Condor ferry & Fog!

[Capt Cautious]

From how far away would someone on the Condor be able to hear a standard foghorn?

Fog sigs - Approx 2 miles.

I frequently have small vessels appear and then disappear, their aspect, radar reflectivity, and the vertical beam characteristics all play their part. One way around this problem is to use trails judiciously - that way you can pick up the faint trails of poorly reflective vessels, floating objects, helicopters etc, that appear every 3 or 4 sweeps.

CC

 

[Ubergeekian]

Fog sigs - Approx 2 miles.

In the bridge? Or do they have someone listening outside? A microphone?

 

[Capt Cautious]

In the bridge? Or do they have someone listening outside? A microphone?

It is a requirement of vessel construction that if you have an enclosed bridge you must have monitoring devices fitted externally.

CC

 

[Capt Cautious]

Sound sigs

Ubergeekian - you asked for "standard sound signals" - I quoted 2 miles - however - if you were actually looking for the audible range of say, a fishing vessel less than 20m in length, rather than a standard commercial vessel - Annex III of colregs. 0.5 miles. Thats "audible range". The criteria are fairly well described.
CC

 

[Capt Cautious]

Fog signals

Its an interesting point, but even if the fishing vessel was sounding a signal at 1 minute intervals - the ferry would probably never have heard it. She was doing approx .6 miles a minute and the signal was probably only audible at 0.5 miles. This really does start to show that rules are seriously groaning under the weight of progress, and the cracks are starting to appear. Standards have now dropped so far as to be practically irretreivable - we need rules that cater for the lowest common denominator, not ones that need lawyers, either in the focsle or ashore, to decode. A bit of seamanship wouldnt go amiss either.
CC

 

[timbartlett]

Mr TB , I suspect you should re read the MAIB report before making any further comment on the conduct of the officer of the watch.

I know it has become some kind of hobby for one or two people on this forum to try to find fault with anything and everything I say, but it is pretty stupid to try to do so when I am simply reporting the content of published reports. Please look again at what I said, and then follow your own advice, and look at the MAIB report:-
I wrote:

IIRC, the watchkeepers on the Pride of Bilbao believed they had had a near miss, and both believed they had seen the lights of the yacht astern of the ferry afterwards.

The MAIB report http://www.maib.gov.uk/cms_resources/Ouzo_.pdfsaid
2.8.7 Conclusion
Ouzo probably passed within 20 metres from the bow of Pride of Bilbao, and then passed close down the windward side of the vessel and out into her wake. Ouzo’s navigation lights remained on for a period, despite the yacht being catastrophically affected by the encounter.
The officer of the watch on Pride of Bilbao did not positively seek confirmation that the yacht and her crew were safe after the near collision because:
o The second officer believed that he had passed a safe distance from the yacht;
o The second officer believed that the sighting of a single red and/or white light astern was sufficient proof that the yacht was safe;
o The second officer lacked an appreciation of the likely or possible effect of the close encounter with the yacht.
Whatever the views of the officer of the watch and the bridge team, the master should have been called and told of the incident.

I wrote:

And the OOW was acquitted of all charges relating to the incident.

I'm afraid I cannot find a truly authoritative source for the verdict, but every source I've found with a quick google agrees with the RYA summary:-
http://www.rya.org.uk/newsevents/news/Pages/ouzo.aspx
Following a six week trial the Second Officer of the Pride of Bilbao, Michael Hubble, was found not guilty of three counts of manslaughter and not guilty of engaging in conduct as a seaman likely to cause death or serious injury (pursuant to Section 58 of the Merchant Shipping Act 1995).

 

[mcframe]

Incidentally I completely agree with you about reliance on technology, which is why I am dubious about adding yet another piece of active electronics to the mix ...

One the one hand, I wonder whether a chaff-bomb might be more useful than a foghorn or white flares under certain circumstances. On the other hand, an emergency-use-only S-band SART might work. The gripping hand wonders whether the sudden appearance of an AIS target (AIS-SART) would be noticed.

(I'm not suggesting AIS TX for pleasure boats all the time, but if that's what big ships watch in fog, then that's where we'd like to be seen - after all, that's why more of us have got radar /reflectors/ than receivers)

 

[Capt Cautious]

AIS tx makes perfect sense. It neednt be mandatory, seamanship should dictate its use. Its a wonderful benefit in restricted vis simply to let us guys on the big ships know that something is there. If you are considering sailing in busy waters, in dubious or changeable weather - just do it.
CC

 

[prv]

Between the forward staff and the anchor, it appears there is a hatch with a lookout standing in it.

Obviously it's hard to tell as the picture isn't the clearest. I took that to be the anchor windlass and associated machinery. If you think it's a lookout, why do you think he's there on a sunny day in Poole Harbour?

Pete

 

[timbartlett]

I've read an awful lot of scientific papers in my day and I can recognize hand-waving, waffle and unconnected arguments when I see them!

It's worth bearing in mind that the stated object of the exercise was "to better inform yachtsmen of the most appropriate choice of radar reflector for their craft from among those currently being produced". Officials of the MCA and MAIB had, at the time, been totally duped by the sales pitches put forward by radar reflector manufacturers, and the MCA, in particular, was still basking in the rosy glow of having got radar reflectors made compulsory under Solas V.

The intention was that the Funtingdon report into radar reflectors would be released as an annex to the Ouzo report to validate that belief. What the MCA/MAIB did not seem to be prepared for was the possibility that Funtingdon would produce a report that said (in effect) that there were no radar reflectors available to small craft that met the performance standards. That is why the report was delayed by several months. It also includes signs of what might appear to be no more than very clumsy editing:-
"The POLARef shows excellence is possible but at a price, technically it just fails
meet current ISO8729" (excellence = fails to meet standards )
The Large Tri-Lens performs well especially at larger angles of heel and
elevation, it just falls short of ISO8729(performs well = fails to meet standards )

Some of the most remarkable claims in the report - of periodic appearance and disappearance as the target gets closer - could easily have been demonstrated with a straightforward experiment but were not. I would be very interested to know if anyone with a radar has reliably and repeatably observed the appearance and disappearance of an approaching target.

I doubt whether anyone at Funtingdon saw the need to demonstrate the appearance and disappearance phenomenon, because the scientific basis for it is very well documented (Fresnel zones). And from MAIB and MCA's points of view, anything that further undermined the credibility of radar reflectors would have been distinctly counterproductive.

There are countless other issues that are not addressed by the report: in particular, it does not address the issue of interference effects between a radar reflector and the boat it is mounted on. In other tests that Funtingdon had carried out a few years earlier (1998? 1999?) for PBO we saw that even a small boat (we used my Sonata) had a bigger RCS than any radar reflector, and that the effect of adding a radar reflector (apart from making it horribly tippy) could, in some cases, be to reduce the mean RCS.

So you're right that it is a more complex issue than the Funtingdon report suggests, but I think that is partly because there are some issues that radar specialists take for granted (eg Fresnel zones) and perhaps because there were some issues where they may have been told not to look to closely.

 

[Greenheart]

Is it the pic from post#26, to which you (Cruiser2B) refer? If so, I have to agree with PRV. That's no more identifiable as a human on lookout-duty, than a couple of half-full bin-liners might've been.

Surely there's no great secret, in respect of whether these big power-cats post a watch near the bow, for the duty of care that no-one on the bridge could equally attend to. Isn't it on public record?

One might expect that the companies which run these vessels would desire some degree of transparency to have a beneficial effect on their reputation. It can't look good, if the ships' design is intrinsically part of a problem that may have caused a fatality.

 

[timbartlett]

I have been on the bridge of a Condor ferry in fog and, yes, their radars can pick up even a 12' dinghy at 3 miles travelling at 30 knots.

To us, sea clutter is something that is of relatively little significance, except when it is "rough" (by our standards) or when the boat is heeling over. That's because our scanners are only a few metres off the surface, so we only get reflections from the faces of waves. But a ship's radar may be 30m off the surface. It is "looking" downwards at the sea, so it "sees" reflections (i.e. sea clutter) even in relatively calm conditions. And in rough conditions, the clutter may extend several miles from the ship. A dinghy may well be visible at three miles, but at two miles or one mile it may be producing a weaker echo than the ruffled surface of the sea around it.

An inquest will find out more, I wouldn't want to speculate.

That would be nice. But by the time we have enough facts about this specific incident to go on, no doubt the forum will have moved on.

 

[Greenheart]

The forum will move on, doubtless. But its past detail will still be of greatest interest to anyone who seeks answers to vital matters that seem previously to have been overlooked, despite their gravity and significance for persons at sea in the future.

 

[timbartlett]

Quote from Tim Bartlett: IIRC, the watchkeepers on the Pride of Bilbao believed they had had a near miss, and both believed they had seen the lights of the yacht astern of the ferry afterwards.

Kind-of makes it worse, doesn't it? They said one of the dead from the Bilbao collision had been alive in the water for at least twelve hours. Yet rather than make sure there had been no harm done, the ferry just took off.

I'm still not clear if it was the Bilbao that clobbered the yacht and didn't stop (in which case, what the hell do we have courts for?), or whether it may have been a quite different collision, in which case, tragic but uselessly inconclusive.

The thought of being left bobbing around in the water to die is certainly horrific. But I don't accept that that is what the watchkeepers on PoB thought they were doing. My interpretation of the (necessarily limited) information that was available was that the watchkeepers believed their last-minute avoiding action had been successful. They checked and saw what they believed was the other vessel sailing away unscathed.

When (two days later) the first bodies were found, they still had no reason to believe that they came from the vessel that they believed they had successfully avoided. They were not alone in believing that Ouzo had been hit by a different ship in a completely different incident.

Yes, they made mistakes -- lots of little mistakes, from choosing Reactolite glasses to relying on the automatic sea clutter control. But sometimes little mistakes have big consequences -- and I can't see anything in the available evidence that makes it sound as though they did anything malicious, or even particularly careless.

 

[Cruiser2B]

Obviously it's hard to tell as the picture isn't the clearest. I took that to be the anchor windlass and associated machinery. If you think it's a lookout, why do you think he's there on a sunny day in Poole Harbour?

Pete

Admittedly the picture is unclear. If someone is there, they might be up there to act as an extra lookout in a busy harbour or to stand by the anchor (common procedure in confined waters). Of course it might just be the anchor gypsy, but there is definitely a hatch there, that presumably can be used to post a fog lookout - clearly visible in these photos:
http://www.incat.com.au/domino/incat/incatweb.nsf/0/B869EC002037BCA9CA25739C0002D268/$File/0450039EH.jpg
http://www.incat.com.au/domino/incat/incatweb.nsf/0/3E625C0F78CCDFAACA25742B0020A04C/$File/0430018EH.jpg

 

[Cruiser2B]

Its an interesting point, but even if the fishing vessel was sounding a signal at 1 minute intervals - the ferry would probably never have heard it. She was doing approx .6 miles a minute and the signal was probably only audible at 0.5 miles. This really does start to show that rules are seriously groaning under the weight of progress, and the cracks are starting to appear. Standards have now dropped so far as to be practically irretreivable - we need rules that cater for the lowest common denominator, not ones that need lawyers, either in the focsle or ashore, to decode. A bit of seamanship wouldnt go amiss either.
CC

The point about the legislated minimum audibility range is just that - a minimum. We know that 6-mile masthead lights are seen at much greater ranges, and in the same way most fog signalling devices can be heard beyond their minima, and I submit that fog actually increases the range of a fog signal. But as you've accurately pointed out, the legislated requirements would suggest 36 knots would not meet the criteria to be considered a "safe speed" - it still remains to be determined what speed Condor was at. I also agree with your assessment of the Rules and standards.

 

[Ubergeekian]

Ubergeekian - you asked for "standard sound signals" - I quoted 2 miles - however - if you were actually looking for the audible range of say, a fishing vessel less than 20m in length, rather than a standard commercial vessel - Annex III of colregs. 0.5 miles. Thats "audible range". The criteria are fairly well described.
CC

That's not what I meant. I would like to know at what range the Condor can hear a standard foghorn, taking into account engine noise and so on. That may well be rather less than the range at which a quiet man in a rowing boat could hear it ...

 

[Ubergeekian]

I doubt whether anyone at Funtingdon saw the need to demonstrate the appearance and disappearance phenomenon, because the scientific basis for it is very well documented (Fresnel zones).

Is it an established phenomenon, then, that, as suggested in that report, marine radar is incapable of seeing any passive target whatsoever at a range of three miles?

 

[timbartlett]

Is it an established phenomenon, then, that, as suggested in that report, marine radar is incapable of seeing any passive target whatsoever at a range of three miles?

Sorry, I'm not sure which report you are looking at, because the Funtingdon report shows that probability of detection reaches a peak at about three miles, with minima at just over 2 miles and just under 4 miles. There are several maxes and mins at ranges of less than 2 miles, and another minimum at about 11 miles.

Nor does it suggest that this prediction is true for all marine radars: it says "These predictions are only valid for the specific case shown below; different radar antenna heights, sea conditions and target heights will affect the probability of detection against ranges shown." and specifies that the predictions were made on the assumption of a 30m antenna height and a 4m reflector height.

The gist of the Fresnel zone issue (called "multipath" in the Funtingdon report) is that in perfectly smooth water, radar waves can travel from antenna to target by one of two paths -- the direct route, or by being reflected from the surface of the sea. Reflection inverts the wave, so if the reflected route is an exact number of wavelengths longer than the direct route, the two wave patterns will be out of phase with each other, so they will cancel each other out -- and produce no echo.

The ranges at which this occurs will depend upon the wavelength of the radar, on the height of the antenna above WL and on the height of the target above WL

In practice, the sea is almost never perfectly smooth, so there are lots of possible reflected paths, of slightly differing lengths. Neither the antenna nor the target are perfectly still, so both direct and reflected paths are constantly changing in length, and a real target is never a single point. So although the probability of detection is reduced at some ranges, multipath effects can never (on their own) reduce it to zero. The flip side, of course, is that although multipath can enhance the probability of detection, it can never guarantee it.

 

[PilotWolf]

I make no bones that TB and I have disagreed on things and that I don't agree with a lot of his posts however...

As a professional Skipper, (professional I hope in my decision making/judgement rather than just being paid to do a job) I have to say his comments and views here are pretty much spot on.

The POB issue was something I followed very closely for reasons I won't go into and rightly Capt Hubble was cleared in a court of law. However innocent he was I have little doubt that his career is over and I am sure that he will always have that what if thought in the back of his mind..

Radar is a tool for navigation/collision avoidance BUT it is fallible as are all computer/electronic systems, (I cringe when people suggest that flares are no longer needed as they have VHF/PLB/EPIRB/mobile/etc.)

As far as I know none of the posters here were on board so other than press reports we don't have accurate details of speed or visibility at time of impact. eg. Relying on AIS for speed is not a good idea as the update period is not instant. Unless you have a reference and something to check it against like a radar it is very difficult to judge visibility.

Similar threads run on aviation websites when an accident occurs and some argue that speculation is a good thing and makes people think - others say it is wrong and we should wait for the official report. Personally if it makes you think twice and maybe stops you becoming the next statistic then speculate away.

I started my sea going life as a fisherman so I have no axe to grind against them, especially as another family has lost their father/son/husband/brother but remember that the onus is on both vessels to avoid collisions and maintain a look out by all available means.

From experience if you can afford it buy an active radar reflector like the SeeMe. As shown by the study most passive reflectors are simply ballast that satisfies the SOLAS requirements to carry a reflector.

I worked for a while in a maritime enforcement role and we used radar to track vessels to a standard that would stand up in court as evidence (acquired target, no loss of tracking, etc.) so I hope my radar skills are pretty good but even with ARPA and the latest radar software some small craft simply do not show up reliably. We are fortunate that we can run 2 radars (and effectively as many slave stations as we have computers on the network) on different ranges - one usually on 6 mile range and the other on .75 mile range for close targets.

W.