Hello and griezi!
It’s autumn 2022, and I’m in Basel in Switzerland.
And today we’re asking the question:
how do you power a ferryboat across a river
without using a motor?
The most obvious answer is you put a person on board
with some sort of paddle or a pole,
or I guess you could try using a sail,
if the wind is strong enough and the current is weak enough.
But here in Basel they said no.
You don’t need any of those things.
You can make a ferry cross a river
using nothing but two bits of wire
and the power of basic physics.
So how exactly does it work?
Well let’s get on this one and see what happens.
This is the Münster ferry,
one of four motorless ferries that cross the Rhine every day in central Basel.
And it’s going to carry us over the river
to what I was going to call Basel Cathedral,
but technically it’s a minster, or Münster.
Anyway.
The ferry has been doing this journey for more than 100 years,
and with none of the noise that you would get from a motor,
or a person paddling,
it’s an incredibly chilled out, quiet, and calm way of travelling.
But how does it do it?
Now obviously, if you just drop a boat in a river and leave it,
it’s going to float off downstream.
So there's a cable at the front
that keeps us tethered to a wire
that is strung across the full width of the river.
But crucially, the tether is free to move along the wire from left to right,
and therefore the ferry is also free to move to the left and to the right.
All we need to do now is... make that happen somehow.
So here’s the clever bit:
we already did!
At this end, the tether is attached to a lever on the boat.
If the operator puts the lever on the left-hand side,
- like they just did -
we naturally swing around to the right
until we hit equilibrium.
And at this point the whole boat effectively becomes a giant rudder.
The force of the water flowing into the angle of the hull
pushes us backwards and to the right,
but because we can’t go backwards,
we just go to the right,
and the ferry crosses the river
powered purely by the force of the flow of the water.
If you want to go back the other way,
all you need to do is flip the lever.
It’s so simple that it’s genius.
The technical name for this is a Reaction Ferry,
and once it’s moving, there’s not much the operator needs to do.
They have a paddle on board in case of emergencies
and there’s also a conventional rudder at the back
which they can use to make precise manouevres
like lining us up with the pier at the end of the journey,
although from what I saw,
half the time they don’t even need to use that.
But if the system is so brilliant, and so effortlessly efficient,
why don’t we make all ferries like this?
Well, it only works under certain conditions.
You need a river with a strong, fast, and consistent flow of water;
If the current is too slow or too weak, it’s not going to work,
and if the river is seasonal or tidal, it’s not going to work enough of the time.
But here in Basel the conditions are perfect,
and the boats run reliably every day all year round.
And this isn’t the only place you’ll find reaction ferries
– there’s a few in Canada, a few in Germany,
and loads in Poland apparently.
So if you want to see this for yourself,
you might be able to find one that’s nearer you
rather than coming all the way to Basel.
But if you do happen to be near Basel
and you’d like to take a trip on one of its magic ferries,
a single journey costs 2 Swiss Francs for adults
and 1 Franc for kids, dogs, or bicycles.
And you can just rock up and pay as you get on board.
There are four different routes in the city -
Sankt Johann,
Klingental,
Münster,
and Sankt Alban.
If you need wheelchair access,
or you’ve got a kid in a pushchair,
the Sankt Johann ferry is the one to go for.
Meanwhile it’s worth mentioning that for a couple of hundred francs,
it’s also possible to prebook up to 12 people
for an on-board cheese fondue.
And as always, thank you all for watching,
and I’ll see you soon.