Two of the most imposing and famous yachts in the world have together taken their places in La Grande Forme dry dock of La Ciotat Shipyards for a refit orchestrated by the operator MB92 La Ciotat. Before the refit, Head of the maintenance department, Philippe Marrot, and his teams, supervised the (very) delicate dry docking operation of these two vessels.
On paper, the dry docking operation seems very simple: bring a ship into La Grande Forme, seal the dock by closing the gate, then pump out the water to completely empty the dock and allow the dry refit of the vessel.
But in reality, it is a very delicate operation, which requires real know-how, a lot of coordination, an experienced team of several trades… and favourable weather. All the more so when it comes to bringing two of the most famous and imposing ships on the market into La Grande Forme: one 3-master 143m long (and 13,000 tons) and a 123m motor yacht (and 8,489 tons)!
As Manager of the maintenance service for La Ciotat Shipyards, Philippe Marrot is in charge of the pumping systems that allow La Grande Forme to be emptied. He was therefore in charge of supervising this extraordinary operation, in close communication with 6 divers.
The Story.
“This operation had the particularity that it was a question of bringing not one, but two vessels into La Grande Forme, so that MB92 La Ciotat could carry out the refits of the two vessels in parallel. Work began 15 days before the arrival of the vessels. We first emptied La Grande Forme in order to prepare the keel blocks. This involved installing concrete blocks and wooden blocks of 1 to 4m in height, intended to accommodate the keel of the ship without damaging the hull. An important operation, considering the value of these two vessels! We then re-flooded La Grande Forme for their arrival. This keel block preparation took two weeks.
To optimise the dry docking, we first brought the sailing yacht into La Grande Forme, then the motor yacht. We started pumping out the water. The 3-master having a draft of 8m and La Grande Forme a depth of 9 to 10m depending on the tide, we emptied barely 1.80m of water before the vessel reached the blocks.
The divers coordinated the positioning of the keel on the blocks underwater, with the head of the divers, the MB92 La Ciotat project managers and the crew of the yacht on the surface. The work lasted no less than 14 hours!
The following day, we carried out the same operation with the motor yacht. Pumping was more significant since this vessel has a draft of 4.90m, but the positioning is less time consuming and complex.
Once the two vessels were positioned on their keels, we finished pumping the water from La Grande Forme, which took 10 hours. In total, the operation involved 60 people for more than 48 hours!
And that’s not all! When MB92 La Ciotat has completed the refit of the two vessels, we will have to float them again. The divers will enter La Grande Forme to ensure that the keel does not get damaged, but also to remove the pieces of soft wood used to prop up the vessel, which remain stuck to the keel.
This sailing yacht is the largest vessel we have welcomed in La Grande Forme to date. But manufacturers still have space to spare, because with its dimensions, La Grande Forme could in theory accommodate vessels of … 330 m long, 65m wide and up to 9m draft!”
