The Port of Mahon restricts the manoeuvring conditions of large cruise ships
Maó
29/09/2017
The Port Authority of the Balearic Islands (APB) has now received the findings of the viability study on large ships accessing the Port of Mahon.
The study, entrusted to the Jovellanos Centre and Engineering, Resources&Development, S.L. (ENRED), builds on the preliminary analysis performed in 2016, which only considered the maximum length of ships that could operate at this port.
This study –much more extensive than the first analysis– looks at other aspects, such as transversal power at bow and stern, draught or prevailing winds, which are also key considerations for safe manoeuvres.
The findings of these studies confirm the maximum acceptable length for ships with or without azimuth thrusters, which allow propulsion to be controlled on multiple axes. In addition, the findings optimise the thresholds of required power for manoeuvring propellers (bow and stern), according to the length of the ship. This optimisation was made possible by refining analysis of the human factor, bringing pilots from the Port of Mahon onto the control bridge to perform the manoeuvres.
Safe operation
The ships considered in this study are over 220 metres long. It has been decided that these ships will access the port through the North channel (Isla del Rey), advancing to the turning basin and passing the jetties at the Naval Station. As such, this is the strategy that must be followed for the manoeuvres.
The manoeuvres were successful under all simulated conditions, even with winds of 30 knots. However, it is recommended that in winds of over 20 knots, ships over 220 metres long should not perform the manoeuvre, due to the increased requirements.
The study also confirmed that the mains problems posed by large cruise ships entering the Port of Mahon refer to geometry and available space, rather than the difficulties created by local wind conditions.
Another key conclusion concerns the availability of azimuth thrusters, which allow longer ships to access the port thanks to their enhanced manoeuvrability.
Powerful transversal propellers at the bow are essential for turning in such a tight space. Finally, the study recommends restricting the ships' draught to 8 metres.
As for manoeuvres in night-time conditions, the study highlights the excellent signalling at the Port of Mahon, which allows for these manoeuvres to be performed with the same safety as during the day.
It is recommended that captains of ships over 235 metres long without azimuth thrusters or over 245 metres long with azimuth thrusters, which are scheduled to operate at this port, first complete a simulation workshop (certified at an official centre) to accredit their knowledge of the specific characteristics of the roadstead.
