Despatch: ATS vs AWTS comparison

Compare despatch payable under 'all time saved' (ATS) vs 'all working time saved' (AWTS) conventions. The two methods can differ substantially when significant time has been excluded from laytime.

CharteringDespatchATSAWTS

Laytime allowedhElapsed clock hours (commencement to completion)hExcluded hours (SHEX, weather, breakdown)hDespatch rateUSD/d

ATS despatch: 22,500USD

AWTS despatch: 27,500USD

Difference (AWTS minus ATS): 5,000USD

Changing the inputs requires JavaScript. The calculator above shows its default inputs and result. The formula, symbols, and regulatory sources are shown in the Formula section below.

Formula, assumptions, and limits

\text{ATS} = (\text{Allowed} - \text{Elapsed}) \times \text{Rate}; \quad \text{AWTS} = (\text{Allowed} - (\text{Elapsed} - \text{Excluded})) \times \text{Rate}

Symbol	Meaning	Unit
$Allowed$	Laytime allowed	h
$Elapsed$	Clock hours commencement to completion	h
$Excluded$	Hours excluded from counted laytime	h
$Rate$	Despatch rate per day	USD/d

Source: John Schofield, Laytime and Demurrage, 8th ed

In short

Side-by-side despatch payable under all time saved vs all working time saved.

Learn the theory Laytime: Voyage Charter Time Accounting