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Nederlandsche
P&I Club

Update Volume 2020/22 Weather Working Day (of 24 consecutive hours) vs. Weather Permitting

Published on 29 june 2020

When dealing with laytime related disputes we are often asked to comment on the differences between “Weather Working Day” (WWD), “Weather Working Day of 24 consecutive hours” (WWD 24 hours) and “Weather Permitting” (WP). In this article we hope to provide some guidance on the distinctions of these terms and how they can impact laytime calculations.

By way of guidance we refer to the BIMCO definitions of these terms:

WEATHER WORKING DAY shall mean a Working Day or part of a Working Day during which it is or, if the Vessel is still waiting for her turn, it would be possible to load/discharge the cargo without interruption due to the weather. If such interruption occurs (or would have occurred if work had been in progress), there shall be excluded from the Laytime a period calculated by reference to the ratio which the duration of the interruption bears to the time which would have or could have been worked but for the interruption.
 
WEATHER WORKING DAY OF 24 CONSECUTIVE HOURS shall mean a Working Day or part of a Working Day of 24 consecutive hours during which it is or, if the vessel is still waiting for her turn, it would be possible to load/discharge the cargo without interruption due to the weather. If such interruption occurs (or would have occurred if work had been in progress) there shall be excluded from the Laytime the period during which the weather interrupted or would have interrupted work.
 
WEATHER PERMITTING shall have the same meaning as WEATHER WORKING DAY OF 24 CONSECUTIVE HOURS.

As you will see, the differences are limited in the case of a port where it is customary to perform work continuously over 24 hours, whereas WP is considered to have the same meaning as WWD 24 hours. In the definitions of both WWD and WWD 24 hours periods of rain preventing cargo operations need to be excluded from the laytime calculations.

Things become a little bit more tricky when it is customary in a port to work only certain parts of the day. By way of example, let’s take a look at a situation where the vessel is in a port where the working hours are from 01.00 hours to 07.00, 08.00 to 15.00 and from 16.00 to 23.00, and rain preventing operations occurred from 06.30 to 09.30 and again from 14.00 to 18.00 hours.

  1. If the parties have agreed WWD, the time saved for the charterer should be calculated as follows:

    Working day/total working hours = 20 hours
    Rain interference during working hours = 5 hours
    Rain interference outside working hours = 2 hours
    "Lost" = 5/20 of a "working" day (or 1/4)

    This results in 5/20 of a “working” day being lost. This ratio is then applied to the actual length of a day i.e. 24 hours. As 5/20 of the day has been “lost” due to rain interference 6 hours, being 5/20 of 24 hours, will not count for the purposes of the laytime calculation.
     
  2. However, whenas previously explained parties have agreed on WWD 24 hours or WP, no ratio is required. The actual time lost due to rain interruptions does not count as laytime and is simply deducted from laytime for that day. Therefore, in the example given above, there were 7 hours of rain, 17 hours will count as laytime with 7 hours to be excluded.

Whereas the underlying intention of these definitions is the same, the application will depend on the actual working hours of a specific port. We therefore always recommend checking the working hours of the port in question before agreeing to WWD terms and otherwise to always insist on time being calculated on the basis of WWD 24 hours.

We trust that this is of assistance, however members can always contact the NNPC for follow-up questions on this matter and/or to assist in specific laytime related discussions.

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