What is a loading or discharge rate?
A loading or discharge rate is the speed of cargo work, agreed in the charter party, that the parties use to fix how much laytime the charterer is allowed at each end. It is most often quoted in metric tonnes per weather working day. Divided into the cargo quantity, it produces the allowed laytime.
In a voyage charter the owner prices a finite number of cargo-work days into the freight. The load and discharge rate is the lever that sets how many days those are. A high rate compresses allowed laytime and raises the risk that actual cargo work overruns it; a low rate buys the charterer a longer allowance and a thinner demurrage exposure. The rate is therefore not a technical detail. It is a commercial term that owner and charterer negotiate against the realistic cargo-handling capacity of the load and discharge berths, the gear on the vessel, and the cargo itself.
The rate is distinct from the actual achieved rate of work. It is the contractual rate, the agreed yardstick, against which the master’s statement of facts is later measured. Whether the berth in fact loaded faster or slower than the fixed rate does not change the allowed laytime; it only changes whether the charterer ends up paying demurrage or earning dispatch. The Laytime Definitions for Charter Parties 2013 (LDCP 2013), published jointly by BIMCO, the Baltic Exchange, CMI and FONASBA, give the agreed market meaning of the day types and rate terms used to quote and count it.
How a load or discharge rate converts to allowed laytime
The whole purpose of fixing a rate is to turn a cargo quantity into a number of allowed days. The core formula (T1) is:
Allowed laytime (days) = Cargo quantity (tonnes) divided by Agreed rate (tonnes per day)
Where the variables are:
- Cargo quantity: the bill of lading quantity, or the charter-party quantity if the clause fixes laytime on the contractual figure rather than the loaded figure.
- Agreed rate: the load or discharge rate stated in the charter party, expressed in metric tonnes per day or per weather working day. A separate rate normally applies at each port.
- Day definition: whether the day is a running day, a working day, or a weather working day, and whether Sundays and holidays count. This is what converts the raw division into countable laytime once interruptions are applied.
The conversion below shows a single load-port example with representative, anonymised numbers. The same arithmetic runs again at discharge, usually at a different rate, and the two allowances are then either pooled (reversible) or kept separate.
| Input | Value | Notes |
|---|---|---|
| Cargo quantity | 30,000 tonnes | Bill of lading quantity loaded at the port |
| Quoted rate | 10,000 tonnes per weather working day | The contractual load rate fixed in the recap |
| Day definition | Weather working day, SHEX | Sundays and holidays excepted; weather stoppages not counted |
| Allowed laytime | 3.00 days | = 30,000 / 10,000; the budget before interruptions |
| Worked line | 30,000 t / 10,000 t per WWD = 3 days | Quantity divided by rate gives the allowance directly |
The allowed figure of three days is the budget. It is not affected by how fast the berth actually works. If cargo work in fact takes longer than three countable days the vessel goes on demurrage; if it finishes inside three days the charterer earns dispatch. The day definition in the third row is what keeps the conversion honest, because it decides which hours of elapsed time are countable against the budget.
How the rate connects to the laytime regime
The rate does not operate in isolation. It is the denominator of the laytime calculation, which means it touches every clause in the laytime regime. Change the rate in the recap and you move the demurrage exposure, the dispatch entitlement, and the realistic arrival window all at once. The dependency map below sets out the adjacent terms and how each connects to the load or discharge rate.
| Related term | How it connects to the load or discharge rate | Page |
|---|---|---|
| Laytime | The rate sets the size of the allowance: cargo quantity divided by the agreed rate is the allowed laytime, so the rate is the lever that lengthens or shortens the budget. | Laytime |
| Demurrage | A rate fixed too fast to meet at the actual berth burns through the allowance and tips the vessel into demurrage; the rate is the first cause of most demurrage claims. | Demurrage |
| Notice of readiness | The clock the rate is measured against starts only on a valid notice of readiness; an invalid NOR can mean the rate never begins converting elapsed hours into countable laytime. | Notice of readiness |
| Laycan | Terminal rate capacity influences the arrival window, because a berth that cannot sustain the fixed rate makes the laycan and the demurrage budget harder to honour at the same time. | Laycan |
| Dispatch | If the actual rate of work beats the fixed rate, the charterer finishes inside the allowance and earns dispatch on the time saved, conventionally at half the demurrage rate. | Dispatch |
Read together, these clauses form the operational spine of the voyage charter. The rate sets the budget, the notice of readiness opens the clock, laytime counts the budget down, and demurrage or dispatch settles the difference at the agreed money rate. For the wider contractual frame in which these clauses sit, see the ship chartering hub.
How a rate clause is worded
A load or discharge rate clause in a GENCON-style voyage charter does three things: it states the rate, it attaches a day definition, and it says how the rate is to be applied across the vessel’s holds. The annotated wording below is representative GENCON-style drafting, not text copied from any confidential fixture.
Riders commonly bolt on a turn-time allowance before laytime starts, a notice period for the NOR, and a list of excepted periods. The exact words matter: switching a port from SHINC to SHEX, or from a whole-ship to a per-hatch basis, can move the demurrage outcome by a full day or more.
Worked rate-to-laytime conversion
The following worked example (T2) shows the full path from rate to result at both ends, using representative, anonymised numbers.
A vessel fixes a 50,000 tonne parcel of coal on a Panamax, non-reversible laytime, with a load rate of 12,000 metric tonnes per weather working day and a discharge rate of 10,000 metric tonnes per weather working day.
Step 1, allowed laytime at load: 50,000 tonnes divided by 12,000 tonnes per day = 4.17 days, which is 4 days 04 hr 00 min allowed.
Step 2, allowed laytime at discharge: 50,000 tonnes divided by 10,000 tonnes per day = 5.00 days, which is 5 days 00 hr 00 min allowed.
Step 3, time used at load: per the master’s statement of facts, countable time at the load port is 4 days 12 hr 00 min after deducting 6 hours of rain on a weather working day. Used (4 days 12 hr 00 min) exceeds allowed (4 days 04 hr 00 min), so the load port is 0 days 08 hr 00 min on demurrage.
Step 4, time used at discharge: countable time at the discharge port is 4 days 18 hr 00 min, inside the 5-day allowance, so the discharge port saves 0 days 06 hr 00 min.
Step 5, result on non-reversible terms: because the laytime is non-reversible, the load-port overrun and the discharge-port saving are settled separately. At a demurrage rate of USD 16,000 per day pro rata, the load overrun is worth (8 / 24) x 16,000 = USD 5,333 of demurrage payable by the charterer. The discharge saving earns dispatch at half the demurrage rate: (6 / 24) x (16,000 / 2) = USD 2,000 payable by the owner. The net is USD 3,333 owed by the charterer.
Had the laytime been reversible instead, the two allowances would have pooled to 9 days 04 hr 00 min against total used of 9 days 06 hr 00 min, leaving the vessel just 0 days 02 hr 00 min on demurrage and no dispatch. The same cargo facts and the same rates produce a very different settlement purely because of the reversibility term, which is why the rate and the day-counting basis must be read together.
Per-hatch rates, weather terms and CQD
The conventions that govern how a rate is applied are where most rate disputes start. The non-obvious points (T3) are these.
Per-hatch or per-hold rates versus whole-ship rates. A whole-ship rate applies the fixed tonnes-per-day figure to the entire parcel regardless of how the cargo is distributed across the holds. A per-hatch (or per-hold) rate sets a rate for each hatch and works out the allowance on the basis of the largest hold, since that hold determines when cargo work can finish. Per-hatch wording protects the owner where one hold carries a disproportionate share of the parcel, because an even whole-ship rate would understate the time genuinely needed. The exact basis, largest hold, average hold, or a fixed per-hatch figure, must be spelled out, because the difference can be a full day on a multi-hold Capesize parcel.
Weather working days versus running days. A running day is a full calendar day that counts regardless of weather or working hours. A working day is a day on which work normally takes place at the port. A weather working day (WWD) is a working day on which weather permits cargo work, so time during which weather actually prevents loading or discharging is not counted against the rate-derived allowance. The LDCP 2013 definitions distinguish a “weather working day” from a “weather working day of 24 consecutive hours,” and the difference changes how a partial weather stoppage is deducted, so the exact phrase in the clause governs the count.
Customary quick despatch (CQD) where no rate is fixed. Some fixtures, particularly for parcels into berths with no reliable published rate, omit a fixed tonnes-per-day figure and instead require the cargo to be loaded or discharged at customary quick despatch. Under CQD there is no fixed allowance to divide the quantity into; the charterer must simply work the cargo as fast as the custom of the port reasonably allows, and demurrage and dispatch in the conventional sense usually fall away. CQD shifts the analysis from a clean quantity-over-rate calculation to a question of what the port customarily achieves, which is harder to prove and a frequent source of dispute. Owners generally prefer a fixed rate precisely because it removes that uncertainty. Named P&I clubs such as Gard, the UK Club and the North of England club publish claims guidance on rate and laytime wording, and terminal or operator norms published around the major load ports give a sense of achievable rates by berth.
Scope and what this page does not cover
This page explains what a loading or discharge rate is, how it converts a cargo quantity into allowed laytime, how it connects to the rest of the laytime regime, how a rate clause is worded, and the per-hatch, weather and CQD conventions that drive the result. It keeps to dry bulk: tanker analogues such as pumping rate warranties and total laytime work differently and are out of scope here. It does not provide live demurrage or freight rates, which move daily and should be taken from the Baltic Exchange, and it does not give berth-specific achievable rates, which depend on terminal and operator norms at each port. It is not clause-by-clause drafting advice. For a binding calculation on a real fixture, work from the executed charter party and the master’s statement of facts, and take legal or P&I advice on disputed deductions.