The calculations involved are based on PIANC (The World Association for Waterborne Transport Infrastructure) guidelines.

The calculations take into various key factors that include: wind, current, waves, ship particulars (dimensions, displacement, projected areas, UKC), berth characteristics(depth, type) and tug characteristics (bollard Pull, winch-type and effectiveness ).

There are few other factors to be kept in mind that are not included in the App, such as yaw, trim, towing angle, tug propeller wash, tug position relative to the ship pivot point, length of towline, ice conditions and age of tug.

The App can be used as a preliminary design method to determine the total bollard pull required to berth or un-berth ships or to determine the number of tugs required based on the bollard pull of each tug.

The preliminary design results can then be tested in a berthing/un-berthing simulator to confirm and /or finalize the results.