Tres Unidos Footbridge Project
Newsletter Issue 7, December 2006
previous issues
April, May, June, August, September, October
Finale
A year has passed since we first have been in Tres Unidos to start our German-Peruvian bridge building project. It is now time to finish the construction. Flights are booked and five of our employees will travel to Tres Unidos in January to help the villagers to finally finish the bridge.
Together we will erect the pylons, stress the cables and install the bridge deck. But before, some steel parts still need to be transported to Tres Unidos and have to be painted there.
After all, we plan to stay two weeks and want to finish the project with an inauguration party. Sure, we will document this with pictures in our next newsletter!
Pylon foundations
Pictures of the finished
pylon foundations have reached us recently. Though the villagers had to
struggle a little with casting pits full of water from the latest
rainfalls, it all worked out well at the end.
What we want to do together, when we arrive in Tres Unidos, is casting the so-called "steel shoes" into the concrete. The shoes form the connection between concrete and wooden pylons (we reported in our last issue) and will be placed, where plastic bottles full of water act as placeholders
The
bridge deck is the last constructive element we have to plan for. It is
the one that is most difficult to realise when you want to work with as
less connecting elements as possible, get a stable construction and still
be flexible in terms of motion.
How the floorboards
will be formed to create stiffness we described before. What was still
an unsolved question was the way we connect the upper and lower cables
and make the passage safe enough for even the smallest person, who
walks on the swinging bridge.
Our solution are hangers made out of reinforcement. This will probably not get a design award but it is the cheapest alternative with material that is easy to get for everybody.
In distances of about one meter, rods of eight millimeter thickness will be twisted around the upper and lower cable and around an extra reinforcement rod on top of the boards. The space between will be secured with manila ropes or something similiar.
A different solution would be wire mesh as it is used by "Bridges to Prosperity" in their bridge building concept. This certainly is safer but it also is more complex and costly. This is why the majority of us opted for the small scale solution. Should this turn out to be a mistake during the construction phase we still can change plans.
Plautstraße 80, 04179 Leipzig
www.tresunidos.alpintechnik.de