Submitted: Sagami Bay Convoy Raid, 2022

[DESRON420]

While reading up on fixed sonar for my Baltic question elsewhere I discovered that the Russian Northern Fleet MGK-608M system was damaged by fishing trawlers in 2016 and remains out of commission because the Ministry of Defense refuses to spend the money to fix it. No hackers needed! [:)]

https://www.globalsecurity.org/military ... k-608e.htm
https://twitter.com/I30mki/status/1098728385822580736

[AndrewJ]

Is anyone else finding that this scenario has trouble running at high speeds? It has a low AU count, but for me it barely seems to accelerate at the highest settings, with pulse times bouncing up over 500ms. Puzzling.

[AndrewJ]

PLAN

The east coast of the rugged Izu Peninsula is very steep, so I intend to head east between Niijima and Kozushima island, reach the coast of the peninsula, and turn north along the coast in the deep water there. Hopefully that will get me into the bay. I will then hunt across the bay from west to east. I’m contemplating a blind salvo of missiles to maybe clear out some lesser patrol craft, but that’s a complete gamble, so I’ll probably not do that except in emergency cases.


ACTION

At first there are a number of active sonobuoy contacts, but they seem to be too far away to detect us.

Around 11:30 we start picking up merchant traffic going in and out of the bay, and then occasional fishermen. These aren’t the merchants we’re looking for, so we continue.

First hostile contact comes with a coast-guard cutter at 15:30, but it has no sonar, so is no threat, and we pass it by.

Moving up the coast we find numerous fishermen, and then at 18:30, our operators hear a low-frequency sonar of some sort in the ‘first’ mouth of the bay, only 10 miles away. That’s alarming! A detection at that range is probable.

The captain orders an immediate rise to firing depth for a pair of Clubs, and as we clear the layer, we hear a second sonar adjacent to the first. Four missiles are fired, and we descend back into the layer, hearing explosions and breakup noises as we descend, and hurry away into the shallows between the little island of Hatsushima and the mainland. After a few miles we slow down and creep again, hearts in our throats.

As evening goes on we reach the inner end of the bay and start traversing west, but find nothing. We can hear fishermen from one side of the bay to the other, but nothing else. Is the convoy outside the bay? Puzzled, we turn cautiously southwards towards the area where we engaged the warships. Maybe they are closer to there?

Then, at 23:48, as we are creeping in the layer, there is a violent explosion without any warning, and our brave sub and noble sailors are destroyed.




AFTERMATH

Spies in the Japanese ministry of defence late reveal that the Barry had hear our creeping sub 7.5 miles away, and promptly dropped an ASROC on it. We had sunk two Asagiri destroyers earlier on, but the convoy was completely unharmed.

This is a tough one. The stationary Barry can hear a 5 knot creeper in the layer at 7.5 miles, and even a 2 knot creeper at 6.3 miles, before your sub can detect it in return. Surprisingly, the best tactic is a night-time periscope attack. Testing shows that if I had stuck up the scope shortly before they heard me I would have seen the convoy, and been able to engage. Unfortunately, I was afraid that I would be immediately detected by airborne radar in such close quarters, so I didn’t use the scope.

Fun all the same!

[BeirutDude]

Nice report! Thank you!!!!

[schweggy]

So... here's how my attempt went with this scenario.

I'll note that I read Andrew's AAR and took the coast hugging approach. The layer was mostly between 250 and 500 feet. I stayed at 400 or so feet for the duration... basically "in the layer." It's a long slog up the coast at 5 kts, but more or less undetected. The pop-up periscope recons were quick... maybe 30 seconds or less. The "convoy" was displayed as a semi-regular formation that was not moving... so I decided to put some fish and missiles up their ass. Seemed to work...


Final score: 9000


SIDE: West
===========================================================

LOSSES:
-------------------------------
2x SH-60K Seahawk
1x Commercial Container Vessel - Feedermax [3,000 TEU, 30,000t DWT]
1x Commercial Container Vessel - Small Feeder [100 TEU, 5,750t DWT]
1x Commercial Dry-Bulk Carrier - Handysize [35,000t DWT]
1x Commercial Dry-Bulk Carrier - Small Handysize [25,000t DWT, Helo Deck]
1x Commercial LNG/LPG Tanker [18,000t DWT]
1x Commercial Tanker - Large Range 2 [150,000t DWT]
1x Commercial Tanker - Medium Range [40,000t DWT]
2x DD 151 Asagiri
1x T-AKE 1 Lewis and Clark
1x T-AKR 5051 Cape Ducato [Tombarra Class]


EXPENDITURES:
------------------
80x J/HQS-33B DICASS [AN/SSQ-62]
63x J/HQS-12 DIFAR
5x RIM-162A ESSM



SIDE: Biologics
===========================================================

LOSSES:
-------------------------------


EXPENDITURES:
------------------



SIDE: Merchants
===========================================================

LOSSES:
-------------------------------


EXPENDITURES:
------------------



SIDE: Fishing Fleet
===========================================================

LOSSES:
-------------------------------
1x Commercial Fishing Boat [35m]


EXPENDITURES:
------------------



SIDE: PLAN

[BeirutDude]

NICE!!!!!!!! [&o]

[BeirutDude]

Updated 04-25-2021
Submitted 04-29-2021

1. Rebuilt to the latest C:MO Beta Version 1147.21 & Database: DB3000 v488 to take advantage of the new ASW algorithms
2. Added the Cyber-attack idea (Thanks) and the longer it takes to complete your mission the greater the chance the SOSUS comes back online.

[BeirutDude]

Just got a Major Victory on this one and think it is ready. One tweak I did make today was to turn off "Collective Responsibility" for the sub.