A claim is won on the timeline, not the total

The figure at the bottom of a laytime calculation is never what a claim turns on. What turns it is whether a particular six hours was weather, whether the notice of readiness was valid when it was tendered, and whether the charterparty said the clock ran on that Sunday.

So the sheet here is a timeline first and an arithmetic second. Each row is an event with a time and a reason. The allowed, the used and the difference are computed from the rows, which means a disagreement about the total is always a disagreement about a row you can both point at.

The statement of facts, read rather than retyped

A port agent sends a statement of facts as a PDF, and frequently as a scan of a signed one. Retyping thirty timestamped events out of it is where the errors enter, and it is also the job nobody wants at five o'clock.

Upload it and the events are read out of the document into the sheet, scans included. Every row lands as a draft for a broker to check against the paper, because a misread hour in a demurrage claim is money and the software is not the one signing for it.

What it computes

Allowed laytime

Chartering and above

From the charterparty rate and the quantity actually loaded, taken from the bill of lading rather than the figure written into the charterparty. On a cargo described as 30,000 tonnes with a ten per cent option, that difference is nearly nine hours.

Time used, with exclusions

Chartering and above

Weather working days, SHEX and SHINC periods, breakdowns and shifting, each excluded with the reason attached rather than netted off invisibly.

Reversible laytime

Chartering and above

One allowance across both ports when the fixture says so, or each port measured against its own, which can owe demurrage at one end and earn despatch at the other.

Demurrage and despatch

Chartering and above

At the fixture's rates, with despatch at half demurrage where that is the convention and at whatever the fixture actually says where it is not.

The time sheet as a document

Chartering and above

Issued as it stood when it was issued. The archive keeps the copy that was sent, not a regeneration from data that has moved since, because the thing being argued about is the document the other side received.

Try the arithmetic before you buy anything

There is a free laytime and demurrage calculator on this site. No account, nothing stored, and it runs entirely in the browser. It does the same sum this does; what it does not do is hold the statement of facts, the fixture it belongs to, or the document you issued.

The free calculator, the worked example, or what the desk costs.