Safe navigation in Fehmarnbelt

Femern A/S is examining how the construction work will impact on shipping and is preparing a risk analysis of offshore activities during the construction phase.

The results of the analysis will form part of the maritime authorities’ decision-making process in connection with the initiatives aimed at reducing risk to shipping during the construction work, e.g:

• The VTS system which will assist shipping and provide an update on offshore activities
• Guard vessels that will warn ships of offshore activities
• Limiting offshore activities to give vessels the greatest possible leeway in the area

More than 100 vessels per day
Fehmarnbelt is a very busy waterway. The number of vessels in 2006 and 2007 showed that the belt is used by approx. 47.000 ships per year, and that approx. 38.000 ferries sail between Puttgarden and Rødby every year. Based on these figures, a traffic forecast has been drawn up which shows that by 2030, shipping will total approx. 90.000 ships per year. This is almost a doubling within 20 years.

Simulations for shipping with a bridge
The 2008 treaty between Denmark and Germany refers to a cable-stayed bridge as the preferred technical solution at Fehmarnbelt. In 2009 and 2010, therefore, Femern A/S carried out a number of computer simulations of shipping with a bridge of varying span widths.

A detailed risk analysis comprising different scenarios for a cable-stayed bridge was compared to a scenario that assumed continued ferry operations without a fixed link. At the same time, an analysis of the traffic flow for all scenarios determined the extent to which vessels in Fehmarnbelt would have to adjust their speeds.

Experienced navigators from Denmark and Germany conducted simulator exercises where, using 360° screens, they simulated shipping movements under both a cable-stayed bridge and a suspension bridge across Fehmarnbelt. Recording the navigators’ actions on the computers, the exercise drew an accurate picture of vessel movements through the Fehmarnbelt and under the bridges.

Bridge also safe
The surveys demonstrated that a cable-stayed bridge with two navigational span widths of 724 m combined with a VTS system for the area would improve navigational safety compared to continuing ferry operations with no VTS system.

The simulations were carried out by the Copenhagen-based institute FORCE Technology, which undertook similar investigations for the bridges across Storebælt and Øresund.