![Side-wall concrete in place in diversion tunnel No. 3. Two methods of wetting are shown. At right sprinkler system Stock Photo - Alamy Side-wall concrete in place in diversion tunnel No. 3. Two methods of wetting are shown. At right sprinkler system Stock Photo - Alamy](https://c8.alamy.com/comp/P01KWX/side-wall-concrete-in-place-in-diversion-tunnel-no-3-two-methods-of-wetting-are-shown-at-right-sprinkler-system-P01KWX.jpg)
Side-wall concrete in place in diversion tunnel No. 3. Two methods of wetting are shown. At right sprinkler system Stock Photo - Alamy
![SR 99 på Twitter: "Remember when we did our first-ever test of the deluge sprinkler system inside the tunnel? This is what 6,400 gallons of water pouring out of the sprinkler system SR 99 på Twitter: "Remember when we did our first-ever test of the deluge sprinkler system inside the tunnel? This is what 6,400 gallons of water pouring out of the sprinkler system](https://pbs.twimg.com/media/DuuvtBdV4AAeWLU.jpg)
SR 99 på Twitter: "Remember when we did our first-ever test of the deluge sprinkler system inside the tunnel? This is what 6,400 gallons of water pouring out of the sprinkler system
![PDF] Study on Feasibility of Automatic Sprinkler System Applied in Underground Tunnel | Semantic Scholar PDF] Study on Feasibility of Automatic Sprinkler System Applied in Underground Tunnel | Semantic Scholar](https://d3i71xaburhd42.cloudfront.net/181bc12780ab2ce6f809017623ef9f6dc404dcda/3-Figure2-1.png)
PDF] Study on Feasibility of Automatic Sprinkler System Applied in Underground Tunnel | Semantic Scholar
![General view of operations in placing side-wall concrete in diversion tunnel No. 2. Note truck on floor in foreground and sprinkler system along top of pour at left.; Scope and content: Photograph General view of operations in placing side-wall concrete in diversion tunnel No. 2. Note truck on floor in foreground and sprinkler system along top of pour at left.; Scope and content: Photograph](https://c8.alamy.com/comp/W5NAT4/general-view-of-operations-in-placing-side-wall-concrete-in-diversion-tunnel-no-2-note-truck-on-floor-in-foreground-and-sprinkler-system-along-top-of-pour-at-left-scope-and-content-photograph-from-volume-two-of-a-series-of-photo-albums-documenting-the-construction-of-hoover-dam-boulder-city-nevada-W5NAT4.jpg)
General view of operations in placing side-wall concrete in diversion tunnel No. 2. Note truck on floor in foreground and sprinkler system along top of pour at left.; Scope and content: Photograph
![The Channel Tunnel's ultimate sprinkler system: How fire is a tunnel's worst enemy | The Independent | The Independent The Channel Tunnel's ultimate sprinkler system: How fire is a tunnel's worst enemy | The Independent | The Independent](https://static.independent.co.uk/s3fs-public/thumbnails/image/2015/01/19/16/eurostar_afp.jpg?quality=75&width=1200&auto=webp)