PROTIDE PoLB

UKC safety with PROTIDE

PROTIDE has been implemented as a service for the Port of Long Beach (California). PROTIDE analyzes UKC safety for transits to Berth 121 for tankers with a deadweight over 175000 DWT or with a draft over 55ft. A transit is considered safe, when there is at least 10% UKC and the ship motions do not exceed this threshold. PROTIDE produces transit time windows where these conditions are met. PROTIDE for the Port of Long Beach is operational since the first quarter of 2016. By using PROTIDE, the maximum draft of vessels coming in to the Port of Long Beach has safely been increased from 65ft to 69ft.

Transit time window calculation

To analyze a planned transit, PROTIDE combines astronomical water levels (compared to the LA tide gauge), tanker dimensions and load data received from Marathon Petroleum (formerly known as Andeavor and Tesoro Corporation), channel depth based on soundings produced by NOAA and predicted wave conditions by NOAA NWPS (Nearshore Wave Prediction System) and CDIP (wave buoy driven forecasts and measurements). The static keel clearance is determined by considering the water level, channel depth and ship draft. Squat and ship motions are analyzed using ABB OCTOPUS by calculating the possible response of the ship to expected wave conditions. The result shows a dynamic keel clearance analysis and safe transit time window to enter the port.

The results are are validated by real life on board measurements of ship motions (roll, pitch, heave) during the transit, which are used to determine the vertical motion extremes. Wave buoy readings are imported and the measured motions are compared, to validate used error margins and improve the setup.