Yowling moggy No. 39: why the Stonehenge tunnel is so short!

Ever wondered why they don’t make the tunnel longer than 2.9 km and save all this argument? Well, Highways England implies it’s because “2.9 km is the maximum length a tunnel can have before it becomes necessary to install ventilation shafts along its length.” So not money then! It’s because a longer tunnel would mean unsightly ventilation shafts sticking up. 

But we’re puzzled. There are zero shafts in the English Channel and only four in the 27 km Gotthard Road Tunnel in Switzerland, built 40 years ago! So we searched “types of tunnel ventilation” and the answer popped straight up: “For short tunnels that are 3 km or less in length, longitudinal ventilation systems are generally preferred due to their modest construction cost“.

So there we are! “Modest construction cost“! The shortness of the tunnel isn’t about care – but cost! This is the 39th Yowling Moggy (the sound made by the truth being tortured by the pro-short tunnel lobby). The others are here.

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