Ais - Page 2

donutsina911 · 21 February 2006, 19:31

Quote:

Originally Posted by badbaws

The trouble with being an OOW is that you honestly can't rely on other people doing the right thing when you are on a ship.. people get curious of grey ships and come and visit us... but passing a cable down our ship's side whilst we are in a narrow channel to have a look isn't the nicest thing you can do to us.

Also my previous statement said that big ships like a mile around them in open sea.. in coastal waters you hope for 3 or 4 cables.. that said our ship radars are reliable to +/- 2 cables.. before you add in the effect of weather..
I also work on Grey funnel ships and go out of Pompey aswell as Southampton. SO my humble advice is big ship keep clear(In coastal waters)!! Act within in the colregs if you know them if you don't go get a copy now..
Incidentally a 4000 tonne Destroyer or frigate is not a big ship.. Ours start at 7000 tonnes.. up to 50,000 tonnes.. a UK aircraft carrier only weighs 27,000...

That was my point, abide by the Colregs and the OOW will have a far easier job - he/she will be assuming that you do follow them, with the caveat that you may not, with the likelyhood of having to react to poor seamanship greater or less depending upon vessel type (gin palace at one end of the spectrum and say, the wightlink ferry at the other) Incidently, a 4,000 tonne FF/DD looks pretty big from the jockey seat of a RIB when it's bearing down on you at 30knts and in the scale of things for most users of this forum, its pretty big.

havener · 22 February 2006, 17:52

Interesting debate, this one.

To add another commercial perspective - do we detect ribs by radar from the bridge? Usually not (I drive rather large tankers) but we do get enhanced pickup if they either have (a) a hulking great A frame or (b) an active radar transponder. The active transponders are superb, with a direct feed into the AIS system you can identify virtually anything.

As for the colregs, they're fine...BUT, and it's a big but - most of the time, in coastal waters we are classed as a vessel restricted by draught - i.e. we have very little room to move, so we may not do what the book says. Having said that, we also display the appropriate lights and marks...but how many leisure boaters really understand those ?

In many port areas these days, we're under "active escort" - i.e. a tug behind has a line attached at all times (introduced following the Sea Empress spill). It's not unknown for yotties to not appreciate this, and try and skirt around the stern quickly....makes life interesting for the tug crew, and usually send the pilot boat into a frenzy :-)

houser · 22 February 2006, 21:55

Yes, very interesting reading,

Trying to be safe in the way of big ships is obviously paramount...
So really then, having a radar on your RIB does not make you more visible at all. I allways thought so...please comment on that if you will..
Meaning you need an active radar transponder on a RIb with a radar too...

best regards
jtm

Quote:

Originally Posted by havener

Interesting debate, this one.

To add another commercial perspective - do we detect ribs by radar from the bridge? Usually not (I drive rather large tankers) but we do get enhanced pickup if they either have (a) a hulking great A frame or (b) an active radar transponder. The active transponders are superb, with a direct feed into the AIS system you can identify virtually anything.
¨

jwalker · 22 February 2006, 22:38

Quote:

Originally Posted by havener

Interesting debate, this one.

Agreed.

Quote:

Originally Posted by havener

...we also display the appropriate lights and marks...but how many leisure boaters really understand those ?

Seeing marks at a mile without binos I find virtually impossible. And to identify them I need to be considerably closer than you professionals would like me to be.

Rogue Wave · 23 February 2006, 00:02

Quote:

Originally Posted by jwalker

Seeing marks at a mile without binos I find virtually impossible.

It's a lot easier when you're sober.

havener · 23 February 2006, 10:40

A mile ?

I'm sat on the bridge in a snowstorm at the moment - I can't even see the bow!!

Jimbo · 23 February 2006, 10:45

Quote:

Originally Posted by havener

I'm sat on the bridge in a snowstorm at the moment - I can't even see the bow!!

I'm guessing that's a slightly unnerving experience.

jwalker · 23 February 2006, 11:10

Quote:

Originally Posted by Rogue Wave

It's a lot easier when you're sober.

an oww wud yew noe dat yew nobbur

Steve Waters · 23 February 2006, 20:54

Some really intersing stuff from badbaws ; thank you!
When I go out on the Solent I look at the big ships with considerable awe! I am really happy to hear a bit of advice on the amont of respect I should be showing. I've done RYA 2 but obviously still know very little. I have always looked at the big boys and thought (never having raced them) that they were crawling along at 5 or 6 knots!!
Now I know better than to even cross a bow with my meagre 30hp.
Thank you badbaws and you others who have contributed.
Steve Waters

The depth of H2O varies according to whether you set your sonar.........

badbaws · 24 February 2006, 01:57

One of the Southampton Pilots who has recently been lecturing us at college, quite often comes up the Solent at approx 15 knots slowing down for the bends at Calshot. Bear in mind dead slow ahead on most ships is around 5/6 knots.. slow ahead is up to about 8 knots. As soon as a ship slows down your steering drastically reduces, and bear in mind some commercial ships go up and down Southampton water with only a metre below their keels.. this affects ships big time and reduces their turning capability too. So yes if at sea fine, but in shallow congested waters, with a large draught it can be nerve racking.. especially in fog with 50metres visibilty.. yes sometimes it just decends in the middle of a pilotage and you can't really stop or you will end up aground.. so all we ask as ship drivers is consideration that we may want to get out the way of someone but that may involve beaching a big ship and causing lots more damage.. so help us to like RIB's (but obviously still hate WAFIs.... )

Richard B · 10 April 2008, 16:21

www.shipais.com and www.john-ambler.com

I'll never get any work done now!

BruceB · 14 April 2008, 21:44

I know what you mean, its fascinating watching the ships I know wandering about the country.
The various NLB ships, ferries and other small cargo vessels that I see around the Clyde and Forth of Lorne, its fascinating watching where they are off to when they leave here.
Other things as well like the new type 45 HMS Daring, she has been wandering up and down the Clyde for the alst few days. I wonder what she is up to, trials?
On another tack for the Channel and since I decided not to fit radar after all, mainly because of the expense and hassle of fitting it on such a small craft, is there such a thing yet as waterproof AIS suitable for a RIB at a reasonable cost? Something like the NASA one but that doesn't leak?

Poly · 14 April 2008, 22:42

Quote:

Originally Posted by BruceB

On another tack for the Channel and since I decided not to fit radar after all, mainly because of the expense and hassle of fitting it on such a small craft, is there such a thing yet as waterproof AIS suitable for a RIB at a reasonable cost? Something like the NASA one but that doesn't leak?

Bruce, not sure if there is a fully waterproof unit off the shelf - but you can get AIS to feed into various chartplotters (sods law will be not yours!) and as the box itself needs no user input it could be hidden inside console and if necessary inside an IP67 box. I think someone else may have discussed this here before - otherwise it must have been in a magazine like PBO recently.

Richard B · 15 April 2008, 10:47

Quote:

Originally Posted by BruceB

Other things as well like the new type 45 HMS Daring, she has been wandering up and down the Clyde for the alst few days. I wonder what she is up to, trials?

Yes... "stage 2" apparently.... http://www.baesystems.com/ProductsSe...ct_type45.html

joakimhansson · 13 May 2008, 18:51

http://www.siitech.net/VTSLite/AView.aspx

JABS · 14 May 2008, 13:23

Quote:

Originally Posted by joakimhansson

http://www.siitech.net/VTSLite/AView.aspx

This is absolutely brilliant, but why does it onbly cover certain geographical areas?

Does anyone know?

Richard B · 14 May 2008, 13:46

Beause he's only receiving data forwarded from certain areas. You or I could put up a pole on our roof and then upload our local AIS broadcasts to his site. Obviously it would be better if we lived near the coast, but that's the principle of the thing. http://www.siitech.com/files/doc/aissvr_sp.pdf