Bollard Pull Calculator App Updated

The smart phone “Bollard Pull Calculator” app produced by Captain M. Baykal Yaylali some four years ago has now been updated and expanded in function.

The required tug power and number of tugs needed in variable wind and current currents is typically an assessment made by pilots based on their professional experience. However, these assessments can raise questions from lawyers if something goes wrong, says Yaylali.

“A pilot has not so much time,” he says. “For a pilot, if tugs are needed, it is hard to calculate the required tug power just before or during ship manoeuvring. Furthermore, the more extreme the weather conditions become, the less accurate assessments are and the higher the risk of too little tug power.”

The Bollard Pull Calculator Yaylali has developed calculates in an approximate way the total required tug power for ships in various conditions. It is based on the calculations and graphs shown in chapter 5 of the book “Tug Use in Port” written by Captain Henk Hensen FNI; first published in 1997 by The Nautical Institute, London, UK, with a third edition published by The ABR Company, UK, in 2018.

Formulas of linear and non-linear regressions have been obtained from academic and scientific studies and digitalized for use in the application. (These include: BS 6349-1, OCIMF Mooring Equipment Guidelines (MEG4) 4th Edition 2018, SIGTO’s Prediction of Wind Loads on Large Liquefied Gas Carriers (2007), Post-Panamax Full Loaded Cond. Jare, Andersen I.M.V. (2003), Parameter identification of wind loads on ships, Werner Blendermann [1993])

The app has been tested and in use for over five years and has been observed to work well.