(つ◔౪◔)つ━☆゚.*・。゚ The 2022 TKSST Gift Guide ✩°。⋆・゚  
Get smart curated videos delivered to your inbox.   SUBSCRIBE
The Kid Should See This

How does a tunnel boring machine work?

Watch more with these video collections:

How are new subway tunnels constructed underneath a busy city like Barcelona, Spain? This promotional animation demonstrates how a tunnel boring machine—specifically a Herrenknecht TBM with an Earth Pressure Balance Shield—excavated a 3.6 kilometer (2.24 mile) long line extension between Barcelona’s Gornal and Zona Universitària metro stations:

“In order to avoid any damage to the sensitive buildings, subsidence, heave and vibrations must be avoided at all cost. In addition, the impact on traffic above ground must remain as small as possible.”

boring machine below a city

“The S-442 is a classic EPB machine with an outer diameter of 12.06 meters and a total length of 95 meters. With its rotating cutting wheel, the tunneling machine breaks the material from the tunnel phase. The material is then transferred to the belt conveyer system in the rear of the shield via a screw conveyer while the hydraulic cylinders press the machine forward continuously.”

boring

“The reinforced concrete segments, known as lining segments, are installed under the protection of the shield’s skin. When the ring building has been completed, the machine can push itself against the new tunnel ring and drill further into the soil.”

pressure sensors

This updated video was originally posted by San Francisco’s Central Subway Project YouTube channel in 2011.

Next, find more incredible engineering projects:
The Archaeology of Crossrail and the history of London
• How deep have humans dug into the Earth?
London’s historic Mail Rail ride
A monster-sized bridge building machine in action
Annotated time lapse assembly of a wind turbine
The Ingenious Design of the Aluminum Beverage Can.

This Webby award-winning video collection exists to help teachers, librarians, and families spark kid wonder and curiosity. TKSST features smarter, more meaningful content than what's usually served up by YouTube's algorithms, and amplifies the creators who make that content.

Curated, kid-friendly, independently-published. Support this mission by becoming a sustaining member today.

🌈 Watch these videos next...

Woolly mammoth remains discovered in a Michigan field

Rion Nakaya

What Happens When You Put a Hummingbird in a Wind Tunnel?

Rion Nakaya

The physics of ‘skydiving’ wind tunnel acrobats

Rion Nakaya

The Liebherr T-284 Ultra Class Mining Truck

Rion Nakaya

The Erie Steam Shovel Type B in action

Rion Nakaya

The Archaeology of Crossrail and the history of London

Rion Nakaya

Subvisual Subway, the Art of New York City’s Bacterial World

Rion Nakaya

Squeeze in where you can! – The World’s Busiest Railway

Rion Nakaya

Riding a Hong Kong tram, a time lapse

Rion Nakaya