Frustrated

[J0313]

I hate the fact that you cant radio in a convoy/task force report in SH4 unless you have eyes on the ship and/or ships in the group. I think that if you have a solid radar contact and you know that it cant be anything but an enemy task force then you should be able to give a position report based just off of radar data. Last night I had a positive ID on at least 2 of the ships in the task force and since I was at radar depth I also think that you should be able to send a message when you are at radar depth.

[J0313]

How would you change this? If some one could point me in the right direction then I will try it myself and hopefully come up with something.

[Sailor Steve]

I don't think you can change it. It's the same with SH3. You should be able to report anything you want without being in contact at all. The games forget things that aren't there anymore. It's just like in SH3 where if the wounded sailor has been healed you can't give him a wound badge because he's not wounded anymore.

Silly, really.

[J0313]

That really blows. Right now I am in the mission during the Battle of the Phillippine Sea where you run into the big Jap TF. I was going to report the TF but decided against it becouse I was picking up alot of radar signals. Soooo, I just went for the approach and got the Taiho with 4 out of six fish. She went down in about 4 minutes.Anyhow I dont think its going to give me credit for completeing the mission becouse I didnt report the TF.

[Webster]

yep you might fix it to be able to report but the "what" you report is decided by the game and as steve pointed out the game would forget and report nothing in your report.

then again reporting can give your position away "in theory" so you certainly wouldnt want to do it unless you were 100% sure it wasn't friendly or neutral shipping and you can only do that visually

I would like to be able to "save" a contact report so I can get out of the area before sending a report and revealing myself to any enemy listening nearby but this too cant be done because of the way the game engine works

[J0313]

That would be to much like real life. Shame on you for even considering that Webster! LOL!!:haha:

[Armistead]

check your PM.

[ETR3(SS)]

Transmitting without an antenna above the water won't work. So transmitting at radar depth isn't feasible either.

[J0313]

Transmitting without an antenna above the water won't work. So transmitting at radar depth isn't feasible either.


So where is the antenna?

[J0313]

Transmitting without an antenna above the water won't work. So transmitting at radar depth isn't feasible either.

Then do you want to explain to me how come you can recieve transmissions at radar depth?

[J0313]

Dont worry there ETR. Both of those questions are retorical. I already know the answers. YES you can transmit and recieve at radar depth and you can do both when using low frequency radio at periscope depth. Check out this site if you dont believe me.

http://www.ka8vit.com/subops/subop4.htm

[ETR3(SS)]

Take a closer look at my sig. Comms Div stands for Communications Division. Also your link made no mention of transmitting and receiving at any depth.

[J0313]

Gee, were you a submariner 60 years ago? Didnt think so. Dont really care what your rate is and I happen to know that they could transmit and recieve at radar depth. So take a hike.

Also take a closer look at the shears in the external diagram. Notice the DF loop and the radio antenna, both of which would be well out of the water at radar depth.

[Redmane]

Really, I'm gonna have to go with ETR3 on this one. Got curious about this and checked out that link, and ETR3 is correct, the fellow who wrote that makes no mention at all regarding the capabilities of the equipment to receive or transmit while submerged at any depth. Here's another link that sort of covers the subject, and explains exactly why a submerged boat would not be able to transmit at all on any frequency, but could recieve a VLF (very low frequency) signal. http://en.wikipedia.org/wiki/Communication_with_submarines

[J0313]

Really, I'm gonna have to go with ETR3 on this one. Got curious about this and checked out that link, and ETR3 is correct, the fellow who wrote that makes no mention at all regarding the capabilities of the equipment to receive or transmit while submerged at any depth. Here's another link that sort of covers the subject, and explains exactly why a submerged boat would not be able to transmit at all on any frequency, but could recieve a VLF (very low frequency) signal. http://en.wikipedia.org/wiki/Communication_with_submarines

Yes Redmane I agree that WW2 boats couldnt transmit while COMPLETLEY submerged. They could only recieve LF transmissions and even then they had to be shallow. The point I am trying to make is that a Fleetboat could transmit and recieve at RADAR DEPTH. The shears are out of the water and the radio Antenna is completely out of the water. I read the same wiki article you did before you even brought it up. The reason I pointed to the article is becouse of the external diagram. It shows the positioning of the antenna. And it clearly shows that AT RADAR DEPTH, the radio apperatus is out of the water HELLO.

[Sailor Steve]

HELLO.
You are making your point quite well, and up to this point in a rational manner. I understand that you may be getting frustrated, but there is no reason to be snarky about it. This applies to your previous post as well.

It also applies ETR3(SS). Your expertise is valued, but saying "Look at my sig" says you're trying to win an argument by simply saying "I know more than you, so there!" Better to show that you are right, rather than just saying so.

This is my opinion, but it is also the moderator saying let's keep it calm please.

[BigWalleye]

J0313, your statements caught my attention, because I have researched the question of whether a WW2 US fleet boat could transmit when not fully surfaced and not found conclusive evidence that they could.

The reason I pointed to the article is becouse of the external diagram. It shows the positioning of the antenna. And it clearly shows that AT RADAR DEPTH, the radio apperatus is out of the water.

What diagram are you referencing? There is no diagram accompanying the Wikipedia article, although there is a photo of a VLF (receiving) antenna. The accompanying text makes clear why that antenna is necessarily receive-only.

Straub's site does not address radio transmission while at radar depth. It only makes a distinction between surfaced and submerged. I am unable to find any support for your statement that "they could transmit and recieve at radar depth" on Straub's site.

Straub does have a link to the external diagram of a fleet sub at the HSNA site: http://www.hnsa.org/doc/fleetsub/appendix/pages/figa-02.htm
This diagram identifies the radio antennas as one long-wire antennas running forward from the shears and two others from either side of the conning tower coaming. Portions of these might be out of the water when the boat was at radar depth, but the end of the long wire closest to the deck stanchion might well not be. It's hard to see how any of these antennas could be energized with transmitter voltages when not completely surfaced. Even when surfaced, it would seem that heavy seas might ground them out.

I have wondered about the possibility of transmitting from a sub which was not fully surfaced. The first-person accounts only refer to transmitting while "surfaced" but that is negative evidence, as is the evidence of Straub's site. The HSNA diagram infers that WW2 US fleet subs were not equipped to transmit unless fully surfaced, but certainly doesn't prove it. You state pretty strongly that it was possible. Could you provide me with your sources for this?

[Sailor Steve]

SH3 allows u-boats to recieve messages at depths up to 25 meters (80 feet), but send only on the surface. At the time the developers said that their information said that was possible. I don't know, but if it was possible for u-boats I don't know why it wouldn't be for fleet boats.

[BigWalleye]

Steve, I don't recall ever seeing any indication that US fleet boats could (or did) receive radio messages when as deep as 80 feet. And I believe u-boats did so, routinely. I suspect this may have been a result of the fact that the fleet boats operated at much greater distances from base. Pushing a radio signal through water takes a lot of power. Power falls off with the square of the distance from the transmitter. Double the distance and you get only one-quarter of the power. So getting a message to a sub 4000 miles from home would take four times as much power as would be needed to send the same message to a sub 2000 miles away. Another way of looking at it is that the farther sub would have to be a lot closer to the surface to receive the message. Which seems to match the first-person reports of American subs usually getting messages when at or near periscope depth and the German subs receiving messages when much deeper.

[Redmane]

I've been doing quite a bit of research on this topic today, and am unable to find anything that suggests that US Fleet Type submarines were capable of transmitting radio signals in any condition other than surfaced [edit] with the exception that later in the war VHF transceivers were installed and the antenna for these was mounted atop the periscope shears. Here's an excerpt from a webpage decribing the radio gear and antenna array on the USS Pampanito:

All of the original radio equipment is in working order. The transmitter is a TBL-7 with coverage on 175-600 kHz and 2.0-18.1 MHz. The transmitter is capable of 50 watts on AM phone, and 200 watts on CW. RAL and RAK receivers can still hear signals, sometimes better than modern receivers. Three long wire antennas are mounted on the port side of the conning tower, running aft to a stanchion near the stern. The original transmitter has been used on many occasions for QSOs and contesting on the amateur bands. With the long wire antenna mounted 20 feet above the salt water of San Francisco bay, signal reports are surprisingly good. The salt water acts as an excellent ground plane, and most stations are very impressed with the signal.

This antenna arrangment is very similar to that described by the radioman who wrote the article referenced by J0313, with the exception of his description of an antenna mounted on the periscope shears. Additionally, all shipboard radio transmitting antennas of this era that I have found were long wire dipole antenna assemblies. The long wires you see running from superstructure to masts and then down again to anchoring points at other places on the upper works of surface ships and submarines are exactly this: dipole antenna arrays. Such dipole assemblies were designed to the standard required for half-wavelength antennas, which explains why they were so long. Much more information on this type of antenna can be found here:
http://www.hnsa.org/doc/radio/chap20.htm

Given the antenna assemblies in use, their required length, and the fact that the mounting arrangment on Fleet Type boats required at least one end of the antennas to be mounted to a stanchion on the deck, either fore or aft, drives to the obvious conlusion that it was impossible to get the antenna entirely clear of the water without surfacing the boat.

Finally, in Chapter 20 of the Fleet Type Submarine manual, page 197, the following prodecure in preparation for a dive is described for the Radio Room: M. Radio room. 1. Disconnect the antenna lead and shut the trunk flapper. Also, given the description of his duties reported by the radioman in the article referenced by J0313, in which the writer states that while submerged his duty station was on the sonar set, and only upon surfacing would he report to the radio room, it seems very clear that WW II US Fleet boats were NOT capable of radio transmission other than while surfaced.

[Sailor Steve]

I suspect this may have been a result of the fact that the fleet boats operated at much greater distances from base.
...

So getting a message to a sub 4000 miles from home would take four times as much power as would be needed to send the same message to a sub 2000 miles away.
A very good point. As I say, I only know what I've heard, and that could be wrong.

[J0313]

Look here. Notice the location of the VHF antenna.

http://www.maritime.org/tour/pier.php

[J0313]

J0313, your statements caught my attention, because I have researched the question of whether a WW2 US fleet boat could transmit when not fully surfaced and not found conclusive evidence that they could.



What diagram are you referencing? There is no diagram accompanying the Wikipedia article, although there is a photo of a VLF (receiving) antenna. The accompanying text makes clear why that antenna is necessarily receive-only.

Straub's site does not address radio transmission while at radar depth. It only makes a distinction between surfaced and submerged. I am unable to find any support for your statement that "they could transmit and recieve at radar depth" on Straub's site.

Straub does have a link to the external diagram of a fleet sub at the HSNA site: http://www.hnsa.org/doc/fleetsub/appendix/pages/figa-02.htm
This diagram identifies the radio antennas as one long-wire antennas running forward from the shears and two others from either side of the conning tower coaming. Portions of these might be out of the water when the boat was at radar depth, but the end of the long wire closest to the deck stanchion might well not be. It's hard to see how any of these antennas could be energized with transmitter voltages when not completely surfaced. Even when surfaced, it would seem that heavy seas might ground them out.

I have wondered about the possibility of transmitting from a sub which was not fully surfaced. The first-person accounts only refer to transmitting while "surfaced" but that is negative evidence, as is the evidence of Straub's site. The HSNA diagram infers that WW2 US fleet subs were not equipped to transmit unless fully surfaced, but certainly doesn't prove it. You state pretty strongly that it was possible. Could you provide me with your sources for this?

Yes in that diagram you notice there is a loop antenna and a radio antenna. The loop was for DF and recieving VLF transmissions. The other antenna is for VHF radio ops. Now in the photo and expalaination in the link I just provided in the post before this one you see that the VHF antenna was moved forward to the Scope shear rather than in between. I am sure that early tower configs used the cable style antenna but when as the war progressed they moved to the "stick or mast style and mounted them on the shears. Thus back to my old assertion that yes, you can transmitte and recieve while at radar depth.

[Redmane]

If you do some research into VHF, and its application during the war, you will notice two things. It is capable only of line of sight reception and transmission, meaning that is a relatively short range method of communication. This limitation on VHF still exists today. Also the following procedural guidelines were in place regarding communications using VHF:


5305. Very-high-frequency (VHF) tactical radiotelephone circuits have proved their value in war. The following general rules are set forth for the guidance of responsible commanders in the use of such circuits in wartime:
a. They may be used for initial contact reports, emergency maneuvers, and the transmission of important information when visual means are prohibited or too slow.
b. Only a minimum of transmission should be permitted during darkness or reduced visibility.
c. Caution must be exercised in the use of plain language transmissions of vital importance which would be of value to the enemy if intercepted.
5306. Detailed instructions supplementing or modifying the foregoing general principles shall be issued by responsible commanders as appropriate and necessary, depending on the situation existing.

Note that under conditions of darkness or reduced visibility, when submarines or other vessels might be within range without being detected, use of VHF radio was discouraged.-RF

The above referenced procedural statment can be found here: http://www.virhistory.com/navy/flory/id11.html

[BigWalleye]

From the Straub website (http://www.ka8vit.com/subops/subop1.htm):

"VHF TRANSCEIVERS:
Later on in WWII SCR522 and SCR624 VHF transceivers were added to the Radio Room. These were multi channel crystal controlled transceivers used primarily to communicate with aircraft, particularly during Life Guard operations."

Redmane, this seems consistent with your observation that VHF is (and was) only useful for LOS.

I am sure that early tower configs used the cable style antenna but when as the war progressed they moved to the "stick or mast style and mounted them on the shears. Thus back to my old assertion that yes, you can transmitte and recieve while at radar depth.

J0313, I don't mean to denigrate your expertise, but an independent source would certainly confirm your statements. There seems to be considerable evidence against your position, and so far, no evidence that supports it. Do you have family members who remember such submerged transmisions from their WW2 days? A first-person account you have read? NavPers manuals?

BTW, the diagram at HNSA is of a Balao, IIRC. The Balao class was the standard US fleet boat at the end of the war, and didn't enter service until mid-43.

[J0313]

If you do some research into VHF, and its application during the war, you will notice two things. It is capable only of line of sight reception and transmission, meaning that is a relatively short range method of communication. This limitation on VHF still exists today. Also the following procedural guidelines were in place regarding communications using VHF:


5305. Very-high-frequency (VHF) tactical radiotelephone circuits have proved their value in war. The following general rules are set forth for the guidance of responsible commanders in the use of such circuits in wartime:
a. They may be used for initial contact reports, emergency maneuvers, and the transmission of important information when visual means are prohibited or too slow.
b. Only a minimum of transmission should be permitted during darkness or reduced visibility.
c. Caution must be exercised in the use of plain language transmissions of vital importance which would be of value to the enemy if intercepted.
5306. Detailed instructions supplementing or modifying the foregoing general principles shall be issued by responsible commanders as appropriate and necessary, depending on the situation existing.

Note that under conditions of darkness or reduced visibility, when submarines or other vessels might be within range without being detected, use of VHF radio was discouraged.-RF

The above referenced procedural statment can be found here: http://www.virhistory.com/navy/flory/id11.html

Okay. I dont want to get off on a tangent here. The only point I am trying to make is that Fleet boats with the proper conning tower configuration could make transmisssion at parascope depth. Wether they did so commonly or thier procedures in doing so are not important to my point.

[J0313]

I guess this will never be solved. There arent any first person accounts that I can find. So I will continue looking but its probably going to be fuitless.

[J0313]

And besides this whole thing took off when ERS3 made his comment about not having an antenna out of the water when submerged. Well it sure looks like there is a few out of the water at radar depth. Granted VHF was only for LOS. As far as ranges go. I havent been able to find anything on what the ranges for those sets are. But I am going to keep looking.

[Redmane]

Ultimately, you are not wrong in asserting that a US Fleet Type boat could both transmit and receive at radar depth. The only provisos are that they would have to have a VHF rig, and the communication would be limited to the capabilities of that gear. In other words, Fleet units close enough to receive the signal could do so, but by no means would it be possible for the boat to contact a ground station on this gear unless in range, not blocked by any interference, and the ground station would also need to have the appropriate gear. Additionally, I make this observation: I have been at radar depth on approach to a target in high sea states, had the periscope raised just enough to clear the housing, and had it be regularly washed by the wave action. So there also would be that factor of limitiation on the VHF.

[EDIT] Found this on Wiki regarding standard range of VHF transmissions:
http://en.wikipedia.org/wiki/Very_high_frequency

[Sailor Steve]

And besides this whole thing took off when ERS3 made his comment
Okay, you're still trying to make a fight out of this and blame someone else. This kind of behavior is not allowed here.

[J0313]

Ultimately, you are not wrong in asserting that a US Fleet Type boat could both transmit and receive at radar depth. The only provisos are that they would have to have a VHF rig, and the communication would be limited to the capabilities of that gear. In other words, Fleet units close enough to receive the signal could do so, but by no means would it be possible for the boat to contact a ground station on this gear unless in range, not blocked by any interference, and the ground station would also need to have the appropriate gear. Additionally, I make this observation: I have been at radar depth on approach to a target in high sea states, had the periscope raised just enough to clear the housing, and had it be regularly washed by the wave action. So there also would be that factor of limitiation on the VHF.

Check this out. http://books.google.com/books?id=7qztw0sO2NgC&pg=PA165&lpg=PA165&dq=Submarine+flat+top+antenna&source=bl&ots=_NqQcuARtv&sig=ukNzSml2EMsBRean8ENXkaQ7Q9w&hl=en&sa=X&ei=4_6XUcipF4fu8QTw8IGoCg&ved=0CDkQ6AEwAw#v=onepage&q=Submarine%20flat%20top%20antenna&f=false.

Look at page 165 and 166. Bottom right of 165. Upper left of 166 and tell me what you read there.

[J0313]

Okay, you're still trying to make a fight out of this and blame someone else. This kind of behavior is not allowed here..

No I'm not. Just stating a fact.

[BigWalleye]

J0313, Steve is trying to tell you something important. If a policeman pulls you over and says that you need to slow down, it is prudent to take his advice. There is nothing to be gained by arguing yourself into a ticket.

[Redmane]

Check this out. http://books.google.com/books?id=7qztw0sO2NgC&pg=PA165&lpg=PA165&dq=Submarine+flat+top+antenna&source=bl&ots=_NqQcuARtv&sig=ukNzSml2EMsBRean8ENXkaQ7Q9w&hl=en&sa=X&ei=4_6XUcipF4fu8QTw8IGoCg&ved=0CDkQ6AEwAw#v=onepage&q=Submarine%20flat%20top%20antenna&f=false.

Look at page 165 and 166. Bottom right of 165. Upper left of 166 and tell me what you read there.

I read that the boat could transmit via radio at periscope depth, provided they could get the antenna clear of the water. What I don't read is that this arrangement was still in place on the Fleet type boats used during the war.

[CaptBones]

Well, since I was a Navy Communications Officer and Electronic Systems Engineer for nearly the first decade of my career...and I do have first person experience with submarine radio communications in GUPPY-converted Fleet Boats... I suppose I could make a couple of points here.

The discussion is, to some degree, mixing apples and oranges. In WWII, receiving broadcast messages and sending Contact Reports to HQ (which is the game "issue" that started this discussion), dealt with HF CW ("Morse code") radio communications. Tactical communications with other ships and aircraft was done with VHF and UHF voice radio as well as voice/CW at the low-HF/high-MF frequencies.

The primary Fleet Broadcast in the 60s and 70s was still the "Fox" broadcast, even though by then it was a machine-encrypted radio-teletype system and in WWII it was a Morse code, manually encrypted system (yeah, we had "Enigma" machines too). Yes, there were early TTY communication links being used during the war, but they were almost exclusively land-line (including transatlantic cable). Towards the end of the war, such technology was starting to be implemented in the forces afloat, but the equipment wasn't yet suitable for submarines.

There's a world of difference between transmitting and receiving equipment used in WWII and now-days. But, back when I started out, we were still using the WWII equipment and systems on the shore-side of long-haul communications. The long-haul system, both send and receive, was high frequency (the "HF" part of HFDF) 3-30MHz. HF is also commonly known as "short-wave" radio; the wavelength is 100-10m (higher freq = shorter wavelength). The full-wave transmitting towers at NAVCOMSTAs Washington D.C. (Annapolis), Wahiawa (Lualaulei), HI and Stockton (Dixon), CA were landmarks that I remember well.

I can assure you that an HF radio signal, of as little as 500W at the transmitter, can be received via sky-wave refraction, at a distance of some 6000 miles or more and at a receiving antenna depth (not keel depth!) of 33 ft (10m) or more. You're not pushing a signal through the water, you're bouncing it off an ionospheric scattering layer. The trick is that the receiving antenna is a bare long-wire, or two or three in parallel, insulated from ground and connected to an ungrounded receiver, the earth is the ground plane for the signal transmitter at the radio communication shore station. The signal strength that can be detected by a full-wave or half-wave wire antenna is incredibly small; a few milliwatts will generate a very solid signal voltage. Remember, you're picking up a radio wave that is between 10 and 100m long...it will definitely penetrate the water to a depth equal to the wave-length. We routinely had to practice establishing long-haul duplex terminations across the Pacific, between Japan, Guam, Hawaii, and California, with 100W transmitters (the really good operators could do it with 10W!).

It doesn't work in reverse, the transmitting antenna has to be high-and-dry, or at least not immersed in good old salt-water; that will definitely attenuate the outgoing signal, totally. You need to be well above the water's surface to use it as the antenna's ground plane. As I noted, the shore station transmitting antennas were 350ft tall full-wave towers. Typically, the shipboard HF transmitting antennas were both long-wire (10-50m or so) and base-loaded 8ft and 16ft whip antennas. In the case of WWII US submarines, the whips were retractable, but not nearly capable of being extended sufficiently above the water when at periscope depth or radar depth to keep from being grounded by passing waves (US subs also had rod antennas incorporated in the SD radar supports). Early-on, US subs also had retractable, vertical wire antennas, consisting of a mast with a cross-head that supported two or more wires per side.

Most of the 1/4 wave and dipole VHF and UHF tactical radio antennas were small and could certainly be attached to or incorporated into a periscope, radar antenna mast, the shears, or a snorkel mast. Those you could use while the boat was submerged at either periscope or radar depth; I can guarantee they don't work underwater though.

Although it's too late to make this long story short...getting back to the topic...for both US and German WWII submariners, receiving HF "broadcast" messages at shallow depths was possible and done routinely, but transmissions to HQ had to be done on the surface.

[J0313]

Well, since I was a Navy Communications Officer and Electronic Systems Engineer for nearly the first decade of my career...and I do have first person experience with submarine radio communications in GUPPY-converted Fleet Boats... I suppose I could make a couple of points here.

The discussion is, to some degree, mixing apples and oranges. In WWII, receiving broadcast messages and sending Contact Reports to HQ (which is the game "issue" that started this discussion), dealt with HF CW ("Morse code") radio communications. Tactical communications with other ships and aircraft was done with VHF and UHF voice radio as well as voice/CW at the low-HF/high-MF frequencies.

The primary Fleet Broadcast in the 60s and 70s was still the "Fox" broadcast, even though by then it was a machine-encrypted radio-teletype system and in WWII it was a Morse code, manually encrypted system (yeah, we had "Enigma" machines too). Yes, there were early TTY communication links being used during the war, but they were almost exclusively land-line (including transatlantic cable). Towards the end of the war, such technology was starting to be implemented in the forces afloat, but the equipment wasn't yet suitable for submarines.

There's a world of difference between transmitting and receiving equipment used in WWII and now-days. But, back when I started out, we were still using the WWII equipment and systems on the shore-side of long-haul communications. The long-haul system, both send and receive, was high frequency (the "HF" part of HFDF) 3-30MHz. HF is also commonly known as "short-wave" radio; the wavelength is 100-10m (higher freq = shorter wavelength). The full-wave transmitting towers at NAVCOMSTAs Washington D.C. (Annapolis), Wahiawa (Lualaulei), HI and Stockton (Dixon), CA were landmarks that I remember well.

I can assure you that an HF radio signal, of as little as 500W at the transmitter, can be received via sky-wave refraction, at a distance of some 6000 miles or more and at a receiving antenna depth (not keel depth!) of 33 ft (10m) or more. You're not pushing a signal through the water, you're bouncing it off an ionospheric scattering layer. The trick is that the receiving antenna is a bare long-wire, or two or three in parallel, insulated from ground and connected to an ungrounded receiver, the earth is the ground plane for the signal transmitter at the radio communication shore station. The signal strength that can be detected by a full-wave or half-wave wire antenna is incredibly small; a few milliwatts will generate a very solid signal voltage. Remember, you're picking up a radio wave that is between 10 and 100m long...it will definitely penetrate the water to a depth equal to the wave-length. We routinely had to practice establishing long-haul duplex terminations across the Pacific, between Japan, Guam, Hawaii, and California, with 100W transmitters (the really good operators could do it with 10W!).

It doesn't work in reverse, the transmitting antenna has to be high-and-dry, or at least not immersed in good old salt-water; that will definitely attenuate the outgoing signal, totally. You need to be well above the water's surface to use it as the antenna's ground plane. As I noted, the shore station transmitting antennas were 350ft tall full-wave towers. Typically, the shipboard HF transmitting antennas were both long-wire (10-50m or so) and base-loaded 8ft and 16ft whip antennas. In the case of WWII US submarines, the whips were retractable, but not nearly capable of being extended sufficiently above the water when at periscope depth or radar depth to keep from being grounded by passing waves (US subs also had rod antennas incorporated in the SD radar supports). Early-on, US subs also had retractable, vertical wire antennas, consisting of a mast with a cross-head that supported two or more wires per side.

Most of the 1/4 wave and dipole VHF and UHF tactical radio antennas were small and could certainly be attached to or incorporated into a periscope, radar antenna mast, the shears, or a snorkel mast. Those you could use while the boat was submerged at either periscope or radar depth; I can guarantee they don't work underwater though.

Although it's too late to make this long story short...getting back to the topic...for both US and German WWII submariners, receiving HF "broadcast" messages at shallow depths was possible and done routinely, but transmissions to HQ had to be done on the surface.

Thank you for this info. I have a question. Could it be done in calm sea's?

[BigWalleye]

CaptBones, you've settled most of our questions. I still have just one. Most of the US accounts I've read describe receiving radio transmissions at shallow depth, as you say about 30ft antenna depth. But the German accounts routinely describe receiving messages at 30 meters. In your professional opinion, what was the reason for this difference?

EDIT: I regret that my terminology confused you. By "pushing the signal through the water", I did not mean to imply that the signal propagated through water all the way from the transmitter to the sub, only the last few meters. I recognize that it was primarily atmospheric propagation.

[Redmane]

Thanks Capn, your expertise and knowledgeable reply is appreciated.:salute:

[Sailor Steve]

.

No I'm not. Just stating a fact.
You didn't bring it up again after my warning because it was a fact. You brought it up again because you wanted to show you were right. Otherwise it didn't need to be mentioned at all. This is your last warning.

[Sailor Steve]

I can assure you that an HF radio signal, of as little as 500W at the transmitter, can be received via sky-wave refraction, at a distance of some 6000 miles or more and at a receiving antenna depth (not keel depth!) of 33 ft (10m) or more.
Thank you for that wealth of information. I was an apprentice radioman myself in 1969-70, so you would think I'd have some of that knowledge, but I wasn't in long enough to learn that much, or to retain it after I got out.

But the German accounts routinely describe receiving messages at 30 meters. In your professional opinion, what was the reason for this difference?
I might be able to help shed some light on that. It was my understanding that the mentioned depth was closer to 20 meters, but I haven't read the same accounts you have, so you may be right. Don't forget that whatever the depth was, it was measured at the keel. The Type VII u-boat is 9.4 meters from the keel to the top of the conning tower. If 20 meters is correct then the recieving antenna at that depth is only 10.6 meters beneath the waves, or about 35 feet, which is in line with what CaptBones gave for the US boats. If it was indeed 30 meters then the antenna depth would be closer to 70 feet, so that does invite questions.

[BigWalleye]

Thank you for that wealth of information. I was an apprentice radioman myself in 1969-70, so you would think I'd have some of that knowledge, but I wasn't in long enough to learn that much, or to retain it after I got out.


I might be able to help shed some light on that. It was my understanding that the mentioned depth was closer to 20 meters, but I haven't read the same accounts you have, so you may be right. Don't forget that whatever the depth was, it was measured at the keel. The Type VII u-boat is 9.4 meters from the keel to the top of the conning tower. If 20 meters is correct then the recieving antenna at that depth is only 10.6 meters beneath the waves, or about 35 feet, which is in line with what CaptBones gave for the US boats. If it was indeed 30 meters then the antenna depth would be closer to 70 feet, so that does invite questions.

And a further point CaptBones makes is that the signal penetrates easily to a depth of "about one wavelength". Physically, the one wavelength criterion makes sense. Thats a minimum of 33ft for HF. Lower frequencies would penetrare further. My question could be restated as "Why didn't our subs receive messages at greater depths, like the German subs did?" Why were we more limited?

[Sailor Steve]

Answer 1: If the 20-25-meter depth is the correct one, then the recieving depths were about the same. If your 30-meter depth is indeed correct, see answer 2.

Answer 2: I don't know. I hope he does.

[CaptBones]

Thank you for this info. I have a question. Could it be done in calm sea's?

Could what be done...tactical voice communications while at PD/RD, or HF transmissions?

A "qualified" yes for both, actually. As you have found, by late '43 there were tactical voice VHF and UHF antennas that were useable at periscope depth/radar depth. But calm, or at least "low" sea states were necessary (they can't transmit when under water, even just temporarily). Except for unusual circumstances (or unique designs today), VHF and UHF are USUALLY line-of-sight. For all practical purposes, you had to have the station you wanted to talk to in sight and the distance to the horizon for a sub at PD ain't very far...and it's not much farther when you're surfaced either! Although, before Secure Voice equipment became common in the '70s, the biggest COMINT security concern was people jabbering away on tactical circuits with the misperception that you absolutely couldn't be heard "over the horizon"...tain't so.

So, for submarines, the tactical communication sets were most handy for talking to aircraft; "line of sight" to an A/C at 20,000-30,000 ft or even 10,000 ft, is a lot farther than you can actually "see". The other welcome use of those tactical voice sets in US submarines came later in the war, when we started forming "Wolfpacks" in October '43. You should also note that the antennas you see in photos, most often mounted high on the shears or in a periscope/snorkel head are the ESM and IFF antennas, receiving units only...it's nice to know before you surface, if somebody up there is sweeping or has locked-on to you and whether or not it's a "friendly."

Also by late war, several types of whip antennas with tunable VSWR antenna couplers were developed for HF use in submarines. In some photos they can be seen at the aft end of the shears or on a stub mast on the cigarette deck, in both raised and lowered positions. They didn't retract vertically, they had motor operated geared trunnions to lower them to a horizontal "trailing" position when submerged. Again, the sea state would generally determine whether or not you could transmit (receiving is easier, the antenna isn't "hot", you're not trying to push electromagnetic energy out into the "ether", just trying to collect a few stray electrons here or there, riding their wave). Practicality would again dictate the purposes to which you would put that equipment. It wasn't usually suitable for the long-haul HF transmissions (especially at PD/RD), but was used for tactical medium range communications in the low-HF/high-MF band (frequencies assigned usually between 2200-2800KHZ). Again, good for keeping the "Wolfpack" spread out searching for targets and calling them together when one (target) is found.

I suppose that's some more of the "long way around" to an answer, but I hope it helps (and everybody can calm down again).:up:

[J0313]

Could what be done...tactical voice communications while at PD/RD, or HF transmissions?

A "qualified" yes for both, actually. As you have found, by late '43 there were tactical voice VHF and UHF antennas that were useable at periscope depth/radar depth. But calm, or at least "low" sea states were necessary (they can't transmit when under water, even just temporarily). Except for unusual circumstances (or unique designs today), VHF and UHF are USUALLY line-of-sight. For all practical purposes, you had to have the station you wanted to talk to in sight and the distance to the horizon for a sub at PD ain't very far...and it's not much farther when you're surfaced either! Although, before Secure Voice equipment became common in the '70s, the biggest COMINT security concern was people jabbering away on tactical circuits with the misperception that you absolutely couldn't be heard "over the horizon"...tain't so.

So, for submarines, the tactical communication sets were most handy for talking to aircraft; "line of sight" to an A/C at 20,000-30,000 ft or even 10,000 ft, is a lot farther than you can actually "see". The other welcome use of those tactical voice sets in US submarines came later in the war, when we started forming "Wolfpacks" in October '43. You should also note that the antennas you see in photos, most often mounted high on the shears or in a periscope/snorkel head are the ESM and IFF antennas, receiving units only...it's nice to know before you surface, if somebody up there is sweeping or has locked-on to you and whether or not it's a "friendly."

Also by late war, several types of whip antennas with tunable VSWR antenna couplers were developed for HF use in submarines. In some photos they can be seen at the aft end of the shears or on a stub mast on the cigarette deck, in both raised and lowered positions. They didn't retract vertically, they had motor operated geared trunnions to lower them to a horizontal "trailing" position when submerged. Again, the sea state would generally determine whether or not you could transmit (receiving is easier, the antenna isn't "hot", you're not trying to push electromagnetic energy out into the "ether", just trying to collect a few stray electrons here or there, riding their wave). Practicality would again dictate the purposes to which you would put that equipment. It wasn't usually suitable for the long-haul HF transmissions (especially at PD/RD), but was used for tactical medium range communications in the low-HF/high-MF band (frequencies assigned usually between 2200-2800KHZ). Again, good for keeping the "Wolfpack" spread out searching for targets and calling them together when one (target) is found.

I suppose that's some more of the "long way around" to an answer, but I hope it helps (and everybody can calm down again).:up:

Thanks again for the educated information. I appreciate it. I knew that it could and was done in those days. Maybe not to the extent or purpose that I thought but its all good historical information to know. My Grandfather was a plank owner on the Grenadier. He was with her from the start to the end when they had to scuttle her. Then he got to be a guest of the Emperor for a few years. He raised me and I got to go to quite a few Sub Vets of WW2 conventions growing up. It was great. I wish he was still around so he could see stuff like the SH series games. He would get a kick out of them.

[Redmane]

Just a note regarding wolfpack comms during the period mentioned: I've read a couple of patrol reports from the USS Sea Cat (SS-399) which mention the fact that the boats involved also sometimes used radar to communicate, and while the reports don't mention the specific method it seems pretty obvious that it would involve pulsing the radar set on an off to send morse code type messages.

[CaptBones]

OK...let's see if I can get to everything in one post...first some social commentary...

BigWalleye...I really did think that you knew what you were talking about (you're from northern WI too...it's self-evident!), and perhaps it just didn't come out right...but I'm easily confused anyway.:huh:

Sailor Steve...I do recall that you mentioned your Navy RM days in another thread; particularly the delightful times you had, trundling bags of shredded documents to the fantail to toss them overboard, in calm and peaceful seas of course.:haha:

J0313...It's good to hear that you had the opportunity to know your Grandfather and hear his first-hand accounts of the war. I had a few relatives to tell me their stories; my Dad was an Electrician's Mate in a Pacific Fleet DE, my Mother was in the Marine Corps and worked at USMC HQ Henderson Hall in Arlington, I had two uncles in the Army/Army Air Force in Europe, two in the Marine Corps in the Pacific, another was a Navy Flight Surgeon and my maternal Grandfather was in the Navy in WWI, a Plank Owner in the battleship NEW MEXICO. I never got a single one of them to write down any of their stories, but I'm trying to do that from memory to pass on to my kids/grandkids, along with my own content.:cool:

Redmane...As one of my grizzled old Chiefs used to say "perzactly!" You can pulse the transmitter completely on/off (not good for the equipment though) or just vary the pulse width. Also, you're very welcome...all of you are welcome, of course; I hope it is interesting, if not useful information. Nothing is more wasteful and wasted than unshared knowledge.:know:

So, back to business...

First item...wavelength is the most obvious reason for differences in capabilities...frequency bands are assigned to nations by international treaties...even valid during time of war (that way makes "snooping" easier too y'know!). If the Deutchers were using their lower authorized HF frequencies (longer "short" waves) and we were (still are, when we use them at all) using our authorized higher HF frequencies (shorter "short" waves), they could get reception at deeper depths than we could. Push the freq down to 3MHZ and the wavelength is up to 100m; IIRC our old Fox Broadcast freqs were as high as 10-12MHZ, which brings the wavelength down to 25-30m or so. But also realize, that in any case the depth for good reception will usually be less than the theoretical depth. Variations in salinity, temperature, density and plain old "crud" (plus "critters") in the water cause interference and signal strength attenuation; even if your gear is perfectly designed, flawlessly manufactured and incredibly well-maintained, you will seldom experience "design performance" specs. Being able to move in three dimensions through the water column means a submarine can pass through several water masses with significantly different characteristics in a matter of minutes.

Second...they relied more on clean CW (carrier wave) Morse code, while we really fell in love with SSB/DSB (single sideband/dual sideband) multiplexed Morse code transmissions. They could send a lot of slow, reliable dits and dahs on CW and encode deep meanings into short "words", whereas we could easily lose a lot of the encoded "intelligence" in garbled multiplex transmissions. So we would be forced to seek better reception at shallower depths.

You have to think about the antenna length too; they're not hauling a 100m wire a couple of hundred yards behind the boat (like we/they do today), but the German fore and aft wire antennas look to be about 15m antennas with a "wired gap" of 10-15m between them. If I couple the bow and stern wires and the gap in series, I've got a 40-45m half-wave antenna good for 6.67-7.5MHZ, 80-90m wavelength (take her down and tune in Radio Berlin).

Early USN wire antennas were a little longer individually, but couldn't be coupled in series. With the more complex transmission modes and the frequencies we used, they needed to function as full-wave receiving antennas at depths that didn't achieve the "theoretical" maximums of 20-30m. You will also see that the long wires running to the "T" poles fore and aft were typically taken down when leaving on patrol. At the faster underwater speeds the Fleet Boats would typically run at (battery capacity differences, not actual speed limitations), those long straight wires attached to tall poles on the decks fore and aft would make a lot of noise and cause drag. Instead, they'd use shorter wires from the shears to the conning tower sides or cigarette deck railings. The USN also opted for "improvements" (as we are s-o-o-o-o wont to do) and started completely removing long wire antennas by mid-war, leaving the boats with only 1/2 wave and 1/4 wave wire and rod antennas or whips with tunable couplers to adjust the frequency, which add attenuation losses and meant the depths for good reception were even shallower.

Last but not least (whew!) the most important factor might well be the way in which the boats and their entire support and command network were designed and intended to be employed by those two very different Navies.

The KM U-bootwaffe was utilized in precisely the way it was planned and built for, a commerce war in the Atlantic. The operational doctrine required reliable and frequent two-way communications between BdU and each/every/all the boats. Regardless of being surfaced or submerged and at any depth (er...survivable depth, that is), the U-Boat had to be able to receive broadcast messages as well as specific message orders/instructions 24/7. Their equipment was designed for that purpose and functioned as intended.

The USN Fleet Boats were designed and intended to be used as a Scouting/Screening Force for the Battle Fleet. Although they did get some cleverly obtained "additional capabilities", they were initially equiped with medium-range radio communication capabilites in order to coordinate/cooperate with the Battle Fleet Commander Afloat. Even after the "blessing" of Pearl Harbor caused a complete and total revision of that Pacific War Strategy, the radio communication capabilites of the submarines fit perfectly into the USN way of conducting unrestricted submarine warfare. Our boats were much more "lone wolves" and their Commanding Officers (once the pre-war strategic/tactical crap was knocked out of them) had no need to report contacts to HQ or to get detailed instructions for coordinating attacks on convoys (some of that did come later, though the doctrine was still very different from the KM's methods).

OK...did that cover most or all of it? I was up 'til midnight reading the flurry of replies and comments/questions, but didn't have enough caffiene on hand to make even a game attempt to write this before going to bed. But, it's laundry day today and this was something to do while waiting to tend to the shifts from washing to drying to folding and putting away (yes dear, I'll be right there).

Have a nice day all...:salute:

[Sailor Steve]

Dang! If anybody doesn't understand it after that they weren't paying attention! That's about the best explanation I've ever read on the subject, and it makes perfect sense now. It might be a good idea to repost the relevant parts (the 'non-personal' ones) to the 'Technical Help' sticky thread.

[BigWalleye]

Thank you, CaptBones. That definitively and completely answers my question. Excellent, clear explanation.

[J0313]

You da man! Thanks Capt Bones. I was in the Corps myself until I committed a sin and become a doggie. 17 years total.

[Redmane]

Once again a very thorough reply, Thanks Cap!

[ETR3(SS)]

It also applies ETR3(SS). Your expertise is valued, but saying "Look at my sig" says you're trying to win an argument by simply saying "I know more than you, so there!" Better to show that you are right, rather than just saying so.

Yeah bad judgement call on my part and was in response to what I felt was a series of snarky comments. And I will say I could've explained myself better but oh well. I'm past it now. Lots of good info came out in the end. :yep:

[troopie]

Thanks 'Bones! Very usefull info to all here and I'm glad you took the time to share it! :salute:

[periunder]

I don't think you can change it. It's the same with SH3. You should be able to report anything you want without being in contact at all. The games forget things that aren't there anymore. It's just like in SH3 where if the wounded sailor has been healed you can't give him a wound badge because he's not wounded anymore.

Silly, really.
I didn't notice this. thanks for pointing out this shortfall. Is there a way to prevent sailors from being healed during patrol?

[Sailor Steve]

I didn't notice this. thanks for pointing out this shortfall. Is there a way to prevent sailors from being healed during patrol?
Don't put the Sani in there with them. Of course then they might die, in which case they'll certainly get a medal. :dead:

Seriously, I don't think so.

[TorpX]

I didn't notice this. thanks for pointing out this shortfall. Is there a way to prevent sailors from being healed during patrol?
I never thought about this either.

Maybe, if you knew which file was associated with crew status, you could hand edit it, so they would be "wounded" again as you enter port?