Found on YouTube. Created by "Dleep Fotedar". Originally published on 2021-01-29.
Educational and descriptive video Join the conversation...
MH
Mike Harrison
United Kingdom
on 22 September 2023, 11:38 UTC
I'm an Engineer, not a Mariner, but the physics are fascinating and I've experienced bank effects first hand on a number of transits. Closely related issues apply to moored vessel motions caused by passing ships and there are a few great YouTube examples of the initial big surge of a moored vessel, counterintuitively towards approaching passing ship (which can render the spring lines), before the onset of yaw and sway which, more dangerously, can render or break bow/stern lines. Speed, distance, draft, seabed profile and the inclination of approach (i.e. maybe not parallel on river bend berths etc) all play a big part. I've used high end PPUs to monitor and analyse moored vessel movements and the results are fascinating, sometimes alarming as the loads can quickly exceed the winch/bollard/line capacities.
A moored vessel will continue to oscillate for a long time after the other ship passes, which slows/delays cargo transfers, even if the moorings remain intact. Ships get bigger, docks and rivers don't, so clearance and speed are the key controllable factors.
A moored vessel will continue to oscillate for a long time after the other ship passes, which slows/delays cargo transfers, even if the moorings remain intact. Ships get bigger, docks and rivers don't, so clearance and speed are the key controllable factors.
on 4 July 2022, 14:55 UTC
Good representation of the specific aspects. One other aspect that appears to left mute is the fact that it is Speed Through Water that is the important factor. Working as a Pilot in a district where neap tides rates can range between 1.5 to 3.8 knots, and with Spring Tide Rates between 2.6 and 5 knots (subject to location); it is two widely different scenarios going with the tide as apposed to against the tide.
We experience all the aspects frequently within our district.
We experience all the aspects frequently within our district.
on 30 June 2022, 16:53 UTC
This is a very clear and helpful presentation about shallow water effects etc. However, please note that the equation of Bernouilli contains v^2, meaning that all effect are in square when the vessels speed is double. In my opinion this is very important for pilots/captains to understand. Again well done!
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