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Author Topic: Harpoon Cold War Sub Ratings?  (Read 555 times)

Offline Mako

  • Mad Scientist
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Harpoon Cold War Sub Ratings?
« on: February 17, 2018, 02:24:39 AM »
I have the 1990/1991 GDW Data Annex for Harpoon, and upon looking at it again, was surprised to see no data for the following Cold War subs included in it:

Maximum Depth
Sub Size Rating
Sub Noise Rating

These are included in Harpoon 4, but not with the older data booklet.

So, is this info for US, UK, NATO, Swedish, and Soviet subs available somewhere?

Also useful, would be maximum depth ratings for ASW torpedoes too.  Can't recall if that info is available, or not.

I posted this query on the Harpoon 4 Yahoo Group as well, but its been 2.5 years or so since anyone has posted anything there, so I suspect the info may not be forthcoming from there, anytime soon.

Some of the stuff I can guesstimate, by comparison to other classes, but other stuff is a bit harder to nail down, e.g., I suspect the later classes of Swedish subs are most likely Very Quiet, since the Sjoormen is rated as Quiet in H4, and is a much older design.

I was surprised to see old, 1950s and 1960s era subs rated as "Quiet" in H4, since that just seems very, very optimistic, based upon what I know of Soviet designs from back in the day, e.g. their Golf II, Whiskey, and Romeo boats.


Offline Ockman

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Offline Mako

  • Mad Scientist
  • Posts: 696
Re: Harpoon Cold War Sub Ratings?
« Reply #2 on: February 21, 2018, 11:41:51 PM »
Thanks for the reply.

Yea, that's why I'm interested in them, and some of the other D/E boats, and AIPs too.

Ran across one reference listing average D/E boats at about 105 dB, which apparently is a bit quieter than the old, Los Angeles SSNs, and level with the new, Improved L.A. class, when they're creeping along at silent speeds.

The 877 Kilo is rated at about 115 dB, and the 636 Kilo is rated at about 110 dB, by comparison as well, so a bit noisier than the L.A., and Western D/E (diesel-electric) boats.

Apparently, dB's aren't a liner scale, so a 3dB difference means a doubling of noise radiated at 1 meter from the target (standard unit of measure).  A 10 dB difference is roughly a 10X increase in radiated noise level.

Haven't found any good sources for D/E or AIP noise levels, even for old boats that have been decommissioned, but did find a decent, Russian naval source for US and Soviet subs.

Would love to find some more info on the UK, French, and Chinese SSNs and SSBNs, and the Japanese D/E and AIP boats as well, either comparing them to other classes, or with ratings in dB as well.

Offline Mako

  • Mad Scientist
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Re: Harpoon Cold War Sub Ratings?
« Reply #3 on: February 21, 2018, 11:46:00 PM »
Note - I did find some info on the old Soviet boats mentioned above, and listed as "quiet" in H4, and those ratings, as I suspected are just plain wrong.

The older 1950s and 1960s era Soviet subs were anything but quiet, being about 140 - 152 dB, or louder.  Using the dB log scale, you can see they might as well have almost been surfaced, for ALL the noise they'd be putting out, when moving underwater, even "quietly" - the noise ratings given are for vessels moving in "silent mode", so at about 4 knots for nuke boats, and 2 knots for D/Es.

30 - 40+ times louder than the L.A. class, is not "quiet".

I've also run across mention of 160+ dBs, which is what they'd give off, when not moving in silent mode.
« Last Edit: February 21, 2018, 11:48:18 PM by Mako »


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