Real Submarine Technology & History Q&A

[virtualpender]

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?

[DaveyJ576]

Originally Posted by virtualpender

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]

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.




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

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

Thanks, Dave!

[Nuc]

Originally Posted by virtualpender

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]

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]

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!

[LukeFF]

Originally Posted by DaveyJ576

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]

Originally Posted by LukeFF

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. Soon I hope!

[Diopos]

Originally Posted by Jan Kyster

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And a question regarding The Plotting Party... if you please?

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Maybe this is of some help...




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