The water slope at Montech

This pleasure barge was just entering the lock as I arrived to see the famous water slope, la pente d'eau, at Montech in south west France.  Actually, I'd never heard of it before but there were an awful lot of direction signs to it, so I followed them.  The canal is the Canal des Deux Mers, made up of the Canal du Midi and the Canal de Garonne, connecting the Atlantic with the Mediterranean Sea. 

The barge, or maybe I should call it a bateau mouche, faced several other locks in quick succession before being able to continue.  It was for this reason that the water slope was developed.

All these locks can take up to 45 minutes to negotiate so a team of engineers designed a totally new method of transporting larger vessels up (or down) the required height.  Alongside the canal, they constructed a new channel which follows the slope of the land.

Two high-powered locomotives equipped with a watertight gate to push the boats up the slope.

This shows the view from the back end of the contraption.  The boat enters the channel and the gate is closed at the bottom, sealing in a wedge of water with it.  The locomotives then push the wedge of water along and up the slope with the boat floating in it.  When it reaches the top, the water level is equalised with the canal, the gate opens and the boat floats on. The slope was first opened in 1974.

In the meantime, however, it has been closed again, "for reasons of security". I'm not sure what that means but the other similar slope at Fonserannes was closed too, in 2001, because it really never worked all that well.

I noticed that they have described the route alongside the canal as a "voie verte" or green way and have planted wild flowers.  They say you can cycle/walk from London to Paris along these routes.  I'm not entirely sure how.