To my embarrassment and astonishment, I learned that the Dali, built by Hyundai Heavy Industries in South Korea, meeting the designs of the owner Oceanbulk Maritime SA and ocean transport service Maersk:
https://en.m.wikipedia.org/wiki/MV_Dali
was “a single screw.” I incorrectly assumed at least “twin screws” - 1 port side plus 1 starboard side.
A single screw boat / ship / vessel is prone to the propellor “walking” (known as paddlewheel effect or asymmetric blade thrust) - partcularly when the vessel is set to run in Reverse motion.
From the rear view: A right hand prop rotates clockwise when the vessel is set to run in Forward motion . . . and counter-clockwise when the vessel is set to run in Reverse motion.
In Reverse, the stern of the vessel “walks” to port - to the left.
(In my previous considerations (twin screws), I imagined that, in Reverse, only the starboard prop was functioning during the emergency reverse. And thus, ONLY the right rear of the ship was pulling toward the rear.)
So, in the crosswind of 8 knots from the east “working” on the very high and large “sail” of the vessel+containers ship heading southeast, and now including the prop “walking” the stern to port . . . the FSK Bridge support was in the way.
The ship has 1 stern rudder, plus 1 bow thruster.
When in forward motion (”under way”) and very heavy, but single screw in reverse, the rudder is initially not a significant contributor. The bow thruster also not much help - if it was working.
The container ship was being piloted by local pilots at the time of the collision, not its own crew, according to CNN. Local pilots, who are familiar with the harbor, are used to move cargo ships out to open water in hopes of avoiding accidents.
Also: The Singapore-flagged ship, called DALI is chartered by the Danish shipping company Maersk, the company told CNN. The ship was carrying Maersk customers’ cargo, according to the company, and was on its way to Sri Lanka from the Baltimore Harbor.
https://www.dailywire.com/news/8-people-were-on-baltimore-bridge-at-time-of-collapse-ship-issued-a-mayday-before-collision-authorities
Thanks for the information.
Don’t be too embarrassed or hard on yourself...if you know the difference in ship handling that exists between a single screw vessel and a multi-screw vessel, then you are ahead of the game.
I haven’t had time to look at it in much detail, but I do appreciate the information.