Aerials and/or Arrays

[ivorthediver]

I don't know about Squirrel Harry,.... your more of a Ferret ......how do you source all these snippets of information , me thinks we better get M I 5 up your neck of the woods [ forgive pun ]

[Little h]

HMAS Melbourne R21 losses a radar in storm - HMAS Vendetta D08 provides a replacement

Lost over the starboard side from it's pedestal on a platform high on the island ... 1 in No. Antenna LW-04; Long Range search radar for the use of.

During exercise TASMANEX 79 in extremely bad weather, the antenna disappeared from on it's pedestal over the starboard side into the sea. On returning to harbour it was decided to remove the LW-02 antenna from the now decommissioned HMAS Vendetta D08 and refit same on HMS Melbourne R21

A 'before' image now contiguous with an after image!!

Screenshot (4215) copy.jpg

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An image showing Melbourne R21 in background prior to losing her antenna; and in the foreground Vendetta D08 with the replacement still in-situ on the destroyer

HMAS Vendetta and HMAS Melbourne - Copy.jpg

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Attachments are derived from images posted by another of our old WNSF friends Kookaburra from his photostream on Flickr


Some comments associated with the images, read as follows:-

1st link;

Yes the LW02 replaced one of the large Dutch-type antennas, but it didn't last too long did it, and then back went the big old one which stayed in place until decommissioned in 1982.
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The word at the time was that the LWO2 was placed on the previous LWO mounting and the mounting failed during the night. It would have been very interesting if the aerial had fallen inboard instead of outboard, as there was a USN helo (Sea Stallion?) onboard for the night and it was parked about where the aerial would have landed if it fell inboard.
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It was an LWO4 that was lost, not an LWO2. I was part of the Radar Party on this trip and on watch shortly after it happened, in the middle of the night invery rough weather. My shipmate Kim Fischer came down form doing rounds and reported "LWO is down", which usually meant it was not functioning , then he had to reiterate NO it's down ,,gone!! The LWO4 Dish we lost was replaced with the LWO2 taken off HMAS Vendetta which had just paid off. Hilarious time back in Sydney, $62,000 was the figure the papers were bleating about under the old jinxed ship guise, as we had also lost a Skyhawk and a Seaking that year. So some mischievous Sailor put a sign on their old LWO2 on the wharf stating "For Sale $62,000 - Will fit any Aircraft Carrier" Ha Ha!

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2nd link;

In fact we find the oval radar dish was only carried for only a short period - from MELBOURNE's emergence from an eight-month refit on February 15, 1979 to August of that year. There's a different outfit in 1980 photos - and all that reminded us of something...

This is the radar dish that FELL OFF in rough weather during Exercise TASMANEX, August 17-24, 1979. And as Sam rightly says below photos show she was wearing the radar dish in Wellington, August 11-17, immediately prior to that exercise.

There was not much else happening in the first part of 1979, which was mainly spent working up after the long refit, so we're now guessing that this photo shows MELBOURNE's ceremonial departure from Sydney on August 3, 1979, for Exercise TASMANEX, the exercise during which she lost the radar dish.

ADDENDUM. Contributor Kim Dunstan adds - from a chronological table of events in MELBOURNE'S lifetime - that the radar dish fell from its pedestal at sea on August 22, and that the cost of the loss was $60,000.

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3rd link

Geoff Eastwood adds an interesting detail for the photograph above: 'Melbourne is sporting her LW08 radar which was fitted shortly before this shot was taken . Soon after it fell overboard during a storm in the Australian Bight, and had to be be replaced by Vendetta's LW02 ! So a bit of a rarity .'
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Congratulations on a fantastic resource of photos kookaburra2011. Many memories here as I served on both these ships. Historical correction if I may..the LWO8 was lost in the Tasman off New Zealand. ( I was the catapult chief at the time.)
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Horatio, Are we talking LWO2,4 or 8 my friend?
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A good question since there appears to be some confusion whether the earlier LW-02 antenna was replaced by an LW-04 or LW-08. What all are agreed on is that the antenna lost over the side was replaced by an LW-02 off the Vendetta D08.

So Melbourne R21 went back to square one.

[ivorthediver]

As he said Harry , could have been a right " pain in the neck" had you been out jogging beneath it at the time , and must have made a fair old splash as it went in

[Little h]

Further to the opening post in this thread:-

NVIS (Near Vertical Incident Skywave) aerial array.

A Type HF230L-N (or similar) compact HF aerial array for naval applications (frequency range of 1.6 to 30 MHz) - in this instance mounted on Danish Naval Frigate; HDMS Thetis F357.

x DSC_0374 (2).JPG

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[ivorthediver]

Knowing my backlog of naval tech ignorance Harry...... to what application are all these put to please , as the whole back of the superstructure is like a hedgehog bristling with spines
And the Onions on top I assume hold's yet another array of antenna , so why are they enclosed , is it to mask the size / shape of the "bits" so the advisory won't know what range they are searching on or some more succinct reason
and the smaller inverted egg cups either side of the main one.... what are they GPS locators

Surely this chapter falls under the remit of "coms" so pray explain what it all is please .....or is it a case of" you could tell me but you would have to shot me"

........Alright ..alright.... form an orderly line please , lets show them we are not a disorganised rabble this is a " NAVY " Forum after all is said and done .

[Little h]

And the Onions on top I assume hold's yet another array of antenna , so why are they enclosed , is it to mask the size / shape of the "bits" so the advisory won't know what range they are searching on or some more succinct reason
and the smaller inverted egg cups either side of the main one.... what are they GPS locators

The 'onion' atop the foremast houses a Plessey AWS-6 air search radar:-

Screenshot (4287).png

Screenshot (4289).png

Screenshot (4288).png

Source; The Decca Legacy

The 'inverted egg cups' will propably cover various Satcom antenna etc.

Wiki credits the ship as having:-
Sensors and
processing systems:
1 Terma Scanter Mil 009 navigational radar
1 Furuno FR-1505 DA surface search radar
1 Plessey AWS-6 air search radar
1 SaabTech Vectronics 9LV 200 Mk 3 fire control system
FLIR Systems AN/AAQ-22 SAFIRE thermal imager

Electronic warfare
& decoys:
1 Thales Defense Ltd Cutlass radar warning receiver
1 Thales Defense Scorpion radar jammer
2 Sea Gnat launchers (for chaff and flares)

Wiki provides a great photo taken off port bow - Date 1 June 2012 Source konflikty.pl Author Łukasz Golowanow

F357_Thetis_6018.JPG

Note the 360 degree crows nest and several RESM(?) antenna have since disappeared

[Little h]

......as the whole back of the superstructure is like a hedgehog bristling with spines

If your description is relating to this...

DSC_0375 (2).JPG

it is simply a ladder with near full height/length safety guard attached...

DSC_0315 (2).JPG

[ivorthediver]

Thanks for a great picture and taking the time to educate this ignoramus

Are those whip aerials telescopic as I note the variation in thickness overall .
Why are there double red lights either side of the " Mast " beneath the onion above the crows nest please.

Never mind ' Fishery protection' its like a floating "Joderal bank" with all the attendant comms and surveillance gear aboard and its got more Domes than balls in a bowling ally

Can only thank you for your patience Harry , and whilst I appreciate its a subject close to your heart , its kind of you to share your vast knowledge with us all despite our apparent lack of appreciation to the subject in hand which you labour to describe .......much appreciated mate .

[ivorthediver]

......as the whole back of the superstructure is like a hedgehog bristling with spines

If your description is relating to this... DSC_0375 (2).JPG


it is simply a ladder with near full height/length safety guard attached...DSC_0315 (2).JPG

No Harry I sussed the ladder chute it was the endless vertical antenna which seemed to be sprouting up from every vacant bit of roof .....why so many.....surely there cant be that much built in redundancy

[Little h]

Are those whip aerials telescopic as I note the variation in thickness overall .

As will become clear (when you open the links included below) the subject of Communications equipment is hugh, so I have reverted to that which is already in print and from a thoroughly reliable source, see:-

AERIALS (INCLUDING RADHAZ)

TYPE (followed by) BRIEF DESCRIPTION



AWF

A permanent fixed transmitting whip aerial fitted in many surface units. It operates in the HF band with a maximum efficiency in the region of 7MHz and with medium powered transmitters - up to 1kW. The aerial rod consists of four tapered steel rods screwed together to form a length of 35 ft. With light weight rods it becomes AWF(M). It is mounted on a base tuner, the ETA. The aerials are usually sited in the after part of the ship or well away from the receiving whip aerials. Connected directly to associated transmitter in non-ICS ships and through the EY Exchange on ICS ships.
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AWN

This is an entirely lightweight monopole whip aerial outfit designed primarily for use with common aerial working (CAW) for receivers. Four tubes, when assembled together, form a 30 ft whip aerial of 2� inches outside diameter at base and tapering to 1 inch diameter at top. It is mounted on a Group 'OA' deck insulator and fitted forward in the ship (including on top of the main gun) and away from the ship's transmitter aerials.
For further details of AWN CLICK HERE and HERE
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Source of the above rnmuseumradarandcommunications2006.org.uk

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COMIST = Communications Improvement in the Short Term
ICS = Integrated Communication System

The following linked item opens with this 'alert':-
I would suggest before starting to read this page that you make yourself a cup of tea and get comfortable - yes this is a large page by anyone's standard.

TRANSMITTERS & TRANSCEIVERS - COMIST and ICS

..... and includes passages thus:-
The accuracy for ICS equipments transmission and reception was 100% perfect, and aerials ultra efficient, many broadband which used parts of the ships superstructure as radiating elements supported by base tuned whip aerials, and transformer coupled whips aerials for reception depending upon the frequency it was expected to receive. As always, yes even today, the main stand alone power amplifier WBA/B/C produced a 1000W to the associated aerial (depending upon output frequency) but not before taking enormous amounts of power from the main ships switchboard to amplify 100mW (at source) to 1kW. The problem of standing waves on aerial systems was resolved in ICS and a forward power of say 1000W could be virtually assured (into the ether) by holding the VSWR (voltage standing wave ration) to ideally 0.85, resulting in 85% of that forward power leaving the ship.

10 Leander.jpg