fisherman
Well-Known Member
Problem with small echoes, some don't show until inside 1 or 2 miles, these people will be fixed on stuff further away, at that speed.
Condor ferry & Fog!
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Cruiser2B
Well-Known Member
In suggesting you need to be able to come within visible distance, it's evident you've never been on the bridge of a large ship. 30m vis means the crew of the Condor can't see anything beyond the pointy part of their own ship - do you suggest they come to a complete stop? Or what do you consider a safe speed - 1 knot? Is it realistic to expect a ferry on an expected 1-hour hop, to spend the next day and a half at sea, because a fog rolls in? Radar and fog signals should be sufficient to warn of a potential collision situation that would then neccessitate slowing or stopping - it says that in colregs. Until there is an indication of a vessel ahead, there is no reason that a vessel should not proceed at a reasonable speed.
Talulah
Well-Known Member
IIRC there was a close quarters incident in the Solent a couple of years ago. The yacht owner made a formal complaint after one of the Fast Ferries came perilously close at speed in thick fog. The ferry was clearly travelling much faster than would be appropriate if it was an 'eyes only' watch. However, the investigation accepted the ferry's argument that their radar was so good it could pick up even the smallest of items in the Solent and therefore the use of high speed in fog was perfectly safe.
Greenheart
Well-Known Member
Cruiser2B; it's just a question of what a reasonable speed is. Aboard a tanker, the bridge might be many hundreds of feet from the bow. That doesn't prevent a person, or an effective observation device being mounted at the bow, so the prospect, good or grim, is available for the crew's consideration.
Do I think serious, timetable-screwing reductions in commercial shipping speeds ought to apply, when the visibility is seriously reduced? You're damned right, I do! This fisherman is dead only because 'practicality' got in the way of safe, seamanlike control of the vessel that hit his, so effectively, he was sacrificed.
Ferries have got heaps quicker in recent years, and their use has gone through the old rules with a samaurai sword. As long as there wasn't an evident danger, who could object to the progress? But after this, who can fail to object?
Do I think serious, timetable-screwing reductions in commercial shipping speeds ought to apply, when the visibility is seriously reduced? You're damned right, I do! This fisherman is dead only because 'practicality' got in the way of safe, seamanlike control of the vessel that hit his, so effectively, he was sacrificed.
Ferries have got heaps quicker in recent years, and their use has gone through the old rules with a samaurai sword. As long as there wasn't an evident danger, who could object to the progress? But after this, who can fail to object?
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timbartlett
Guest
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.
And the OOW was acquitted of all charges relating to the incident.
T
timbartlett
Guest
Just a thought ---
There are still a lot of people -- including watchkeepers on commercial vessels -- who honestly believe that radar reflectors work, in spite of the research that was published in the Ouzo report (and several years before that) in PBO and MBY and others.
I'm afraid Solas V, by making radar reflectors compulsory, has perpetuated the myth.
If you were a ship's master, and you knew that all small craft were legally required to deploy a device that you believed would make them visible on radar, would you feel a little more relaxed about relying on radar alone?
There are still a lot of people -- including watchkeepers on commercial vessels -- who honestly believe that radar reflectors work, in spite of the research that was published in the Ouzo report (and several years before that) in PBO and MBY and others.
I'm afraid Solas V, by making radar reflectors compulsory, has perpetuated the myth.
If you were a ship's master, and you knew that all small craft were legally required to deploy a device that you believed would make them visible on radar, would you feel a little more relaxed about relying on radar alone?
Greenheart
Well-Known Member
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.
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.
jimi
Well-Known Member
"2.6 WHY WASN’T OUZO DETECTED BY RADAR OR OTHER MEANS
The MAIB has examined in detail the “X” Band radar picture from Pride of Bilbao, as recorded by the vessel’s VDR. Even with the benefit of hindsight, it showed no trace of the yacht Ouzo during the incident, either ahead or, later, astern of the vessel. Other evidence indicates that the yacht probably did not show on the other, “S” Band, radar either.
Radar experts from QinetiQ Funtington were contracted to investigate the reasons why the yacht did not show on the vessel’s radars. Their report is attached at Annex 4.
2.6.1 The radars
The Sperry Bridgemaster E radars on board the vessel are a type fitted to numerous merchant vessels worldwide.
The serviceability of the radars on board Pride of Bilbao was tested, and it was found that both main radars were operating correctly and within the operational limits of their specification.
2.6.2 Radar lookout
The “X” band starboard radar was being operated on the 12 mile range and the sea clutter was set to automatic control.
In accordance with good watchkeeping practice, the second officer regularly checked this radar for targets, and acquired various distant vessels prior to the incident.
His last check for targets had been just 3 minutes prior to the lookout sighting the yacht’s lights. The yacht was about 1 mile ahead of the vessel, and not showing on the radar screen.
In areas where small craft may be expected, it is good practice, when using automatic sea clutter, to regularly change to manual control to improve the chances of detecting them. During this incident, the second officer did not do so in an area where small yachts might be encountered, especially during the summer months.
2.6.3 Radar cross section
The ability of a properly functioning radar to detect a target such as a small yacht is dependent upon a number of factors, including the yacht’s radar cross section (RCS) and the prevailing sea conditions. The best chance of detection occurs with a large RCS and calm seas.
Using the best available information, it appears that Pride of Bilbao approached Ouzo from her port quarter. Ouzo offered a very small RCS in this direction. The QinetiQ report concludes that this, coupled with the moderate sea conditions, made it unlikely that the radars on board Pride of Bilbao would have been able to separate Ouzo from the sea clutter.
It is possible that the crew of Ouzo had hoisted their radar reflector in the expectation that the yacht’s RCS would thus be substantially improved."
"2.6.7 Conclusion – radar detection
The yacht Ouzo was not detected by the radars on board Pride of Bilbao due to a combination of the following:
o The small radar cross section area of the yacht;
o The poor performance of the yacht’s radar reflector;
o The sea conditions;
o The use of auto-clutter suppression combined with an absence of periodic manual adjustment of the clutter controls to search for small targets."
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.
The MAIB has examined in detail the “X” Band radar picture from Pride of Bilbao, as recorded by the vessel’s VDR. Even with the benefit of hindsight, it showed no trace of the yacht Ouzo during the incident, either ahead or, later, astern of the vessel. Other evidence indicates that the yacht probably did not show on the other, “S” Band, radar either.
Radar experts from QinetiQ Funtington were contracted to investigate the reasons why the yacht did not show on the vessel’s radars. Their report is attached at Annex 4.
2.6.1 The radars
The Sperry Bridgemaster E radars on board the vessel are a type fitted to numerous merchant vessels worldwide.
The serviceability of the radars on board Pride of Bilbao was tested, and it was found that both main radars were operating correctly and within the operational limits of their specification.
2.6.2 Radar lookout
The “X” band starboard radar was being operated on the 12 mile range and the sea clutter was set to automatic control.
In accordance with good watchkeeping practice, the second officer regularly checked this radar for targets, and acquired various distant vessels prior to the incident.
His last check for targets had been just 3 minutes prior to the lookout sighting the yacht’s lights. The yacht was about 1 mile ahead of the vessel, and not showing on the radar screen.
In areas where small craft may be expected, it is good practice, when using automatic sea clutter, to regularly change to manual control to improve the chances of detecting them. During this incident, the second officer did not do so in an area where small yachts might be encountered, especially during the summer months.
2.6.3 Radar cross section
The ability of a properly functioning radar to detect a target such as a small yacht is dependent upon a number of factors, including the yacht’s radar cross section (RCS) and the prevailing sea conditions. The best chance of detection occurs with a large RCS and calm seas.
Using the best available information, it appears that Pride of Bilbao approached Ouzo from her port quarter. Ouzo offered a very small RCS in this direction. The QinetiQ report concludes that this, coupled with the moderate sea conditions, made it unlikely that the radars on board Pride of Bilbao would have been able to separate Ouzo from the sea clutter.
It is possible that the crew of Ouzo had hoisted their radar reflector in the expectation that the yacht’s RCS would thus be substantially improved."
"2.6.7 Conclusion – radar detection
The yacht Ouzo was not detected by the radars on board Pride of Bilbao due to a combination of the following:
o The small radar cross section area of the yacht;
o The poor performance of the yacht’s radar reflector;
o The sea conditions;
o The use of auto-clutter suppression combined with an absence of periodic manual adjustment of the clutter controls to search for small targets."
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.
Ubergeekian
Well-Known Member
From how far away would someone on the Condor be able to hear a standard foghorn?
Ubergeekian
Well-Known Member
I happily cede to Mr Bartlett regarding his far greater knowledge and experience of radars, but 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!
I've read the Qinetic report on radar reflectors and found it extremely unconvincing. They measured the cross-section of various reflectors but then used those cross-sections in theoretical measures of radar performance which did not appear to be backed up by experiment.
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.
In fact, that periodic effect was the only thing which "proved" radar reflectors to be less than adequately effective, and even then they - or at least the better ones - were absolutely fine at many ranges.
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.
Searush
Well-Known Member
Thanks for that Jimi, a useful input, please correct me if I am wrong, but from that,
1/ at speed, the radar watch is looking for bigger targets further away & the auto clutter control will tend to hide a small target close up.
2/ the MAIB recoommended that clutter control should be adjusted to make smaller targets more visible in locations where there is a likelyhood of small boats.
Looks very similar to what might have happened here doesn't it? So, sure small boats can be seen with fine tuned radar, but radars aren't often used like that . . .
Now how safe do you feel with a radar reflector? Suddenly I feel a lot more exposed.
1/ at speed, the radar watch is looking for bigger targets further away & the auto clutter control will tend to hide a small target close up.
2/ the MAIB recoommended that clutter control should be adjusted to make smaller targets more visible in locations where there is a likelyhood of small boats.
Looks very similar to what might have happened here doesn't it? So, sure small boats can be seen with fine tuned radar, but radars aren't often used like that . . .
Now how safe do you feel with a radar reflector? Suddenly I feel a lot more exposed.
Shibumi
Guest
If the photograph in post 39 is accurate, then it would seem that the fishing vessel was fitted with radar (Furuno 2/4kw?).
If so, it begs the question of whether she herself was maintaining a radar watch commensurate with the prevailing conditions.
Tidal heights at destination port, ferry timetables, and commercial costs (all previousely mentioned) are, in my opinion, irrelevant to the Command questions;
a) 'Safe to proceed?'
b) Safe speed?
and
c) Prudent lookout in view of prevailing conditions?
Just my 2p.
Steve
If so, it begs the question of whether she herself was maintaining a radar watch commensurate with the prevailing conditions.
Tidal heights at destination port, ferry timetables, and commercial costs (all previousely mentioned) are, in my opinion, irrelevant to the Command questions;
a) 'Safe to proceed?'
b) Safe speed?
and
c) Prudent lookout in view of prevailing conditions?
Just my 2p.
Steve
Mark-1
Well-Known Member
The OOW did believe he had seen the white light of yacht and a sail astern of the ferry afterwards. On that basis they assumed it had been a near miss. The OOW was acquitted of manslaughter.
Greenwichman
Well-Known Member
Trust technology; or sail defensively?
At risk of repeating part of my earlier post (apologies), but to answer the Q above .... yes, more than 20 years in command of large vessels of various kinds at sea, with radars of all kinds have taught me:
1. small craft come and go on big ship radar; all kinds of reasons, mainly to do with physics
2. clutter increases with sea state; worst up-wind; echoes near own ship are often invisible
3. operator settings are vital; but depend on skill; not always optimised for small fry
4. radar reflectors make little difference, are false security; active transponders are better
5. yachtsmen who believe their yacht WILL paint on radar are running a big risk
Sorry to be a bit gloomy, but this thread has some flavours of undue trust in technology!
At risk of repeating part of my earlier post (apologies), but to answer the Q above .... yes, more than 20 years in command of large vessels of various kinds at sea, with radars of all kinds have taught me:
1. small craft come and go on big ship radar; all kinds of reasons, mainly to do with physics
2. clutter increases with sea state; worst up-wind; echoes near own ship are often invisible
3. operator settings are vital; but depend on skill; not always optimised for small fry
4. radar reflectors make little difference, are false security; active transponders are better
5. yachtsmen who believe their yacht WILL paint on radar are running a big risk
Sorry to be a bit gloomy, but this thread has some flavours of undue trust in technology!
jimi
Well-Known Member
Not correct.
He was cleared of manslaughter, but jurors could not reach verdicts on charges of endangering the men's lives under the Merchant Shipping Act.
At about 0107 BST, the ferry was involved in a close encounter with a yacht, but the OoW maintained it was not Ouzo and that the boat sailed away safely.
During the trial, jurors were told by the defence team that experts from South Tyneside College calculated Ouzo was close to a 3,000-ton coastal tanker called Crescent Beaune at 0140 BST on 21 August.
A report into Ouzo's disappearance by the Marine Accidents Investigation Branch (MAIB), published in April, was not shown to the jury.
The MAIB investigates all maritime accidents but does not apportion blame, and therefore its report could not be used as part of any prosecution.
It concluded Ouzo was almost certainly affected by a collision or near-collision with a large vessel.
It also said it was of the "firm opinion" that Ouzo was the yacht involved in the close encounter with Pride of Bilbao.
I reiterate , read the MAIB, it is worth scrutinising.
Greenheart
Well-Known Member
Even though I can't claim to know anything, everything Greenwichman writes, makes very believable sense and I trust both my own equipment, and shipping operators, less as a result. Probably that'll do me a lot of good, one foggy day when I'm not sure where I am, and a fastcat skipper doesn't care.
jimi
Well-Known Member
I had a close encounter with a ferry going from Portsmouth to Spain at the end of the Solent several years ago, Sea state smooth, visibility good. They crashstopped and looked via searchlight on their Port side. We were well clear by c 250 yards on their starboard side.
They obviously did'nt have a clue where we were despite us having the nav and steaming light on.
That encounter (subsequent to the Ouzo disaster) has led me to have a lack of faith in the watchkeepers and their ability to use either their eyes or radar.
Mark-1
Well-Known Member
We'll have to agree to disagree, as they say. Kind regards.
idpnd
Well-Known Member
They need a different schedule for fog then, can't be manslaughtering people once a week can we
Ubergeekian
Well-Known Member
Thanks. What I was referring to was Figure 1 in the http://www.maib.gov.uk/cms_resources/Radar%20reflectors%20report.pdf Qinetiq report which suggests that a 4 m^2 RCS reflector - which is typical for an octohedral one - will have a 65% chance of being seen at 3 miles, 0% chance of being seen at 4 miles and a 95% chance of being seen at 6 miles.
Do you find that on particular days all targets vanish at the same distance as they get closer only to reappear again as they get even closer, then disappear again, reappear again and so on.
The Qinetiq evaluation assumed that no reflector of any size could be seen at 3 miles. I find that hard to believe without corroborating evidence.
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 ...