The adventures of the first scaphs: the LANCY rodeo

He had gathered for this a band of young fellows of which I was one of the turbulent members. He wanted us all to come from learning centers rather than from high schools. Exaggerating a little, but leader of a charismatic man, often overwhelmed by a certain lyricism, he did not hesitate to say that a diver "instead of hands, he must have claws". He said it very well and he thought so too, because he foresaw our professional orientation to underwater public works.

The major administrations, first and foremost EDF, faced with the ease of use of this new type of personnel, did not hesitate to entrust us with latent problems such as the rehabilitation of submerged concrete structures. And in order for the material to be solid, it had to be put in place as gently as possible, transported from the concrete mixer to the surface in the formwork or the cavity to be filled at the bottom, in the best conditions. To do this, André Galerne discovered a beautiful day the "Lancy", originally designed for the projection of fluid concrete and various coatings on vertical walls, surface.

And it was there that one had to know how to invent, every day, and adapt to create a submarine material that did not exist: it was the daily life of the Frogs, as we were called on public works sites. The Lancy, conical tub prolonged with a plastic tube like horn elephantine, had to be filled with concrete, and closed by a hatch with lever arm. Compressed air then chased the concrete into the trunk, and conveyed it gently to the place planned for its final submerged deposit. Until then, everything should have gone at best.

Yes, but in practice the result was not as convincing. Especially from handlers who were not from the École des Roches but rather from a suburban learning center, municipal schools of the City of Paris, or the National Navy. The whole sometimes mixed with an education worthy of that of the salons of Madame FOURINA. So… then, nothing was easy. In fact nothing has ever been easy in underwater public works and that is what certainly made it a passion. I go back to Lancy, this "peeled, this mangy, where all the evil came from ..." who has rendered us so many services and that we have treated so badly.

Dosed at 450 kgs, it is necessary to use sand and “rolled” aggregates, that is to say resulting from dredging of rivers to manufacture the submerged concrete. Not that crushed material from a quarry. Le Lancy doesn't want them, he doesn't digest them. Soon, when you send the air under pressure, your crushed items will get stuck in the panties. Because there is that in this machine, pants. And as the name suggests, just like its female disambiguation, it's a sensitive part. No matter how much you stir, everything may stop. So let's be nice to this big delicate.

The Lancy is placed in position on the platform, the plastic tube unrolled and if the place and the climatic conditions allow it lying in the sun to make it more flexible. This is a challenge however, given the original rigidity of said plastic. But finally, we must put all the chances on his side. A straight tube, it stuck "less than a tube with elbows" said one of our team leaders in the southern accent. This tube is put in position after having screwed on the pants of Lancy and introduced into the formwork deep within the cavity. We start by sending a clear water content to lubricate. The Lancy must be "nickel": André Galerne went up to the culinary comparisons, claiming "it must be clean as a pan"

The sturdy guy presses on the closing hatch by pulling the lever arm, another member of the team is already brewing inside and finally, gently, the air valve is opened. Be careful, no sudden movements, the animal could get upset. We then see the white plastic tube darken and the concrete move forward. All is well, there is a diver at the bottom, next to the formwork. The method is simple and depends on the feeling of the surface operator, who is in charge of the internal mixing of the concrete. If he understands that the lever turns empty, he quickly opens the air drain valve ... and opens the hatch for a new filling.

But if you have to use a very fluid colloidal concrete the brewing lever will not warn you. So as we did not lack ingenuity, we hit the flanks of the apparatus with a hammer "until it sounds the hollow" Some stronger than others, hearing more sensitive, were very sought after for this delicate maneuver. If for some reason, despite our continued attention, the Lancy gets stuck on the site turns to natural disaster. And the diver screams in his phone: "Hello Surface! So it does not flow anymore! "

The atmosphere crumbles, depression awaits us and the site manager speaks: "We will have to take off his pants ..." The work is stopped, the diver comes out of the water, waiting for us to have everything dismantled, washed, cleaned ... tank, panties (especially!) plastic tube ... And the work resumes. According to the mood of the men and we are convinced of it, the Device, we will make up for lost time. "Inanimate objects, do you have a soul ...?" ”In any case, we, for Lancy, we never asked ourselves the question! The answer is yes.