The Silent Service: Creeping Death 1998

[Zathred]

Tactics and a large dose of good luck saw me sail through this difficult scenario first time. Here's how it played out...

The Silent Service: Creeping Death 1998

Submarine warfare is a combination of stealth, patience, tactics and no small measure of old-fashioned good luck! In this scenario you are in command of a Russian Akula II class SSN tasked with covertly sinking a USN Ohio class SSBN sailing out of Pearl Harbour as retribution for the prior sinking of one of our own SSBNs, the K-44 Ryazan.

First Contact

I won't bore you with full details of the long journey to first contact with the SSBN. I steered onto a reciprocal course to meet the enemy head-on by using the surveillance asset reports tracking the position of the SSBN. I travelled within the layer at ~500ft no faster than 15kt to reduce the risk of detection. I regularly rose to shallow depth (131ft) whilst going to full stop to listen for contacts and to receive VHF signals. Occasional excursions to periscope depth allowed me to receive updated intelligence reports over the satellite link.

I was fortunate to avoid several close calls with active sonobuoys that appeared nearby on the way to contact.

The SSBN appeared above the layer south-east of my position during one of the periods I went shallow. Only the Shark Tail towed array was able to pick up the faint sound of the SSBN, hence the need to be shallow in order to place the array above the layer. The contact appeared to be in the 2nd CZ about 45nm distant although later post-action analysis revealed that it was in fact much closer in the 1st CZ. Sonar is a fickle tool!

Shortly after contacting the SSBN the escorting USN SSN (698 Bremerton) was also detected. Both subs were rapidly type-classified by my passive sonar as an Ohio and a Los Angeles respectively. The SSBN was soon lost but the SSN stayed in contact as it steered north-east at 20kt and was classified as the Bremerton itself.

I proceeded slowly due south in the layer aiming to arrive just north of the SSBN’s predicted track based on the intelligence reports and my contact data. The trap would be set!

[Zathred]

Approaching the Target

I decided for three reasons not to use my long-range SS-N-16 Stallion missiles for a stand-off attack:

(1) I did not have enough confidence in the accuracy of the CZ contact, which in post-analysis was indeed much closer than indicated.

(2) As soon as a missile breached the surface it would probably be detected by US surface and airborne radar systems giving an accurate datum for my location. This would invite an immediate counter-attack as the presence of sonobuoys indicated nearby ASW helo or fixed-wing assets. The missiles may even have been intercepted by a USN surface asset if I was unlucky.

(3) Given the Alabama and the Bremerton were close to each other the missile-borne torpedoes may well have acquired and attacked the SSN instead of the SSBN.

A close-range torpedo engagement was required.

The move to position for an attack with torpedoes went without any issues. I lost contact whilst within the layer and proceeded using dead-reckoning based on the Alabama's course and speed in order to put myself into an ambush position within 5nm north of the expected track of the enemy. Several full-stop excursions to shallow depth were made to check for re-acquisition. Would they detect me?

At the predicted intercept point I went to full stop. I held position within the layer awaiting re-acquisition hoping that my location would be such that I would not have to move once the expected close-range contact was established in order to avoid being detected myself. Was I close enough? Would I hear the target through the layer at short-range? An active sonobuoy at 14nm gave me the shivers. ASW assets were in the vicinity. Even if I succeeded in sinking the Alabama would I escape? What about the escorting SSN which I'd lost contact with?

[Zathred]

SHOOT!

Lady Luck was with me and the SSBN, without the escorting SSN, appeared above the layer when 8nm away heading due west at 12kt. Clearly I had not been detected but I dare not move or risked giving myself away and no doubt becoming the hunted instead of the hunter! Would the SSBN pass close enough for a torpedo shot? My USET-80K torpedoes were rated for 5nm against a sub and a 12nm kinematic range at 50kt. It looked like the SSBN would just breach the 5nm range as it passed south of me. It was going to be touch and go as to whether I'd get a shot at her.

The Alabama held her course, depth and speed and breached the 5nm range as expected. I immediately launched x3 USET-80K torpedoes at her whilst maintaining my position within the layer and at full stop. Now the big decision, hold position or move away from the launch datum? I held my nerve and stayed still as a mouse.

The torpedoes moved out above the layer at 50kt. The Alabama did not change course or speed after the launch, she'd not heard the transients and the initial torpedo runs. How long would she stay ignorant of the weapons heading her way? Until she started to run I dare not move.

About 10s after the final torpedo left its tube the Alabama started a turn to the south and increased speed, she'd heard the weapons in the water. Would she shoot back? Would a helo drop a torpedo on me in short order? It would be time to start moving once the SSBN reached flank speed but only at 5kt lest we make ourselves known to the missing SSN. Hopefully the noise of my torpedoes would mask me from the Alabama itself although she may fire a bearing-only torpedo against my azimuth based on the incoming weapons tracks.

The fight was now on...

[Zathred]

Death of the Alabama

The Alabama dives below the layer and is now running at flank speed with three USET-80K torpedoes in chase. I use the wire link to send the torpedoes into the deep to follow her. Would they have the kinematic range to catch her? I would likely not get another shot with torpedoes and would thus have to risk SS-N-15 Starfish missiles if the torpedoes ran out of fuel or missed. That would probably be signing my own death warrant when the nearby ASW assets saw them breaching the surface.

My luck held out and the torpedo seekers were in contact with the Alabama as they closed in for the kill. At 8nm the first torpedo struck home and the Alabama died. Mission accomplished but now we had to escape any retribution heading our way. Slow and silent? Fast and deep? Which direction?

It's not over yet…

[Zathred]

Exiting The Arena

I decided to initially withdraw due south away from the PROBSUB datum I'd no doubt created and towards the sounds of the imploding wreckage of the Alabama as it sank into the abyss. I would stay within the layer at 5kt at first and then increase to 15kt to put some distance between myself and the datum. A dog-leg to the south-east would then mask my planned final exit course and help break any USN sonar contact. I would then turn south-west as I headed towards the safe zone. I would use the same pattern as on approach with regular reductions to a full stop and rising above the layer once further away from the combat datum in order to check for pursuing assets.

Once again my luck held and apart from some active sonobuoy drops to the north I encountered no issues during the withdrawal and transit home to safety.

Mission accomplished (Triumph, 350 points): the Alabama was destroyed and the USN did not establish sonar contact with my Akula throughout the entire scenario. Uncle Sam will have humble pie for dessert tonight comrades.

[Zathred]

God's Eye

Time for a post-analysis review courtesy of God's Eye cast across various saves of the scenario as it played out.

At the initial contact point both the Alabama and the Bremerton were in the 1st CZ and thus much closer even though the sonar plot indicated they were further away in the 2nd CZ. I was lucky to get to the intercept point in time with a suitable range for attacking and that the Bremerton decided to be elsewhere at the critical moment.

On the post-combat escape I got lucky steering directly between two passive sonobuoys and through the corridor between two further lines of passive sonobuoys before turning south-west. ASW assets failed to locate me while near the PROBSUB datum. The SSN 698 Bremerton was nearby during the combat (shallow at 5kt) but did not detect me as I was in the layer and too far for contact. I never re-detected the Bremerton myself after the initial CZ contact.

[Zathred]

Conclusion

Sometimes luck is on your side!

I hope you enjoyed this debriefing. This was by far the most enjoyable session I have had with CMANO to date. If you'd like to experience the action yourself I've attached a selection of game saves made at the key action points described above for your delectation.


Footnote

In real life Zathred is a veteran IT professional with over 30 years practical experience who worked on a number of projects for the UK Government and military including IT security evaluation for GCHQ and systems development for the Royal Air Force. Today he battles orcs in LOTRO, flies F-16s in Falcon BMS, sends spacecraft to other worlds in Kerbal Space Program and faces down the enemy in CMANO.

Happy hunting!

[Zathred]

Addendum

Due to a bug in the version of CMANO that this scenario was played against (B1009.27.2) the AI sent non-player controlled submarines to just over the layer regardless of the depth set for the sub by a mission etc. If you play the scenario or my saves once the bug is fixed then your experience may be different from mine!

Submarine depth bug