “High speed underneath the Chilterns...”, in RAIL, number 1005, page 33

Forms of porous portal

pluralporous portals

Questions about porous portal

What does porous portal mean?
Porous portal means a type of extended and perforated tunnel portal on high-speed railways, designed to reduce the build-up of pressure when a train enters a tunnel at high speed.
What part of speech is porous portal?
Porous portal is a noun.
What is the plural of porous portal?
The plural of porous portal is porous portals.

Words near porous portal in the dictionary

  1. porotta
  2. porottas
  3. porotype
  4. porotypes
  5. porous
  6. porous portal
  7. porous portals
  8. porously
  9. porousness
  10. porousnesses
  11. poroviscoelastic

Source and license

Adapted from Wiktionary: porous portal (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

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