The Tube Is the World's Oldest Underground Railway
A tube is a hollow cylinder. In London it is the name of the underground railway.
A tube is a hollow cylinder, and in London the underground railway. The nickname is engineering rather than affection: the deep lines were bored as circular tunnels lined with cast-iron rings, and those tubes dictate the trains' rounded carriage shape to this day. The Metropolitan Railway of 1863, the world's first underground, was built by cut-and-cover and is not a tube at all. Latin *tubus* gives *tuba*, *tubular* and *tubing*.
- A hollow cylinder. *A copper tube.*
- The London underground. *The Tube.*
- A container. *A tube of paint.*
- Television (informal). *The tube.*
- Latin — *tubus*. *The root.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | tube | A tube. |
| Plural | tubes | Tubes. |
| Adjective | tubular | Tubular. |
| Related | tuba | A tuba. |
| Latin | tubus | A tube. |
- A tube of toothpaste.Container.
- Take the Tube.London.
- Bored tunnels are circular.Engineering.
Cut-and-cover versus deep tube
- Cut-and-cover — dig a trench, build the line, roof it over
- Used for the earliest lines, which run just below street level
- Deep tube — bored with a shield far below the surface
- Circular cross-section gives the rounded train profile
- Only the deep lines are properly tubes
Latin *tubus*, a pipe or tube, through French *tube*.
Why is the London underground called the Tube?
Because the deep lines were bored as circular tunnels lined with iron rings, which also gives the trains their rounded shape.
Are all London underground lines tubes?
No. The oldest were built by cut-and-cover just below the street and are not bored tubes.