There RP FLIPan acronym that stands for “Floating Instrument Platform”was an Office of Naval Research laboratory “ship” capable of rising vertically in about 30 minutes thanks to a controlled sinking. Built in 1962 and in operation until 2023, when it was dismantled, it was more precisely a research platform and in fact it had no engines and could not move independently, needing to be towed by another vessel.
It was built in flood Cold War and indeed his purpose was military: it was used to study the propagation of sounds in water and to improve techniques for detecting Soviet submarines – it was without an engine precisely to prevent vibrations from influencing the detections. And these measurements were made with great precision thanks to the vertical position. But how did he get into this position?
How the RP FLIP maneuver worked
The FLIP was divided into two parts. The front one, which we could mistake for the bow, that is, the nose of the ship: here the controls and cabins were located and it was about 17 meters of the total 108 and it was also the only part that, vertically, remained out of the water. The rest of the structure was a hollow cylinder about 90 meters and its interior was in turn divided into different compartments which performed different functions.
The secret of the maneuver was right here, in this cylindrical part, which, to simplify, was in turn divided into two sections, one narrower and one wider. In the widest part there were the ballastsone made of a concrete block, and the others of gods tanks filled with air which contributed to the floating of the structure in a horizontal position. At the time of the maneuver, the air was let out to let the water in, increasing the weight of the structure at the rear of the platform.
Why didn’t it sink completely? Why the weight difference it made the lighter part, i.e. the bow, rise and the heavier part, i.e. the stern, sink, triggering rotation. To avoid complications during the change of structure, the water was let in very slowly, otherwise the movement would have been too sudden, risking accidents. There in fact, the maneuver lasted about half an hour and the inclination changed gradually, almost imperceptibly, except in the last minute when the shift was most evident. Once upright, the FLIP could both free float and use three anchors to a depth of 5000 meters to remain attached to the seabed.
In the other cylindrical part, the narrower one, there were some tanks full of compressed airwhich were used for the opposite maneuver: to return to the horizontal position, in fact, air was introduced into the tanks full of water, to let it come out and carry out the re-emergence. In short, the submersion and emergence mechanism was the same as that of submarines.
How were the interiors and cabins made?
But what happened to the furniture, people and equipment during the maneuver? Meanwhile, the entire crew had to leave the cabins and stand on the external decks. As for the furniture, this was one of the bizarre features of this establishment. Refrigerators, stoves, pantries, but even toilets were mounted on pins which allowed them to change orientation depending on whether you were vertically or horizontally. While for the elements that were difficult to rotate, such as sinks, two were mounted, one for the horizontal position and one for the vertical one. And in many rooms there were too two doors to enter and exit depending on the location of the structure.
What was the vertical position of the FLIP boat for?
The vertical orientation was more functional than the horizontal orientation for two reasons. The first is that when the FLIP was in a vertical position, its center of gravity was in the immersed part and this greatly increased the stability of the structure: if the center of gravity had been at the surface of the water, or even higher, the FLIP would have been much more exposed to the movements of the waves. Second, in the vertical position the surface of the FLIP in contact with the water was much smaller than that of a normal ship and this ensured better stability against the oscillations of the water. These characteristics of the FLIP allowed it to collect very precise data, which were not greatly disturbed by oscillations caused by the waves.
The effectiveness of the detections immediately made the scientists working there realize that FLIP had boundless potential for scientific research. And in fact, despite belonging to the US Navywas then used above all for studies in the oceanographic, meteorological or climatic fields. Do you think that the structure could accommodate a crew of 11 people plus 5 scientists and could stay at sea until 30 days, thanks to supplies and a water tank obtained thanks to a desalination plant.
What instruments did he use for scientific surveys?
The conformation of the FLIP was also very versatile, because all the instrumentation for the surveys was external and was lowered into the water via the three movable arms mounted on the top of the platform: all this made it very easy to move and replace individual instruments. Or they could also be hooked to the base of the structure, on the side that sank, to reach greater depths. The tools were above all hydrophonesthat is, microphones for use under water, but were also used sonar or sensors for pressure or temperature. Among the cabins there were also two laboratories used to receive and process the data collected.
The scientific discoveries and engineering legacy of the RP FLIP
The FLIP could also be easily towed to different places to carry out studies in multiple places: in short, a set of extremely functional characteristics, which meant that the FLIP was used for decades for numerous studies, until it was dismantled after a long time 390 maneuvers performed correctly.
Thanks to the studies carried out by FLIP, very precise data have been obtained on the influence that sound waves suffer from temperature, pressure and salinity. These studies also allowed us to find out what Whales swim deepthat is, more than 2000 meters. And FLIP’s atmospheric and oceanographic measurements also revealed information and data that are still used today in weather and climate forecasts. As if that wasn’t enough, it also pioneered new engineering frontiers.
If the vertical structure in water is somehow familiar to you, it is because the FLIP has been a great source of inspiration, data and useful information for building, for example, the stations for the extraction of gas and oil at sea. Obviously in this case no horizontal to vertical maneuvers, but the physical principle on which these stations are based is the same. Then there are also “heirs” in the scientific field: in fact, they are now very common vertical pole buoys for oceanographic studies precisely because the vertical structure, as we were saying, allows for more precise measurements – in fact the FLIP itself is a sort of giant pole buoy. In the
in the case of buoys then there is no need for an entire station and a team of ad hoc scientists and you simply place the buoy to collect data. And there is even a project, called Polar PODwhich is strongly inspired by FLIP in its structure and which aims to carry out studies in Antarctica.
