Frustrated

[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/Communi...ith_submarines

[J0313]

Originally Posted by 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/Communi...ith_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]

Originally Posted by J0313

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.

[ETR3(SS)]

Originally Posted by Sailor Steve

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.

[troopie]

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

[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.

Originally Posted by J0313

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/app...es/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]

Originally Posted by BigWalleye

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]

Originally Posted by 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.



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/app...es/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

[J0313]

Originally Posted by 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

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.