Just a point of note: UK rail lines are not grounded to earth, they sit on insulation pads. Both rails are used for track circuit detection. When a train runs on the track, it's wheels electrically bridge the two rails, this provides detection location of a train on the track, it's the detection that runs automatic signals. Because of this the track is on sections usually 440yds that are electrically isolated from each other using a device known as an IBJ, or Insulating Block Joint. So there is not a continuous rail of metal from one end to the other, even though it's called CWR Continuous Welded Rail, the IBJ's effectively break up the conductivity over each section. Also, the overhead electric gets it's return path through the rails to return sections. It does get a bit complicated, but essentially it's impossible for any UK railway to be used an an ELF antenna..
It seems that the track(s) are used as the electrical return path on the ECML, and are also bonded to earth. (safety.networkrail.co.uk/wp-content/uploads/2022/05/Journal-2022-01-Vol140-Pt1_Earthing-and-Bonding-on-ac-Electrified-Railways.pdf). As such they'd make a poor aerial.
You are just about to get the launch codes for armageddon when suddenly you hear "British Rail regrets that the 3.35 to Manchester will be delayed for 40 minutes and will no lnger have a buffet car due to equipment shortage. Due to the limited delay no refunds will be available".
"...this train only stops at Halslow-Willow, Snodsbury, Knobwallop, Todger Circus and Tinkerbush" - this won't excite the KGB agents, but when a Brit sub crew hears it :D OMG the codes!
That really reminds me of the coded messages on the London Underground: "Would Inspector Sands please report to the operations room immediately". That's actually real as far as I know, to announce that there's a fire somewhere.
" We regret to inform passengers that the 4:32 to Cardiff has been vaporised. This is due to the presence of incoming Russian ICBMs and the resulting thermonuclear detonations. All enquiries regarding refunds will be addressed after the nuclear winter, thank you for your cooperation "
A friend of my father’s was on Polaris in the 1970’s. He said that on an exact time every Saturday, the submarine would launch a tethered radio receiver which broke surface for a second. This captured a high speed encrypted pulse which was taken to comms and decrypted. It was the football pools results.
Imagine being on a fishing boat and all of a sudden a small radio antenna pops up out from the sea next to you before slowly sinking back under again...
I know a ham radio operator over here in the states, that loaded up a set of abandoned rail road tracks on 10 meters once using a 100 watt radio. He had a lot of people coming back to him once he let them know what his antenna was. But on the other hand, that was 10 meters not VLF or ELF frequencies.
I also remember reading about an AM radio station covertly doing the same thing to increase their broadcast radius, although they had to stop before the FCC caught them.
It is quite interesting to experiment with things like this. I have stopped in Wales and loaded up a wire fence through an impedance matcher on HF. On 160M and 80M I was getting loads of contacts. That was on 5 Watts. The fence must have been a mile long on a hill. I am very much in to "stealth antennas" and have a full set up for HF to UHF, no one spots them unless they really know what to look for. I've even used a wire clipped on the back of a gutter around as house as a loop antenna on HF. I also tuned up a length of 75ohm coax going up a wall to a pole and TV antenna on 10M. Aerials don't have to be high up for HF, you can run them 2ft off the ground and get great results.
I can tell you that using the railway as an antenna would drive the S&T technicians mad. I'm sure that they wouldn't be happy with any potential interference or spurious voltages from transmissions, as how trains are detected on the railway is (mostly) by how they pass electricity from 1 rail to another (track circuits). That and if there was a track gang out, then I think they'd appreciate not being shocked by RF. I don't think their industrial equipment would like it either.
@@lordmuntague Track circuits are a mix of different technologies, but tuned frequency tracks are fairly common at the 1-2kHz range, you can sometimes hear the electronics in the transmitters humming at this frequency.
@@jacklamb2904 The question isn't the traction alternatic current circuit (which is A LOT of trains on the East Coast Main.) The question is about how the signalling track circuits will work if the rails also has a strong VLF signa..... As soon as track circuits comes into focus - you have a BIG railway security issue.
@@GEdgemaster can't speak for the railway in question but AC or DC track circuits are uncommon. What would support the usage of the track as an antenna tho would be axle counters
Hey, Lewis. I agree with you about the problems with using a rail line as an antenna. I used to work at a railroad years ago. There are several problems that come to mind for me. 1. Insulated rail joints for signal blocks. 2. Track switches when switched would change the antenna profile. 3. Track work and broken rails taking the antenna down. 4. How do you protect the security and secret while trying to run the railroad? I remember seeing a US Navy submarine transmitter site in Hawaii. The antenna cables were huge. Around 3' to 5' in diameter, and they run up and down a mountain. I think that sight is now defunct. Because an old episode of Magnum P.I. filmed there back in the 80s. Just my thoughts from my time on the railroad.
Geophysicists use (or used to use) the VLF transmissions to detect buried ore bodies and other conductors. Your playing of those transmissions from Cumbria brought back memories of days having to listen to (and try to null out) those signals when doing VLF surveys.
British Rail did have something called the 'Close Call' radio system on the old 1500V DC Woodhead Railway Route where I understand that locomotive crews could talk directly to one another between the front/head locomotive(s) & the banking/rear locomotive(s) by means of using the OLE Overhead catenary system as an antenna. It was discussed at an open day at Reddish TMD back in the 70s I understand that it was mainly used on the Worsborough Incline/Bank, so perhaps the possibility of maybe using something like OLE catenary & British Rail infrastructure as a means of radio communication might not seem as weird as it sounds. I'm not a radio expert, it's just something that I was told.
This system was known as clear call, and passed messages in voice format between the loco's. This was achieved as you state, throgh the ole. The problem with the ECMLhowever is that this system uses 25,000 volts AC which would presumablycause too much interference to be able to use it as a n antenna.
EDF in France used something similar for data and voice communication over their high power lines. They were certified as a full telecom operator but only used the network internally so control centres, switching centres and power stations had indépendant national communications through their own power network.
@@fouloleron2002 That's it.. 'Clear Call'.. I knew that it was something along those lines (no pun intended). It was back in the 70s when I heard about it & the old grey matter ain't what it used to be. Plus the Worsborough incline/bank closed in 1981 so it's all history now & non existent. I replied to you previously but for some reason it disappeared.
Submarines use Meshtastic on 869.525MHz. The range isn't always great, but if you get a few subs close together they can relay messages back to Blighty in a series of hops. My mate Bob (actually a woman) told me this, so it must be true.
@@paulsengupta971 Suchhhh it's on 869.525 kHz not MHz. Specifically chosen so that it is lost amongst all the other signals around that frequency coming from all the Ethernet over Power and switched mode power supplies crap that invades the RF space.
@@barrieshepherd7694 That explains why I had a lot of interference listening to BBC Radio Wales on 882 kHz yesterday, especially when a special refrigerated lorry drove next to me.
Think about powerline (home networking over your domestic Electric cables), but I dont know enough about it to say one way or the other. My concern would be a broken rail, engineering work, rail replacement, insulated joints etc. :) Then you have the return current from the Transformer, and I had to do an EMF survey for one of my drivers who had a Pacemaker, to see if it was safe for him to travel on a train, we had the dusty bins at the time, the PMS/PMOS was very electrically noisy, especially on the through bushing on the early units, the Renatus ones were better.
I live next to a railway line with 25 kV overhead lines. We are bathed in electrostatic interference. I have to heavily shield audio equipment to keep the interference out. I have a couple of high quality German microphones from the '60s that pick up the interference. The railway seems the like the last bit of infrastructure to make a radio emitter out of.
@micksmithson6724 your powerline idea would be the only way it would work. A frequency band far removed from any possible interference or railway use. The amount of maintenance carried out on the ECML would prove problematic though, how much interference would it cause? How would the submarines be aware of such activity possibly causing issues? And the existence of track circuit block sections isolated from each other renders this idea unlikely too.
@@richardwillson101 I did put the issues with IBJs, etc in my post. However what if everyone has the wrong end of the stick, what if instead of the running rail, they have strung another cable between stanchions, a dummy eart return wire. They tell the OHLE team the cable is to do with S&T and the S&T team its to do with OHLE. It wouldnt be affected by engineering work, no IBJs, no Neutral sections, it just sits there in plain sight. I recall reading a bit in Rail news back in the early 90ss when British Rail Telecom (as they then were) from memory it mentioned running telephone cables along the mainline on the ECML. It was 30 years ago so the details may be wrong.
I know more about US rail than UK, but I assume the signal systems work basically the same… There’s low voltage that goes through the rails. Sections are blocked off. When axles short the rails it activates the signals and provides a location for the trains. So yes, you would not have one giant unbroken line. There’s about 20 other reasons why it wouldn’t work well.
You could in theory couple the blocks with a high pass filter circuit if you were really motivated, and this does prove that the rails are not perfectly grounded. Just thinking out loud
Not the actual rails of course, and probably not even the catenary... But rail lines (the route) are often used to sneak in long distance communications and power distribution. There are many random cables parallel to it belonging to just as many agencies. Especially if it's just a feed line for the earth rods at each end it could make for a cheap and quite unsuspicious backup system. Compared to how the other stations jump out in satellite imagery
Not just agencies but commercial operations too. There's a lot of optical fibre runs around the country along railway lines and also along the canal system. I used to buy fibre capacity from the people that had the first licence from the British Waterways Board to use the canals for fibre routes.
Was just thinking why not the overhead catenary (not on the ground) but perhaps cables in the trackside trenches (or whatever they are called) could be easily hidden as you say.
For years, many years, the National Grid provided a service whereby you could carry communications along their pylon network. They come clean and started saying they run fibreoptics on them a few years ago, saying it was for Internet. When pylons were installed with mains cables they also had telephony cables running with the earth wires.
"LNER apologises for the late departure of the 09:00 Trident service for Moscow owing to the late arrival of the 08:50 train from Peterborough..." And technically: - the nucular-armed subs are Ships Submersible Ballistic Nuclear (SSBNs); - Sub-Launched Ballistic Missiles (SLBMs) are their weapons-delivery systems; - the weapons are Multiple Independently-targetable Re-entry Vehicles (MIRVs).
A couple of immediate thoughts: I don't think continuously welded rail was a thing until the 1980s or 1990s and the ECML wasn't electrified until the 1980s. I suspect someone somewhere said "lads, this could be an idea" but never really made it out of the lab/tests but the rumour remains.
I enjoy your videos. You’re discussing a topic I know very little about, but I always find them interesting. Have you ever done a video on what I believe was called ‘Project Backbone’? I grew up very close to a large antenna, which I was always told was for TV signals, but strangely it didn’t appear on local OS maps. It was only later whilst reading a book about the UKs Cold War Defence that I found a picture of the exact same antenna that was on the opposite side of the valley to my parents house.
How about digging into criggion Radio station rum by BT for the MOD, supposedly for submarine contact. One of my customers did his early years there. Towers have since gone, ( 700 ft ) but the trasnmitter hall is still there, and the BT Buildings
At Gatwick airport the railway runs at 90 degrees to the runway about 400 metres from the eastern end. In the old days of analogue instruments landing system if an aircraft was on approach to that end of the runway and a train was passing by it often caused problems with the instrument landing system signals. I got some seriously strange looks from pilots when I debriefed them about an ILS problem when I asked if a train was passing the airport. Apparently the passing train could set up an harmonic signal causing the aircraft system to get confused and disconnect. Sure enough if we function tested an ILS that had failed on approach it would normally work perfectly when tested. The problem went away when the ILS worked on a digital system, it still used the base frequency peculiar to the airport, with the 90Hz and 150Hz lobes superimposed on it, but the aircraft processed the signals differently. So I’d be surprised if a railway track with trains on it could be used to transmit data, the interference would be too great.
SSBN submarines tow a very long cable behind them that comes up close to the surface just to receive VLF signals , the Royal Navy still has an active comms base up here at Crimond Airfield ( formerly RNAS Rattray or HMS Merganser ) , there are 3 masts ( 900ft tall and all have multiple red warning lights on them for aircraft / helicopters ) which we used to use as landmarks when we were fishing as we could see them from 20 miles away on a clear night
Subs DO NOT just tow a line with an Antenna on the end at all times, they only use "The Buoy" if THEY CAN'T come up to Periscope Depth to recieve "Flash Traffic". The "Cable" you are reffering to is actually a Hydrophone Array that is designed to reduce the blind spot that is the Ships Baffles.
What also makes a cheap and easily accessible antenna for VLF is the guardrail along the highway that can be conveniently tapped from a mobile setup with a special transverter to allow for the secret frequencies below the capability of ham transceivers.
What Anthorn also transmits, of course, is the MSF civil time clock signal on 60kHz. That used to come from Rugby until that station closed. Rugby is in the centre of the UK whereas Anthorn is way further north on the Solway Firth, north of Silloth. Being now so far from anyone in the South of the UK it is noticeable (such as when in the UK we put our clocks forward on to BST a week ago) how long it can take for more remote receivers to update.
Interesting! When i visited the UK and travelled the tube in 2007 i remember seeing the LF tx there underground... It was a inductiive loop antenna system from memory. Be great to see a story about that if you can dig it up 🙂
Back in the 1980 when I was going to Ham Radio morse classes, there was a student who talked about a VLF system in a disused mine in Cornwall that went out several miles under the sea. This was just a rumour that sounded plausible, and we kicked the idea about when we stopped doing morse and had a tea break.
He is probably referring to CAVE RESCUE RADIO systems. A little known fact is that only certain frequencies are any good for cave rescue! VLF too. They are often tested in old mines and caves for ground penetration. Idea for another video there!
I used to work in Woolworths in Morpeth in the 80’s. The upstairs floor in the building was accessed separately from the rear. It was supposedly a laundry, but there used to be quite a bit of coming and going of various vehicles and people. Anyway, I was having a cig out the back one day and got chatting to a decorator who was working there. He said it was some kind of communication building to do with the railway, but only what he’d worked out from working there for a few days 🤔
If you're looking for a sign I s'pose Morpeth is your best bet! (This message was brought to you by Railway Nerd Ltd, a subsidiary of Asperger's International Inc.)
There's quite a lot of comms infrastructure that lurks quietly in places that people never notice. There's a shared comms hub (commercial) in a basement in the Birmingham Bull Ring Centre (I've installed kit there). I know an ordinary office block in London where the unoccupied top floor is full of one company's assorted comms kit, and there's a nondescript house in Dock Street, London that is actually a telephone exchange (was Cable and Wireless, don't know who owns that bit of C&W now).
@@ianmason. You should see how many nuclear fallout shelters there are! I have built and installed lots of equipment in them since the 80s. If anyone is in the North West, there is one under the council building extension in Ellesmere Port town centre. Access via a door from the car park that looks like it goes in to the offices, or via a manhole in the car park that has a 5ft diameter concrete tube running about 20ft on an angle. Inside is a submarine door as I call it - the room is tiled and has a brush with hose attached on the wall ! Down there is a command and control centre, air/water purifiers and storage and a diesel generator and storage. There is a room with bunkbeds and a kitchen, toilets and storage. This was completed in around 1991. Access down the main stairs leads to a thick door hinged on the right. On entering the shelter, rooms to the right are beds, then the escape tunnel and tiled room with showers, toilets and a kitchen area. On the left after entering from the main door are air purification, water treatment and storage, generator. Straight ahead is a large room of about 20ft by 25ft with various computer equipment and radios. This has all been updated since. Some of the aerials on the council buildings were connected at one point. Many shelters existed like this, but were demolished. One or two still exist.
In the 1980s there were plans for an ELF transmitter on Sròn a' Choire Ghairbh above Loch Lochy in the Great Glen (now home to a pumped storage construction site.)
Nice one Lewis.! If you have portable HF or low band VHF, go stand near any rail line, orient the antenna (1/12th of a wavelength) with the rails. DO NOT touch the rail or overhead. Gaps in the track less than 1/4 wave are no issue at those frequencies. Check "end effect". I know a guy, he's passed on now. He uced a little 30cm jumper cable to the copper telephone line. Although underground he could out-DX us day or night.
There is something in the back of my mind that there was some sort of a backup system that would transmit either a regular pulse or tone. If the pulse/tone stopped, that was the cue to light the blue touch paper and stand well back. Could be talking cobblers though, and it was all a dream.
And i was always told that the tune "sailing on by" that radio four plays at the end of every days transmition was the signal that the apocalyps had not yet hapened
@@ellenorbjornsdottir1166 The idea is not that this a basic indicator of trouble but the backstop if all communication has broken down so orders as to what to do are unavailable when there is obviously a nuclear war going on. The submarine commanders have sealed last resort orders (this is a known verified fact) and the claim is that the absence of R4/today/whatever is the final step in the protocol for triggering opening these sealed orders.
If I had to guess, they'd probably be using the overhead power lines of the electrified section instead of the rails themselves, you can easily superimpose a radio signal onto active AC lines and the transformers on the trains would stop the signal from reaching the actual rails and interfering with signaling.
One way to do this would be to phase modulate the national grid subtly. ELF on 50Hz. The bitrate would be abysmal and you'd have to correct for natural frequency variations with load changes. Even if it's never been done, I'd bet that someone is bound to have thought about it. You'd need a power source that could switch in and out at short notice, perhaps a pumped storage system. Does tinfoil block ELF? 😂
Have you ever looked at the US Navy Jim Creek station in WA state with transmission on 24.8 khz at 1.2 megawatts? I can receive the apparently unmodulated carrier but have never seen any sign of data.
Track circuits use spaced insulators to break the continuous length of rail into Blocks (distinct DC circuits) to detect the presence of a train. This not only enables the signallers to know which blocks are occupied but for automatic signalling to prevent a train entering a block of track before it is clear. It’s a nice story but I don’t know if there is a length of rail long enough to act as a transmitter?
Only way I'd see it working would be if the power distribution lines were used. If those lines are routed straight, and being connected via series resonant circuits.
I doubt you could use one rail as the element and another as the reflector - the trains on the track would electrically short them. That's how track circuits work as far as I know. Plus there are breaks in the rails.
I don't exactly know how this is in Great Britain, but I am a railway engineer in Germany and I would like to weigh in. First of all, the rails are very well grounded. Of course, due to the extreme currents caused by train traffic, there might still be a significant potential difference between the rails and ground, but that is only due to the trains drawing literally hundreds of amps. Therefore, I don't believe any transmitter could acheive any significant transmission. Many people here mention track circuits as a reason why rail lines would not work as an antenna. Personally, I think that track circuits might actually be a great candidate for such a system, as on lines equipped with a track circuit, one rail is insulated from the other and ground. Therefore, that rail might be a feasible antenna. Also, track circuits operate well within the Kilohertz range and are designed to ignore lower frequencies, as those may also be caused by the movement of the trains themselves. But are those common in Great Britain? At least here in Germany, track circuits are largely replaced by axle counters. Another thing that comes with the rail lines and could feasibly serve as a VLF antenna in my opinion are the overhead lines. I mean, the high voltage is a hinderance, but they are isolated, conveniently accessible and even slightly elevated. But quite honestly, even if it might technically be possible, I think there are easier ways to build a transmitter, even if it has to be secret.
You probably know more than me about the technical details, but having read what you said, I definitely think that it could be technically possible (excluding the whole grounding issue with rails), but there would definitely be much easier systems, with less secrecy and reliability issues, making this not really practically possible, even if technically possible (thinking specifically about power isolation between sections, engineering works, and outages, which would mean no transmitter - so what's the point in having the transmitter that can't transmit, leaving the SSBNs uncontactable via that method). In the UK, we mostly have track circuit detection, though axle counters are used in some places (wet tunnels, sea walls, near-sea bridges, etc, and also some areas which were resignalled more recently, and the few odd places for experimentation, etc), though I'm not quite sure if track circuits are slowly being replaced with axle counters as the preferred option or not. We also use old absolute block, a slightly more modern version of it which is essentially the same thing, or the more modern radio electronic token block in some remote areas (~4 instances), or even old token block, in some places still. Physical token systems aren't widely used, but they are still around in some more remote/lesser used areas, and whilst quite a few IECCs have been replaced by the more modern ROCs, we still have many signal boxes using mechanical interlockings. The ECML wasn't electrified north of Luton/Stevenage area until 1985, Leeds until August 1988, finally reaching Edinburgh in June 1991, so I think we can probably rule out them using the overhead lines during the cold war for VLF/ELF transmissions though🤷♀.
The railway lines of an electrified railway form the return path for the traction current from the overhead line via the train. So they are earthed. And of course points and crossings would electrically connect one rail line with another.
It would be possible to use it for RX, but due to public safety not on TX. There would be issues with joins in lines, breakages, constant impedance changes etc. What you might like to look at is how HV electrical cables were used as VLF aerials. All those pylons... Many things are "hidden in plain sight". Some fields have miles and miles of fences, trying measuring for RF on them with a frequency counter etc.
The frequency’s mentioned are very close to the remote control frequencies used by traditional British Rail (Remote Control) TDM frequencies by power signal boxes to control remote interlockings. So an urban myth as they would have caused havoc with signalling systems.
First this: (as mentioned) the rails are grounded. Also, railway signalling relies on isolated gaps in the rails to control crossing lights/guards, and reporting the position of trains.
Therefore only one of the rails can be grounded. The gaps in the other rail could be bypassed by high pass filters. Not that I think that this scenario is likely.
Running rails are used for passing signals in most train systems so it’s possible to do that. However at the time, most rails were bolted not chemically welded, and even when welded they don’t have a constant resistance or cross section so there would be so many internal reflections it would be chaos. Could they use a single section? Possibly. They added overhead electric power lines (better suited as an antenna) in 1970s but that’s too late to be helpful
A railway easement would be a nice site for a long antenna, if you are the government and you are looking for a long stretch of land then land you already sort of own would be perfect. There would be no landowners to negotiate with and a nice long stretch in a rural area would cause minimal interference to civilian radios and TVs .
i thing the confusion is something to do with a Track circuit that detects the train within a block by useing a small amount of voltage in the running rails
8:26 Not to mention that the rails themselves _are_ part of the electrification system, serving as the power return for the trains. And the rectifiers and SMPSes on electric trains output _a lot_ of dirt on the airwaves. In France, some of the pioneering locomotives equipped with solid state power electronics used to jam each other and malfunction when they were in immediate vecinity! Imagine what that would do to a radio signal! And then the tracks themselves are broken into 3/4 to 1 mile long, electrically insulated sections (don't know the exact distance for the UK ones) that are connected by (very) low pass filters to allow the power return to work but not the railroad automation signals (which need to be confined to each of these sections). Those things usually stop basically anything above 50Hz. And then there's the railway automation signals themselves which in some countries can reach as high as 2.1kHz!
the rail sections are actually really short, they are isolated for each other as the wheels short out the rails to trigger the signalling. Also they are the return for the 25kv locomotive power supply. I'm not sure you could use the rail as a transmitter with such other power supplies running through them?
Thanks Lewis. There was an X-Files episode loosely based on the ulf transmitter up in Wisconsin or wherever. Back when conspiracy theories were just a bit of fun. Ah the good old days.
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We need to be careful when we are preparing trains and with cab GSM-R test, 1900 echo test (please speak after the tone)…. Flash bang 😂😂😂
James Follett was a technical writer for the Ministry of Defence. His experience directly refutes your statements Re: "if they didn't receive the signal, they were instructed to launch their missiles" (paraphrased). Perhaps he was fed inaccurate information as a means of obfuscating the truth--I dunno. But I wouldn't be so quick to call it a "myth."
It would be difficult to use the rail lines as transmitters since, despite appearances, they are not continuous - railways use isolated sections of rail to regulate block signalling. A train entering a block creates a short-circuit triggering a red light at the entrance to the block. The OHLE could provide some sort of solution if a continuous link were made from end to end in addition to the standard wiring...
While we're on the subject of the Cold War and British Rail, what about the 'strategic steam reserve'? Supposedly the last BR steam engines (which were only a few years old when they were replaced by diesels), were stashed in Box Tunnel near Bath (or an old mine,, or an offshoot of the London Underground etc. etc.), ready to be used after a nuclear war when there would be no diesel but plenty of coal. Or something.
I've heard this before And I'm pretty sure I've asked someone about it, and they said 'No' However... I can ask someone who knows every single inch of all those quarries around that area.. (One of the founder's of the Bath Stone Company) Possibly one of the three Box quarries Or Spring Quarry ( Corham - government nuclear bunker) I do know that Corshams bunker waste water was designed to flow down and out of a culvert into a tributary by Box tunnel. I'm also aware that Corsham has become a bit "active" again. This chap recently gave me a guided tour down in the Monkton Farleigh limestone Quarry (later used by the ministry of defence to store munitions in) All I can say is.. Wow, what an incredible place.. A maze of 60 miles of tunnels.. There are videos on RU-vid that only go a very small distance in the Quarry. However.. we went to places unknown to most.. I did take a couple of videos. However, out of duty of care I'd never show them on anywhere like RU-vid As folks would seriously get lost down in there..
I could see the MoD running a project to experiment with using rail lines as antennas. But it woudn't necessarily have to be for transmitting. They could have been trying to use the East Coast Mainline to monitor VLF stations in the Soviet Union and satellite nations.
Technically it would make sense for broadcasting VLF signals, even if not for the entire length of track, a few kilometers would suffice, and the ionosphere would compensate for the track's flat position.
I've been trying to build my own dipole for 868 lately and something I read and disregarded was to pick braid over solid core due to "stretching". I figured an ~8.2cm pole will have a low margin there. As I understand it that can impact resistance / velocity and thus SWR? But if this is true and I guess you're the man to declare I guess; I would think surely railway lines are subject to the same issues but amplified? Or Maybe I have this all erse over elbow and that's why my dipoles ain't getting an SWR below 1.2ish. What you said about grounding has to be big too, unless they're energised but they aren't right? That's all in the lines overhead the whole way? If anything the lines would fit the bill more, but then how many breaks / junctions along the way which would make that, "a not very good antenna"? Anways, if you don't know .... can you ask Rodney errrr..... Dave errr ..... Kevin for me?
Track circuits? Level crossing activator? Signalling circuits? There's quite a lot of potential interference sources on a main line railway. Secondary or branch lines, even heritage, a different story.
When I was studying Electrical Engineering at college in the 1980's one of the lecturers often used to claim that part of the national grid was used to communicate with subs over VLF. There might be some element of truth in these stories. The transmitting stations are obviously sitting ducks and an easy target in any conflict so it would be sensible to look at other options to make the nuclear firing chain more resilient as it really needs to be. Perhaps tests were done at one point hence these stories and even there maybe a highly classified system ready to plug-in to some element of infrastructure in a dire emergency. Let's hope we never find out.
Isn't it a problem on it's own that the tracks used as an antenna probably are not even near to be tuned to the wavelengthes you would probably use? How long is that line? some hundred kilometers, perhaps? At 67Hz, wavelenth is about 4474 km. So a simple dipole would be about 2235 km, if I am not wrong?
I really can't believe they'd use rails as an antenna. The only thing that could be advantageous is that Long Wave travels along the surface. Everything else is loaded with disadvantages.
I mean, they could have used the overhead electric lines, at least in case of a nuclear war. They are lifted off the ground, are properly isolated and have many big supply stations that could be used to hide a transmitter.
The OHLs are not continuous - there are frequent neutral sections where the breaks between supply points, or level crossings are, there are also loading coils (called Booster Transformers) in many systems to counteract the induced voltages into linesdie cabling. Over the years Railways have tried - with various degrees of success - to use the OHL for communications with trains. The various gaps, getting signals across switching and transformer equipment have generally meant that even those that were adopted have been replaced by other more conventional radio systems.
@@barrieshepherd7694 I mean, one can overcome these hurdles though. Maybe not if the railway has to operate normally, but I guess in case of a nuclear war, no one really cares anymore. They cut power, disconnect the transformers, add some bridges between junctions, done is your antenna. Definitely less work than burying miles of cable
There was an ELF transmitter site in the same state I live in. Clam Lake, WI. Look up Project Sanguine on the Wikipedia. They used to transmit at 76 Hz
Hello your videos inspired me to buy a shortwave radio i wanted to ask do you think the Tecsun PL-330 would be a good choice ? its the best available to me right now . thank you.
Location of ELF stations are just as important in many ways as HF stations, but for different reasons. Ground permanently etc. so an east coast system for appropriate direction and propagation cannot be ruled out. But how about a report on the role of the now decomissioned criggion station which was 100% known for shallow submergence submarine Comms during the cold war.... Allegedly 😉
The two reasons I can think of why this wouldn't work is the operating principle of Track Circuit Block, which controls signalling whereby a a signal is sent down one of the rails and if a train is present in that section its axles short the signal and send it back via the other rail, automatically switching the signal behind the train to danger. This also means the tracks aren't one continuous conductor. The other is that 25kv overhead line equipment usually has a frequency of 50hz and I'm guessing that would interfere with ELF signals
To be fair, given how original some British technological solutions were (whether they worked or not) I can believe that they had at least considered such a thing.
Maybe the idea is that in case of a nuclear war, if known transmitters got destroyed, then maybe a part of the rail line (or better, a part of the overhead line) could be used as antenna. Just disconnect power and connect to a transmitter. Of course this disrupts the train service, but I don't think that it's such a problem while being bombed. Of course you'd need a transmitter somewhere near the line.
I'm not a signal tech but I am of engineering grade on the railway. Electrified railways use both running rails as a return path for the overhead lines, the catenary is energised to 25kV AC nominal. As well as this, trains are 'detected' in a given track area by a few means but for this example, the wheelsets cause a short circuit condition between both running rails which tells the signalman which tract circuit area the train is in. These track circuits are also electrically insulated from each other. I'm no radio expert but I suspect these two factors as well as interference from high voltage transformers on electric trains, and, trains fitted with Tract Circuit Assisters (leak a frequency into the track) would cause a fair amount of interference to the original broadcast. Very interesting theory though and I wouldn't be surprised if it ends up being true.
The Droitwich/Submarine communication was confirmed by the MoD in the 90s. I understand there are problems obtaining the large valves used at Droitwich.
I had a friend who worked at the Rugby transmitter facility during the 1980s. He looked after the VLF Transmitters that communicated with submerged Submarines. Whilst there, during the 1980s he went out to the Offshore Radio station Radio Lazer to help get them on the air. He said he wasn't the only one who did this, as there was more than one engineer from the BBC. I don't know who he actually worked for at Rugby, and when I asked him he said he couldn't talk about it. There was another guy I met who also worked there. Not sure when my friend left there or if he transferred to another location, but when the Lazer ship Communicator came back to England (after its voyage to Portugal, and the Netherlands where she was used by Radio Veronica, Arrow, and another station), he often spent time on the vessel by this time in Ipswich I believe. He said they would get regular visits to from the DTI to check on things. The vessel then ended up in the Hebredies to be used by a Community Station, but the deal fell through and the ship was left to rot, and was eventually broken up. Last I heard this friend of mine was still living on the Hebredies.
So he wasn't working at Rugby, didn't help pirate stations, isn't your friend and you have no contact with him - you just "believe" all that. Any time someone says "I believe" or "he couldn't talk about it" we know it's rubbish. Don't forget, it was mainly radio amateurs that worked at Rugby and all well known. Backgrounds were fully checked and any activities of a criminal nature would mean termination of employment. I know you want to tell us all about pirate stations on ships, but that's not what this video is about.
I understand there is one or more very long continious aerials streaching from the USA into Canada. I would have thought if there are such aerials, they would be very prone to lightining strikes and emp.
It's worth mentioning that should this system actually exist, then both rails would have to be used since the axles of passing trains shunt the two rails together electrically. It's this principle which formed the basis of the simple track circuit- it uses the conductivity of the rails and the axles of passing trains to complete a circuit to tell the signaller if there is a train or not. The circuit created by the rails and axles would also form a rudimentary inductor with changing inductance as trains pass over it. This change in inductance is used in more modern track circuit systems but also to detect the speed of approaching trains. Having a constantly changing inductance on your antenna would completely screw with the signal. Also, in order for simple track circuits to not interfere with each other, there will be insulating joints between lengths of rail plus there would be breaks wherever there are switches so the rail is discontinuous.
Maybe as a last emergency backup antenna, an interconnect to be used only if nothing else is working, if this was a thing, shutting down the trains, and traction electricity would be the last of the worries
ELF is used to send orders to submarines I think the antenna ONLY needs to be 5 miles long It would be easy enough to run a cable along phone poles in rural areas and no one would notice it. No one would notice anything strange, just another cable that looks like a phone cable The ELF can go through the earth. It can get a lot deeper than 300 meters The regular antenna that is used is the one that you need to be near the surface.
