Collision Avoidance, Cones of Uncertainty, and Appropriate CPA

[conachair]

Originally Posted by ramblinrod

Incorrect.

Most Lake Ontario cargo ships are 600 ft long and travel 15 knots +. There are defined lanes north and south of Main Duck Island, but that's it. There are no buoyed channels or fairways.

I don't see any difference. Do you see any difference?

Yes.

Nothing that fast and not much traffic , what there is looks to stay mainly in very predictable tracks.



Busy looks like this...

https://www.youtube.com/watch?v=c01e3Hb1LaQ&vl=en-US

[El Pinguino]

Originally Posted by conachair

Yes.

Nothing that fast and not much traffic , what there is looks to stay mainly in very predictable tracks.



Busy looks like this...

Very predictable tracks? A bit like this?

[conachair]

Originally Posted by El Pinguino

Very predictable tracks? A bit like this?

not much traffic.... ? And an'r quite see the similarity of a little line with some red and a big bit of all red..

lets face it , Ontario looks like a lovely place to sail but not what you'd call busy, is it?

[El Pinguino]

Originally Posted by Dockhead

Two miles is widely considered and widely taught to professionals as a good minimum CPA when traffic allows it. You should know that. By now this is part of the Ordinary Practice of Seamen, Rule 2.

From the story you posted earlier, we can guess that standards of professionalism are quite a bit more relaxed in Argentinian waters, than they are up here. Up here you can't get within a mile of a ship in open water without avoiding action or an angry VHF call.

I should know that? Really.... thanks for the tip.....

Argentinian waters? Not sure where I would find them... and not sure why standards would vary from the norm when I did.

This was in international waters... one Russian ship ... the other one Bahamas registered..... same as most passo boats these days.

Angry VHF calls ?? The air must be blue in the South China Sea....

[El Pinguino]

Originally Posted by conachair

not much traffic.... ? And an'r quite see the similarity of a little line with some red and a big bit of all red..

lets face it , Ontario looks like a lovely place to sail but not what you'd call busy, is it?

When did the degree of 'busyness' enter into the debate... I see no mention of 'busyness' in the rules.......

Oh I see.... one's knowledge base is automatically linked to the number of ships passing one's marina.... I didn't know that...

[StuM]

Originally Posted by ramblinrod

Incorrect.

Most Lake Ontario cargo ships are 600 ft long and travel 15 knots +. There are defined lanes north and south of Main Duck Island, but that's it. There are no buoyed channels or fairways.

I don't see any difference. Do you see any difference?

I looked at Lake Ontario last night on marinetraffic.com and again just now. Not one of the ships was traveling faster than 14 knots. Generally they were travelling at 12-13 knots

[El Pinguino]

Originally Posted by StuM

I looked at Lake Ontario last night on marinetraffic.com and again just now. Not one of the ships was traveling faster than 14 knots. Generally they were travelling at 12-13 knots

So pretty much like most of the world then?

Oooops.... sorry... forgot that this is the 'Let's kick Rod' thread..... my bad.

[evm1024]

Originally Posted by StuM

I looked at Lake Ontario last night on marinetraffic.com and again just now. Not one of the ships was traveling faster than 14 knots. Generally they were travelling at 12-13 knots

Ditto. At the moment there is only one ship showing over 10 kts.

There are some "lakers" that were built that are around 1000' long. But due to the limits of the locks outside of the lakers the upper limits for ship size is 740' long, 78' beam and 26.5' draft.

There are strict speed limits on any of the canals and (non great) lakes of the seaway. See page 50 of the handbook indexed below. This tells us that any close encounter with a ship outside of one of the great lakes will have the speed of the ship limited to less than 10 kts (with an exception or 2) and have the ship limited to specific channels.

It is one thing to stand next to a freeway and watch the cars go by - or to have them go by you at Bonneville salt flats.

http://www.greatlakes-seaway.com/sea...procedures.pdf

Further, as noted by others ships on lake Ontario have a limited number of ports to call on. And if they are transiting Lake Ontario they follow specific routes. The routes are no codified in a VTS but are SOP reqardless. )74, 254 degrees with a 3.5 nm separation as an example. Locking through for ships is not first come first served. Racing to a lock is not really an option.

[Lodesman]

Originally Posted by El Pinguino

So pretty much like most of the world then?

Oooops.... sorry... forgot that this is the 'Let's kick Rod' thread..... my bad.

So most of the world use lakers, then?
Open water for them is a couple hundred miles at a time - the rest of it is speed limited, so it makes no sense to build them speedy.

As to Rod, you have got to be kidding. He has carried on with childish antics, complaining that he hasn't had his questions answered, when 3 or more different people have answered them; ironically refusing to answer questions that are pertinent to the discussion, but he has dismissed as silly (Rod-speak for "too difficult or embarrassing"); and persisting in his ******** suggestion that one can pass a ship going 20 kts by 180 feet, regardless of whether or not you believe ships can go 20 kts, when it is clear he hasn't come any closer than 1/2 mile or even greater to ships in a narrow channel limited to 10 kts. Only reason to keep reading is for the comic relief.

[ramblinrod]

[QUOTE=Lodesman;2509064]
As to Rod, you have got to be kidding.....

Ladies and gentlemen, this is the kind of stuff someone may resort to when they can no longer defend their flawed position with logic and reasoning.

The true answer is, there is very little difference whether crossing a ship at speed in Lake Ontario or any other body of water.

If you mess up and run into one of these ships, you are just as f'd up, as anywhere else in the world.

All Dockhead had to do was pass between 2 ships, 1-1/4 nm apart. Whether the following ship he ran into was in the English Channel or Lake Ontario makes little difference how smashed up his vessel would be.

I don't know why anyone would think we should be impressed by some ridiculously accelerated cartoon video when just two ships to go between is apparently too much.

[evm1024]

I'm thinking that I should take the time to go back through the thread and list the fallacies that I come across.

I could use this as the fallacies list: https://en.wikipedia.org/wiki/List_of_fallacies

Let's play spot the fallacy starting with these two - Appeal to the stone and Shifting the burden of proof.

Lets see - I dismiss your claim as absurd without demonstrating proof and I need not prove my claim, you must prove it is false.

The prevailing logical error is of the ID tenT type.

[Stu Jackson]

Originally Posted by Juho

We don't have record of the course and speed history of the vessels, so it is hard to tell exactly what went right and wrong, or how close to each others the vessels could have crossed. But based of the description of the crossing, it seems that one contributing factor was unwillingness to confuse and cause distress to the other vessel. I'm not sure if this action should be called "wrong". Maybe better "right".

It is possible that he could have taken a more aggressive course, pointing in front of the bow of the ferry, and thereby getting closer or even hitting the ferry. But he decided to follow the spirit of the colregs, and keep his course such that the other vessel would understand that his intention was to cross behind the ferry, not in front of it, and not with a course that would carry with it a risk of collision, or what would seem to the captain of the other vessel as a course that might aim at collision.

Thank you, Juho, that was the flavor of the concept that I envisioned, described and hoped to convey, anticipating a welcoming response, like yours.

[donradcliffe]

Well, you have managed to generate over 750 posts on how WAFI's abuse the COLREGS, so its time for my two cents.

First, I've spent a fair bit of time playing in traffic, like the straits of Mallacca, NY and SF harbor, approaches to the Panama Canal, etc. I'm in Rod's camp when trying to cross a line of ship traffic. I'd much rather come with one cable of the stern of a ship than 10 cables of the bow of the next ship. When I make may turn to cross behind the first ship, I'm using bearing changes to figure out whether I'm going to hit its stern, and, as most bridges are on the stern, the ship' watchkeepers can make the same observations on my little boat. The part that makes me more nervous is watching the bearings on the next ship's bow.

Secondly, I'm not going to stand on if it means crossing within 2 or 3 miles in front of a large vessel in open water. It is nonsense to say that as a WAFI I have no situational awareness. With a Class B AIS I will be aware of the ships before they are aware of me. I usually use that fact to get the CPA where both I and the ship are comfortable with it before they even know that I am there. I'm aware that the professionals average one collision a week by following the Colregs as they are taught, and the consequences of a collision between me and a ship are one sided.

[markpierce]

A frequent tactic of mine is to turn parallel and then duck behind when safe.

[Dockhead]

Originally Posted by donradcliffe

Well, you have managed to generate over 750 posts on how WAFI's abuse the COLREGS, so its time for my two cents.

First, I've spent a fair bit of time playing in traffic, like the straits of Mallacca, NY and SF harbor, approaches to the Panama Canal, etc. I'm in Rod's camp when trying to cross a line of ship traffic. I'd much rather come with one cable of the stern of a ship than 10 cables of the bow of the next ship. When I make may turn to cross behind the first ship, I'm using bearing changes to figure out whether I'm going to hit its stern, and, as most bridges are on the stern, the ship' watchkeepers can make the same observations on my little boat. The part that makes me more nervous is watching the bearings on the next ship's bow.

Secondly, I'm not going to stand on if it means crossing within 2 or 3 miles in front of a large vessel in open water. It is nonsense to say that as a WAFI I have no situational awareness. With a Class B AIS I will be aware of the ships before they are aware of me. I usually use that fact to get the CPA where both I and the ship are comfortable with it before they even know that I am there. I'm aware that the professionals average one collision a week by following the Colregs as they are taught, and the consequences of a collision between me and a ship are one sided.

Everyone agrees that if you are trying to get between two ships travelling in a line, that the closer you can pass behind the ship ahead, the more room you have to the ship behind. That is extremely obvious.

The controversy was over how close it is possible to get to the ship ahead, without an unreasonable risk of getting run down by the ship AHEAD. The key is the difference in speeds and the angle of approach which results from this difference in speed. If you and the ships are travelling at similar speeds, say no more than 2:1 difference, then you can get very close to the ship behind -- once you see his transom, as we all know, there is no danger already. But at 4:1 it's a WHOLE different ballgame. I doubt if anyone is going to be interested in re-hashing the discussion yet again -- we did it pretty much to death -- but if you read through the thread, you'll get all possible points of view and you can choose for yourself.

Cheers.