Praenuntius Futuri Parts I and II

Jim Ferrero was the Engineer on Albacore at the time of writing this piece. This article was published in a submarine "Combat Readiness" publication and in a SubLant Information Bulletin in the 1956-57 time frame.

When I was editing this article for inclusion on the website, Jim wrote the following:

When I wrote that paper, it was based upon the "War" potentials at that time (the mid 50s). Our submarine force was just beginning to increase in numbers of attack subs and ballistic missile subs (the boomer force). The Navy was building towards 100 attack subs and 40+ boomers. The USSR, like the Germans, made the submarine their capital ship and built a force structure of over 500 subs of various configurations. My ideas were also tempered [by] how the sub was used in WWII. I envisioned sub-to-sub conflicts with many targets for our boats plus the USSR ASW force. Since that time, much has changed and technology advances (the digital world) made my concept good. Also the EDO world, led by Rickover, negated the "fighter sub" idea. Based upon today’s advances in aircraft integrated weapon systems, such as in the F-14 and F-15, I suggest we not add this paper to the Albacore readings. I don't think our audiences would find it interesting. Of the ideas contained in this paper, I can only think of one which materialized--the conformal sonar array.

By the way, many of the weapons used in my paper some were under evaluation by SUBLANT'S SUBDEVGRP 2, located at that time in New London. The data I got on the D-40 eval came from my skipper, Jon Boyes, who was involved in it on his previous sub. The missile came from an Army program, mounted in small tubes attached to the sail, and could be launched submerged (much like today's VLS used for Harpoon). It was to be used by the sub against enemy ASW forces. A like eval used Sidewinder missiles. The rest of the weapons you questioned were sub-to-sub and sub-to-air missiles in various stages of development, now in the fleet. I do not know the status of the integrated weapons control systems concept on today subs. Having been personally involved in today's airborne multi shot systems from a single weapon platform, I tend to believe that the sub force is years behind in multi shot system development. They are years behind in man-machine relationships - but then maybe it isn't important since the target rich environment afforded by the USSR is no longer available.

I disagree with Jim about not adding this paper to the website. I think it provides a well thought out concept on how to use the tactical advantage provided by a nuclear Albacore.

(Note: Words in italics are the editor's.)

Part I:

The art of flying a submarine has at last become a reality. As one steps aboard the Albacore, he becomes aware of a whole new concept in submarining. Terms here-to-fore foreign to submariners resulted from many months of experimentation by Albacore and her crew. These terms were developed to adequately and precisely describe what happened to the ship, her control surfaces and to her relative position in the sea's depths.

It was indeed a problem to explain a maneuver in which a submarine descends from a depth of 100 feet to 600 feet and in doing so performs a "Diving-S-Turn" or "Figure 8" evasive or counter-attack maneuver! "Aerobatic Flying" is our answer. Such similar terms as "level flight," "roll her over," "less bank" and so forth have been accepted by us and are used freely to describe the desired behavior of the submarine.

The Albacore today is to the conventional submarine as the jet fighter was to the propeller-driven aircraft. Hydrodynamically, the new terms of submarining are basically sound and accurate. Whereas the older surface vessel was able to submerge and thereafter acted more or less as a free balloon that was capable of being moderately directed and driven through the water and was satisfactorily controlled with "plane angles," "bubbles," "blow negative to the mark" and so forth, the Albacore necessitates changed thinking and reaction.

This vessel was basically designed as a true submersible. She was meant to spend months underwater. Because of the limitation imposed by a conventionally designed power system, this is not possible. Albacore is truly "flown" through the water as either a heavier-than-aircraft or a lighter-than-air-craft. Hydrodynamically less dependent on neutral buoyancy than one imagines, she is as much in her element, water, as a blimp is in its element, air.

The analogy between blimps and Albacore is very similar. The blimp is restricted to a certain altitude as the Albacore is restricted to a collapse depth. The speeds of both units are closely akin, the blimp slightly higher. Both share the problem of ballast, trim, buoyancy, and bank. As a matter of fact, as one looks at the Albacore, he can easily visualize a blimp upside down!

The designer of the Type 21 German submarine is reputed to have said: "The future of sea warfare belongs to that which can maneuver in three dimensions - the airplane and the submarine." At long last, we feel that our navy has developed and built the submarine that will fulfill the undersea portion of this saying.

Perhaps as we continue to investigate the problems of high speed submarining, we will turn more and more to the aeronautical field for the results and techniques which they obtained years ago in the wind tunnel and in the air.

One of the many problems to be faced with such a vehicle is the development of a different concept in control necessities and terms. Appreciation of the safe and reliable maneuvering of this "male whale" at speeds of more than 25 knots requires greater controllability than was necessary for the 9 knot "fleet boat" of yesteryear. We can no longer speak in terms of bubbles, depths, plane angles, and rate control systems. We must speak in terms of predictions, errors, and position-control systems in order to use to the fullest the capabilities of the Albacore-type hull.

The following abbreviated glossary of terms is listed in order to promote an understanding and discussion of the instrumentation deemed essential in this vessel.

DEI - Depth Error Indicator
DGI - Digital Gyro Indicator
RDI - Rate of Dive Indicator
AS - Automatic Steering
AH - Artificial Horizon
ADC - Automatic Depth Control
BPI - Bow Plane Indicator
SPI - Stern Plane Indicator

The DEI is a linear gauge that represents, by sliding pointer, the difference between actual depth and the desired depth. It is a differential type instrument, the desired depth being an input manually set by the pilot. It is graduated from 50 feet above depth, through 0 error, to 50 feet below the depth.

The RDI presents the absolute rate of rise or of dive in feet per second. It is dependent, or is the result of the speed of the vessel through the water and the pitch angle of the ship. A range pf 30 ft/sec in either direction will suffice.

The AH is the same type of instrument used by airmen to maintain level flight. From it, the pilot may read the submarine attitude of up or down angle and bank.

The DGI is used for steering and presents the course when read vertically from top down on three display wheels.

The BPI and SPI display the number of degrees the planes have displaced from their neutral or "0" position.

The AS and ADC are equipment systems used as "Iron Mikes" or "auto pilots" to maintain the ship in level flight over extended periods of time while in transit or on patrol station.

These "sensing" instruments show the pilot what he wants to do. Let us momentarily look at what he has in the way of hull appendages and controls thereof. The Albacore has the usual bow planes, stern planes, rudder planes, a single propeller, and a separate dorsal rudder at the trailing edge of the sail fairwater. Her controls consist of "position" type sticks, wherein the pilot turns his helm wheel a given arc or amount and the rudder follows up until it reaches this ordered signal and then moves no further. Similarly, by pushing or pulling a given displacement on the bow and/or stern plane sticks, the planes follow until they have reached the ordered position and remain there until a new position is ordered.

Before proceeding into the use of the operational controls of a high speed submersible, the necessary accurate, compact, and minimum number of indicators must be arranged so that the pilot has easily available, within a small field of vision, only those instruments he needs.

The following sketch of such a panel is proposed as a simplification and rearrangement of instruments presently installed. Such a panel is being built by a commercial company and will be soon evaluated on board this vessel.

Now that the basic terms and a desirable control panel have been discussed, we will go into their use. The two basic stations will be located in the Control Room. Each station will be identical as to instruments and controls and will be capable of controlling all appendages or of selected parts of them. The Diving Officer will be the pilot in one seat and a well-trained enlisted man will be in the co-pilot seat. This idea has been investigated by Albacore and the results have been very encouraging. The Diving Officer, after sounding the diving alarm, takes over the pilot’s chair, which may be called the Stern Plane Station for these are the controlling diving appendages. The handling of routine reports, opening the vents and items involving destroying positive buoyancy, are handled very efficiently by the Chief of the Watch, who might well be called the Flight Engineer, with a complete absence of spoken words if conditions are normal. The Diving Officer orders the remainder of the diving evolutions by setting rate of dive desired and by setting the desired depth. The co-pilot, using single stick control, rolls the ship over until he obtains the desired rate of dive.

The Flight Engineer shuts and cycles the vents, blows Negative and turns "on" or "off" the hydraulic plants as the ship passes stated depths.

Notice that the actual position of the planes, the speed of the boat, or angle of the boat does not matter to the co-pilot. He is solely interested in the effect of his planes to obtain the rate of dive. This again is similar to the method used by airmen to control a blimp.

A new "stick" is being investigated that will give the pilot a greater sense of feel for his planes. In this manner, he will be able to tell by the amount of force necessary to displace the stick, increasing as the distance from neutral is increased, the approximate position of his appendages without having to look down at the relative movement out of the zero position or at plane angle indicators. From experience, the co-pilot will soon learn about how much planing is required, at a given speed, to initially obtain the an angle such that the ordered rate of dive may be reached quickly and the planes then eased to hold the rate of dive. The RDI is the only instrument the co-pilot has looked at thus far. He now shifts his gaze to the DEI which is pegged at 50 feet above ordered depth. When the pointer begins to move, the co-pilot pulls back on his stick to level the ship and to settle down at the ordered depth. Both RDI and DEI will now read "0." Any displacement denotes the need for corrective action.

While the co-pilot holds the depth, the pilot notes on the AH the attitude of the ship and orders the changes in trim and speed such that the ship may settle down to an ordered speed with minimum use of the planes.

At such a point, the ADC would be turned on. Similarly, the course would be set and the AS started. Such would be the normal procedure.

Note that, with high speed submarines, an angle over twenty degrees need never be used in attacking, evading or in large depth changes for the increased speeds at the smaller angles easily accomplish the large rates of rise or dive. As a matter of fact, the Albacore changes depth very rapidly even with zero angles on the boat and full bow plane action. This tactical feature may have value in the fire control and weapons launching program.

The major reason for two stations is that the Diving Officer can instantly take over the control of the vessel by turning one selector switch and can save a considerable number of seconds that would be wasted had he needed to order his ideas to the human amplifier, who would then react to do what he thought the Diving Officer wanted done, in coping with a casualty, attack or evasion. Normally, the co-pilot would fly the ship; the pilot would rest in his seat constantly observing what was going on. The Flight Engineer would observe those gauges, lights, indicators, and manifolds that tell the story of the performance of the ship, but which the pilots need not have in their normal field of vision to successfully fly the submarine in its controlled movement through the depths.

Without actually riding the Albacore and experiencing the great strides that have been made in submarine design, controllability, and reaction time, some of the ideas expressed may seem radical and difficult to believe. Perhaps by listing some of the tactical characteristics and performance data, the reader may more readily accept the necessity for new words and controls. Appreciate, if you will, that all of the facts stated herein have been checked and proven by exhaustive controlled tests and were used recently by the vessel in ASW operations at Key West, Florida against the best equipped and manned ASW surface ships.

Albacore can turn at a rate of 5 degrees per second (a jet plane has a standard rate turn of 3 degrees per second). In diving, a rate of descent of 25 feet per second is possible. Acceleration from 2 knots to 27 knots is accomplished in 2 minutes 40 seconds (a destroyer takes almost 7 minutes to do this). The Albacore may be slowed from maximum speed to 7 knots in a matter of about half a minute. The Albacore can turn in a tactical diameter of 165 yards (DD's require some 1,100 yards at the same speed). The Albacore's eleven foot, slow speed propeller is located in the uniform flow wake and therefore can be run at a speed 50% greater than a conventional guppy before cavitating.

It is readily seen, we believe, that there is little comparison between Albacore and the best of the conventional submarines. The one obviously limiting factor in the Albacore's performance is the endurance of a battery-propelled submarine. However, this will not long remain a problem, for with the marriage of the Albacore hull and the nuclear power plant, the endurance problem will be resolved and continuous speeds in the range of 35-45 knots will result.

The purpose of this article has been to acquaint as many submariners as possible with the latest trends in our chosen profession and to aid all to better anticipate the changes and philosophies that will be forthcoming in our submarine force. Whole new concepts of words, tactics, communications and weapons are necessary to utilize the vehicle that is at hand. We on the Albacore are proud of our motto "PRAENUNTIUS FUTURI" which means literally "portent of the future" or "forerunner."

Part II:

During the past few years, great strides have been taken in submarine hull design and power plants. The Nautilus has convincingly proved the use of nuclear power to be feasible, practicable, and acceptable. During this same period, Albacore has proved the need for an idea hull form and adequate control systems. When these ideas are brought together in the form of the Skipjack (SSN 585), this new submarine will have the possibilities of being the most formidable weapon of modern warfare. Based on the performance of Albacore, she will have the following tactical capabilities:

a. Turning diameter -- 165 yards

b. Turning rate -- 50/sec

c. Rate of depth change -- 25 ft/sec

d. Acceleration (2 - 26 knots) -- 2 min 40 sec

e. Hydrodynamically stable at all speeds

f. More speed for less shaft horsepower (7,360 shp = 26 knots)

g. Speeds in excess of 35 knots predicted for 15,000 shp.

In order to adequately use this vehicle at hand, it is necessary that we investigate a fire control system that is entirely new. It is the purpose of this paper to discuss our present submarine fire control systems in respect to the "NEW" submarine and then to present a system which could use the potentialities of our new weapon to the greatest advantage.

The fire control systems presently being employed by our operational submarines are modifications to basic systems used during World War II. This system was built around a commanding officer getting information from his periscope, radar, or sonar. This information was then put into a torpedo data computer and a lead angle for the torpedo would result. The fire control party involved some 15 to 18 men. Ship control was maintained by two enlisted men and an overseer, the diving officer. This system worked well for the type of war which the U.S. fought. It was based on a slow moving surface craft which was designed to submerge and which could gain a favorable firing position. Our enemy did not have a good sonar or good radar. With this system, only one target at a time could be taken under fire.

With the advent of the nuclear Albacore, this type of fire control system would not utilize the capabilities of [the] weapons being made available. There would be too much dead time between the C.O.'s decision and [the] results desired. This new vessel is just too fast and too maneuverable to be hindered by inefficient human amplifiers. Our potential foe has sonar and radar which we believe to be equal to ours. Take, for example, the AN/SQS-4 Sonar; it has active ranges out to 10,000 yards. Radar can detect a snorkel or periscope at long ranges. Just think of trying to get through our present screens using the tactics of World War II. We are going to have to shoot our way through the screen in order to get at the main body. We surely cannot do this with our present systems! Or consider being engaged by an enemy sub in a dogfight beneath the seas. [That] sub could easily have the same capabilities of our nuclear Albacore. Due to these factors and current weapon developments, the old fire control system would not fill the bill.

It is therefore necessary that some new concepts be accepted in the submarine service. Consider the analogy between aerial dogfights and SS vs SS in a dogfight. It is going to be necessary that the Commanding Officer or the Executive Officer become the submarine pilot. We cannot accept the dead time [that] is inherent in our old system. We must have almost the same conceptual FCS as that of an all-weather fighter pilot. All equipment must be at the pilot station in order to conduct an efficient attack.

Many new weapons are presently being designed and evaluated for submarine use. The D-40 missile, SLIM, SAM, and hydroduct will be used by our new submarines. These missiles do not lend themselves to the type of FCS which we HAD. The D-40 missile, for example, will permit a submarine to launch a missile submerged. This missile will then become airborne and can be directed at nearby helicopters or surface craft. (Editor's note: The anti-helicopter missile is still a submariner's dream). The hydroduct is being designed to run about 20,000 yards at 100 knots. (Editor's note: The Mk 48 ADCAP - ADvanced CAPability torpedo approximates these capabilities). This weapon could be used very effectively in submarine dogfights with other subs or surface craft. Plans are presently being made for a missile (SSM - Surface to Surface Missile) which can be launched submerged, become airborne and travel some 60 to 80 miles to hit a distant task force. (Editor's note: Submarine launched HARPOON and TASM - TOMAHAWK Anti-Ship Missile -missiles did become deployed on SSNs).

Presently, the primary mission of our submarine force is anti-submarine warfare. For that reason, it is necessary that our FCS be made to accomplish this mission.

It is proposed that an experimental fire control system as described herein be considered for installation on the Albacore during Phase III of her test period. This paper is not designed to go into all of the "nuts and bolts" of this system, but rather to establish the parameters for it. In the interest of consolidating this new idea with present shipboard control installations, this system will fit in with the present experimental diving panel, automatic pilot, and automatic helm, all produced by Sperry Gyro Co.

The fire control problem for the Navy's all-weather fighter aircraft is identical to that of a submarine except for the media in which each operates. The systems installed in these aircraft have several desirable features and therefore will be used as the basis for the submarine system. This particular system is compact and will save much space on a pursuit submarine.

Basically, this new system must accomplish two things: (1) Locate submerged or surfaced targets and provide information enabling the S/M pilot or autopilot to maneuver into a firing position; (2) Direct a lead-pursuit or lead-collision attack with the weapons previously discussed. In the past, due to the slow submerged speeds, it was necessary to attack our targets from ahead. This resulted in a lead-collision type of attack. With the higher speed and more maneuverable submarine, an attack from any sector may be made. That is the reason for the use of a lead-pursuit attack.

The system will have the following modes of operation: (a) Autopilot controlling, (b) Pilot controlling, (c) Pilot control to override autopilot signal. As in the all-weather fighter aircraft, it is necessary that we have automatic control systems. These systems must be directed by certain target inputs to a computer and the end results monitored by the S/M pilot.

The heart of this FCS will be good sonar equipment. It is necessary that it have the following characteristics:

(a) Passive range of 50 miles

(b) Active range of 10 miles

+/- 1° at 10-50 miles
+/- 1/4° at 0-10 miles

(d) Be faired in with ALBACORE hull design

The sonar gear desired will probably be large and bulky. However, there is no reason why it cannot be built into the basic hull configuration of an idea submarine form.

Reference was made previously to a computer. An analog computer, such as the one used in the Navy fighter plane, must be developed for use with this system. The computer will be capable of accepting initial manual inputs of target's angle-on-the-bow and estimated target speed during the passive sonar phase. During this phase, it must solve for a course that will close the target's track. The solution will be presented on a sonar PPI scope at the S/M pilot's station as a virtual target. When active sonar is used, an exact target's course and speed, based on steady or intermittent range information, will result. Once again, the solution will be presented on the S/M pilot's attack scope.

The sonar PPI scope at the pilot's station will present the following information:

(a) Direction to steer.

(b) Target's bearing.

(d) Range to target (when active)

(e) Three range selections (50 mi, 10 mi, 2 mi)

(f) An artificial horizon in order to show whether the target is above or below the S/M.

In order to aid the pilot during his attack, certain auxiliary devices will be needed. A visual or audible system should be used to tell him: (1) When within the selected weapon firing range, (2) Weapons are ready to fire, (3) Test depth is being exceeded, and (4) A break-away point indication so as to avoid a collision with the target.

The diagram that follows proposes the arrangement for this new system. It is shown as being integrated with presently installed equipment. In this manner, many of the sub components of each system may be eliminated and much space may be saved.

Now that all the components of this new FCS have been set forth, it is necessary to describe how it might be used. We therefore must assume that our Commanding Officer or Executive Officer will be the pilot. He will be in charge of running the entire approach and attack from one position, called the S/M attack station. Only one man makes the attack.

When a target is detected by passive sonar, it will be tracked for a short period of time by a sound operator. Based on observed information, the S/M pilot will crank in an assumed angle-on-the-bow and speed. This information will go to the computer. It will solve a maneuvering board problem and send the solution, a course to steer, back to the attack scope. The course may either be steered by the autopilot or the pilot. Periodic single ping ranges will be attempted by the pilot. When active contact is made, the pilot will go to active sonar. With steady or intermittent range information, the computer will present a real target, or targets, to the pilot. Target pip will be maintained in the center of the scope in order to close the target. The scope will also present to the pilot information previously discussed. These inputs will also go to the weapon's computer which will be continuously putting information into our weapons. When within firing range, a buzzer will let the pilot know that he can fire at any time.

The question may arise as to what would be done "if" a helicopter had contact on such a submarine trying to attack a carrier task force. The C.O. could launch a D-40 missile against such a vehicle! Another question might arise as to multiple targets. It is exceedingly easy with this system to take a new target under fire. It is only necessary for the S/M pilot to lock onto another target and fire his weapons.

In retrospect, it can be seen that our present submarine fire control systems are inadequate for our new submarines. By modifying such equipment, the desired results cannot be obtained. It is necessary that a complete, new system be designed based on ideas contained herein. The new submarine is useless unless we have efficient means of employing its potentialities.

The ideas presented here may sound as if we are in the "Buck Rogers" era -- well, we are.