This week in 1875: the Channel Tunnel

First proposed in 1802, then alternately rejected and resurrected over the course of the following two centuries, the Channel Tunnel was back on the agenda in 1875.

And with a recent act of parliament authorizing preliminary explorations, The Engineer turned its attention to the  very practical issue of how a tunnel beneath the channel would be ventilated.

‘No-one  has expressed a well-considered opinion in public as to how the trains are to be propelled, or the ventilation of the tunnel be effected,’ wrote The Engineer. ‘The problem is one of unexplained difficulty, and of the greatest possible importance, for on it hangs the whole future of the gigantic scheme.’

The article goes on to consider the impact on the air within the tunnels of the proposed  target of thirty-six steam trains every 24 hours. ‘We should have per mile per train about 520 cubic feet of carbonic acid gas discharged into the tunnel…if fifteen or eighteen parts of carbonic acid in 10,000 were found in the air of the channel tunnel, passengers would suffer seriously.’