Thanks for your video. It brought back memories. I served at a loran station in the 80"s. Sadly, all the stations were decomissioned in 2010 in favor of GPS. A big mistake in my opinion. Loran cant be spoofed like GPS, which the Iranians did to steal one of our drones.
My buddy, Mike Fair, was a WW2 veteran who, as a coast guard mechanic was tasked with regularly visiting and maintaining the diesel generators powering LORAN stations in the Pacific.
I worked on F-4 fighters in the 80s that had LORAN systems installed. A long black low profile antenna on the backbone of the jet. This was before even military GPS so they had this and inertial nav. Well a late version of LORAN. Dash C I think.
His name was Robert Dippy and he was British!! He invented GEE, which LORAN was developed from after the US were told about it in 1940/41. After he had got GEE up and running, he went over to the States and helped get the various bugs out of that system. The Best thing he did however was get the LORAN guys to build the Loran A black boxes in the same configurations, mounting and connection wise as GEE. Thus, any British or American Bomber could be fitted with LORAN one day (because the mission required it), and GEE the next). Just swap out a couple of Boxes and an Aerial. Main RAF users of SS LORAN were 5 Group (Lancasters) and 8 Group Light Night Striking Force (Mosquitos).
Thanks very much for the informative video. It is easy to think about all the sexy direct combat inventions of WWII but I had not thought about the importance of improved navigational aids. In retrospect I really should have.
@@CA999 agreed but WWII was the first war where casualties from combat surpassed casualties from disease. Again not a sexy combat weapon but saved more lives than almost any other single cause.
With each one of these vids on the B-29, I'm starting to see why it was so revolutionary for the time and by extension, very expensive for the time. I was far more than just a bigger B-17 in every way possible.
I always thought Loran was something from the early 50s. With the advent of microprocessors in the 70s the computerization of the position fixing process resulted in Loran C, mainly for both the marine world but also used by general aviation. It was considered a poor man's area navigation system (RNAV) for flying and was the Next Big Thing for about 10-15 years until GPS made it redundant. It had its limitations, with coverage gaps in areas away from large bodies of water (Loran C transmitters were located for marine use with aviation just piggybacking on it). It also, oddly, had a coverage gap in the NE Great Lakes area. I was bush flying in Ontario in the area north east of Lake Huron in the early 90s, and my seaplane had a Loran C unit, but I never used it, not being able to trust the thing. I navigated by 50,000:1 scale topographical maps, aided occasionally by ADF when returning to base in really low visibility (I would tune in an AM radio station whose tower was adjacent to our base lake).
Again another interesting video you’ve made. That’s a crazy antenna length hanging from the bomber. I think both the Germans and British used similar ideas on nav using radio waves and once both realised its importance learned how to jam or spoof it.
Extendable wire antenna was a new apparatus to me, in WW2. Positioning took 2 minutes with accuracy 10 miles; in that time the plane had flown over 10 miles !
Theres an old Loran-C station in North Dakota, converted to VLF after GPS tech did away with the Loran system. High power VLF stations are used for navigation in some mines in the USA and Canada. Not their intended purpose but it works.
Surprised to see coverage over southeast Asia for WWII The US had to build Loran-C coverage for the Vietnam war so they could bomb with precision. I used to use Loran-C on a boat in the 1980's. Even if it was not as accurate as GPS, it was more precise. Mark your mooring and return to it with
Interesting that US's Loran and UK's Gee were competitors... As a young, off-watch greenhorn, I used to sail across from Gosport to France using Loran C...
I used to have one of those astrocompases when I was a kid, complete with the wooden box they carried and stored them in, and until now I never knew what it was. My grandfather was a naval officer in the wae that taught the mathmetics of navigation to flight cadets at the naval training center at Jacksonville Florida, he gave it to me about 1972 or so when I was around 7 years old but passed away before I really knew what it was. He'd been a math teacher and school principal before the war, because of that the navy took him in and gave him a commission via the "90 day wonder" program I suppose and sent him to Jacksonville to train flight cadets, he might have trained George HW Bush as he went through training there when my grandfather was an instructor.
Given that LORAN relies on the transmitters sending out their signals at exactly the same moment, how was this achieved? What method was used to ensure that transmitter stations hundreds of miles apart broadcast their pulses at.precisely the same time?
My father was a loran operator at the slave station on Saipan. He was in the US Coast Guard during WWII. They manually adjusted the slave pulse timing to maintain the required timing relationship.
To align a slave station to a master station timing, use a receiving station (which can be located at a master or slave transmitter site) to measure the time difference. This receiving station's location can be accurately known from repeated careful astronavigation fixes, so it is a matter of adjusting the slave timing until the system says the receiving site is where it actually is. If a telephone-grade landline is available between the receiver and the slave, this adjustment can be automatic and continuous.
I think the master station sent out a signal (at a different frequency) that triggered the slave station to automatically respond immediately and then a monitoring station at a known point measured how quickly the slave station responded. They picked up a telephone and told the master station to send the priming signal sooner or later to calibrate for the slave station's response time so they were in sync.
@@Treblaine The trouble with your method is that it depends on very accurately knowing the distance between the master and slave. Any error in this is added to the errors in knowing the absolute positions of both master and slave. With using a third station, for any location near the position line of that station, the only significant error is the careful astrofix of that third station. For locations on position lines further away, the error contributed by uncertainty of knowing the master and slave locations is much reduced. Note that transmitter timing is determined by a reference oscillator. No oscillator is perfect, so each will slowly drift out of time. Hence an automatic system of correction on a continuous or frequent basis is very desirable. I once had a neighbour who worked for a company called Offshore Navigation. What they did, under contract to the military, was set up a recieving station at a given location, do really careful repeated astrofixes over several days to average out the errors, then measure the location given by the hyperbolic navigation (not necessarily LORAN - there were competing systems, GEE, Omega, etc) and tell the system operators what the errors were. Then move to another location and repeat. This also let them work out what the local effects of propagation quirks were - radio waves don't actually travel at the speed of light in a vacuum, they travel slightly slower by an amount that depends on air temperature and earth conductivity. It also depends on frequency, so sending a calibration signal over the air on a different frequency is not a good idea.
How were the base station's clocks synchronized? The military required micro-second accuracy. No GPS back then. Did the military have a portable atomic clock they would ship around?
Thanks for covering LORAN. It just doesn't get the credit it's due because in a world of GPS phones, people take how difficult navigation is.
Thanks for your video. It brought back memories. I served at a loran station in the 80"s. Sadly, all the stations were decomissioned in 2010 in favor of GPS. A big mistake in my opinion.
Loran cant be spoofed like GPS, which the Iranians did to steal one of our drones.
Didn't know Loran was WW2 - thought it was later. Thanks for the effort in all of your vids.
Took a while to set up a worldwide network of stations.
My buddy, Mike Fair, was a WW2 veteran who, as a coast guard mechanic was tasked with regularly visiting and maintaining the diesel generators powering LORAN stations in the Pacific.
Likely helped save a lot of lives without knowing it
I've got a WW2 (all tubes marked 1944) LORAN unit in my shed got it at a garage sale because it was interesting, didn't know what it was.
Always appreciate your expert commentary and brilliant use of primary sources. Excellent video!
Much appreciated. LORAN was truly a revolution!
I worked on F-4 fighters in the 80s that had LORAN systems installed. A long black low profile antenna on the backbone of the jet. This was before even military GPS so they had this and inertial nav. Well a late version of LORAN. Dash C I think.
Somebody really smart figured all this out, is all I can say. And they made it GI-proof. Greatest respect.
His name was Robert Dippy and he was British!! He invented GEE, which LORAN was developed from after the US were told about it in 1940/41. After he had got GEE up and running, he went over to the States and helped get the various bugs out of that system. The Best thing he did however was get the LORAN guys to build the Loran A black boxes in the same configurations, mounting and connection wise as GEE. Thus, any British or American Bomber could be fitted with LORAN one day (because the mission required it), and GEE the next). Just swap out a couple of Boxes and an Aerial.
Main RAF users of SS LORAN were 5 Group (Lancasters) and 8 Group Light Night Striking Force (Mosquitos).
Thanks very much for the informative video. It is easy to think about all the sexy direct combat inventions of WWII but I had not thought about the importance of improved navigational aids. In retrospect I really should have.
Interesting medicine, antibiotics made 3rd place on that top 10 list... Just 2 spots below the Atomic Bomb.
@@CA999 agreed but WWII was the first war where casualties from combat surpassed casualties from disease. Again not a sexy combat weapon but saved more lives than almost any other single cause.
Another excellent video.
With each one of these vids on the B-29, I'm starting to see why it was so revolutionary for the time and by extension, very expensive for the time. I was far more than just a bigger B-17 in every way possible.
An "Integrated Weapons System"? Correct interpretation?
Except LORAN was used on a lot of aircraft, the Germans used an adaption of an early version for their blind bombing system in the night blitz.
I always thought Loran was something from the early 50s. With the advent of microprocessors in the 70s the computerization of the position fixing process resulted in Loran C, mainly for both the marine world but also used by general aviation. It was considered a poor man's area navigation system (RNAV) for flying and was the Next Big Thing for about 10-15 years until GPS made it redundant. It had its limitations, with coverage gaps in areas away from large bodies of water (Loran C transmitters were located for marine use with aviation just piggybacking on it). It also, oddly, had a coverage gap in the NE Great Lakes area. I was bush flying in Ontario in the area north east of Lake Huron in the early 90s, and my seaplane had a Loran C unit, but I never used it, not being able to trust the thing. I navigated by 50,000:1 scale topographical maps, aided occasionally by ADF when returning to base in really low visibility (I would tune in an AM radio station whose tower was adjacent to our base lake).
Incredible History
Pretty Good presentation as usual
A bit more sophisticated and more accurate than the earlier British "GEE" and the even earlier German system 'X-Gerät'
I didn't know that LORAN dated back that far! Thanks!
😎👍
Modern GPS receivers use similar time differential principle.
Loran use 3 stations to obtain fix instead 4 satelites due skipping altitude measurment.
This is why p51s followed the b29s back from their japan raids. P51s were to small for this equipment
Again another interesting video you’ve made. That’s a crazy antenna length hanging from the bomber.
I think both the Germans and British used similar ideas on nav using radio waves and once both realised its importance learned how to jam or spoof it.
260 Watts and 42 valves. That's a pretty sophisticated device. I'd love to see the schemstics
Extendable wire antenna was a new apparatus to me, in WW2. Positioning took 2 minutes with accuracy 10 miles; in that time the plane had flown over 10 miles !
Theres an old Loran-C station in North Dakota, converted to VLF after GPS tech did away with the Loran system. High power VLF stations are used for navigation in some mines in the USA and Canada. Not their intended purpose but it works.
What were the other 5 innovations of WWII according to that list you showed in the video please?
Surprised to see coverage over southeast Asia for WWII The US had to build Loran-C coverage for the Vietnam war so they could bomb with precision. I used to use Loran-C on a boat in the 1980's. Even if it was not as accurate as GPS, it was more precise. Mark your mooring and return to it with
Interesting that US's Loran and UK's Gee were competitors... As a young, off-watch greenhorn, I used to sail across from Gosport to France using Loran C...
I used to have one of those astrocompases when I was a kid, complete with the wooden box they carried and stored them in, and until now I never knew what it was.
My grandfather was a naval officer in the wae that taught the mathmetics of navigation to flight cadets at the naval training center at Jacksonville Florida, he gave it to me about 1972 or so when I was around 7 years old but passed away before I really knew what it was.
He'd been a math teacher and school principal before the war, because of that the navy took him in and gave him a commission via the "90 day wonder" program I suppose and sent him to Jacksonville to train flight cadets, he might have trained George HW Bush as he went through training there when my grandfather was an instructor.
Given that LORAN relies on the transmitters sending out their signals at exactly the same moment, how was this achieved? What method was used to ensure that transmitter stations hundreds of miles apart broadcast their pulses at.precisely the same time?
Look up "GEE" a very similar system which came before LORAN. There is a good wiki page which goes some way to explaining this.
My father was a loran operator at the slave station on Saipan. He was in the US Coast Guard during WWII. They manually adjusted the slave pulse timing to maintain the required timing relationship.
To align a slave station to a master station timing, use a receiving station (which can be located at a master or slave transmitter site) to measure the time difference. This receiving station's location can be accurately known from repeated careful astronavigation fixes, so it is a matter of adjusting the slave timing until the system says the receiving site is where it actually is.
If a telephone-grade landline is available between the receiver and the slave, this adjustment can be automatic and continuous.
I think the master station sent out a signal (at a different frequency) that triggered the slave station to automatically respond immediately and then a monitoring station at a known point measured how quickly the slave station responded. They picked up a telephone and told the master station to send the priming signal sooner or later to calibrate for the slave station's response time so they were in sync.
@@Treblaine The trouble with your method is that it depends on very accurately knowing the distance between the master and slave. Any error in this is added to the errors in knowing the absolute positions of both master and slave.
With using a third station, for any location near the position line of that station, the only significant error is the careful astrofix of that third station. For locations on position lines further away, the error contributed by uncertainty of knowing the master and slave locations is much reduced.
Note that transmitter timing is determined by a reference oscillator. No oscillator is perfect, so each will slowly drift out of time. Hence an automatic system of correction on a continuous or frequent basis is very desirable.
I once had a neighbour who worked for a company called Offshore Navigation. What they did, under contract to the military, was set up a recieving station at a given location, do really careful repeated astrofixes over several days to average out the errors, then measure the location given by the hyperbolic navigation (not necessarily LORAN - there were competing systems, GEE, Omega, etc) and tell the system operators what the errors were. Then move to another location and repeat.
This also let them work out what the local effects of propagation quirks were - radio waves don't actually travel at the speed of light in a vacuum, they travel slightly slower by an amount that depends on air temperature and earth conductivity. It also depends on frequency, so sending a calibration signal over the air on a different frequency is not a good idea.
So it was copied from the British GEE system which was accurate to about 50 yards though Loran had more range due to working at a lower frequency?
How were the base station's clocks synchronized? The military required micro-second accuracy. No GPS back then. Did the military have a portable atomic clock they would ship around?
Oh the irony this video interrupted with an ad for adblock.
How ever did they synchronize the two stations so accurately over such distances?
Especially if they bounced signals off the ionosphere, which had to add some uncertainty.
Do you have any information regarding the "Mark Twain" sights used on the Doolittle Raid?
Are you planning a video on SHORAN bombing? I don’t know if it was used before Korea.
It was used in the MTO (Italy) in 1944/45.
Thanks! Do you have a video on RDF? Loop antenna
LO LO LO. Lo Lo LO-Ran... 🐿
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