Trubble at Matelot Mill (VFD drive issues?)

The Sea wolf system is meant to catch them things in mid-air, as is the newer Aster system

(Sea wolf could even sometimes catch an occasional 4.5 inch shell in the 1980s)

Ah, the much maligned Sea Wolf. I had almost forgotten about that system.

I worked for the company that did the development work on Sea Wolf, it was called Marconi Space & Defense Systems back in the days. The RN kept telling us there was no money for its production year after year.

And then the Falkland War in 1982 suddenly made it "extra high priority" and their lordships wanted it like yesterday. It was a brilliant system.

Basically it was the sea borne version of the DN181 Rapier missile system but it had a self leveling gymbal platform to counter the pitching and rolling on board a ship. The RN finally got it into service about 3 years after the Falklands crisis was all done and dusted, just as we had told them it would take after receipt of order many years before.

HMS Duncan conks out on maneuvres

Royal Navy’s hi-tech destroyer breaks down in NATO wargame, towed back to port

One of the Royal Navy’s cutting edge Type 45 destroyers had to be humiliatingly towed back to port just two days after setting off to take part in NATO exercises.

The HMS Duncan is believed to have suffered total propulsion failure, forcing it back into Plymouth harbor on Wednesday, according to the Telegraph.

The 4,500 ton hi-tech ship left Davenport naval base on Sunday to take part in naval exercises alongside Spanish, Portuguese and German warships.

**LINK**

The US Navys latest offering is also prone to conking out with the same drive system

The Navy's New Stealth Destroyer Broke Down in the Panama Canal

The USS Zumwalt experienced an "engineering casualty" and collided with the canal walls.

The US Navy's newest destroyer broke down while transiting the Panama Canal, colliding with the Canal lock walls and forcing the $4 billion dollar ship to resort to a tow from a tugboat. The USS Zumwalt was towed to a former U.S. naval station in Panama where it will undergo emergency repairs. This is just months after a similar incident in September.

**LINK**

The 'stealth' motor needs a new rubber band.

Might by interesting to explain why these 'stealth' machines always have lots of flat surfaces. Imagine light or radar hitting a typical convex surface - the light is reflected away at all angles, with a flat surface it all bounces off in one direction so the foe has to be exactly aligned with the surface. Clearly other ships will never align with the stealth ship's angled surfaces and a plane or missile would have to fly directly towards the ship at exactly the right angle to get a steady signal.

It isn't unusual to see reflections of the sun on car windscreens from many miles away, yet imagine how hard it would be to use a mirror to exactly illuminate a spot at such a distance.

Neil

Edited By Neil Wyatt on 25/11/2016 09:06:51

Yes, Neil. Also the surface, at least on aircraft, is covered with radar-absorbent paint, or other material. This goes back to WWII when U-boats were covered in 'Stumpf', for the same purpose. There are also no straight edges, like round the cockpit cover, it being broken up in a zig-zag fashion to reflect radar signals in all directions. The Zumwalt's (and Type 45) superstructure is angled off the vertical, so reflections go skyward. The engine exhausts are also dispersed to hinder heat-seeking missiles, like the Stealth bomber, and even in tanks. This is in addition to towed or free decoys, flares, etc.

Geoff

Thanks Ady I really enjoyed reading that. Brightened my lunch break

It couldn't be that they just wanted it to look a little space age?

I'd be a little annoyed if all that money made it look like an ugly tugboat regardless of wether or not it was good for radar.  

I suppose like anything, it would have to impress the owners as well as deter an enemy. 

Michael W

Edited By Michael Walters on 25/11/2016 14:51:03

Do you rally think the Beeb get the whole story or just what the MOD want people to know?

Neil

if that was the case ( Curved surfaces etc etc) why is it that the radar reflector on my boat is made from flat surfaces which are inclined at 45 degrees from the horizontal or vertical ( thus directing the reflection away from the transmitter one would have thought)& not simply a circular ball that would always display a section of its surface directly at the transmitting radar?

& if it is that hard to direct a mirror why did Colonel Custer & co use them to signal to the rest of the cavalry in all the westerns ( up to the bit where he got an arrow through his hat that is !!) & why have I got one as a signalling mirror as standard equipment in my liferaft.

The left leaning BBC will always publish anything that helps the "other side"

Sam,

If your radar reflector is the usual form it is what is known as a 'triplane target'. It is a geometrical fact that three mutually perpendicular plane surfaces reflect an incoming 'ray' from plane to plane in such a way that it returns in a direction parallel to that from which it arrived. So it gives a very strong echo back to each illuminating source.

Best regards,

Swarf, Mostly!

.

Also known as a retro-reflector ... found in bicycle reflectors, and on the Moon.

MichaelG.

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https://en.m.wikipedia.org/wiki/List_of_retroreflectors_on_the_Moon

Edited By Michael Gilligan on 25/11/2016 17:05:22

Hollywood.

I'm sure an expert will correct me if I'm wrong but I think the US Army at that time used a semaphore system called 'wig wag' rather than mirrors.

Sunny conditions in India, and later South Africa, favoured Heliographs in British service. Surplus Heliographs are fairly common because military map makers used them as theodolite targets until microwave and aerial surveying took over. I don't think they were used much for signalling in morse.

All a life-raft mirror has to do is attract attention. It would be quite hard to hit one with an anti-ship missile, though it might be fun to try!

Dave

Edited By Michael Walters on 25/11/2016 17:57:10

Because three plane surfaces at exactly 90-degrees create a shape that will reflect an incident beam back out the way it came; the same effect is used in various types of reflectors including the ones left behind by apollo missions as laser targets. They fit small reflectors like this to stealth aircraft when being used in civilian airspace (and its why the avoid 90-degree corners at all costs on stealth machines).

The sun's angular diameter seen from earth is 0.5 degrees, so the beam from a signalling mirror spreads at this angle. At a mile the beam becomes about fifteen yards across. A small spot to hit a target by chance, but possible to hit with a bit of skill. Proper heliographs used for signalling (where actual messages not just random flashes are needed) were equipped with sights for accurate setting up.

Little extra info I found when reading up on the F117 earlier - it was all flat plates because 1970s computers couldn't do the hard maths to design a stealth plane with curved surfaces.

Neil