Hello, bonjour and bonjorn –
it is January 2021 and I’m in the south of France
at the canal staircase of Fonseranes.
Built way back in 1697,
it allows boats to climb more than 20m uphill
over a sequence of 8 consecutive locks.
And boats were doing that for nearly 3 centuries before someone said
hang on,
isn’t there a better way to do this?
That someone was a French engineer called Jean Aubert.
And in the early 1980s, he got permission to construct an experimental alternative
right here next to the canal staircase.
And what he came up with…
was this.
So in today’s video we are answering the question:
what the consecutive lock is that?
This is the town of Béziers in the deep south of France,
and we’re in the historic region of Languedoc,
and the official modern region of Occitanie.
And it’s a beautiful old town,
it’s famous for its thirteenth century cathedral,
its annual bull-fighting festival,
and the local rugby club,
who were the best team in the country back in 70s and 80s.
Meanwhile geographically the town lies at the crossroads of the river Orb and the legendary
Canal du Midi.
And of course, we’re not here to see any of...
oh hang on wait we actually sort of are.
The 240km long Canal du Midi is quite simply
one of the greatest engineering achievements of the 1600s.
It was built to connect France’s Mediterranean coast to the city of Toulouse,
where it met the river Garonne, which flows into the Atlantic at Bordeaux.
And because the Garonne was, according to Wikipedia,
“more or less” navigable,
when the canal opened in 1681 it meant that French boats could more or less navigate
all the way from the Atlantic to the Mediterranean.
And later on, in the 1800s, that journey became much easier
after the French dug a new canal parallel to the Garonne,
joined it all up to Canal du Midi,
and called the whole thing le Canal des Deux Mers,
or in English the Canal of the Two Seas,
because it connects the Mediterranean Sea and the Atlantic
Sea.
Now obviously doing that trip in a canal boat is not as easy as all that
because for a start, the junction with the Garonne in Toulouse is more than 130m above
sea level,
which means, science fans,
to get your boat from the Mediterranean Sea to Toulouse,
you don’t just have to get it to go along a bit,
you also have to get it to go up a bit.
And to do that on a canal you are going to need locks.
Lots of locks.
Originally there were 86 of the things.
And each time you have to open it, close it, fill it, open it, close it…
and going through something like the staircase at Fonseranes can take as much as 3 or 4 hours.
But at the end of the day you can’t avoid it.
Or can you?
3 centuries after the Fonseranes locks first went into operation,
Jean Aubert, who himself was in his 80s by this point,
came up with an experimental alternative solution.
He was going to bypass the staircase,
he was going to make the whole process much quicker,
and all he was going to need
was a giant 400m waterslide
and an insane monster vehicle straight out of a Gerry and Silvia Anderson series.
And here’s how it worked.
The boat would enter the slope at the bottom end, passing underneath the parked vehicle.
Once it was in position, a barrier would be lowered into the water behind the boat
and the machine would then start,
pushing the barrier, the boat, and the water it was floating in,
all the way up the slope.
As far as I can tell there is only one video on the whole of YouTube,
possibly the whole internet,
that actually shows it working.
It was filmed on a camcorder in 1990
and uploaded back in 2009,
but by sheer luck they still check their comments
and gave me permission to share a few seconds of it here.
I’ll put a link in the description in case you want to go and see the full 3 minute video.
Unfortunately though, this is what the water slope and the vehicle look like today.
So what went wrong?
In theory, it was a very clever piece of engineering,
it did make the journey a lot quicker,
and it probably would have worked
if it wasn’t for several catastrophic flaws.
Firstly it was about 200 years too late for there to be enough canal traffic to make it
worth building in the first place.
Secondly they had all kinds of trouble with oil leaking out of the vehicle’s hydraulics
and dropping onto the tracks below,
which had the effect of, thirdly, lubricating the slope.
And from there, well,
it all went downhill very quickly.
But it really did, there were further problems with insurance and contracts,
but what really killed it off was a complicated hydroelectric power system
that I won’t pretend to understand
but basically the machine was supposed to regenerate its own electricity
from water pressure on the way back down.
The system was never reliable,
it kept failing,
and on 11 April 2001,
after 17 years of extremely sporadic service,
the authorities officially gave up,
and it was abandoned forever.
Since then the machine has sat here in silence as a giant rusting monument to civil overengineering.
To be fair to Mr Aubert, it was was only ever supposed to be an experiment
and in the end it feels like he just tried too many things at once.
Maybe it would have been different if he’d built a water slope but with a more conventional machine,
or even built the same machine but with a more conventional engine,
maybe diesel engines
like he did on his other water slope at Montech.
Wait.
You’re telling me there’s another one of these?
WHAT
If you’d like to visit the Monster of Fonseranes,
and the historic canal staircase next door,
it’s an easy half hour walk along the canal from central Béziers and its railway station.
The site was upgraded a few years ago,
obviously it’s all closed right now,
but there’s an information centre,
there’s toilets,
there’s a really nice looking restaurant,
and it’s all fully wheelchair accessible,
apart from the monster itself,
which you’re not supposed to access anyway,
but because the place was closed, there was no-one around to shout at me.
If you enjoyed this video please do subscribe if you haven’t already so that you can get
part two,
and until then, thank you very much for watching
and I will see you soon.