Actualités

Maintenance works: focus on piles

They often go unnoticed, and yet… piles play a fundamental role in the operation of the marina. These vertical structures hold the pontoons in place and ensure the safety of both the installations and the users.

In total, the marina has 469 piles, distributed throughout all the basins, including 2 in the Port-Neuf cove. Made of steel, they are protected against corrosion by specialist paint and sacrificial anodes, a cathodic protection system. This system is inspected every 10 years to maximise their lifespan.

The average lifespan of a pile fitted with anodes is 25 years, compared to 15 years for a pile without anodes.

In most cases, the piles are hollow. Only the piles supporting structures and buildings (dock gates and the Harbourmaster’s Office) are filled with concrete to reinforce their strength. Depending on the nature of the seabed, they are anchored to depths of over 10 metres, ensuring excellent stability.

The oldest piles in the marina date back to 1978, in the Lazaret basin, while the most recent ones were installed in 2022 at the wave breaker in the Tamaris basin. Following Storm Xynthia in 2010, all piles were raised to meet the new reference water level standards. More recently installed piles directly incorporate this raised height and have a reference level of 9.50m Chart Datum.

 

In the Old Port, you will not necessarily see piles: the pontoons there are held in place by chains or rails. The few piles installed in the Old Port are sliding piles, working like pistons to accommodate water level variations, notably on the Médiathèque, Épi de dragage and C3 pontoons.

An annual monitoring campaign

Every year, during the spring tides in March, an inspection campaign is carried out across all piles. This operation mobilises the entire technical services team, who inspect each structure with particular attention to the tidal zone — the section between two water levels, which is the most exposed and therefore the most vulnerable.

Following this assessment, any necessary works are scheduled. Depending on the case, repairs are carried out in-house by the marina’s welders or entrusted to companies specialising in underwater works.

 

As an example, in 2024, 2% of piles were identified as damaged — 9 piles found to have holes. Of these, 6 were repaired in-house and 3 required the intervention of a specialist contractor.

This year, only 6 piles were identified as having holes, for which repairs will be scheduled.

These results demonstrate the effectiveness of the monitoring system and the action plan implemented by the marina.

Furthermore, more extensive campaigns are organised every 10 years to replace the most structurally deteriorated piles whose condition no longer allows reliable pontoon anchoring.

 

 

All eyes on deck

Boat owners are also invited to report any disorder or anomaly observed on the installations. This collective vigilance helps maintain the quality and safety of the marina.