Distances & Tonmiles Methodology
Voyage distances in the Oceanbolt platform are calculated in two ways:
Calculated Distance - measuring the shortest distance port-to-port of the voyage route
Actual Distance - measuring the length of the AIS track for the duration of the voyage
These two distance measures form the basis for tonmile calculations and provide the basis for Calculated Tonmiles (i.e. using the Calculated Distance) and Actual Tonmiles (i.e. using the Actual Distance).
In addition to Tonmiles, Oceanbolt also provides Tondays, which you can refer to as “volume x duration”. The Tondays are calculated as volume x total duration of the voyage [in days].
Tonmiles for Parceling Voyages
For parceling voyages, Oceanbolt uses the following logic for tonmiles.
Take an example of a voyage with a load event in Australia (specifically, Iron Ore in Port Hedland) and two discharge events (First to Caofeidian, China, and then to Incheon, Korea).
This voyage will generate two cargo flows:
Flow 1: Iron ore, Port Hedland -> Caofeidian
Flow 2: Iron ore, Port Hedland -> Incheon
For calculated tonmiles the distances that are used are:
The shortest route from Port Hedland to Caofeidian for Flow 1
The shortest route from Port Hedland to Incheon for Flow 2
For actual tonmiles the distances that are used are:
The length of the AIS track from Port Hedland to Caofeidian for Flow 1
The length of the AIS track Port Hedland to Caofeidian and then to Incheon for Flow 2