Anticipating the unforeseen

A project like Monaco’s offshore extension Portier Cove means finding solutions to deal with uncertain factors, notably the weather.  

“Monaco’s meteorological model is particular,” says Christophe Hirsinger, Director of Bouygues TP Monaco. The company works with two external weather forecast specialists to give itself the best chance of anticipating unusual weather conditions and preparing a response.

Reactive strategies

The two meteorological services issue weather reports and often update them several times a day so they are as precise as possible.

“We have set up procedures for protecting our equipment since the site opened,” explains Christophe Hirsinger. “During the period of rough seas in October and November, based on the protocol we had developed, we were able to move the vessels to Imperia, Nice and even Toulon.”

The problem was not solved by this measure of protection alone; there was a more global strategy and conscious decision-making. When the boats are evacuated for a few hours, operations are suspended for a few days. The ships have to be taken to their safety zone and then returned there before work can begin again. In addition, regulations at certain ports require the tug that accompanies the vessel to remain alongside it, which means it can’t accompany another vessel. A hasty decision can result in significant delays but a decision taken too late can lead to waste. It is not simple.

Sea Extension Portier Cove

“Significant swell”

“As far as swell is concerned,” explains the Director of Bouygues TP Monaco, “we work on the basis of what we call the HS – the notion of significant swell. This data has different implications for the different work sites. As each operates differently, some are only very slightly affected, while others are very significantly affected by the same swell intensity.” For example, if we take the need for precision into consideration – and we should remember that the tolerance margin is less than ten centimetres – the installation of the caissons can only be carried out under optimal conditions. As a result of the delay last spring, the installation phase had to be postponed to closer to winter, which complicates planning management.

“In our original schedule, we considered an average ratio of 30% in terms of meteorological hazards, which left us with a certain margin,” explains Christophe Hirsinger. But meteorological hazards also involve management, as the recent high winds and seas clearly demonstrated. While some of the teams were extremely active in implementing out the various protection measures as bad weather approached, others were unable to work because their site had been suspended.

“We work by taking two risk concepts into account,” says Christophe Hirsinger. “The first is identified risk: that is, what can reasonably be predicted as problems associated with meteorology and breakages of certain equipment. The second is unidentified risk, which is by definition very difficult to predict”. According to the director, the leitmotiv is: “Take no risks of any kind for humans or equipment.” Hence the application of the very topical notion of the principle of precaution.


This is based on an article by Georges-Olivier Kalifa, published on 27 December 2018 in the Gazette de Monaco.