by Stephen Makk
“Sonar, keep a check on the layering as we get towards our depth.”
“Aye Sir.”
In the deep sea, warm layers of water lie above colder layers. Sonar is refracted from the various temperature layers present in the ocean, allowing submarines to hide in the deeper cold layers.
From its fifteen degree dive, the boat’s deck levelled out.
“One eighty Sir, zero bubble.” called out the planesman.
“What’s the sonar story Ratty?” asked Luke.
“Way aye Sir,” he said in his Geordie vernacular, “we had a cold slice at one six three.”
“Come to three thirty Planesman. Stream the Lure fish Ratty.” The Lure streamed by reel far out into the submarine’s wake and trailed behind, communicating by cable. It was a listener, a detector of submarines and a deceiver of any weapons tracking the boat. Lures were at the cutting edge of NATO and Soviet technology. They can calculate the distance and the direction of a sound source, and identify the type of ship or submarine by the unique, acoustic signature of noises from its machinery. This is most effective when the cable is in a straight line. So rapid course changes degrade its effectiveness. The Ghost streamed out her towed array sonar equipped Lure, hundreds of meters behind the boat. Where it could listen in the dark silence for any sign of a vessel, both surfaced and submerged.
“I want ten minutes with the tail above the layer, then turn for the return leg and ten minutes with the tail below. Keep that up, one leg with tail up, the return with tail down. Make rectangular passes four runs to the north-northwest, then four to the south-southeast. If a Whale farts off Jeddah I want to know.”
“Lure fish streamed Sir.”
A good towed sonar array can detect propeller noises and other acoustic anomalies from distances of up to hundreds of kilometres. These are then passed by fibre optic cable for processing by a powerful computer in the submarine.
Luke picked up the microphone and addressed the boat’s company. “We are now under silent running, I repeat silent running.” The boat sailed north-west listening. Ratty Southworth turned to his Captain.
“Sir, permission to transfer the Vyborg and the Vologada to the Iranian library?”
“Yes Ratty, the Vyborg is now the Nahang and the Vologada is the Siyah Bambak. That’s Crocodile and Black Shark to you.”
“I expect they’ll be in line astern, probably. You never know though, they won’t be expecting any trouble down here. However, they may go wide. You know their sounds, we’ve tracked them before.”
“They’re tricky sods, Sir. But we might get lucky, they won’t be on silent running
I’ll bring up the libraries. They’re quiet the Kilos, but we can hear them.”
“One thing to watch for is every twenty three or so miles, they’ll have to surface or put the snorkel up. I doubt they’ll be on the surface for hours even though it’s dark, they’ll be too slow there. At the end of the Ghost’s first run, it was a slow wide turn to starboard and then the run west-northwest. Luke headed aft down the companionway. He entered CPO Salt’s cabin.
“Hi Salty, how’s Lieutenant Pearl Turner settling in?”
“Fine Sir, I showed her around the boat, she’s in her working area getting it sorted out to her liking. She’s got a bunk now, it’s Ascot’s old one.”
“Keep an eye on her, she’s only partially completed her sub conversion course.”
“I will Sir.” Salt started to take out a tablet from his personal drawer.
Sir I know she’s a Medical officer, but what’s a prophylactic?”
“Why?”
“LS Jewel had just got out of his bunk, you know how he looks first thing? She said, “Are you OK sailor?” He grunted. She said the bags under your eyes look like two used prophylactics.”
Luke laughed. “Well, Sir?”
“You’ll have to find out Salty,” said Luke grinning. Luke continued his tour of the boat, Next would be the back aft lot, the Engineers. A while later he walked into the control room.
“Any sign of them?”
“Not really Sir. I had a possible a while ago but it was a false shadow.”
“Control room to red lighting,” ordered Luke. Dull red lighting bathed the room, it was possible to see but it was now semi dark. This is to preserve the Captain’s night vision in case he needed to use the periscope.
Luke started to make an entry in his log via his laptop. Fifteen minutes later Southworth looked up.
“Sir. I might have something. Refining. Refining.” Luke watched him, he noticed Mark Davis the Exec was looking too. Would this be it? thought Luke, it was a hunch he knew, but there had to be a strong chance.
“I’ve lost the surface contact. No sub surface contacts Sir.” Ratty frowned at his scope and continued his scan, adjusting the gain and frequency trawl. It went on for more than an hour.
“Conn Sonar, possible contact. Thirty nine degrees, fifty eight kilometres. Refining, refining.” Luke took a look at Mark his Exec.” He noticed the tension on his face. Mark forced a smile and held up crossed fingers.
“Lost him, Sir. Sorry but they're like bloody shadows on a foggy night.”
“You’ll do it Ratty, keep on em.”
“Exec.” The Exec walked over to Luke’s position at the conn.
“Mark, I’ve been looking at the survey of the sea conditions here, and there’s an outflow from the Red Sea in the upper layers. It’s countered by an inflow in the lower layers. What chance do you think there is that they’ll come through the smaller eastern channel?”
“I doubt it, Sir, it’s only thirty meters deep, they could still just about stay submerged in that, but only just.”
“Yes, they could come through on the surface but there’s a good Moon tonight so I doubt they’ll risk being seen.” Luke lowered his voice. “What I’m thinking is that we get into the narrow channel, sit on the bottom so we don’t need to make a noise fighting the outflow. I think they’ll come through fairly deep so they’ll have to put on more revs to fight the inflow pushing them back in, that’ll make them noisier. When they're behind Perim Island we leave to the north, come around the island and get into their baffles.” Mark smiled.
“Sounds like a plan, you devious bugger.”
“We’ll have to catch them quickly though, they’ll soon be in the Gulf of Aden and then they could go anywhere. Plenty of sea room there.” The Exec nodded.
The baffles are an area directly behind the submarine, where sonar is much less effective. It can interfere with the detection of any pursuing submarine. In the cold war, an abrupt about turn and charge to clear its baffles by a Soviet submarine was called a “Crazy Ivan.” The use of towed array sonar has reduced the effectiveness of a baffle hidden approach.
Long minutes dragged on. Ratty played with his set, a frown on his face.
“Possible contact Sir. I think a boat’s broke surface. Thirty three degrees, range thirty six kilometres.” Luke waited, come on Ratty, come on.
“Lost him.” Damn. An hour dragged on by, like a snail at a funeral.
“I have them, Sir. Definite contact, it sounds like a boat’s broke surface heading our way range twenty five kilometres, bearing thirty four degrees. I’m optimising the search for that range.” The scan took long minutes. “Possible second contact Sir, depth one four five, speed approx. sixteen knots.” Luke punched the air.
“Designate surface contact Tango one.”
“Too early to be sure on the second contact Sir. A screw count isn’t possible yet.”
“Keep up the grid search Exec, maintain speed.” Time passed by, the clock seemed to have ground down almost to a stop.
“Sir, I’ve got faint but good classifications on the contacts now. They’re bearing thirty six degrees, range twenty two kilometres, depth eight zero meters. Screw count and vibration profiles identify the lead contact as the Nahang and the second contact is the Siyah Bambak. The Iranian navy library shows both ratings are above eighty five percent pr
obable.”
“Good work Ratty, you’ve snared yourself two black holes. Weps, designate contacts as Tango’s one, and two.”
“None of them are showing any sign of having detected us, Sir.”
“Good, watch out for any signs of coasting.”
“Way aye, Sir.”
Sometimes a boat will turn off its drive and coast, listening for any other vessels in the area.
“Weps.”
“Yes Sir,” said Lt Commander Savita Kapoor. She looked up at him. He couldn’t help but smirk at her deep beautiful black brown eyes, framed in the white anti-flash hood.
“In your professional opinion Weapons officer, what would you think appropriate?” It was obvious he knew, but it was the usual boat’s banter. Luke couldn’t see her mouth, but her eyes smiled, for him it was as though the sun had come out.
“Captain, I think they’d like to get closely acquainted with a Spearfish.”
“Then load em up.”
She activated her headset and spoke to the torpedo room. “Check Spearfish tubes status.” A few minutes went by.
Savita turned to Luke “Sir, tubes one, two, five and six are loaded and ready in all respects. The fish are greedy today.”
“Sonar Sir, we have a coast,” said Ratty.
“All stop, disengage drive,” snapped Luke. Holy Ghost coasted silently through the dark depths. After several minutes, Southworth spoke up.
“They’ve re-engaged their drive. They’ve bunched up a little, Nahang’s putting on a few more knots to compensate. It looks like they’re trying to maintain a separation of one kilometre.”
“Planesman come to eighty degrees, blow one and two, up angle fifteen.”
“Exec, let’s get into the narrow channel. They’re going right down the middle of the main channel. Rewind the tail. The towed array sonar retracted back into the boat. HMS Holy Ghost rose almost to the surface and made her way east towards the Yemeni coast. After fifteen minutes, Luke thought the time was right. He raised the periscope and did a full three sixty and then returned to look at the east and north. His fingers found the night vision control, the scope returned a green glowing view of the coastline and to the north a low Island coastline.
“Planesman come to fifteen degrees, twelve knots.”
“Fifteen at twelve aye Sir.”
Sir.” The Ghost moved into the channel. When the time was right and she was approaching the north end of the channel, he lowered the scope.
“Flood forward one, come to zero knots. make your depth four zero”
“Zero aye Sir.” The Ghost sank slowly in the dark shallow channel, the current flow out from the Red Sea through the narrow channel slowed her quickly. With a muffled but firm crump, she soon came to rest on the seabed. The Ghost waited for its prey like a patient but deadly Eel.
“Can you hear them Ratty?”
“Yes Sir, not as good as before, but good enough.” Luke waited, come on boys, come to Mother. As the minutes ticked by Luke took what felt like his three hundredth look at the clock.
“Conn sonar, Siyah Bambak’s disappeared.” Luke’s jaw dropped.
“Disappeared?”
Chapter 4
“THE SIYAH BAMBAK’S just disappeared?” asked Luke.
“Yes Sir, Nahang’s bearing two nine two, eighteen knots. But Siyah Bambak’s gone.” He looked to his executive officer. Commander Mark Davis shrugged.
“Hard to say, Sir. They must have come to a stop, whether it’s a tactical move or a mechanical problem,” he shrugged again and raised his palms, “who knows?” This was a problem. A bloody great mother of a problem.
“Bastard,” Luke cursed.
The Nahang was moving into the area where she could best be tracked and followed. He could do that but then the Siyah Bambak’s behind and potentially in his baffles. He shook his head in frustration, he could leave the channel go out and follow Nahang but risk having a Kilo chasing him. On the other hand, if he waited for the Siyah Bambak them the Nahang may get out into the Gulf of Aden where it’d be very hard to find. What to do? That little mischievous Imp called fate was always out there throwing you a wobbler. Like facing a spin bowler in Cricket, you never knew what to expect. Come on MacArthur, think. Luke bowed his head deep in thought. Finally, he reluctantly came to a decision.
“Blow two and four slowly. Come to twenty five meters.” The Ghost rose slowly from the channel seabed.
“Forward six knots.” Luke waited until they were clear of the channel.
“Come to two six zero, speed fifteen knots. Flood one and two, ten degrees down angle, make your depth one hundred.”
“Two six zero, one hundred down aye Sir.” The deck angled down, the crew leaned back to compensate. HMS Holy Ghost was on the hunt and sensing the kill.
“Depth one hundred Sir, zero bubble.” The boat levelled out.
“Stream the Lure fish.” The Lure trailed out behind the boat and listened with its sonar array. Signals flowed back to the boat’s sophisticated computer where Fourier transformation analysis categorised the machinery noises. The high frequency, focused beam, multi-element imaging-search sonar fed the computer. It employed fifth order spatial processing techniques for location data. What all this meant is that Holy Ghost had a serious amount of data about what was going on around her. But it wasn’t infallible.
“Ratty?” asked Luke.
“Faint returns from Nahang Sir, two twenty three degrees, depth one twenty, speed eighteen knots. No sign of Siyah Bambak.”
“Call out when we’re in his baffles.”
“Sir.” He knew it was a risk moving out to follow the Nahang, the second Kilo was out there somewhere. However, when it would emerge from the gloomy depths and follow its fellow submarine was a guess. It had probably developed a mechanical problem, after all they’d been together since they left the Barents Sea. He couldn’t risk losing the Nahang in the Gulf of Aden. You had to play the cards you’re dealt, and he’d been dealt the Nahang. Luke didn’t like it, not one bit, but it was a risk he had to take. After several minutes slipping silently through the depths, Ratty called out.
“In his baffles Sir, Tango one is vectored on one six five, range nine kilometres.”
“Planesman, come to one six five degrees, speed twenty knots.” In the control room the crew leaned to the right as the boat tilted and turned to port. Luke knew it would be best to close the range to reduce the torpedo running time. HMS Holy Ghost slowly closed in on her prey. Her approach, masked by the noise from her opponent’s propeller.
“Call her out Ratty.” The control room became ever more silent, and everyone tensed up. It was a cold heavy silence. Intent on their screens, furrowed brows, licking of lips, eyes stared intently. Luke could sense and smell the air of intense concentration.
“It’s OK people, just think of it as an exercise.” He looked around the room, his words didn’t seem to help much.
“Range six kilometres, Sir.” The minutes counted down.
“Conn Sonar, we have a coast.”
“All stop, disengage drive,” snapped Luke. Holy Ghost slid silently through the darkness. The minutes dragged on. Had they been detected? He knew the MGK-440EM sonar that the Kilo carried made it a formidable foe. In underwater warfare knowledge is power, you could carry all manner of deadly weapons. However, if you didn’t know where your enemy was, you may as well carry sacks of flour.
“They’ve re-engaged their drive, Sir,” said Ratty.
“Possible aspect change, Tango one seems to be turning to starboard.” He knew they could have sensed something and were changing aspect on the passive sonar to better localise its direction. It could also be a standard precaution.
“Hold your course Planesman.”
“He’s re-engaged the drive. Returning to one six five degrees.”
“Make your speed twenty knots.” The Ghost moved off towards her target.
“Conn Sonar, range three kilometres.”
“Speed eighteen knots
.” The Ghost was keeping off by three kilometres.
“Weps, flood tube one, set stealth mode on Spearfish tube one. Open outer doors.” Savita’s hand ran over her console.
“Outer doors open aye Sir. Tube one ready in all respects, the fish is hungry.”
“Weps, launch when ready and go deep for a belly shot.” Savita raised her eyebrows. The fish could be programed to strike from the left, right, top, bottom, forward or aft.
“Sir.” Her hands ran over the control board. There was a pause, then she announced the action phase.
“Warshot red, warshot red,” called out Savita, “launch tube one, the fish is running.” Her pulse was racing, she heard the rushing sound as the water flooded the now empty tube. It was the first time she’d launched a torpedo in action. The control wire trailed out behind the torpedo, Savita waited ten seconds then took hold of the Spearfish control stick, she angled it down diving the torpedo. She levelled the torpedo out at two hundred meters. Running at eighty knots it would take just over one minute thirty seconds to intercept the target.
“Fish running true, she’s greedy, fifty five seconds to run,” said Savita.
“Conn Sonar. Aspect change, Tango one diving and running to starboard, Sir. She’s on max revs.” He’d expected something like that, diving is a common evasion technique. He’d called for a belly shot, ie a strike from below as Nahang would be likely to narrow the distance herself. She’d impale herself on the Spearfish, her own angel of death.
“Conn Sonar, contact, contact astern. Submarine warning red. Submarine warning red. Tango two, range nine kilometres, bearing one four zero, depth ninety, max revs. She’s vectored straight for us.” Bastard, thought Luke. Why must it always happen? The shit hits the fan just when it couldn’t be worse. What a time for the second Kilo to reappear, just when we have a fish in the water.
“Active pulse from Tango two,” seconds passed by, “active pulse. Tango two.”
“Sir, I have a firing solution on Tango two,” said Savita.
“Weps, flood tube two, set stealth mode on Spearfish tube two. Open outer doors.”
“Outer doors open aye Sir. Tube two is ready in all respects, the fish is hungry.”