Wednesday, June 8, 2016

Engineering ingenuity

As we travel along the canals we come across some marvels of engineering. Over the years, due to heavy demand the old lock system in some places became time consuming and needed lots of maintenance so engineers were called in to replace a staircase of locks which, in some cases would take the whole day to climb, with something much more time, energy and water efficient. These range from hydraulic lifts to fununcular style railroads.
The first of these we came across was the Ronquiere incline plane on the Charleroi-Brussels Canal. For more information on this look at my blog titled "Gent-tastic"

looking from the historic canal to the new lift
On the Canal du Centre in Belgium (not to be confused with the canal of the same name in France) we came across the second engineering marvel - the Strépy-Thieu Lift. On the historic canal, which runs parallel to this, there are 4 old hydraulic lifts each lifting boats between 16 and 18 metres in the air. These were, however, ageing and frequently broke down and weren't large enough for some of the commercial barges. The new lift is an enormous structure (in fact the largest of its type in the world), has 2 very large buckets and lifts boats about 73m. The principal of the lift is based on counterweights and as you go up you can see these enormous weights dropping down beside you. The actual journey only takes 7 minutes but the entering, tying up, closing the doors and then the journey etc takes about 40 minutes.

getting ready to enter

inside the lift

at the top and ready to leave

all you see of the lift from the top
The other engineering feat on this section of the Canal du Centre is the Blanc Pain - literally white bread - and it is basically a guard gate to adjust the flow of water after heavy rain or runoff. Similar in many respects to the Thames Barrier, the construction of this barrier started in 2002. When viewed from the water it does look at bit like a baguette, hence its name, I suppose.

Blanc Pain

In France, there have also been some improvements over the years to make the journey time quicker and to lessen the need for workmen to manage the numerous locks in this very hilly countryside. In the Lorraine region, near a town called Réchicourt-le-Château, a series of 6 locks over 2.4 km has been replaced by one lock with a drop of 15.4m. This only takes the same time to descend as a normal lock but saves about 2 hours in overall time. 
        Inside the lock

As we cruised towards our winter destination of Strasbourg we were to come across another engineering marvel - Arzviller Incline. This was completed in 1964 and replaced a ladder of 17 locks that were spread out over 3.8km. The total drop was 44.55m. Due to the difficulty of traversing this number of locks in a commercial barge where the journey could take all day and the fact that it required quite a lot of water to fill and empty each of these locks it was decided to build a "mobile bath tub". Boats sailed into this and were moved up and down the plane by a system of counterweights. The gradient of the plane is 41% and the tank moves at right angles on pulleys and is guided by a longitudinal girder. At each end of the bucket are rising doors which keep the tank water tight while it is in motion. 
    From inside the bucket looking down
    Nearly at the bottom - counterweights visible
      Boats leaving the incline plane
This incline was only recently reopened after an accident occurred in 2013 where a passenger boat damaged the doors of the bucket and started to go over the edge. Water from the canal above overflowed into the valley below flooding some areas. Fortunately no one was hurt.