Placeholder Image

Subtitles section Play video

  • I want to be really clear:

  • the odds of a manhole in a London street suddenly exploding while you're next to it

  • are tiny.

  • This is not something to worry about.

  • And the company that handles the cables under London's streets

  • is spending a lot of money fixing them up.

  • But, yeah, about once or twice a month on average, somewhere in London,

  • a bit of pavement just goes... boomf.

  • But no-one wants to license security camera footage of actual pavement explosions

  • to just someone on YouTube, and no-one wants to be interviewed about it either.

  • So instead, we are going to create our own underground explosion right here

  • with the help of a friendly pyrotechnician.

  • And the easy answer to why London's pavements keep exploding...

  • well, it would be "electrical faults", and that's what the news often blames.

  • As seasons change, the ground is going to get warmer and cooler,

  • it's going to expand and contract, rain and subsidence will move the soil,

  • and over the course of decades

  • that is going to steadily wear out the 36,000km of electrical cables

  • and 100,000 electrical junction boxes that are under London.

  • Most of those were laid decades ago. It's a big city. Things will break.

  • But an electrical fault won't make an explosion.

  • If electricity goes somewhere it shouldn't,

  • then the circuit breakers that control the grid will detect that

  • and shut it off right away.

  • The trouble is that there's a lot of other old stuff under London's streets.

  • Including gas pipes.

  • A steady, slow gas leak in a pipe might not be detected for a while,

  • and in that time the gas can spread a long distance through narrow underground tunnels.

  • So if you've got gas in a tight underground space where it can't expand,

  • thank you, and an electrical spark to set it off...

  • well, that's all we're doing here:

  • under that cover there is a fuel source, not enough room for it to expand,

  • and something to make an electrical spark.

  • That's all you need for an explosion.

  • Fire in the hole.

  • "This looks devastating in slow motion.

  • "The burst of flame, the flying manhole cover,

  • "at 1800 frames per second on a zoom lens it looks like it could do serious damage.

  • "But even this dramatised explosion, made with the help of a pyrotechnician,

  • "this worst-case-scenario... is actually not that bad.

  • "I tried to do the 'cool guys don't look at explosions' shot,

  • "and when you take away all this style..."

  • Fire in the hole.

  • "It'd hurt if you were standing on it, sure,

  • "but like I said, it's not something to be worried about."

I want to be really clear:

Subtitles and vocabulary

Click the word to look it up Click the word to find further inforamtion about it

B1 electrical london explosion exploding gas manhole

Why Do London's Manholes Keep Exploding?

  • 758 32
    林宜悉 posted on 2020/04/01
Video vocabulary

Keywords

stuff

US /stʌf/

UK /stʌf/

  • noun
  • Generic description for things, materials, objects
  • verb
  • To push material inside something, with force
scenario

US /səˈner.i.oʊ/

UK /sɪˈnɑː.ri.əʊ/

  • noun
  • An imagined sequence of events in a plan/project
devastating

US

UK

  • adjective
  • Destroying everything; very shocking
  • Causing great emotional pain and suffering.
  • Causing great emotional pain or shock.
  • Causing great damage or destruction.
  • Causing great damage or suffering.
  • Causing someone to feel extreme emotional pain.
  • Causing someone to feel great shock or distress.
  • verb
  • To cause extensive destruction or ruin utterly
  • other
  • To destroy or ruin something.
  • Past participle of devastate: To cause great destruction or damage to.
average

US /ˈævərɪdʒ, ˈævrɪdʒ/

UK /'ævərɪdʒ/

  • noun
  • Total of numbers divided by the number of items
  • verb
  • To add numbers then divide by the number of items
  • adjective
  • Typical or normal; usual; ordinary
spread

US /sprɛd/

UK /spred/

  • noun
  • A big meal, often laid out as a buffet
  • The distance between two things
  • Soft food thinly applied, e.g. on bread
  • When a disease is passed to more people
  • Range or wide variety of something
  • verb
  • To place over a large area; to cover a large area
  • To apply something thinly, usually onto food
  • To give or be given to other people, as a disease
  • (Of ideas, gossip) to pass to and affect others
  • To move something apart, or to put space between
  • To become known by a greater number of people
odd

US /ɑd/

UK /ɒd/

  • adjective
  • Being unmatched with someone or something
  • Being a number not able to be divided by two
  • Being unexpected or different; out of the ordinary
contract

US /'kɑ:ntrækt/

UK /'kɒntrækt/

  • verb
  • To become ill as a result of getting a disease
  • To make an agreement for doing work for money
  • To reduce in size, length due to heat loss
  • To reduce the amount of
  • Decrease in size, number, or range.
  • noun
  • A written or spoken agreement, especially one concerning employment, sales, or tenancy, that is intended to be enforceable by law
  • Legal agreement, e.g. for doing work for money
  • Agreement to pay someone to kill a person
  • other
  • To enter into a formal and legally binding agreement
  • To catch or develop (a disease or infectious agent)
  • To shorten (a word or words) by omitting or combining some of the sounds or letters
  • other
  • To decrease in size, number, or range
fuel

US /ˈfjuəl/

UK /'fju:əl/

  • verb
  • To give power to (a mob, anger, etc.); incite
  • To provide gas or petrol for something
  • To supply with fuel; to stimulate or intensify.
  • noun
  • A substance that is burned to produce heat or power.
  • Material used to produce heat or power when burned
bit

US /bɪt/

UK /bɪt/

  • noun
  • A former coin worth 12.5 cents.
  • The basic unit of information in computing.
  • The basic unit of information in computing, representing a binary digit (0 or 1).
  • A mouthful of food.
  • Device put in a horse's mouth to control it
  • A particular thing or experience.
  • A person's contribution to an effort.
  • Small piece of something
  • A short period of time.
  • A very small amount of money.
  • A small piece or amount of something.
  • A small acting role or part in a performance.
  • The part of a tool that cuts or bores.
  • other
  • To do one's part.
  • Not at all.
  • verb
  • Past tense of 'bite'.
  • (E.g. of fish) to take bait and be caught
  • adverb
  • Slightly; somewhat.
tiny

US /ˈtaɪni/

UK /'taɪnɪ/

  • adjective
  • Very, very small