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IntoMyHealth · 11-12-2016, 19:35

Thinking ahead about some trips next year I have seen the term, "Traffic Separation Zone" designated on some of the legs (usually around more congested areas) of my routes. At least that's what they're called in Navionics. Traffic Separation Schemes appears to be the official term, maybe I'm wrong. I'd appreciate input on these areas, what they mean, and how they play out in practice to cruisers.

Jd1 · 11-12-2016, 19:55

The equivalent of a yellow dashed line on the highway .... traffic goes one way on one side and the other way on the other side. Although there is a bit more to that which many people will no doubt point out, this is the easiest to explain it

Our charts up here indicate which way the traffic goes .... no idea how you are supposed to figure it out from your chart <shrug>

**Paul Elliott** · 11-12-2016, 20:12

If you want to get really confused about TSS lanes, come on over to the discussion that started with the ferryboat / powerboat collision: http://www.cruisersforum.com/forums/...de-176756.html

It's actually pretty interesting.

conachair · 11-12-2016, 22:40

IRPCS rule 10 tells you all you need to know

Teknishn · 11-12-2016, 23:07

Jd1's simplified explanation pretty much sums up what a TSS is. My Navionics (Platinum Plus) charts also do not indicate traffic directions here in the Red Sea for the Suez canal and the Straits of Gubal or Tiran. I think that it is just assumed, unless noted elsewhere on a chart, that vessels are to pass port-to-port. As to how it pertains to cruisers, which I am admittedly not at the moment (however I do occasionally get underway in these areas for sea trials deliveries, and heading to dive destinations), the TSS indicates areas of the presence of commercial traffic (i.e. vessels restricted in their ability to maneuver, stop, etc.) and thus forewarns cruisers of the presence of bulk carriers, barges in tow, supertankers, etc. so that they can plan accordingly and increase vigilance while transiting these zones.

conachair · 12-12-2016, 00:07

Another useful resource is the marinetraffic density map, shows 2 years of tracks:

http://www.marinetraffic.com/en/ais/...tery:42/zoom:8
5th menu button down on the left.

The TSS show up on navionics web app..

Navionics Webapp

chuckr · 12-12-2016, 00:47

We have seen a lot of TSS as we have sailed both the Carib, Med and Black Sea. They show on both our Navionics and OpenCPN charts. We have had to cross them at right angles sailed the same directions. With AIS it sure makes it easier to discuss crossing with other boats on how we can avoid each other. When we sail the same direction we try to stay out of the zone, ie on the outside of it we are slower than the boats in it. Only time that did not work was rounding the Crimea in the Black Sea as the Russia CG saw us outside of it and called us on the radio and I acknowledged I was outside the zone and had just turned to enter the zone and would stay in it.

as above total vigilance is required in them and AIS is a huge help as you can see each other. We were crossing from Sardinia to Tunisia one night and had to cross a very heavily traveled zone and saw a passenger ship coming up behind us and called him and we agreed that I would turn 5 deg to port and he would turn a bit to starboard and we would have a good pass. A bit after that we had a boat entering in front of us and we called him and he said yes he sees us and wanted us to turn 10 deg to starboard and I said I could not as there is a passenger ship and I just turned to port to miss him - I suggested he call the passenger ship and work it out I would listen in and do what they agreed to. I did and they agreed and I told to both I would make the course and speed correction and we had a safe passage.

Time2Go · 12-12-2016, 01:10

You cross a separation zone with a heading always 90 degrees to the zone.
Don't crab or make course alterations to make the actual crossing or COG
90. This way other boats transiting within the zone see you beam on
and have an expectation that you are intending to cross
If you crab to adjust for set and drift they are going to think you
are either intending to join or leave the lanes of the zone and are not just crossing.

Cheers
Neil

gamayun · 12-12-2016, 07:48

Another thought when crossing a TSS in busy port areas is to plan it for day light hours, if you can.

Suijin · 12-12-2016, 08:00

Basic rule of thumb: avoid them if at all possible, and when crossing, go fast and go 90 degrees straight across. As gamayun suggested, if you can reasonably avoid tangling with them at night you'll breathe easier. Gauging distances and speeds at night can be very challenging and in busy lanes figuring out when and where to cross can be anxiety provoking. Having AIS helps a lot in those circumstances.

I'm very familiar with the TSS's at the mouth of the Chesapeake, which is a choke point for commercial marine traffic going to and from Norfolk, Baltimore, and everywhere in the Bay, not to mention the Navy ships that go in and out including submarines and aircraft carriers. I've had to deal with it at night quite a few times, and at night it can really set your teeth on edge. In really busy areas the Harbormaster will reach out to you and give you instructions which you would do well to follow.

Different ports have different levels of traffic, but if they have TSS zones it's a good bet that there's heavy enough shipping that you should be on your toes and thinking ahead to how you're going to deal with them.

Stumble · 12-12-2016, 08:26

As a rule of thumb, stay as far away as possible from a TSS.

But as a quick primer, TSS' are generally made up of three zones, the separation zone (median of a highway), the traffic zone (the lanes), and the inshore zone. No one should ever be in the separation zone except while crossing, performing maintenance on the zone or to avoid a collision. It's a no go zone for all intents and purposes and you better have a good reason for being there.

Large ships are obligated to use the traffic zones, and only the traffic zones. Vessels under 20m and sailboats (while sailing) are always the burdened boat. Unlike in normal operation inside the traffic zone <20m craft are obligated to stay clear and are always the give way vessel. Given the speed delta between what a cruiser can do and the speeds commercial vessels maintain it means you will generally be giving way to vessels passing you up, and must get out of their way.

Finally the inshore zone is for small vessels, local traffic, and recreation. If you have to be present in a TSS make sure you are in the IZ and only cross to a TZ when absolutly necessary.

Also it is a good idea to remember that large vessels may take miles to turn around or slow down, so constant radio watch, radar watches and AIS watches are required. But n many TSS' there is also now a growing requirement that you have AIS to traffic the zone (other than crossing) even for vessels that otherwise wouldn't be required to carry one.

Finally in the heaviest traffic areas (like the Lower Mississippi) every vessel, even those just crossing the stream are required to check in and out of the scheme with the controller, and maintain triple radio watches. Usually on the bridge-to-bridge channel as well as a local channel, and as always maintain ch16 monitoring.

Again it depends on the TSS but since I know the Lower Mississippi... you are also responsible for knowing local conditions, because passage rules can change depending on the weather. On the LMR for instance if river height is above 15' you must maintain a minimum speed of 10kn. In fog they can issue an 'all red' meaning that all traffic is suspended, or a 'half red' where traffic is shut down to one way for a period of time.

You really need to find and read the guide book for the TSS you are in and become familure with the rules. Because the guys who run those waters all the time are very serious about keeping traffic moving in them.

**Paul Elliott** · 12-12-2016, 08:28

In some situations it can be useful to listen to VTS (Vessel Traffic Services) on the VHF. At least in San Francisco, VTS makes regular broadcasts, announcing ship traffic entering and leaving San Francisco Bay.

Having AIS is great, but it doesn't tell us when a ship is about to head out under the Golden Gate bridge because of how all the TSS traffic lanes converge inside the Bay. Especially in foggy weather it can be quite difficult to know if it's safe to enter the Bay, since the channels and entrance are narrow, there are shoals offshore outside of the lanes that can have breaking waves, and the currents can be stiff.

When entering the Bay in these conditions I will listen to the VTS broadcasts, and on occasion have called VTS to ask if there are any ships heading out. They have always been very helpful. You can find the particulars for each VTS region through the USCG website, or in the Coast Pilot.

IntoMyHealth · 12-12-2016, 11:29

Great responses. So, either fall in line or cross at 90 degrees. Always keep your radio on (and listen). AIS and RADAR are extremely valuable. Oh yeah, and eyes. Do I have it?

The TSS actually does show up upon zooming in a bit on the Navionics app.

Suijin · 12-12-2016, 11:39

Quote:

Originally Posted by IntoMyHealth

Great responses. So, either fall in line or cross at 90 degrees...

No, don't fall in line in the TSS. STAY OUT OF IT unless it's impossible to do so. Run parallel to it until it ends and even then be very careful of ships entering it and exiting it.

They are a means of organizing big heavy fast slow to maneuver/stop ships. It's like a landing pattern of jetliners around an airport, and you're a little drone. Stay away. It's not for you.