When you read a charter party, some clauses feel straightforward… and then you stumble on something like “WWD 24 Consecutive Hours.” Suddenly, what looked simple becomes confusing. Does laytime count during the night? What if stevedores only work in the daytime? Does demurrage start earlier or later?
This clause is one of the most misunderstood in commercial shipping—and yet it has a very real impact on the vessel’s time at port and on who pays what.
Let’s break it down in a way that feels real, simple, and connected to everyday port operations.
1. What “WWD 24 Consecutive Hours” Actually Means
The simple version:
- WWD (Weather Working Days): Laytime excludes periods when weather prevents cargo work.
- 24 Consecutive Hours: Laytime runs clock-to-clock, not shift-to-shift.
What this means in real life:
Even if the port works only one shift per day, the clock keeps ticking for all 24 hours as long as weather is good.
So even when the berth is empty at night and nothing is happening, laytime still counts.
This is why owners usually prefer this wording—it burns laytime faster.
2. What Happens When “24 Consecutive Hours” Is NOT There?
When the clause is missing, laytime counts only when the port actually works.
So if a port works 08:00–17:00, then only nine hours count toward laytime per day.
Nights and closed periods simply don’t exist for the laytime clock.
This is why charterers prefer to avoid “24 consecutive hours.”
It gives them more “free time” before demurrage kicks in.
3. Real Port Example to Make It Clear
Let’s use a real scenario many operators face.
Stevedore Shift Timings
| Shift | Time | Working Hours |
|---|---|---|
| Morning | 08:00–12:00 | 4 hrs |
| Lunch Break | 12:00–13:00 | 0 hrs |
| Afternoon | 13:00–17:00 | 4 hrs |
| Evenings/Nights | 17:00–08:00 | 0 hrs |
Even though a vessel is berthed 24 hours a day, the port only works 8 hours per day.
4. Example That Shows the Real Difference
- Laytime allowed: 96 hours (4 days)
- Weather: All days workable
- Port operations: 8 hours per day
- Berth always available
Let’s see how this plays out with and without the clause.
5. Comparison Table (Clear and Simple)
A. With “WWD 24 Consecutive Hours” included (Laytime burns 24 hrs/day)
| Day | Stevedore Work Hours | Laytime Counted |
|---|---|---|
| Day 1 | 8 hrs | 24 hrs |
| Day 2 | 8 hrs | 24 hrs |
| Day 3 | 8 hrs | 24 hrs |
| Day 4 | 8 hrs | 24 hrs |
| Total | 32 hrs worked | 96 hrs consumed |
Even though only 32 hours of real work happened, the vessel uses all laytime in 4 calendar days.
→ The vessel reaches demurrage much sooner.
B. Without “24 Consecutive Hours” (Laytime counts only during working hours)
| Day | Stevedore Work Hours | Laytime Counted |
|---|---|---|
| Day 1 | 8 hrs | 8 hrs |
| Day 2 | 8 hrs | 8 hrs |
| Day 3 | 8 hrs | 8 hrs |
| Day 4 | 8 hrs | 8 hrs |
| Day 5 | 8 hrs | 8 hrs |
| Day 6 | 8 hrs | 8 hrs |
| Day 7 | 8 hrs | 8 hrs |
| Day 8 | 8 hrs | 8 hrs |
| Total | 64 hrs worked | 64 hrs consumed |
At this pace, it takes 12 days to burn 96 hours of laytime.
→ Charterers get much more “free time” before demurrage begins.
6. Side-by-Side Summary (Easy to Understand)
| Feature | With “WWD 24 Consecutive Hours” | Without “24 CH” |
|---|---|---|
| Time counts 24 hrs/day | ✔ Yes | ✘ No |
| Stevedore shift timings matter? | ✘ No | ✔ Yes |
| Nights count as laytime | ✔ Yes | ✘ No |
| Weekends count (if weather OK) | ✔ Yes | ✘ No |
| Demurrage starts earlier | ✔ Yes | ✘ No |
| Favors | Owners | Charterers |
7. A Simple Way to Visualize the Difference
Imagine the clock on the wall.
With “24 CH,” the clock never stops.
Without it, the clock only runs when stevedores are physically onboard working.
It’s like:
- 24 CH: Your phone battery drains even if you’re not using it.
- Without 24 CH: Battery drains only when you actively use it.
8. Quick Formulas
With WWD 24 Consecutive Hours
Laytime = Calender hours – weather stoppage
Without 24 CH
Laytime = Actual port working hours – weather stoppage
9. The Real Takeaway
The phrase “WWD 24 Consecutive Hours” may look small, but it decides:
- how fast your laytime burns
- how soon demurrage applies
- who pays more at the end
It’s one of the most influential clauses in voyage chartering—and one of the most debated in laytime disputes.
Understanding this clause clearly helps brokers, operators, and chartering managers avoid unnecessary friction and surprises at the end of the voyage.
