SUBSIM Radio Room Forums

SUBSIM Radio Room Forums (https://www.subsim.com/radioroom/index.php)
-   Silent Hunter 4: Wolves of the Pacific (https://www.subsim.com/radioroom/forumdisplay.php?f=202)
-   -   Real Submarine Technology & History Q&A (https://www.subsim.com/radioroom/showthread.php?t=147577)

DaveyJ576 04-22-10 06:04 PM

Quote:

Originally Posted by LukeFF (Post 1363964)
Possibly.

Dave, while we're at it, I've come across a pic of an S-18 class submarine I've never seen before. I found it at the U.S. Navy and Marine Corps Museum Photo Archive, and it depicts an S-18 class sub at Dutch Harbor:

http://img.photobucket.com/albums/v2...BoatAlaska.jpg

Any guess as to which boat it might be? The only 3 S-18s I know of that got a AA gun platform are S-28, S-31, and S-35. Also note the spray shield mounted on the bridge. Not something I've seen on any other S Class pics!

That site is really fascinating, showing some pics of American subs I've never seen before. Really worth checking out!

The following Electric Boat design S-boats (S-18 type) can be confirmed to have carried a raised AA gun deck aft of the conning tower fairwater as part of their wartime upgrades, as shown in Luke's photo above: 23, 28, 30, 31, 32, and 35. Insufficient photographic evidence exists to verify the configuration of the following: 34, 36, 37, 39, and 40. Based on the trends in what I have seen, it is unlikely that the boats higher than S-35 had this mod. The rest of the boats had completely different mods and did not have this AA gun platform, were leased to the RN and did not get these mods, or were lost or decommissioned prior to these mods being installed.

The structure on top of the bridge in the photo in question is actually a wind venturi. It was designed to deflect wind up and over the bridge watchstanders. It is an unusual configuration and can be used to narrow down the suspects. I found a photo of S-23 that nearly matches the one in the photo. Therefore, I will say, with a reasonably high degree of certainty, that the boat in the photo is S-23, with S-28 being a close 2nd.

How's that for a little detective work? :D

LukeFF 04-23-10 04:55 AM

Quote:

Originally Posted by DaveyJ576 (Post 1370042)
How's that for a little detective work? :D

Sounds good to me! Thanks!

DaveyJ576 05-12-10 08:46 PM

Hey there!

I am currently working on "A Visual Guide to the U.S. Fleet Submarines Part 2: Salmon & Sargo Classes 1936-1945". Should be done and uploaded to Navsource in a week or so. This one took longer than I thought. Discovered some very interesting stuff!

I will let you know when it is done!

Dave

LukeFF 05-13-10 02:00 AM

Quote:

Originally Posted by DaveyJ576 (Post 1390680)
Hey there!

I am currently working on "A Visual Guide to the U.S. Fleet Submarines Part 2: Salmon & Sargo Classes 1936-1945". Should be done and uploaded to Navsource in a week or so. This one took longer than I thought. Discovered some very interesting stuff!

I will let you know when it is done!

Cool!

Nuc 05-14-10 06:14 AM

Quote:

Originally Posted by DaveyJ576 (Post 1390680)
Hey there!

I am currently working on "A Visual Guide to the U.S. Fleet Submarines Part 2: Salmon & Sargo Classes 1936-1945". Should be done and uploaded to Navsource in a week or so. This one took longer than I thought. Discovered some very interesting stuff!

I will let you know when it is done!

Dave


Great! I just read part 1 on the Gato. I'm sure there was a link in an earlier post but those who missed it (like me) here it is:

http://navsource.org/archives/08/pdf/0829294.pdf

virtualpender 05-14-10 08:38 AM

Dave, can you explain the significance of the red arrow markings on the shallow depth gauge seen here? And why do these arrows vary from boat to boat, even in the same class?

http://i205.photobucket.com/albums/b...n_DSCF5640.jpg

DaveyJ576 05-14-10 05:16 PM

Quote:

Originally Posted by virtualpender (Post 1392267)
Dave, can you explain the significance of the red arrow markings on the shallow depth gauge seen here? And why do these arrows vary from boat to boat, even in the same class?

In this particular case, were the arrows moveable or were they permanently fixed in place?

virtualpender 05-14-10 08:13 PM

The arrows are painted on the face of the gauge. That particular photo is from the COBIA but I saw similar markings on the shallow depth gauges of PAMPANITO a couple weeks back. I also dug up some photos online from COD and it also has the markings although they are at very different depths.

http://www.fleetsubmarine.com/graphics/224-cr-006.jpg


I'm very stumped. Your expert opinion is very welcome.

Also, I can't wait for your SARGO guide!

Thanks, Dave!

Nuc 05-15-10 04:28 PM

Quote:

Originally Posted by virtualpender (Post 1392267)
Dave, can you explain the significance of the red arrow markings on the shallow depth gauge seen here? And why do these arrows vary from boat to boat, even in the same class?

Probably related to the operational depth for specific operations on that boat (e.g. certain radars, ECM masts, Snorkeling for Guppy conversions etc.)

DaveyJ576 05-16-10 06:13 PM

Red arrows on the depth gauge
 
To tell you the truth, this one kinda has me stumped. We didn't use any such markings during the Cold War on the Darter. The fact that they vary greatly from boat to boat belies one all encompasing explanation.

So my answer is this: they probably denote a variety of things, which would be determined by the specific boat's crew depending on what visual reference reminder they wanted for the planesmen. I agree with Nuc in that they may mean operational depths for specific operations. For instance, 48 feet would be about the depth that the bridge went under, leaving just the shears visible above the surface. 67 feet would be about the depth that the head of the periscope would dip under. These markings may also have a relationship to calculated buoyancy, i.e. the depth that you would flood or blow the negative or auxiliary tanks to achieve positive or negative buoyancy

DaveyJ576 05-16-10 06:21 PM

Michael Mohl over at Navsource has posted Part 2 of the fleet boats article. here is the link: http://www.navsource.org/archives/08/10idx.htm

This part covers the Salmon and Sargo classes. Even though it only covers 16 boats, it ended up being just as long as Part 1. The modifications to these boats were more singular in nature and I found it necessary at some points to go boat by boat.

Next up will be the Porpoise/Shark/Perch class. Due to an upcoming move to New York, that one will not hit the streets until late summer.

Enjoy! :)

Diopos 05-19-10 09:43 AM

Quote:

Originally Posted by Jan Kyster (Post 1397094)
---
And a question regarding The Plotting Party... if you please? :D

...

Maybe this is of some help...:hmmm:




.

LukeFF 05-25-10 03:04 AM

Quote:

Originally Posted by DaveyJ576 (Post 1394871)
Michael Mohl over at Navsource has posted Part 2 of the fleet boats article. here is the link: http://www.navsource.org/archives/08/10idx.htm

This part covers the Salmon and Sargo classes. Even though it only covers 16 boats, it ended up being just as long as Part 1. The modifications to these boats were more singular in nature and I found it necessary at some points to go boat by boat.

Next up will be the Porpoise/Shark/Perch class. Due to an upcoming move to New York, that one will not hit the streets until late summer.

Enjoy! :)

Great job, as always! :) As for the lack of info about Mod2/2A for these boats, I've read through the patrol reports for the Salmon and Sargo class boats and found very little evidence of this mod being applied to these classes. It may be that the majority of these boats simply "jumped' over these early mods and were modified from their original form into Mod 3.

I've not read entirely through the PDF file yet, but did you cover the deck-mounted torpedo containers at all?

DaveyJ576 05-25-10 04:24 PM

Quote:

Originally Posted by LukeFF (Post 1402559)
Great job, as always! :) As for the lack of info about Mod2/2A for these boats, I've read through the patrol reports for the Salmon and Sargo class boats and found very little evidence of this mod being applied to these classes. It may be that the majority of these boats simply "jumped' over these early mods and were modified from their original form into Mod 3.

I've not read entirely through the PDF file yet, but did you cover the deck-mounted torpedo containers at all?

Your conclusion concerning these boats jumping over the Mod 2 and 2A's is entirely plausible. By the time that most of the Salmon/Sargos returned for their first overhauls the Mod 3's were already in vogue and they may have gone from a Mod 1 directly to the Mod 3. As I gather new info like this, I will incorporate it into the articles via revisions.

I puzzled for a bit over why the SJ radar was consistantly mounted on the starboard side of the shears as opposed to forward as in the Gatos. Then it suddenly hit me. In order to get a useful range, the dish had to be mounted fairly high above the water. This height also dictated how high the support bracket for the SJ mast had to be mounted. On the Gatos this was not a problem. The support shear for #1 scope provided the perfect height to mount this bracket. However, on the Salmon/Sargos with their 34 foot #1 scope, this shear was not high enough so the bracket was attached to the #2 scope shear. If they had placed the radar mast in the traditional location forward of the scopes, this support bracket would have been in the way of the #1 scope and would have prevented raising or lowering it. The solution was elegantly simple, attach the SJ bracket to #2 scope shear, just move it out of the way to starboard. This seemed to work quite well, as only 6 of the 16 boats had the radar moved to a "normal" location, even after receiving a 40 foot #1 scope. Interesting

Only one Salmon/Sargo boat had deck mounted, external launching tubes, the Stingray (SS-186) and I documented that in the article. As for the stowage tubes that were mounted inside the superstructure forward of the conning tower I have yet to turn up good information on their configuration. The thrust of the article was on visually identifying the boats and since these stowage tubes can not be seen from the outside I did not cover them. However, I have not given up. I am working on obtaining a set of plans for these boats that may show how these tubes were configured. Got to find the dough, though and that is in short supply right now. :x Soon I hope!

LukeFF 06-14-10 05:31 AM

Dave,

On the fleet submarines, how much of an effect did the trim and drain pumps have on a boat's ability to maintain a given depth? Could a boat maintain a certain depth at All Stop, given that the pumps were in operation?


All times are GMT -5. The time now is 11:36 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright © 1995- 2025 Subsim®
"Subsim" is a registered trademark, all rights reserved.