# e-Loran



## Julian Calvin

Wonderful article published in GCaptain today.
Apparently merchant vessels have no backup navigation system if GPS fails (what planet do some of these guys come from). 
Therefore consideration is to be given to developing e-loran as a backup.
Apparently some vessels had their GPS signals hacked and had to return to port!!!!


----------



## Julian Calvin

Best quote is "if the GPS fails, ships run the risk of colliding or running aground".
Wow, sounds dangerous to be at sea nowadays.


----------



## Varley

But Julian haven't you been following the blogging here on reliance on GPS. There is a body of experienced navigators who are happy to rely on just GPS (of course not for ship dodging)? We have been fed the need for spending on hybrid Glonass/GPS receivers and the development of Galileo as back ups. I would favour something that did do entirely without the space segment preferably a ham bone, charts and sensible passage plans that did not seek to squeeze passed geology unsuitable for the passing of by squeeze. Failing that eLoran would do.


----------



## Dave McGouldrick

I guess mates' tickets these days don't require the ability to use a sextant and tables.


----------



## Varley

I think the USA dropped the requirement for a while and then had second thoughts. I am sure we could all manage the theory for an exam but is a sight taken once a week or month for compliance with operational procedures enough to keep up the skill and accuracy that comes with that?


----------



## 5036

Decca Main Chain was developed for the Normandy landings. Ships travelled down an allocated lane and then switched to the second allocated lane giving them a dog leg into the beachhead. It was not a position fixing system, merely a guide and without it, Normandy would not have been possible considering the number and complexity of craft involved. It was switched off immediately after the landings in case the Germans realised what it was and how it worked.

It was developed from an idea from an American engineer whose career was on hold after contracting TB and the initial trials took place in California but neither the US Airforce or Navy were interested. The UK eventually saw its potential and developed it off Angelsey.


----------



## BobClay

Perhaps it's worth mentioning also that some decapitating event such as an exceptionally huge solar flare could not only knock out GPS but all the Comms as well, world wide. We might be able to repair or counter a hack, but the Sun is a whole different ballgame. Not that a rusting old Morse key would be of any help because it needs both ends.

We all saw recently how a minor software failure bought BA to its knees.

I sort of have a hankering to be in a 'post apocalyptic' world, and each day I see the news, I think it's getting closer. [=P]


----------



## John Cassels

nav said:


> Decca Main Chain was developed for the Normandy landings. Ships travelled down an allocated lane and then switched to the second allocated lane giving them a dog leg into the beachhead. It was not a position fixing system, merely a guide and without it, Normandy would not have been possible considering the number and complexity of craft involved. It was switched off immediately after the landings in case the Germans realised what it was and how it worked.
> 
> It was developed from an idea from an American engineer whose career was on hold after contracting TB and the initial trials took place in California but neither the US Airforce or Navy were interested. The UK eventually saw its potential and developed it off Angelsey.


I always understood that Decca was developed for bomber command to improve their bombing accuracy.


----------



## cajef

John Cassels said:


> I always understood that Decca was developed for bomber command to improve their bombing accuracy.


Sorry but Nav is correct it was developed by Decca and first used by the navy for the D-day landings.

https://en.wikipedia.org/wiki/Decca_Navigator_System


----------



## IDH

Looks like GEE was the first hyperbolic navigational aid and that that was used by the RAF bomber command. 

The latest form of navigation aid being investigated by the Chinese is X-ray pulsar XNAV using X ray emission from space.

Another interesting one being investigated at the NPL is quantum inertial systems http://www.npl.co.uk/news/quantum-timing-navigation-and-sensing-showcase-at-npl


----------



## 5036

John Cassels said:


> I always understood that Decca was developed for bomber command to improve their bombing accuracy.


John, the RAF was approached but opted to stick with the problematic Gee system, it was the Navy that spotted the potential especially in that Gee and Gee H were limited in user numbers, Decca was unlimited.


----------



## BobClay

IDH said:


> Looks like GEE was the first hyperbolic navigational aid and that that was used by the RAF bomber command.
> 
> The latest form of navigation aid being investigated by the Chinese is X-ray pulsar XNAV using X ray emission from space.
> 
> Another interesting one being investigated at the NPL is quantum inertial systems http://www.npl.co.uk/news/quantum-timing-navigation-and-sensing-showcase-at-npl


The X ray pulsar is an interesting idea since you have a large constellation of free natural sources which even the most ardent hacker is going to have trouble messing with. (EEK)


----------



## Cisco

Julian Calvin said:


> ........
> Apparently some vessels had their GPS signals hacked and had to return to port!!!!


One is left to wonder how they found their way home (?HUH)


----------



## trotterdotpom

Let's not forget Consol .... But don't lose count of the dots.

John T


----------



## John Cassels

nav said:


> John, the RAF was approached but opted to stick with the problematic Gee system, it was the Navy that spotted the potential especially in that Gee and Gee H were limited in user numbers, Decca was unlimited.



I stand corrected , thanks for the explanation.


----------



## Ian Lawson

Cisco said:


> One is left to wonder how they found their way home (?HUH)


Somebody, just might peek inside that wooden box in the chart room covered in dust. Finding it is one thing. Using it is another.(Night)


----------



## janmike

janmike
Ever tried finding your longitude by watching the sun set. It was an idea for use in lifeboats. Interesting it does work to a degree or so


----------



## Anabasis

Varley said:


> I think the USA dropped the requirement for a while and then had second thoughts. I am sure we could all manage the theory for an exam but is a sight taken once a week or month for compliance with operational procedures enough to keep up the skill and accuracy that comes with that?


The US has never dropped the celnav requirement for the ocean Merchant Marine licenses. I think that you are referring to the US Naval Academy dropping the requirement for all midshipmen. The QM's still have to know it.

In fact, the CM/Masters exams has some odd-ball reductions like ex-meridian of lower transits and circles of equal altitude. For assessments they have to shoot a non-solar transit and an ex-meridian. So celnav is alive and well, but how much anyone really remembers is up for debate. I am currently mentoring my 2nd mate on the fine art as she is slated to take her CM/Master test after this tour.

I harp on celnav on my ship, but I'm one of the few masters who seems to understand that if the GNSS fails, we are back to DR's and Celnav until we can get within radar range of land since there isn't anything else out here.


----------



## Varley

Jeremy. I said I am sure we could manage the theory not that we HAD managed the theory.

Good to hear you are following the true path. Many here would see it consigned to the bin. Would they go for a drive without the wherewithal to overcome a punctured tyre? (Yes, probably!)


----------



## lakercapt

trotterdotpom said:


> Let's not forget Consol .... But don't lose count of the dots.
> 
> John T


Dash I lost count !


----------



## tsell

... so, if/when this happens and you were still around, how would you approach navigation? 
$1.00 minimum, for each interesting/original answer... (?HUH)  (Smoke)

https://news.nationalgeographic.com...d-flip-poles-spinning-magnet-alanna-mitchell/

Taff


----------



## BobClay

PAH !! ….. more spherical heresy. … :sweat:


----------



## Anabasis

tsell said:


> ... so, if/when this happens and you were still around, how would you approach navigation?
> $1.00 minimum, for each interesting/original answer... (?HUH)  (Smoke)
> 
> https://news.nationalgeographic.com...d-flip-poles-spinning-magnet-alanna-mitchell/
> 
> Taff


Flip the Flinder's bar, reverse all of the magnets in the binnacle as well as the quadrantal spheres, put an overlay 180 degrees out on the compass card, and swing the ship for residual deviation. Then adjust the magnets/spheres for minimum deviation.

It's not like anyone looks at it anyhow...


----------



## tsell

Anabasis said:


> Flip the Flinder's bar, reverse all of the magnets in the binnacle as well as the quadrantal spheres, put an overlay 180 degrees out on the compass card, and swing the ship for residual deviation. Then adjust the magnets/spheres for minimum deviation.
> 
> It's not like anyone looks at it anyhow...


Jeremy, you have just won the jackpot for the most credible answer out of... well anyway, $10.00 will be on it's way to you as soon as you PM me your address. Please enclose a transfer for $20.00 to cover postage and handling, to my Nigerian address which I will forward by return.

Taff


----------



## 5036

Anabasis said:


> Flip the Flinder's bar, reverse all of the magnets in the binnacle as well as the quadrantal spheres, put an overlay 180 degrees out on the compass card, and swing the ship for residual deviation. Then adjust the magnets/spheres for minimum deviation.
> 
> It's not like anyone looks at it anyhow...


What about my Wayfinder shoes? Will the compass be out of warranty?


----------



## Anabasis

nav said:


> What about my Wayfinder shoes? Will the compass be out of warranty?


Absolutely! Unless you got Taff's extended warranty, you will have to pay for service.


----------



## 5036

Anabasis said:


> Absolutely! Unless you got Taff's extended warranty, you will have to pay for service.


They were a cult back in the 1960s, did they have them in the USofA?

https://bearalley.blogspot.com/2007/12/wayfinders.html


----------



## lakercapt

Anabasis said:


> Flip the Flinder's bar, reverse all of the magnets in the binnacle as well as the quadrantal spheres, put an overlay 180 degrees out on the compass card, and swing the ship for residual deviation. Then adjust the magnets/spheres for minimum deviation.
> 
> It's not like anyone looks at it anyhow...


The Magnetic compass.
Oh yes threre is many who look at it. When undergoing an inspection by the US coast guard the rating who was doing the pilothouse inspection asked to see tthe laminted compass. Don't know what that is I told him and asked to see his check list.
It was a bad photo copy and some letters were missed. What he wanted to see was in fact the illuminated compass!!


----------



## Anabasis

lakercapt said:


> The Magnetic compass.
> Oh yes threre is many who look at it. When undergoing an inspection by the US coast guard the rating who was doing the pilothouse inspection asked to see tthe laminted compass. Don't know what that is I told him and asked to see his check list.
> It was a bad photo copy and some letters were missed. What he wanted to see was in fact the illuminated compass!!


And these are the guys who are supposed to keep us safe! I was joking a bit about no one looking.

I have been asked to see the spare compass before, and of course the deviation table. I was master on a ship that had been detained on the trip before for an excessively large bubble in the compass. I often wondered what the previous Master had done to upset the PSC inspector to inspire him to look at something like that. I had the same inspector before and after and he never left my office.

I harp on the mates and AB's to watch the magnetic to know the CE in case the gyros fail and also to look for unusual anomalies. For a young captain, I am very old school about such things.


----------



## sternchallis

Varley said:


> Would they go for a drive without the wherewithal to overcome a punctured tyre? (Yes, probably!)


Many cars now don't come with a spare tyre or jack, but just a bottle of shaving foam and an air compressor that barely does the job.


----------



## Varley

Barely. Well barely does the job with a tyre seems acceptable, like barely the proper change. Barely missed the reef is not as comforting.


----------



## BobClay

Barely does the job with a tyre is likely to kill you. Soon as I got the current car and found to my astonishment there was no spare !! just as described above a bottle of foam and a compressor, I went on Ebay and bought a spare wheel with tyre.

Much more likelihood of getting zapped on a road than at sea without risking a bit of glue in a punctured tyre.


----------



## NoR

Flip the Flinders Bar ?

It's soft iron so why would you do that ?


----------



## Varley

Much as it would sadden us on SN to have you lost to juggernaut while squirting up on the shoulder of the M1 that would be only you Bob (and suggest we were discussing 'barely' not 'almost'). a reef offers the opportunity to loose not only a ship but her whole crew, too.

As an aside. When run over my mentally unstable neighbour I held him off while deflating one tyre of the VW Van in which he did the running over. By the time I had rung the boy's in blue he had used the tinned tyre stuff and was racing down the drive at me again. Rather quick and effective I'd have thought.


----------



## BobClay

Statistically you are in far more danger on the road than any form of sea transport I can think of, (with the possible exception of X boats.) And your direct point of contact with the road is a sliver of rubber, which really doesn't want to be glued up as a repair.


----------



## Varley

The energy converted in a sea collision/allision is vastly more than one on the roads (unless in some way your car, tyre rubber long vapourised, were to be re-entering the atmosphere after posing as an asteroid).


----------



## 5036

Varley said:


> Much as it would sadden us on SN to have you lost to juggernaut while squirting up on the shoulder of the M1 that would be only you Bob (and suggest we were discussing 'barely' not 'almost'). a reef offers the opportunity to loose not only a ship but her whole crew, too.
> 
> As an aside. When run over my mentally unstable neighbour I held him off while deflating one tyre of the VW Van in which he did the running over. By the time I had rung the boy's in blue he had used the tinned tyre stuff and was racing down the drive at me again. Rather quick and effective I'd have thought.


Your life cannot be described as dull!


----------



## Bill.B

You're lucky your drive is long enough to race down. Mine would be a mere lurch possibly one rotation of a tyre.


----------



## Varley

nav said:


> Your life cannot be described as dull!


Then why can I bore so well?


----------



## 5036

Varley said:


> The why can I bore so well?


Boring is not something that we, here, recognise in you.


----------



## Varley

One tyre rotation was just about what my legs did round his port fwd wheelarch after he hit me. I think a shorter drive might well have been the luckier length, Bill, although then he was coming up it.


----------



## Varley

Is it, then, that I do nothing well? Oh, woe! (but thank you, I have a few friends and were their number enough for a quorum I fear you would loose the vote).


----------



## Peter Martin

Bushmills 266 Kc/s, Ploenis & Stavanger all ,sadly, silent; but memories of the ‘equisignal’ live on!


----------



## Varley

Can the 'market' for a super accurate system with universal coverage be so large that it brings the cost of maintaining at least one satellite network (two actual and a third almost there) down to that of maintaining a terrestrial hyperbolic system or systems? Does the conventional cargo ship pay less in light dues because it does not need the precision of GPS (which for DGPS shares some terrestrial infrastructure)? How much of the overall maritime contribution to maintaining the satellite systems goes then on providing 'time' to almost every gadget imaginable?

Or is it the other way round? The marine industry is paying for the satellite systems only through their national taxes used for support of the military and no specific contribution is made. If we choose to parasitise instead of maintaining a more appropriate set of aids for 'ourselves' we will have to live with any consequences.


----------



## Geoff Gower

*Navigating in the 1950's*

How the hell did I sail on tramps going round the world -out East and back West, twice before I was 18 and continue to trade the world on a magnetic compass and sextant ???


----------



## Varley

Lunar distances then, Geoff?


----------



## Rosie

Just a lighthearted look at all the comments above. During the early 70s I was on the Berkshire as Purser sailing through the Inland Sea of Japan, and on the bridge with the old man looking at all the lovely islands, we had a Japanese PPilot andHong Kong Chinese helmsman, listening to the pilots orders the old man said who is speaking what? Sounds like the pilot knows Contonese, so asks thePilot who was speaking what? Ah says the pilot we both speak engerish


----------



## callpor

You may find eLoran making a prompt return?

I have just disembarked a bulker in Kalamaki, Greece after a short 2.5 day passage from Haifa, Israel. About 8 hours out of Haifa, when 75 nml south of Cyprus, the vessel suffered severe jamming of all GNSS/GPS signals for a period of 3.5 hours over a distance of about 50 nml. The navigators were prepared for it, as the ship had similar problems a fortnight earlier on the way to Haifa. As a chartless/full ECDIS vessel the system reverted to DR' positions so didn't pose a problem.

This is just one of five GNSS/GPS jamming episodes in various locations that I am aware of over the recent past. A fortnight ago I had experience of false signals on a vessel in the Southern Red Sea/Gulf of Aden over an extended period, there are reports from many vessels of jamming in the Black Sea off the coast of Crimea, off the east coast of Korea and strangely, off the east coast of UK.
Seems that this is a growing problem? Just wait for the mess when signals over the land are jammed!
Cheers. Chris


----------



## BobClay

I can remember going up the Gulf during the Iran/Iraq war and the Decca Navigator system was unusable because at least one transmitting station had been switched off for military purposes.

Likewise in the event of any future war no radio wave based navigation system is likely to be relied upon as it can be jammed, put into a strictly military encoding system or simply switched off.

Best keep those sextants lubed and polished.


----------



## 5036

callpor said:


> You may find eLoran making a prompt return?
> 
> I have just disembarked a bulker in Kalamaki, Greece after a short 2.5 day passage from Haifa, Israel. About 8 hours out of Haifa, when 75 nml south of Cyprus, the vessel suffered severe jamming of all GNSS/GPS signals for a period of 3.5 hours over a distance of about 50 nml. The navigators were prepared for it, as the ship had similar problems a fortnight earlier on the way to Haifa. As a chartless/full ECDIS vessel the system reverted to DR' positions so didn't pose a problem.
> 
> This is just one of five GNSS/GPS jamming episodes in various locations that I am aware of over the recent past. A fortnight ago I had experience of false signals on a vessel in the Southern Red Sea/Gulf of Aden over an extended period, there are reports from many vessels of jamming in the Black Sea off the coast of Crimea, off the east coast of Korea and strangely, off the east coast of UK.
> Seems that this is a growing problem? Just wait for the mess when signals over the land are jammed!
> Cheers. Chris


Big NATO annual exercise on off west coast of Scotland just now, "Ocean Warrior" with GPS jammed.


----------



## pkirk70

I was wondering if the sextant I was presented as Cadet Captain at the Boulevard Nautical School was now obsolete. I know we had Loran and Decca and the Echo sounder, for crossing the fathom lines on the charts along with radar if making a landfall. but sun and star sights were always taken where possible. The brown trousers always came in handy if you were navigating in Fog.


----------



## Varley

With you expert navigator decrying the use of hambones and other paraphernalia of celestial navigation I am pleased to hear one of you, at least, is not suggesting that navigating in fog is best done FAOP in order to get through it quickly (or is that why you had the extra laundry on standby!)


----------



## pkirk70

That extra laundry was a must if navigating in heavy rain or fog. 
Regards Paul.


----------



## callpor

Apologies for returning to the thread subject, but some of you may have noted the following which recently appeared in the Master Mariner forum on LinkedIn:-
Openquote:-Korea institute KRISO awards UrsaNav an eLoran test bed contract.
The Korea Research Institute of Ships and Oceans Engineering (KRISO) has awarded UrsaNav a contract to supply an eLoran Transmitter Test Bed System in the Republic of Korea. UrsaNav, the exclusive, worldwide distributor of Nautel’s NL Series transmitters, will provide eLoran transmitter technology, as well as timing and control equipment.
The contract, awarded through UrsaNav’s agent Dong Kang M-Tech, represents the first phase in a broader program to upgrade Korea’s Loran-C stations to be the foundation of a sovereign Enhanced Loran (eLoran) positioning, navigation and timing (PNT) service. The Republic of Korea recognizes the challenges associated with relying solely on space-based signals (GNSS), the relative ease with which those signals can be jammed or spoofed, and the necessity to provide trusted time and position to its citizens and critical national infrastructure, UrsaNav said in a press release.
"eLoran is exceptionally difficult to spoof or jam, and it is nearly impossible to do so at a distance. Just as equipment required to spoof and jam GNSS must mimic relatively low powered GNSS transmissions, spoofing and jamming eLoran requires very high powered transmissions. Equipment needs alone to disrupt eLoran over a significant area would be almost prohibitive for any actor other than a nation state engaged in open conflict".
UrsaNav is the world’s leading supplier of eLoran technology. Have developed comprehensive solutions for the General Lighthouse Authorities of the United Kingdom and Ireland (GLAs) which include a complete set of nine Differential Loran (Dloran) Reference Station sites and two Monitor and Control System (MCS) sites as part of an Initial Operating Capability (IOC) level Dloran System.Endquote.
So now there are others that see the need?
Cheers, Chris


----------



## Varley

Good,.

Discounting GPS spoofing, which is presently a miniscule risk (and easily detected on commercial tonnage I would claim), I am sure jamming is a reality although I think still more likely at state level than the pirate.

I am surprised that eLoran is considered jam resistant. It would require a lot of power to do it at the same distance as a loran station but I don't think so if closer up.


----------



## callpor

Varley said:


> Good,.
> 
> Discounting GPS spoofing, which is presently a miniscule risk (and easily detected on commercial tonnage I would claim), I am sure jamming is a reality although I think still more likely at state level than the pirate.
> 
> I am surprised that eLoran is considered jam resistant. It would require a lot of power to do it at the same distance as a loran station but I don't think so if closer up.


My experience earlier this year on a trip from Haifa to Greece was a period of severe GPS jamming for about 3.5 hours when around 75 nmiles south of Cyprus. Also had spurious and fast moving unknown radar targets throughout. Vessel had experienced similar two weeks earlier on the inward passage to Haifa. Considering the current military activity in Eastern Med I guess they were the perpetrators?


----------



## Varley

As good a guess as any. Anyone not wanting cruise missile to land on them might be at it. An earlier problem reported (although not experienced) was the aerial being zapped by military radar in the PG.


----------



## sparks69

Memories of sailing up to Kharg Island during the Iran/Iraq war. Ship all blacked out even the nav lights.
Two things I always thought were a bit daft.
1. The 3cm radar was on !
2. The phosphorescence started at the bow and was still glowing ten miles astern in a big VEE.
Money was good though.


----------



## Foca

I was on a supply vessel during the Iran/Iraq conflict, working for the Iranians, I certainly saw close up vessels being hit by missiles......they hit a Chemical Tanker close to Rakksh(R1) Oilfield and they had me up all night plotting it to make sure it cleared the Oilfields. Going back to GPS..when I worked on UCNW Research Vessel we used DGPS forget how much it cost...but I believe there are various similar systems Worldwide now WAAS.EGNOS to name a few


----------



## Baulkham Hills

There was a piece of equipment called racal mns 2000, this had a gps along with omega and decca, it was ok in theory but because it would compare gps with omega and there would always be an error gave a constant alarm. Which of course could be cancelled but a few minutes later would alarm again. You could not use it as a gps alone. These were placed on my ship for evaluation so I don't know it any were improved or continued production.


----------



## Baulkham Hills

In 1990 was I ice bound in the Gulf of St. Lawrence as soon as the first gulf started the GPS was degraded and an error was introduced so that presumably Iraqi missiles could not be pin point accurate. I was obvious comparing with visual sight of land that was indeed the case.


----------



## Varley

Hot stuff in the mid 80s. Now Ebay stuff (800 USD) - includes Transit!


----------

