Why Do MASSIVE Ships Play Chicken?

what if i told you that every single day massive ships play chicken in the classic example of the game two cars are on a road approaching a single track bridge each continues at speed in the hope that the other one will swerve out of the way making themselves the chicken if both cars continue straight however they will collide and annihilate each other well what if instead of small cars we have cargo ships carrying thousands of tons of fuel or chemicals and instead of the bridge we have a narrow channel where both ships need to be in the middle as the distance closes both ships start to get more nervous until they reach a critical point where they both chicken out they each alter course to starboard at the last minute heading towards the banks on opposite sides of the canal it looks like they're both going to go aground but then miraculously they bounce off just as the ships draw level they got away with that bit but now it looks like they will instead run aground against the other side of the channel just as it looks like all hope is lost their stones draw level and the second bit of magic occurs the forces between the sterns suck them together drawing them back to the center line from where they can safely continue their passage okay i may have over dramatized it a little but what you've just seen is an actual shipping maneuver based on the game of chicken it's actually called appropriately the texas chicken and it occurs in the houston ship channel which runs from the gulf of mexico right the way up to the city of houston in texas if there was just one ship it could happily travel up the center of the channel all the way to its berth but as it's around 50 miles long reserving the channel for one-way traffic isn't exactly realistic no you need to find a way for ships to pass the channel itself is physically wide enough to fit two ships side by side but when the ships are that big they can't actually navigate down one side of a narrow channel do you remember the ever given i haven't covered that incident on this channel yet although i did put a video out in the casual navigation community at the time in fact i've recently upgraded the community so if you enjoy my content you should definitely come and check it out you'll get exclusive access to a community where you can get help learning about maritime subjects or just feeding your curiosity higher tiers also get bonus content like two exclusive video podcasts every month free access to my personal image library and now i'm introducing a monthly q a session for any questions about the channel the industry or just a little help with your studies i'm not going to tell you that i need members to sustain this channel but i'm not going to lie to you either every member does help me create content by reducing my reliance on ads and sponsors so i'm genuinely grateful for every member that joins anyway i got off topic a little there as i was just saying how the ever given is probably the best recent example of a thing called bank effect and interaction in open water where pressure areas that develop around a ship's hull there is a high pressure area around the bow where the water is heaping up as the ship is pushing it out of the way along the sides of the ship there are low pressure areas culminating in the very lowest pressure area just in front of the propeller the final bit is the extreme high pressure just behind the propeller where the water's being pushed backwards propelling the ship ahead in open water these pressure zones don't really change much but when things become more confined interesting effects happen if i introduce a bank along the ship here the high pressure area at the bow is going to tend to push the bow away from the bank similarly at the stern the low pressure area is going to tend to suck the stern towards the bank this is bank effect with a single bank on one side it will tend to turn you away from the bank when you introduce a second bank however bank effect will turn you towards that side instead this is the best estimate of what happened to the ever given an initial gust of wind blew her sideways towards one bank bank effect then kicked in turning her towards the other side in an attempt to steady up they will have applied starboard helm but as she was already heading off towards the other bank she started interacting with that too the bow would have been pushed off to starboard the stern will have been sucked to port and maybe the rudder wasn't able to get over in time to compensate so she ran aground with a narrow channel and a large vessel the only way is to navigate in the center of the channel and attempt to keep all the forces in balance that's fine until two ships traveling in opposite directions both want to use the center of the channel if they each move to one side to let the other pass bank effect kicks in and risks pushing them into the path of the other vessel if you attempted to correct it with the rudder the positive pressure at the bow and the rudder movement at the stern will tend to walk the ship sideways back into the center of the channel it's no good instead you want to time the maneuver and work with the bank effect stay in the center of the channel until pretty much the last minute then and only then alter course to starboard and move off the center line of the channel as your bow approaches the side bank effect will act as a cushion straightening you up you're aiming to be straight just as the other vessel approaches the pressure area from the other vessel's bow then counteracts the bank effect keeping you straight as your bowels pass as you continue past the other vessel you'll start to feel the interaction forces again not only from the bank but also from the lower pressure areas along the side of the other vessel once your bow is past the stern of the other ship bank effect alone is acting to push it back towards the center of the channel your stern however is still under the influence of the forces generated by the other vessel as well as the bank bank effect is trying to suck your stern in but the low pressure areas around the other ship are overpowering it and acting to draw your stern out sucking the two vessels together done correctly as your two vessels draw clear of one another you should both be back in the center of the channel free to continue your passage to the outside observer it looks as if two massive ships were literally heading straight towards each other in a reckless game of chicken that might have devastating consequences in reality however communication between the two vessels turned it from a game of chicken into a pre-planned maneuver in the traditional game there are two possible actions for each person straight or swerve when both go straight both lose when one swerves and one goes straight the one that went straight is declared the winner and the other the loser or chicken if both decide to swerve then no one wins outright so no one gets bragging rights but everyone survives the key is that you don't know what the other person is going to do logically they should swerve as it will keep them alive but if logic says the other should swerve then why not stay straight yourself and claim an overall victory this is where communication comes into it turning a texas chicken from a game into a pre-planned maneuver you've both agreed to swerve eliminating the possibility of annihilation but also eliminating the possibility of overall bragging rights when it comes to tens or hundreds of thousands of tons of deadly cargo however bragging rights are irrelevant although it looks like a game of chicken it's actually just two professional crews utilizing the physics of interaction to best pass one another in a narrow channel

Channel: Casual Navigation

Views: 1,091,278

Keywords: casual navigator, marine, shipping, casual navigation, maritime explaination, merchant navy, sailing, marine animation, texas chicken, interaction, bank effect

Id: mGJa2dAlhDg

Length: 7min 0sec (420 seconds)

Published: Fri Aug 12 2022