ETM and innovation
An innovative mooring system, from the dead body to the mooring line
Origin
The idea of a mooring originated from a research and development contract awarded by the Arcachon Basin Marine Natural Park. The purpose of this contract was to develop a mooring infrastructure for pleasure boats that would respect the marine environment by limiting the drag phenomenon caused by the action of chains on the ground.
After analysis of the existing system, we found that the most impacting phenomenon was the scouring of the seabed (destruction of the seabed by the rotation of the chain on the sea floor at low tide).
Several problems were encountered:
- The tidal range will have to be compensated for, the footprint will have to be reduced, the vibration nuisance as well as the mechanical damage linked to the action of the chain on the ground, will have to be corrected.
- Premature wear of materials in the marine environment and damage due to electrolysis must be taken into account.
- The factors of mechanical resistance of the system, the swell, the wind and the current. The existence of areas with different water height characteristics, types of boats.
Prototyping and testing
INPI PATENT DEPOSIT 1870161
A guide wire tensioned by a sub-surface float whose length corresponds to the amplitude of tidal range
A sliding cable connected to the surface by the buoy and maintained in tension by a counterweight mass.
316 L stainless steel set
Assembly of mooring system
- Locate the low cable (4.80 ml) and the high variable length cable
- Extend parallel cables on the ground (Figure 1)
- Assemble Swallow and Subsurface Float on Low Cable (Figure 2)
- Assemble tensioner, strap on the top of the top cable (Figure 3)
- Assemble Counterweights on the lower part of the top cable (Figure 4)
- Identify anti-friction rings (Conical and Cylindrical) (Figure 5)
- Position the low sliding plate assembling the cables above the swivel and the counterweight (Figure 6)
- Assemble the plate making sure to position the conical ring on the counterweight side and the cylindrical ring on the swivel side. (Figure 7)
- Repeat the operation for the high platelet by reversing the positions of the rings. (Figure 8 and 8b)
- Secure the pads with the cable ties (Figure 9)
- Lover the cables and store in the bags provided for this purpose
-
- FIGURE 1
-
- FIGURE 1
-
- FIGURE 3
-
- FIGURE 2
-
- FIGURE 3
-
- FIGURE 5
-
- FIGURE 4
-
- FIGURE 6
Mooring system in situation
-
- FIGURE 1
-
- FIGURE 2
-
- FIGURE 3
-
- FIGURE 4
-
- FIGURE 5
-
- FIGURE 6
EXPERIMENTATION ARCACHON SEASON 2017-2018
-
- FIGURE 1
-
- FIGURE 2
-
- FIGURE 3
-
- FIGURE 4
-
- FIGURE 5
After numerous prototypes, we have developed an innovative anchoring product, based on a dead body and a patented rod, which completely eliminates the effect of scraping the sea bed. The main objective of an innovative mooring was achieved.
Improvements and future of the innovative mooring
Nevertheless, the company did not stop there. Indeed, true to its philosophy, ETM Marine is always looking for innovation, so we pushed for the innovation of the project. This is why we have created a second innovative anchorage model, more successful, responding more broadly to the many constraints encountered by the various marine environments.
Details of the improvements made according to the experience feedback:
- Increase of the counterweight mass which will allow a reduction of the angle of the buoy at the
the angle of the buoy at the head of the dead body. - Replacement of the stainless steel cable line by a technical Dyneema fabric, bringing lightness, a better absorption of lightness, a better absorption of mechanical constraints linked to shearing, resistance to resistance to breakage and longevity.
- Change of the sliding mode by removing the stainless steel plates, and passage inside the subsurface float.
- Machining at the head of the subsurface float to allow multiaxial working of the dyneema cable.
- Reduction of parts, costs and therefore maintenance.
- Increased service life.
Video of the innovative mooring installed in the Bay of Arcachon
Finally, we are working every day to improve it, and other concepts are to be expected, always with the objective that the innovative mooring can be adapted in the future to all maritime areas on land.