SHORAN Gauge.zip

[Mick]

A new entry has been added to Add-Ons Library, category FS 2004 Panels

Description: A SHORAN gauge for the panels of the B-45 Tornado, late WW2 B-17s and B-24s, Korean War B-29s and possibly other early Cold War American bombers. It was made in and for FS9 but should work in any sim that handles XML gauges, or can be placed on a 2D panel in any sim. It doesn't actually work, since there are no SHORAN transmitting stations in FS9, but it can add a bit of authenticity to the panels of appropriate planes. The the instrument face is modeled on a photo of one in a Korean War B-29.

To check it out, rate it or add comments, visit SHORAN Gauge.zip
The comments you make there will appear in the posts below.

 

[Mick]

Well, I see that there have been a few downloads. I wondered if anyone would actually want this little tidbit!

I put in into my own B-45 of course. but I didn't know if anyone else would be that interested. Mainly I made it in case I needed it on future projects, and I'm pretty sure we'll need it for at least one plane that's on the list.

I'm surprised that nobody has done this before. Even though there aren't any SHORAN transmitters in FS9 for it to respond to, I know of at least one other American bomber that supposedly had SHORAN that's been modeled by at least three modelers for FS9 and none of them did this.

 

[Jorge]

... Even though there aren't any SHORAN transmitters in FS9 for it to respond to, I know of at least one other American bomber that supposedly had SHORAN that's been modeled by at least three modelers for FS9 and none of them did this.

Please, Mick, don't tempt me! It's taken forever to work with Tom on the LORAN, AN/APN-4 unit over at CalClassic!

It could be possible to do with "system" gauges like the ones we're using for the LORAN, but this time you're talking about following an arc on one station and waiting until you hit a line of position (LOP) on that arc.

You would need to have a way to set the freq for the first station, then ID the station, then set the distance you want to fly.

You would then go to another "radio" to set the second station, then ID it, then set the "bearing" you want to intercept, then the distance so that it crosses over the "arc" you set for the first radio to.

Of course, you would have to make sure the two would actually cross, otherwise it's a moot point.

Don't ask me what the xml is for this because I have no idea, but if you show me some pictures I can make some nice bmp's for the radios and gauges!

Jorge
Miami, FL

 

[Mick]

Please, Mick, don't tempt me! It's taken forever to work with Tom on the LORAN, AN/APN-4 unit over at CalClassic!

It could be possible to do with "system" gauges like the ones we're using for the LORAN, but this time you're talking about following an arc on one station and waiting until you hit a line of position (LOP) on that arc.

You would need to have a way to set the freq for the first station, then ID the station, then set the distance you want to fly.

You would then go to another "radio" to set the second station, then ID it, then set the "bearing" you want to intercept, then the distance so that it crosses over the "arc" you set for the first radio to.

Of course, you would have to make sure the two would actually cross, otherwise it's a moot point.

Don't ask me what the xml is for this because I have no idea, but if you show me some pictures I can make some nice bmp's for the radios and gauges!

Jorge
Miami, FL

I only have one photo, the one I used as my model for the bitmap. Just imagine that bitmap but sort of soft and grainy, then printed on regular book page paper. It was probably a scrap view cut from a not very high resolution shot of a panel, then blown up a bit for the book, where it's printed small, maybe an inch and a half per side. I couldn't even be certain whether there was one needle or two, both pinned at the center of the face, both pointing vertical because the system was turned off. The caption seemed to suggest that this was all there was of it.

The picture is cropped so closely that you can't see any of the other instruments around it, so you can't tell where it's located on the panel. I knew where it goes on the B-45 because I had a panel diagram that showed it, but not a panel photo that showed it clearly enough to see what it looked like. So I put in the somewhat anachronistic TACAN to fill the spot.

Naturally, a couple weeks after the B-45 went out I got a book about the disastrous B-29 raid in Korea that had the worst loss rate of any bombing mission in USAAF/USAF history, and there was that little picture of the SHORAN indicator.

The photo caption doesn't suggest that there were any other items to the SHORAN, at least not on the panel. I wonder if there might have been more SHORAN stuff on the radioman's panel???

 

[Jorge]

Mick,

I found these two online and they should help.

A good picture of one: https://www.dfwairparts.com/id-103-apn-3-id103apn3-wwii-displacement-rate-indicator-rare! (type APN3 in the search bar)

And a good explination from a 1945 survey: https://www.xnatmap.org/adnm/docs/2013/edmhist/ahistedm.htm (towards the bottom in Annex C)

From what I can tell, you have two stations each sending out a signal. The signal is a distance from the station (i.e. like a DME from a VOR) and is therefore an arc. The aircraft flies on one arc until it crosses the other station's arc, at which point the bombs automatically drop.

The panel piece is called an ID-103 Pilot Indicator, and is 3" if I'm reading that right. I would assume that it's really 3-1/8" overall since that's what most of the dials were for a 3" face.

I think you can make a fairly "usable" xml gauge by making this a dual-DME type thing for VOR's? One station on top, the other below. It would then be a matter of seeing if one VOR's envelope was within the distance of another. Then figure what point you wanted to overfly, then see what the distance was from each of the VOR's. You then set one as the "arc" or "rate" VOR and the other as the "drift" or "displacement" VOR. Follow the arc until you get to the displacement and you should be over the location you chose.

The only thing that would be a challege (for me, anyway) is trying to figure how to enter the value you would want to represent centered needles for a particular situation. I would think that you could use some sort of value parameter (L: maybe?) to be compared to the DME value, but not all the stations have the same range. Guess you could set scales to use for each of the needles so you could use stations with different DME's at the same time?

I would guess that left of center is less and right of center is greater, so if the scale you have is 100 miles, then the centered needle would be 50nm.

You think this is doable for someone that knows what they are doing???

At least we now know how the system worked and what the different units were.

Regards,

Jorge
Miami, FL

 

[Mick]

Mick,
From what I can tell, you have two stations each sending out a signal. The signal is a distance from the station (i.e. like a DME from a VOR) and is therefore an arc. The aircraft flies on one arc until it crosses the other station's arc, at which point the bombs automatically drop.
Jorge
Miami, FL

Yes, that's exactly how it worked, as I explained in the ReadMe. I don't recall whether the drop was automatic. It may have been. Whether the drop was automatic or if the bombardier did it on signal, it would seem necessary for the system to be programmed to account for the predicted winds aloft that would affect the fall of the bombs, but I don't know if it worked that way.

I knew the British had a similar system but I couldn't remember if it was Gee or something else. Now I see that it was indeed Gee. I seem to have a dim recollection that the Luftwaffe had something like that too, but it's a very fuzzy recollection.

In Vietnam the Air Force used a system called Combat Skyspot for bombing through overcast. I wonder if that was derived from SHORAN or something completely new.

By the time I started flying in the seventies there was DME - Distance Measuring Equipment. I don't know when that was introduced in civil aviation or whether it was derived from one of the military systems. Many VOR stations (Very high frequency Omnidirectional Range) also had DME and were cleverly called VOR-DME stations. The military used the same technology and called it TACAN (Tactical Air Navigation.) Many stations combined civil and military systems and were called VORTAC stations. I don't know if VOR-DME and TACAN were identical in all ways, or if maybe they used different frequency bands, but they were the same technology.

I haven't been involved in real world aviation since the eighties and the whole airspace and air traffic control system changed radically just after I stopped flying, so I have no idea whether those systems are still in use. GPS seems to have made them redundant but that doesn't prove they're gone.

 

[SIAI S81]

I just finished to read a document from Italian Air Force about navigation, VOR and ADF are still in use in some parts of the world where technology is still a bit "behind".

 

[Mick]

I just finished to read a document from Italian Air Force about navigation, VOR and ADF are still in use in some parts of the world where technology is still a bit "behind".

Interesting! I've been away from real world aviation for decades, and I don't even know what's in use here in the USA now. In my day it was just VOR, VOR/DME or VORTAC, and for the majority of us who didn't fly planes with high end avionics in the panels, all we could use of any of those kinds of stations was just the VOR.

 

[Mike71]

"--- I don't know if VOR-DME and TACAN were identical in all ways, or if maybe they used different frequency bands, but they were the same technology..

I was a career Naval Aviator in the 60s/70s/80s. TACAN was the principle radio NAVAID in all tactical jets. You are correct, TACAN and VOR/DME seem the same, but TACAN operates in the UHF spectrum vice VHF. TACAN stations can be set up quickly in remote forward areas because it is modular. The military developed DME as inherent in TACAN. The FAA capitalized on it for airways NAVAIDS and ILS at many locations.

We did not have ILS but used a TACAN penetration from high altitude to a GCA (PAR) radar pickup at military bases, minimums were always 200 /1/2 nm, or 500 / 1 if a non PAR surveillance (lineup only radar approach).
IMHO I would take a Navy / USAF GCA controller over flying an ILS any day of the week - they were terrific. I have flown a lot of civil aircraft and some Navy airplanes (C-12B, P-3C, etc) with ILS so I do know the difference.

As far as I remember, the USAF did have VOR / ILS capability as well as TACAN in their jets.

 

[Sbob]

In Vietnam the Air Force used a system called Combat Skyspot for bombing through overcast. I wonder if that was derived from SHORAN or something completely new.

Mick, There's a good description of Sky Spot in a book I recommended titled "Flying From The Black Hole" by Robt. Harder.

Sky Spot was essentially the same high frequency MSQ RADAR that SAC used to score bomb runs over the US.
In 'Nam the system was basically run in reverse, instead of the ground RADAR being used as a silent Referee, it became more like the Quarterback or the Coach.

The lead bomber in a three ship "cell" would contact the Sky Spot station after checking in. The Sky Spot operator would make sure he was painting the lead plane then order (small) course changes to put the entire "cell" on the correct track. The ground operator would then order the bomb drop verbally, "Five, four, three, two, one, HACK!", although some times it came out more like "FiFourThreTwoHACK!!!" if the upper winds were goofy.

Sky Spot was used almost exclusively on the "meat and potato's" ARCLIGHT missions "over South Viet Nam" against the Ho Chi Minh trail. The only gauges the bomber had or needed was a working radio and a stop watch. Only the lead bomber would drop on the "Hack!" command. The others would monitor the radio and start their stop watches once they heard the command then drop at the correct time.

Sky Spot was handy because it allowed for quick target changes in the middle of 10-12 hour flights.

 

[Mick]

Thanks to both of you for those interesting comments!

I had wondered if VOR/DME and TACAN might've worked on different frequencies.