radar reflectors

[binch]

These did not exist before 1947. About that time they were fitted to buoys inthe Thames estuary. They mADE NO DIFFERENCE: THE BUOYS HAD ALWAYS SHOWN UP ON RADAR AND STILL DID SO.(Sorry for caps. Finger trouble) In 1949 HMS Lock Arkaig carried out series of trials to check at what range radar would detect a submarine periscope. Using a type 277 radar 10cm wavelength, the attack periscope was detected at 2000 yards on 60% of runs. The attack periscope is about the size of a fat broomstick and about 3 feet above mean sea level. The search periscope was detected at that range (which was then the max ASDIC range) 100%.
The search periscope is a metl tube about 4" diameter and sticks up about 4 feet above MSL.
You cannot fail to notice that the search periscope is about the same section as a smallm yachts ally mast and about one tenth the height.
If this old ship with her ante-diluvial radar scored 100%, what improvement was necessary?
And why, with all the development of radar, cannot we rely on virtually any metal object being detected at reasonable range?
When we commissioned Faraway (12m loa) we tried out her detectability with and without refelectors using both X-band and S-band radars. There was no difference.
I don't want to deter anyone from taking whatever precautions they think wise, but I question the apparent paranoia of the MCA, and I have grave doubts about he evaluatiion carried out by Qinetic.
In HMS Loch Arkaig, the radar watchkeepers were specialist radar operators who did 30 minute tricks and they all had war experience when concemtration saved their lives very directly. The modern watch officer is not at the same pitch of alertness and his own life is not on the agenda.
Can I add my qqualifivations: Extra Master and Fellow of the RIN., and say that ship watchkeeping has deteriorated to an unacceptable extent and that MCA are dominated by ship men. And the RYA are supine..

 

[sailorman]

watch that space 4 a record post /forums/images/graemlins/grin.gif

 

[Dyflin]

[ QUOTE ]
and say that ship watchkeeping has deteriorated to an unacceptable extent and that MCA are dominated by ship men. And the RYA are supine..

[/ QUOTE ]

Blah, blah, blah, when I was a lad, all this was fields...

As a ships watchkeeper, I have never hit a ship, yacht, buoy or periscope. Your life still depends on your ability to correctly operate a radar and interpret the image on the screen, if you make a mistake you may well hit something and go out with a bang.

Why do you persist in berating highly trained, qualified and experienced seafarers on a leisure boating forum?

 

[saltwater_gypsy]

Ahem, what is the point of this post????
The state of Radar, the level of shipping traffic, the speed of commercial vessels, the status of the RYA, the amount of recreational sailing etc etc in 1949 are COMPLETELY IRRELEVANT to the situation today.
Todays problems have to be dealt with in todays terms.

 

[seaplane]

[ QUOTE ]
, and I have grave doubts about he evaluation carried out by Qinetic.

[/ QUOTE ]

I'm sure that the radar experts at QinetiQ will be hugely concerned by your remarks. I mean, they've only been doing this since the development of radar, have millions of pounds of test equipment, are highly skilled in detection of all manner of objects by use of radar but you know best!

A little knowledge is a dangerous thing!

 

[FullCircle]

I work for the spinning roofrack department of a major defence contractor. It will please everyone to know that we should still be selling 1947 equipment as it was apparently 100% effective on fat broomsticks.
Whether thats true of a fat explosive broomstick heading toward you at mach 2.5 is another matter.

I am not sure whether the OP was using All Weather fat broomsticks in all weather conditions as it is not noted here.

I can say that North Foreland must have been using pre 1947 radars when asked to see if they could spot my missing at sea Evolution 25. I was only 3 miles off North Foreland in visual range, and they could not spot me, much to the consternation of our family making the enquiry.

I also saw HMS Westminster on sneaky-beaky fishing duties last year, and the Galloper buoy was giving out a bigger reflection than the ship, beam on. Must have just been my poxy radar skills.

All this proves it that is by no means a given that you will be spotted in all conditions. If it worries you that much, buy a Sea-Me.

I have an Echomax 230 and a JRC1800 Radar. Oh, and a 43ft Ally reflector.....

And for the record, I am an WAFI 2nd class, and Assistant Master Estuary Wanderer.

 

[Twister_Ken]

Avast ranting you scurvy lubbers and read what the man Pud is saying.

Sixty years ago radar could detect something the x-section of a dinghy mast (but a lot less height) at 2000 yards (1nm, near as dammit). Why can't radar do better than that now, especially as our masts are a lot taller than an attack periscope, and most of them a lot thicker?

 

[FullCircle]

Ken,
I can assure you Radar performance has improved in the military arena.
Consider, 1NM is 3 minutes away or less from the accident in the average TSS. It is not necessarily visible due to wave heights, rain, masts moving back and forth, even the range setting etc etc

 

[nimbusgb]

Perhaps the main problem is that radar these days is so good at detecting things that people tend to turn up the de clutter knob, thus blotting out all the 'fat broomsticks', this necessitates screwing a virtual table top to the broomstick to make sure there is still some vestige of a return on the screen.

Its certainly this kind of thing in aviation. Ground radars tend to filter out traffic moving slower than 60kts or thereabouts. Gliders simply dissapear. To fix this the powers that be are mandating fitting active radar transponders to like gliders. it would be a lot simpler to just crank the filtering down! /forums/images/graemlins/smile.gif

Trouble with that of course is that every flock of birds then becomes an incoming unidentified hostile object! /forums/images/graemlins/frown.gif

 

[Mariner69]

Nimbus has it right.

The average radar height on Merchant vessel's is now twice what it was in 1947, as a consequence the sea clutter is increased to a great degree.

The modern radars have superb signal processing capabilities only dreamed of in the past but none of this guarantees success. As Full Circle says, a Mach 2 object with the cross section of a basket ball can be detected and tracked, as can the telegraph pole sized versions, but sometimes they just get lost in the process, however good the system.

In short, Pud does an injustice to the seamen who have taken his place in the system.

One mile is a close quarter situation. I have had yachts lost in the clutter at two miles and because they were below the horizon and I was 100 feet in the air, the white sails and hull were not clearly visible with the background of white capped waves. I missed them by a good distance but they did scare me. /forums/images/graemlins/cool.gif

 

[binch]

My post was bound to get up noses of the young. I am still at sea quite a lot on bridges as well as in cockpits, and the standard of total watchkeeping (by which I mean the way the ship as an entity is managed) is just not good enough. I do not believe that a big ship with its enormous bridge area and spread of instruments should be under the command of only one man. This is ship economics rather than technical expertise Time makes little difference to individual people, but practices do change.
The area where practice has improved in my lifetime has been in the air. I admire the way the aviation industry has established procedures which completely outlaw the gung-ho attitude that I once worked with in aircraft carriers But there still exist certain airlines that my son-in-law (who is a commercial pilot examiner) will not fly with.
And the height of radar antennae is critical. Air detection radar used to be high up. Navigational radar comparatively low down. But so many ships have it mounted very high up.

 

[Dyflin]

I think old age is clouding your mind, you're confusing opinion with fact... /forums/images/graemlins/blush.gif

 

[PembrokeshirePromise]

Well - having just finished reading about Robin Knox-Johnston solo circum navigation in 68/69, it seems he was less than impressed by watch keepers on many of the merchant ships back then - so not sure that much has changed really

 

[boatmike]

But so many ships have it mounted very high up.
______________________________________________________________

Er..... thats because mounting it lower down would give an excellent radar picture of the superstructure innit......?

Some of your rant regarding the deterioration of watchkeeping standards I can agree with. You do seem to indicate that everyone ( Quinetiq...Kinetiq... Oh F*** DRA, MCA etc) are idiots and you know everything. A bit sweeping surely?
I do have some experience myself and Fullcircle is quite correct. RADAR has improved in performance since the war years and any ship that detected a subs conning tower, let alone their periscope at any distance in anything of a sea was damn lucky then! In a flat calm in the Thames estuary it's one thing. In a gale of wind in the English Channel quite another (as with your superior qualifications you will know of course)

 

[deep denial]

[ QUOTE ]
But there still exist certain airlines that my son-in-law (who is a commercial pilot examiner) will not fly with.


[/ QUOTE ]

Which ones, please?

 

[saltwater_gypsy]

Some odds and ends in response to the original grumpy post.

Search periscopes are now about 10mm in diameter since the use the same type of CCD image detector as in a digital camera. So its not going to be a very good standard for testing Radar.
The recent article in Yachting World (Dec.) about digital radar was very interesting and shows quite clearly how radar technology has progressed in the two few years rather than the last sixty!!.
I cant see what you can complain aboutregarding the radar reflector tests . If you read the full report it is quite clear that Qinetic did an excellent job. They showed that the small tubular reflectors did not work at all and that there was a wide range of performance amongst the others.Acritical factor being the angle of heel.
Since reading the report I have fitted SeaMe and I have noticed a significant difference in the response of large vessels. In speaking to a professional Captain he told me that SeaMe sends out a sufficiently large return signal that the Collision Avoidance signal MUST be responded to if there is any possibility of collision.
Well, that's my pennyworth Happy New Year!!

 

[binch]

I tried to be succinct but only succeeded in upsetting the MN, which was not my intention. You cannot ignore history; to do so is crazy.
After WW2 at sea 60% of the ships sighted were red ensign. When I was a Suez pilot in the fifties that was still true. And at that time almost all officers went though Pangbourne, Worcesteror or Conway and were first class, although their expertise was confined generally to one type of ship, and often on one route.
Now, things are different. On a trip down channel a couple of years ago, the red ensign was rare and there were flags that I could not recognise.
Sometimes an anecdote tells more than statistics: Five years ago, a geneal cargo ship of about 8000 tons sailed from Tunis for Hanburg. Almost at the last minute, she signed on as third mate a 22 year old lady yachtmaster who had no ship experience at all. Halfway up channel or thereabouts the First and second mates came to blows and finished with knives on the bridge. Theey were subdued and locked in their cabins. The Captain and the lay continued to Hamburg, where the incident was investigated.
The Captain had a little English. The First and second had none and could not speak each other's language, raising questions as to how they handed over. Apparently the Captain did not do anything wrong in signing on the lady with no proper certification.
There is such a shortage of good officers (and British ones are in demand) that almost anyone can now sign on as third.
My critique of watchkeeping in ships now was based on this scenario, which we discusssed at an IMO seminar. Nothing can be done because the countries who sell mates and masters' tickets are members too.

 

[binch]

Sorry about the Freudian slip. She was rather a nic gorl.

 

[boatmike]

Unlike your previous post, I can agree entirely with this one Pud. My experience at sea is entirely amateur but most of my life I have been responsible for building, trials, and handover of vessels to so called "professional" crews and you are right. It's going to hell in a handcart! This only makes me more convinced that I need every modern aid to ensure I am visible though. I sail as I drive. Assume the other vessel is an idiot and react defensively. They are not all idiots of course and some are still good but as you said originally, commercial pressures on them are too great.
HAPPY NEW YEAR from one grumpy old git to another! /forums/images/graemlins/smirk.gif /forums/images/graemlins/smirk.gif /forums/images/graemlins/smirk.gif

 

[Refueler]

As the owner of a Marine Inspection Company, which not only covers cargo inspections on many different types and nationalities of vessel / crew, we also Superintend various.

You have an isolated case of a vessel and seem to tar the rest with it. Do you not think that examples of terrible incidents have occurred throughout history ? Do you really believe that it's purely a modern matter that watchkeeping can be sub-standard ?
I can remember walking onto bridge as 2nd Mate to relieve the 3rd Mate and he was curled up in the corner ... he was Cadet of the Year, had Company and College Prizes etc. for best work. He was true blue Brit. Do I now condemn all Brit 3rd Mates ? (I'd been called by my own alarm clock !).
I also remember when Red Ensign could be found everywhere - True Red Ensign as well - not the FOC it's become. But you can blame various unions, MNAOA and politicians for that as well as we training 3rd world.

One of the worst cases of ship conning I saw was that of a US Vessel that ran into Falmouth bay instead of turning left to go up channel ... not a usual MN vessel either - but a Fleet Support Vessel !

60 yrs ago tests carried out. Sea conditions at time ? Did operators know they were to look for such targets ? In so knowing the sets would have been tuned accordingly. Did they have full complement of dedicated radar operators on board and not people doing more than one job - as ALL Merchant Ships have had since time immemorial ?

As I replied to a similar vein post of yours previously - RIN is no advert for unbiased independent opinion IMHO. Having had a Father who was a Guest at various functions of theirs and drinking partner to many - I can personally vouch for the Pink Gin Colonial Types that made up RIN. Hopefully as time goes on and they get replaced by more modern people - the Old Empire British and Commonwealth / Strick Line / Cunard / P&O mentality will fade.

You weren't part of the group that applied to Admiralty for Warrant to wear Swords ?

Onto Pilots ... UK supplied many Pilots around the world. For some reason foreign countries considered Brit Pilots as the best. Even as a Brit - I fail to see why.
Jeddah - Ex Liverpool Pilots interested more in getting a drink on-board than missing the reefs going in - yep - not a few times we took our ships in and pilot stood in corner.
Thames Pilots - we had a Master in Shell, absolute bas**d - but finest ship handler I have ever seen - Charlie xxxxx ... used to just accept TP on board - then tell him- Shut up, stand there and do as I tell you.
Liverpool Pilot of NW Wales pick-up from Cutter .... guy could hardly get up the ladder, he was so pissed. Flaked out in Pilots cabin, suspended passage in claiming weather. Master gave him few hours to rest - then got me to call him ... we started towards LPool bar ...

Shall we continue Captain Pud ? /forums/images/graemlins/smirk.gif