More route advice for container ships near the Wadden Islands

The Netherlands Coastguard will provide more advice in the event of bad weather for container ships that are near the Wadden Islands. Since October 2019, the Netherlands Coastguard has been warning container ships that are over 300 metres in length. On the basis of the report of the Dutch Safety Board (Ovv) and follow-up studies of the Netherlands Maritime Research Institute (MARIN), from 12 November 2020, container ships from 100 metres in length will also be warned of an increased risk of container loss in certain weather conditions. 

Container ships longer than 200 metres are advised to take the northern route in the case of a wave height of 4.5 metres or higher. If the wave height is actually 4.5 metres or higher, these ships are actively called by the Netherlands Coastguard. The advice for container ships that are between 100 and 200 metres in length is to take necessary measures and/or adopt an alternative course in the case of wave heights in excess of 3.3 metres in order to prevent heavy rolling on the part of the ship and the consequent loss of containers overboard.

Active calling
This advice is sent to ships in a navigational warning if wave heights are actually 3.3 metres or higher on the North Sea. In the case of a wave height in excess of 4.5 metres, container ships that are longer than 200 metres are also actively called. The Netherlands Coastguard calls the ship when it is sailing at the latitude of Texel (‘before the exit’). This is because, at this location, they can choose to take the southern or northern route. This is advice for the captain because the Netherlands Coastguard does not have a mandate to impose traffic instructions. The captain is not obliged to follow this advice.

Container ships between 100 and 200 metres
Possibilities are being explored for actively calling container ships that are between 100 and 200 metres in length. The Netherlands Coastguard currently does not have the capacity to do so. The Netherlands Coastguard is of course alert and also monitors these types of container ships in certain weather conditions.

In the case of a wave height in excess of 4.5 metres, container ships that are longer than 200 metres are also actively called.

Different advice
Container ships that are longer than 200 metres are advised to take the northern route because of the chance of hitting the seabed and the green water effect. The green water effect is a solid mass of water that is forced against containers. This risk is greater for container ships that are longer than 200 metres. For container ships that are shorter than 200 metres, the risk of container loss is virtually the same in the same conditions. Advising a route therefore does not limit the risk of container loss.

Navigational warning
If the wave height is 3.3 metres or higher, the navigational warning below is sent to ships. The wave height, direction and frequency are added to the warning.
ZCZC PA29
Netherlands Coastguard
Navigational warning Nr. 29 031412 UTC NOV
TSS Terschelling - German Bight
Following containervessels are at risk of losing containers and touching the seabed
during heavy sea conditions and high waves from a north to northwest direction:
Containervessels with a length of 100-200m and a waveheight above 3.3m.
Masters have to take appropriate measures and alter course if necessary to avoid
coming transverse to the wave direction.
Containervessels with a length above 200m and a waveheight above 4.5m
are recommended to follow alternative route via TSS East Friesland.
NNNN