Construction of the longest zip line in Andalusia (Alhaurín de la Torre, Málaga)
Longest zip lineVK Twin of 1350 m.
We are in the final phase of the implementation of this attraction built by Vertikalist. It only remains to train the monitors and inaugurate. Another milestone that surpasses our previous record of Supertirolina of 900 m.
We finally finish the construction and installation phase. Far is the day when we first set foot on the hill where the departure station is now and only in our imagination there was the Supertirolina
Each phase in the development of a project is fundamental; it is part of a whole and must be infallible. Long hours of projection work, measurements, surveying, calculations, verifications, re-projecting, recalculating, verifying.
The pre-installation process, once we have completed the engineering, is the manufacture of the heavy structures. Man’s ability to develop the technique that allows shaping steel is fascinating, seeing how it takes shape step by step, everything fits together. The logistics to move 30 tons of steel structures, from the factory to the galvanizing plant and then to the site. Unload each piece in its place, assemble it, and plant it in its place, perfectly aligned and level, in coordination with the construction management.
Civil works is another fundamental phase. The footings, with approximately 100 m3 of concrete, are the pillars of this installation, the union with the earth. The fundamental process so that everything else is sustained.
For the construction of this Supertirolina, high-strength steel structures designed and calculated to withstand extreme stresses and 20 mm steel cables with a minimum breaking load of 430 KN have been used. We have developed special tools and pulleys for this cable diameter capable of tensioning up to 11 Tm
The orography of the place has allowed us to lay the cable with terrestrial means, not without having to figure out how to move the 3 coils one by one for almost a kilometer and a half of land, in total almost 9 tons of cables. The maneuver had to be done without dragging the cables across the floor. We manufacture special tools to be able to hang the coils from the arm of an excavator equipped with a system that allowed us to brake the coil and unroll it at a controlled speed. For this, a series of steps were opened in the terrain to allow the excavator to go up impossible slopes. We were very lucky to have Fernando Alonso of the excavators, a true artist maneuvering this heavy machine. We are still amazed at what he did with it.
Once the cables were laid, the most complex and risky challenge began. Handling with these cables and these tensions, with heavy retention and reduction gear, was not going to be an easy task. We have already done similar work but never with such tension. To start we had to acquire a dynamometer of greater capacity since our equipment was limited to 10 tons and our tension limit was 11,500 kg, in the hope of being able to tension below this limit. Everything depended on the ballast reaching the end of the course in the first tests. And it is that the orography of the terrain and the unevenness was what it was and there was no possibility of increasing it. Our fear was that in unfavorable wind conditions “the cargo would not reach its destination.” We decided to acquire a 20 Tm, at the time, when we acquired the 10 Tm, we thought that we would never exceed its maximum load.
There are several factors that influence the speed of a Supertirolina, the greater the length, these factors are maximized to unimaginable levels. Various dilemmas arise and we have to carry out countless tests. If you tense too much they run a lot and the heavy weights come very fast. If you loosen the cable and it is a head wind, the light weights do not arrive. It depends on the type of pulley and if you throw yourself lying down with a hang glider harness or sitting with a paragliding harness, or if the tests are with ballast or with a person, all the tests and measurements give us different results. One by one we are solving them, but without first performing several tensioning/loosening movements.
Finally we managed to calibrate it and find the equipment configuration, voltages and parameters that offer us the necessary range of use. Any builder who has built a zip line over 1000m will know what we are talking about. The secret is in … no, we are not going to reveal it. There are things that it is better to discover for yourself.
Each re-tensioning maneuver requires the assembly of a sling of slings and connection elements that must guarantee a safety factor of 1: 5. Only 50 ton shackles weigh more than 30 kg. The load slings are huge and the dynamometer sensor needs 3 people to move it. Each re-tensioning you manage to recover about 60 cm of cable. And each time the clamp, the troopers, the transmission cables, tare the dynamometer, retrieve the winch cable, extend the cable of the pulley, etc. must be moved, etc. A maneuver that can only be performed manually and that increasingly represents moving more than a thousand kg, tightening huge screws, pulling heavy cables and handling in the middle of cables that are increasingly tightened.
In the tensioning of the cables everything is hard, weighs or punctures and you have to take extreme precautions. Come on, a medal is what the Vertikalist team that has done this task deserves, up to 15 times for each of the three cables. Fran, Rubén and David have gained more muscle than in a month of intensive gym. Also more prestige if possible.
Another strenuous round was the placement of the bird beacons. Once the cable was tensioned, our beloved David gave a lesson in technique, tenacity and work capacity, not to mention sacrifice. A whole day hanging on the cable to place 90 beacons. That day he slept more than flat and satisfied. To his credit is that task that nobody wanted to do and that he stoically assumed with the best predisposition, knowing that he was relieving the team of that headache.
Finally it was time for the first tests with the dummy, 3 drums with 75 litres of water. It is exciting to have everything ready for the first test, when everything is ready, everything is assembled, after so many months of preparation. The moment of truth.
After several satisfactory tests we finally tested it. What a great moment and what great personal satisfaction for all those who have been part of the project. From the promoters to the welder, from the designer to the one who tightens the screws. Seeing successfully completed a project that has taken years of gestation and months of execution, in which each one has had to give the best of himself is gratifying. Seeing the enthusiasm and excitement in each and every one of those who have participated is priceless. There it is!
An artifact, a fun machine that will generate happiness and excitement for thousands of people. This is the true essence of our work, the leif motiveque drives us to be in constant movement, in constant search, evolving with our time and attentive to the vanguard, to trends, creating them.
Now we have to wait for the end of this test of life that nature has imposed on us. We will wait what is necessary to be able to continue, with renewed ideas and hopes, with the predisposition to adapt and to continue, as we have done from day one.
As soon as it can be inaugurated we will celebrate it, because it will be possible, and this inauguration will be the culmination of all this work.