The yellow beacons at Portsmouth

[richardabeattie]

I know the 6 huge beacons are for the aircraftless carriers but does anybody know more specifically what they achieve? Why so many? Why so big with so much equipment on them? Are the carriers really unable to use on board systems to find Portsmouth?

 

[VicS]

I know the 6 huge beacons are for the aircraftless carriers but does anybody know more specifically what they achieve? Why so many? Why so big with so much equipment on them? Are the carriers really unable to use on board systems to find Portsmouth?

They are to gude the carriers through the narrow bit by visual observation ( transits) . There are so many to allow for observation from different parts of the vessel. I guess a different pair whether entering or leaving. There is an explanation on line somewhere

David Ellis posted onon 26 September 2016

Sorry but I have to say that the new navigation marks are incredibly ugly. Utilitarian metalwork like that would look perfectly at home in the middle of an oil refinery, but just off a tourist beach I think you should have made an effort to come up with something more elegant.

Link to this comment
Reply
Replies to David Ellis>
Comment byPeter Mishcon posted onon 03 August 2017

I absolutely agree, David. I am frequently in and out of Portsmouth and I am really sad no one has taken any effort at all to meet these utilitarian structures even mildly attractive. Where has the spirit of our Victorian (and earlier) engineers, such as Stevenson, Brunel and Smeaton, gone? And as David says, with a backdrop of historic Old Portsmouth. As we know, good design need not add a penny to the budget. Another lost opportunity.

Link to this comment
Reply
Comment byGreg Young posted onon 26 September 2016

Will there be any lights on them to help yachts and small vessels that approach the harbour outside the channel to identify their location at night?

Link to this comment
Reply
Replies to Greg Young>
Comment byhelenpickering posted onon 27 September 2016

Hi Greg, thanks for reading. Yes, they do have lights.

Link to this comment
Reply
Comment byMike buggy posted onon 28 September 2016

Why are they placed in this pattern. ?..are some of them transits? Why are there 2 rows of 3 for example?

Link to this comment
Reply
Replies to Mike buggy>
Comment byhelenpickering posted onon 03 January 2017

Mike, sorry for the delay - your comment was missed unfortunately.

The three towers (triple transit lights) align with the vessel's port, centre and starboard lines so it can be aligned with the entry channel.

DIO Communications Team

Link to this comment
Reply
Comment byMiles Stuart posted onon 14 October 2016

Where can I find out how these new nav lights work? I'm a retired Master Mariner and would love to know more.

Link to this comment
Reply
Comment byHarry posted onon 16 October 2016

Why are there 3 lights in each group? How will th lights be used ?

Link to this comment
Reply
Replies to Harry>
Comment byhelenpickering posted onon 03 January 2017

Harry, sorry for the delay - your comment was missed unfortunately.

The three towers (triple transit lights) align with the vessel's port, centre and starboard lines so it can be aligned with the entry channel.

DIO Communications Team

Link to this comment
Reply
Comment byDavid Cummings posted onon 30 October 2016

Why are they in rows of three, ? do they need to line the three up If its for indicting safe route, singles could do it. Please inform, thanks

Link to this comment
Reply
Replies to David Cummings>
Comment byhelenpickering posted onon 03 January 2017

David, sorry for the delay - your comment was missed unfortunately.

The three towers (triple transit lights) align with the vessel's port, centre and starboard lines so it can be aligned with the entry channel.

DIO Communications Team

Link to this comment
Reply
Comment bySean Gage posted onon 18 November 2016

I have gazed at these structures from across the water at Puckpool on the Island and wondered what they were. At last I've found the answer,
Many Thanks
Sean Gage

Link to this comment
Reply
Comment byJoseph Wyatt posted onon 04 December 2016

Why do they need to be in a row of 3 ?

Surly they'd just be lining the outer ones up for the approach or leave

Link to this comment
Reply
Replies to Joseph Wyatt>
Comment byhelenpickering posted onon 03 January 2017

Joseph, sorry for the delay - your comment was missed unfortunately.

The three towers (triple transit lights) align with the vessel's port, centre and starboard lines so it can be aligned with the entry channel.

DIO Communications Team

Link to this comment
Reply
Replies to Joseph Wyatt>
Comment byhelenpickering posted onon 08 February 2017

To provide navigational certainty the vessel’s navigator visually aligns one set of three up with the other (i.e. they act as a pair) and because each of the three lights is a different colour the navigator can be certain he’s lining up the correct lights.

The most critical element of the navigation into Portsmouth is passing through the narrow harbour entrance. We have pairs of triple transits in both the outer and inner harbour to guide the carrier either way through the entrance.

Link to this comment
Reply
Comment bykh posted onon 31 December 2016

Could you explain why some of the marks occur in threes?

Link to this comment
Reply
Replies to kh>
Comment byhelenpickering posted onon 03 January 2017

Sorry for the delay - your comment was missed unfortunately.

The three towers (triple transit lights) align with the vessel's port, centre and starboard lines so it can be aligned with the entry channel.

DIO Communications Team

Link to this comment
Reply
Comment byA Skynner posted onon 09 January 2017

How about a diagram?

Link to this comment
Reply
Comment byChris Sprules posted onon 18 January 2017

Hi Helen
Thanks i understand the 12 lights - do the other 2 navigation marks have a role as well?
"the navigation lights are mounted on top of 14 large steel tower structures rising up to 30 metres from the sea bed"

Link to this comment
Reply
Replies to Chris Sprules>
Comment byhelenpickering posted onon 08 February 2017

Hi Chris, The 12 lights are divided into four sets of three (hence triple transits). To provide navigational certainty the vessel’s navigator visually aligns one set of three up with the other (i.e. they act as a pair) and because each of the three lights is a different colour the navigator can be certain he’s lining up the correct lights.

The most critical element of the navigation into Portsmouth is passing through the narrow harbour entrance. We have pairs of triple transits in both the outer and inner harbour to guide the carrier either way through the entrance.

The other two lights on piles provide visual control for directional changes either before or after passing through the harbour entrance, dependent on direction of travel. These are single lights rather than triple transits.

Link to this comment
Reply
Comment byTerry posted onon 05 February 2017

So, are you saying that The three towers (triple transit lights) align with the vessel's port, centre and starboard lines so it can be aligned with the entry channel? ?

Link to this comment
Reply
Replies to Terry>
Comment byhelenpickering posted onon 08 February 2017

Hi Terry, The 12 lights are divided into four sets of three (hence triple transits). To provide navigational certainty the vessel’s navigator visually aligns one set of three up with the other (i.e. they act as a pair) and because each of the three lights is a different colour the navigator can be certain he’s lining up the correct lights.

The most critical element of the navigation into Portsmouth is passing through the narrow harbour entrance. We have pairs of triple transits in both the outer and inner harbour to guide the carrier either way through the entrance.

The other two lights on piles provide visual control for directional changes either before or after passing through the harbour entrance, dependent on direction of travel. These are single lights rather than triple transits.

Link to this comment
Reply
Comment byjeremy posted onon 08 March 2017

I am sure no potential enemy would provide such facilities. If the ship cannot be safely navigated by her crew anywhere and in any situation and circumstances then somebody has erred - - -

Link to this comment
Reply
Comment bydave posted onon 15 April 2017

waiting to see how these carriers turn in the harbour (without huge lights on towers) - maybe employ a few brittany ferry pilots..

Link to this comment
Reply
Comment bySimon Arnold posted onon 30 May 2017

hi there....looking at the picture with the tower on the pier next to the transit van, the base doesn't look too long ( could be perspective). I've seen these in the Solent and the water comes half way up the base. I was wondering how deep the water is where these have been installed? I thought the Solent was deeper than that.

Link to this comment
Reply
Comment bySimonJ posted onon 07 August 2017

So there is the Queen Elizabeth, next Thursday perhaps, with the port light lined up with the port line, the centre light with the centre line, and the starboard light lined up with the starboard line. After the Queen Elizabeth has run down the centre light, how is it going to leave port safely with only sets of 2 lights remaining?
Your explanation might be self-explanatory to you, because you know the system, but it doesn't mean anything useful (in spite of many repetitions) to a landlubber. As Mr/Ms Skynner suggest, how about a diagram?

Link to this comment
Reply
Replies to SimonJ>
Comment byhelenpickering posted onon 11 August 2017

The 12 lights are divided into four sets of three (hence triple transits). To provide navigational certainty the vessel’s navigator visually aligns one set of three up with the other (i.e. they act as a pair) and because each of the three lights is a different colour the navigator can be certain he or she is lining up the correct lights.

The most critical element of the navigation into Portsmouth is passing through the narrow harbour entrance. We have pairs of triple transits in both the outer and inner harbour to guide the carrier either way through the entrance.

The other two lights on piles provide visual control for directional changes either before or after passing through the harbour entrance, dependent on direction of travel. These are single lights rather than triple transits.

Link to this comment
Reply
Replies to SimonJ>
Comment byKeith W posted onon 17 August 2017

Hi Simon. Helen Pickering's explanation is clear but I wondered the same thing initially - how the ships would use the transits without running them down. Then the answer came to me. The Carrier's Commander would line up the transits in the inner harbour when entering and those outside the harbour when leaving - I think ? Helen, please let us know if this is correct.

Link to this comment
Reply
Replies to Keith W>
Comment byhelenpickering posted onon 18 August 2017

Hi Keith

That sounds right - they use the pair in the inner harbour for entry, and the pair in the outer harbour when leaving, and align them with the lights on the ship.

Link to this comment
Reply
Replies to helenpickering>
Comment byKeith W posted onon 18 August 2017

Thanks Helen. I often come in and out of Portsmouth (in my little sail boat). It is now clearer to me how these new marks will be used by the big boys.

Link to this comment
Reply
Replies to SimonJ>
Comment byKeith W posted onon 17 August 2017

Giving this further thought, the outer ones could be kept in transit astern when entering, with the inner ones in transit ahead thus giving even more certainty to the Commander that he is in the centre of the channel. The opposite when leaving of course.

Link to this comment
Reply
Replies to Keith W>
Comment byAndy Du Port posted onon 19 February 2018

Keith. Your idea would not work because the carrier's bridge is offset to starboard from her centreline/keel. So, the ‘in’ transits (up harbour) are aligned slightly to the east of the middle of the entrance; the ‘out’ transits (near Spitsand Fort) are aligned to the west. As for being certain that the ship is on track at this critical phase, the lights are very bright and very accurate!

Link to this comment
Reply
Comment byTony Clatworthy posted onon 13 August 2017

Surely a simple red- white- green beamed light system, as I installed at the entrance to the Hamble would work equally well and perhaps not cost millions for some defence company to profit from, let alone the ongoing maintenance cost. They look awful stuck out in the Solent. Turned a lovely view into an industrial estate scene.

 

[Cactus Sailing]

HaHa i love it.

I guess its pretty clear why there's three then...

"The three towers (triple transit lights) align with the vessel's port, centre and starboard lines so it can be aligned with the entry channel.
"

 

[richardabeattie]

Still seems weird to me. There are buoys marking the channel and if they need more precision why not lay more buoys?

 

[[3889]]

Still seems weird to me. There are buoys marking the channel and if they need more precision why not lay more buoys?

Because transits are more accurate, perhaps? For one thing they don't swing through 50m or whatever with every change of tide. The MAIB report into the grounding of CMA CGM Vasco da Gama describes the pilot's multiple GPS system giving position data for each bridge wing and the bow and stern. Just as sailing a dinghy up a narrow channel requires no more than a tentative hand on the centreboard it's a different matter in a yacht. Likewise, piloting a large ship with considerable windage is, I imagine, a whole new ballgame.

 

[DJE]

Don't suppose you can see the buoys when they're close with that overhanging deck. And if somebody jams the signal it doesn't matter how many gps receivers you have. But the transits are still there