Strange things sometimes happen at tunnelling sites. Maybe they are not so funny at the time, and nobody wants to talk about them. Then, as the years go by, the tale will unfold, embellished by the natural humour that is an essential characteristic of the tunneller mentality. In other words, take what follows with a pinch of salt. The stories are word of mouth, so no names are mentioned. If you have anything to add to them, let us know. Likewise, if you have a funny story of your own to tell, our listening post is open at sam@tunnelbuilder.com.

Here are two we particularly liked from our archives!

London Water Ring Main - inadvertently plugged
Many difficulties were experienced bringing this landmark project to a successful conclusion, and many stories can be told. The funniest concerns the operation of a pile driver after a section of the concrete segment lined ring main was completed. The story goes that in-situ piles were being installed for an unassociated construction project, when the auger hit into something solid. A piling hammer was brought in, and this quickly relieved the obstruction and completed the hole to full depth. A reinforcement cage was lowered into the hole and concreting commenced. When three times the expected amount of concrete had been poured, operations were suspended and an investigation started. When Thames Water complained that a 65 m length of its newly-completed ring main had been filled with concrete, the mystery was resolved!

Madame Fjelle - sunk without trace
Visitors to Bergen in Norway have been known to make adverse comment on the ragged state of the highway tunnels entering the city. These were driven by Madame Fjelle, or Mrs Rock to the uninitiated, a hardrock TBM bought for the job. The TBM performed its role magnificently, but the diameter selected was somewhat less than the norm for a two-lane highway tunnel. The perfect circular tube needed to be slyped from waist down to form a flat floor for the carriageway. As a result, car occupants have the ragged results of the blasting at eye level, and tend to ignore the perfectly smooth ceiling left by the TBM. Unfazed, Madame Fjelle set out to make her mark on a hydro scheme on the steep side of a fjord. Once again, she did a first-class job. However, misfortune struck as she was being loaded from the quay for her return to base. The cutterhead was being slung using the boat crane, when stability was lost. The crane operator did his best, but, rather than risk the boat turning turtle, dropped the cutterhead into the fjord. Thus ended an inglorious career: Madame Fjelle became the second hardrock TBM on record to be lost by misadventure.

If you have any contributions you would like to make please email me sam@tunnelbuilder.com