Aerials and/or Arrays

[Little h]

Why are there double red lights either side of the " Mast " beneath the onion above the crows nest please.

Do you mean the red - white - red lights bent-on to the inboard halyard on the port and starboard yardarms?

Rigged in accordance with COLREGS = Vessels Not Under Command or Restricted in Their Ability to Maneuver

Rule 27
Vessels Not Under Command or Restricted in Their Ability to Maneuver

(a) A vessel not under command shall exhibit:

(i) two all-round red lights in a vertical line where they can best be seen;
(ii) two balls or similar shapes in a vertical line where they can best be seen;
(iii)when making way through the water, in addition to the lights prescribed in this paragraph, sidelights and a sternlight.

(b) A vessel restricted in her ability to maneuver, except a vessel engaged in mineclearance operations, shall exhibit:

(i) three all-round lights in a vertical line where they can best be seen. The highest and lowest of these lights shall be red and the middle light shall be white;
(ii) three shapes in a vertical line where they can best be seen. The highest and lowest of these shapes shall be balls and the middle one a diamond.
(iii)when making way through the water, a masthead light, sidelights and a sternlight in addition to the lights prescribed in subparagraph (i);
(iv) when at anchor, in addition to the lights or shapes prescribed in subparagraphs(i) and (ii), the light, lights, or shape prescribed in Rule 30.

(c) A power-driven vessel engaged in a towing operation such as severely restricts the towing vessel and her tow in their ability to deviate from their course shall, in addition to the lights or shapes prescribed in Rule 24(a), exhibit the lights or shapes prescribed in subparagraph (b)(i) and (ii) of this Rule.

(d) A vessel engaged in dredging or underwater operations, when restricted in her ability to maneuver, shall exhibit the lights and shapes prescribed in subparagraphs (b)(i),(ii) and (iii) of this Rule and shall in addition when an obstruction exists, exhibit:

(i) two all-round red lights or two balls in a vertical line to indicate the side on which the obstruction exists;
(ii) two all-round green lights or two diamonds in a vertical line to indicate the side on which another vessel may pass;
(iii) when at anchor, the lights or shapes prescribed in this paragraph instead of the lights or shapes prescribed in Rule 30.

(e) Whenever the size of a vessel engaged in diving operations makes it impracticable to exhibit all lights and shapes prescribed in paragraph (d) of this Rule, the following shall be exhibited:

(i) Three all-round lights in a vertical line where they can best be seen. The highest and lowest of these lights shall be red and the middle light shall be white;
(ii) a rigid replica of the code flag "A" not less than 1 meter in height. Measures shall be taken to ensure its all-round visibility.

(f)A vessel engaged in mineclearance operations shall in addition to the lights prescribed for a power-driven vessel in Rule 23 or to the light or shape prescribed for a vessel at anchor in Rule 30 as appropriate, exhibit three all-round green lights or three balls. One of these lights or shapes shall be exhibited near the foremast head and one at each end of the fore yard. These lights or shapes indicate that it is dangerous for another vessel to approach within 1000 meters of the mineclearance vessel.

(g) Vessels of less than 12 meters in length, except those engaged in diving operations, shall not be required to exhibit the lights prescribed in this Rule.

(h) The signals prescribed in this Rule are not signals of vessels in distress and requiring assistance. Such signals are contained in Annex IV to these Regulations.

[ivorthediver]

Hmmmmmmmmmm,makes the 30m range of my Radio Control equipment on test [aerial down] look a tad pathetic

I managed to get the very basic idea , but as I suspected a very complex set of kit .

Whilst looking at the diagram I was saying to myself [ any minute I will find out why some are very short and fixed to the horizontal spacers and are painted white .......noup

Then I found the answer for the whip aerials construction being 4 sections of threaded rod and thought ' getting warmer ' and that they are based on the superstructure as a radiating base..... yes..... and have a collective redundancy / backup ......yes.....then found the wire clothes drying array suspended between masts .....after that it was all down hill

I better stick to what I am good at me thinks [ all I need to do is find out what it is ]

Thank you for the explanation Harry , but acronyms are the kiss of death to dyslexics even when given the key

[ivorthediver]

Why are there double red lights either side of the " Mast " beneath the onion above the crows nest please.

Do you bean the red - white - red lights bent-on to the inboard halyard on the port and starboard yardarms?

Rigged in accordance with COLREGS = Vessels Not Under Command or Restricted in Their Ability to Maneuver

Rule 27
Vessels Not Under Command or Restricted in Their Ability to Maneuver

(a) A vessel not under command shall exhibit:

(i) two all-round red lights in a vertical line where they can best be seen;
(ii) two balls or similar shapes in a vertical line where they can best be seen;
(iii)when making way through the water, in addition to the lights prescribed in this paragraph, sidelights and a sternlight.

(b) A vessel restricted in her ability to maneuver, except a vessel engaged in mineclearance operations, shall exhibit:

(i) three all-round lights in a vertical line where they can best be seen. The highest and lowest of these lights shall be red and the middle light shall be white;
(ii) three shapes in a vertical line where they can best be seen. The highest and lowest of these shapes shall be balls and the middle one a diamond.
(iii)when making way through the water, a masthead light, sidelights and a sternlight in addition to the lights prescribed in subparagraph (i);
(iv) when at anchor, in addition to the lights or shapes prescribed in subparagraphs(i) and (ii), the light, lights, or shape prescribed in Rule 30.

(c) A power-driven vessel engaged in a towing operation such as severely restricts the towing vessel and her tow in their ability to deviate from their course shall, in addition to the lights or shapes prescribed in Rule 24(a), exhibit the lights or shapes prescribed in subparagraph (b)(i) and (ii) of this Rule.

(d) A vessel engaged in dredging or underwater operations, when restricted in her ability to maneuver, shall exhibit the lights and shapes prescribed in subparagraphs (b)(i),(ii) and (iii) of this Rule and shall in addition when an obstruction exists, exhibit:

(i) two all-round red lights or two balls in a vertical line to indicate the side on which the obstruction exists;
(ii) two all-round green lights or two diamonds in a vertical line to indicate the side on which another vessel may pass;
(iii) when at anchor, the lights or shapes prescribed in this paragraph instead of the lights or shapes prescribed in Rule 30.

(e) Whenever the size of a vessel engaged in diving operations makes it impracticable to exhibit all lights and shapes prescribed in paragraph (d) of this Rule, the following shall be exhibited:

(i) Three all-round lights in a vertical line where they can best be seen. The highest and lowest of these lights shall be red and the middle light shall be white;
(ii) a rigid replica of the code flag "A" not less than 1 meter in height. Measures shall be taken to ensure its all-round visibility.

(f)A vessel engaged in mineclearance operations shall in addition to the lights prescribed for a power-driven vessel in Rule 23 or to the light or shape prescribed for a vessel at anchor in Rule 30 as appropriate, exhibit three all-round green lights or three balls. One of these lights or shapes shall be exhibited near the foremast head and one at each end of the fore yard. These lights or shapes indicate that it is dangerous for another vessel to approach within 1000 meters of the mineclearance vessel.

(g) Vessels of less than 12 meters in length, except those engaged in diving operations, shall not be required to exhibit the lights prescribed in this Rule.

(h) The signals prescribed in this Rule are not signals of vessels in distress and requiring assistance. Such signals are contained in Annex IV to these Regulations.

I did actually know of these [ have them on my model Tug] but never seen them bolted to the structure like that on Naval combat vessels , as mine are all fitted.... and switched separately as cause require's , along with the black Spheres and Diamonds shapes.... thats what threw me off the scent Harry.
But thanks for taking the time and trouble it obviously took explaining that to us all ....
but glad to see an eminent techno like you also has spell check errors [2nd line ....did you bean ?....... thought I was unique here ...... huh cant even claim that accolade

[Little h]

but glad to see an eminent techno like you also has spell check errors [2nd line ....did you bean ?....... thought I was unique here ...... huh cant even claim that accolade

I don't have spell check associated with any input I make on the forum Ivor ... the 'bean' error was a typo pure and simple and a failure in my proof reading/editing before pressing the Submit button

[ivorthediver]

And there was I thinking I was the only offender Harry

Whilst on the topic how many other " box of tricks " are sequestered abaft the ship's structure Harry or should these all be re sited to an Electronic naval Warfare thread perhaps as indeed you had singled out lights / aerials /and other specific fixtures and fittings on Naval ships .......just a thought

[Little h]

HDMS Thetis F357

The complexity of antenna arrays is never better illustrated than on this particular ship.

Arising from the photographs I took whilst the ship was in Liverpool, I offer up a selection of my observations to date:-

Foremast; stbd yardarm & obstructed view of port yardarm

DSC_0363 (2).JPG

Taken from wide off the stbd bow.

DSC_0340 (2).JPG

Taken from just fwd of stbd beam.

DSC_0314 (2).JPG

Taken from slightly aft of stbd beam.



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Mainmast port and stbd yardarms

DSC_0317 (2).JPG

Taken from wide off the stbd qtr.

[Little h]

HDMS Thetis F357 -(continued)

The complexity of antenna arrays is never better illustrated than on this particular ship.

Arising from the photographs I took whilst the ship was in Liverpool, I offer up a further selection of my observations to date:-

Bridge roof;Base of foremast port & stbd; Stbd side aft of bridge housing/superstructure

DSC_0322 (3).JPG

DSC_0375 (3).JPG

It would be interesting to see if there were any RadHaz deck markings at the base of these antenna/arrays!!

One must remember the former function of this ship - that of being associated with Fishery Protection ... and her current function as Commander SNMCMG1. Somewhat different requirements communication equipment wise.

_______________________________________________________

DSC_0315 (4).JPG

DSC_0322 (2).JPG

DSC_0315 (3).JPG

[Little h]

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

Been pondering about your concerns/emphasis on 'built in redundancy' ..... note the following opening passages from the linked document titled:- 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 aerials are usually sited in the after part of the ship or well away from the receiving whip aerials.

and

AWN
This is an entirely lightweight monopole whip aerial outfit designed primarily for use with common aerial working (CAW) for receivers. ............... 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.

So; rather than built in redundancy...... to put it in lay speak - there was/is a necessity to site the TX AE (transmitting aerials) in a seperate 'aerial farm' as far apart as possible from the RX AE (receiving aerials) located in their own 'aerial farm' - and there ain't a lot of vacant lots for said 'farms'. Some things are done a little differently these days, but every aerial/antenna/array has a purpose; their location or re-location is hard fought for territory - in most instances a massive compromise is necessary.

I trust also that you picked up on the term 'common aerial working' - self explanitory - an aerial(s) used by more than one designated receiver, see:-

EAL
Common aerial working (CAW) enables six or more HF and MF receivers to be worked from a common wire or whip aerial over the frequency range of 15kHz to 30MHz. The associated receivers are CAY (B40) and CAZ (B41). Associated aerial are AWN whips and wire aerial with Group OA DI's.

(My comment - those equipment types are really old school and modern techniques can utilise forms of time share and compression techniques to maximise the facilities available)

However; all is not as simple as that described above and there are aerials/antenna that were/are commonly used for receivers and transmitters, see this link - hope that helps a bit.

[ivorthediver]

Thank you for taking the time to explain these items Harry , In your simplistic manner [ perfect for simpletons like me ]

As I may have told you before I found telecoms and such like fascinating when I worked for the Phillips group 40 years ago and spent many an hour chatting to technicians about the subject , trying to learn the mechanics of it all , but my involvement was as a Production controller who acted as a conduit between the customer the technicians and the production of the equipment ,but by necessity picked up information along the way in my dept which was ENG and OBV , or in layman's terms Electronic News Gathering and Outside Broadcast Vehicles .
Learnt a great deal of superficial information but none of the nitty gritty

As I say 40 years ago , but now they probably have a 6 camera OBV built into a Drone controlled from the studio

[Little h]

Vive La Différence


NavyLookout Retweeted
U.S. Naval Forces Europe-Africa/U.S. 6th Fleet
‏Verified account @USNavyEurope
Apr 1 2019

The Trifecta!
#USSGravely, #USSCarney, & #USSPorter moor along side one another in Faslane, #Scotland. Gravely is underway as flagship of Standing #NATO Maritime Group 1 to conduct maritime operations & provide a continuous maritime capability for @NATO in the northern Atlantic.

--------------------------------

USS Gravely (DDG-107) Flight IIA; USS Carney (DDG-64) Flight I; USS Porter (DDG-78) Flight II; Moored alongside each other at Faslane.

D3DovaeX4AER6L1.jpg USS Gravely 107 Flight IIA, USS Carney 64 Flight I, USS Porter 78 Flight II alongside each other Faslane.jpg

That snapshot in time (above) provides an ideal opportunity to highlight observations of some of the variations/differences that are clearly apparent when viewing the image.

Legend

Upper port and stbd yardarms

1. USS Carney; this cylindrical shaped antenna array is not on the other two ships
2. USS Gravely; this appendage is different to those installed on the other two ships
3. USS Gravely; these planar arrays (x4) are absent from the other two ships
4. USS Gravely; this appendage is not apparent in this location on the other two ships
5. USS Gravely; this small dome differs from that on the other two ships in not being mounted atop a square box shaped appendage

Lower port and stbd yardarms

6. USS Gravely; these two arrays have a centre stub that is differently configured to those on the other two ships
7. USS Gravely; this appendage differs from those in the same location on the other two ships vis:- it has a dome attached unlike that on USS Porter (outboard ship); whilst the appendage on USS Carney is of an entirely different configuration
8. USS Carney; (see comments at 7. above)
9. USS Porter; (see comments at 7. & 8. above) the appendage differs in that it is without the domed extension attached
10. USS Porter; this appendage does not appear to be installed on the other two ships (in this position)

Superstructure aft of the foremast

11. USS Porter; paired whip antenna (also mounted on USS Carney)
11a. USS Carney; paired whip antenna (also mounted on USS Porter)
11b. USS Gravely; what appears to be an extended whip antenna (apparently not paired as mounted on USS Carney & USS Porter

Fwd of Bridge superstructure

12. USS Gravely; CIWS mounting absent unlike the other two ships
13. USS Gravely; SatCom antenna array covered by spherical dome unlike those on the other two ships

On Bridge Roof

14. USS Carney & USS Porter; possible disparity in the shape of the domed arrays mounted in the respective positions on these two ships

Anchor hawse pipe

15. USS Gravely; this ship appears to have reinforced shape on/around the stem aperature of hawse pipe on the bow, unlike those of the other two ships.


Image copied from NavyLookout on Twitter (see retweet above)

See also WhiteFleet.net Analysis of global military affairs with an emphasis on technology... an article titled:-

The Arleigh Burke-class Destroyer (DDG-51): An In-Depth Guide
Posted By: Alex Hempel July 31, 2017