subordinates whom he could respect. The CIA had too many people whose only skill was kissing ass.
The loss of his left leg above the knee had not taken away Oliver Wendell Tyler’s roguish good looks or his zest for life. His wife could testify to this. Since leaving the active service four years before, they had added three children to the two they already had and were working on a sixth. Ryan found him sitting at a desk in an empty classroom in Rickover Hall, the U.S. Naval Academy’s science and engineering building. He was grading papers.
“How’s it goin’, Skip?” Ryan leaned against the door frame. His CIA driver was in the hall.
“Hey, Jack! I thought you were in England.” Tyler jumped to his foot — his own phrase — and hobbled over to grab Ryan’s hand. His prosthetic leg ended in a square, rubber-coated band instead of a pseudo-foot. It flexed at the knee, but not by much. Tyler had been a second-squad All American offensive tackle sixteen years before, and the rest of his body was as hard as the aluminum and fiberglass in his left leg. His handshake could make a gorilla wince. “So, what are you doing here?”
“I had to fly over to get some work done and do a little shopping. How’s Jean and your…five?”
“Five and two-thirds.”
“Again? Jean ought to have you fixed.”
“That’s what she said, but I’ve had enough things disconnected.” Tyler laughed. “I guess I’m making up for all those monastic years as a nuc. Come on over and grab a chair.”
Ryan sat on the corner of the desk and opened his briefcase. He handed Tyler a folder.
“Got some pictures I want you to look at.”
“Okay.” Tyler flipped it open. “Whose — a Russian! Big bastard. That’s the basic
“Two or three meters’ worth.”
“I heard you were working with the CIA. Can’t talk about that, right?”
“Something like that. And you never saw these pictures, Skip. Understood?”
“Right.” Tyler’s eyes twinkled. “What do you want me not to look at them for?”
Ryan pulled the blowups from the back of the folder. “These doors, bow and stern.”
“Uh-huh.” Tyler set them down side by side. “Pretty big. They’re two meters or so, paired fore and aft. They look symmetrical through the long axis. Not cruise missile tubes, eh?”
“On a boomer? You put something like that on a strategic missile sub?”
“The Russkies are a funny bunch, Jack, and they design things their own way. This is the same bunch that built the
“How ’bout if they trail one screw?”
“They do that with surface ships to conserve fuel, and sometimes with their attack boats. Operating a twin- screw missile boat on one wheel would probably be tricky on this baby. The
“No, I didn’t.”
Tyler looked up. “Damn! I should have realized it right off the bat. It’s a propulsion system. You shouldn’t have caught me marking papers, Jack. It turns your brain to Jell-O.”
“Propulsion system?”
“We looked at this — oh, must have been twenty some years ago — when I was going to school here. We didn’t do anything with it, though. It’s too inefficient.”
“Okay, tell me about it.”
“They called it a tunnel drive. You know how out West they have lots of hydroelectric power plants? Mostly dams. The water spills onto wheels that turn generators. Now there’s a few new ones that kind of turn that around. They tap into underground rivers, and the water turns impellers, and they turn the generators instead of a modified mill wheel. An impeller is like a propeller, except the water drives it instead of the other way around. There’s some minor technical differences, too, but nothing major. Okay so far?
“With this design, you turn that around. You suck water in the bow and your impellers eject it out the stern, and that moves the ship.” Tyler paused, frowning. “As I recall you have to have more than one per tunnel. They looked at this back in the early sixties and got to the model stage before dropping it. One of the things they discovered is that one impeller doesn’t work as well as several. Some sort of back pressure thing. It was a new principle, something unexpected that cropped up. They ended up using four, I think, and it was supposed to look something like the compressor sets in a jet engine.”
“Why did we drop it?” Ryan was taking rapid notes.
“Mostly efficiency. You can only get so much water down the pipes no matter how powerful your motors are. And the drive system took up a lot of room. They partially beat that with a new kind of electric induction motor, I think, but even then you’d end up with a lot of extraneous machinery inside the hull. Subs don’t have that much room to spare, even this monster. The top speed limit was supposed to be about ten knots, and that just wasn’t good enough, even though it did virtually eliminate cavitation sounds.”
“Cavitation?”
“When you have a propeller turning in the water at high speed, you develop an area of low pressure behind the trailing edge of the blade. This can cause water to vaporize. That creates a bunch of little bubbles. They can’t last long under the water pressure, and when they collapse the water rushes forward to pound against the blades. That does three things. First, it makes noise, and us sub drivers hate noise. Second, it can cause vibration, something else we don’t like. The old passenger liners, for example, used to flutter several inches at the stern, all from cavitation and slippage. It takes a hell of a lot of force to vibrate a 50,000-ton ship; that kind of force breaks things. Third, it tears up the screws. The big wheels only used to last a few years. That’s why back in the old days the blades were bolted onto the hub instead of being cast in one piece. The vibration is mainly a surface ship problem, and the screw degradation was eventually conquered by improved metallurgical technology.
“Now, this tunnel drive system avoids the cavitation problem. You still have cavitation, but the noise from it is mainly lost in the tunnels. That makes good sense. The problem is that you can’t generate much speed without making the tunnels too wide to be practical. While one team was working on this, another was working on improved screw designs. Your typical sub screw today is pretty large, so it can turn more slowly for a given speed. The slower the turning speed, the less cavitation you get. The problem is also mitigated by depth. A few hundred feet down, the higher water pressure retards bubble formation.”
“Then why don’t the Soviets copy our screw designs?”
“Several reasons, probably. You design a screw for a specific hull and engine combination, so copying ours wouldn’t automatically work for them. A lot of this work is still empirical, too. There’s a lot of trial and error in this. It’s a lot harder, say, than designing an airfoil, because the blade cross-section changes radically from one point to another. I suppose another reason is that their metallurgical technology isn’t as good as ours — same reason that their jet and rocket engines are less efficient. These new designs place great value on high-strength alloys. It’s a narrow specialty, and I only know the generalities.”
“Okay, you say that this is a silent propulsion system, and it has a top speed limit of ten knots?” Ryan wanted to be clear on this.
“Ballpark figure. I’d have to do some computer modeling to tighten that up. We probably still have the data laying around at the Taylor Laboratory.” Tyler referred to the Sea Systems Command design facility on the north side of the Severn River. “Probably still classified, and I’d have to take it with a big grain of salt.”
“How come?”
“All this work was done twenty years ago. They only got up to fifteen-foot models — pretty small for this sort of thing. Remember that they had already stumbled across one new principle, that back-pressure thing. There might have been more out there. I expect they tried some computer models, but even if they did, mathematical modeling techniques back then were dirt-simple. To duplicate this today I’d have to have the old data and programs from Taylor, check it all over, then draft a new program based on this configuration.” He tapped the photographs. “Once that was done, I’d need access to a big league mainframe computer to run it.”
