Contact Us   |    Join   |    Donate


With only minor editing and exchange of a few buzz words, the article SUBACS – The Submarine
Advanced Combat System, in the July Submarine Review, would have served perfectly as a sales
pitch for the FCS-MK 117/AN/BQQ-5 submarine combat suite of the 1970s.

To the developers of Submarine Combat Systems of the late ’60s, having run the gauntlet of
headaches (and career aches) of integrating the MK48 Torpedo and its 19 plus presets into at least
five garden-variety analog fire control systems (all strangers to the new fangled term
“configuration management”), it was apparent that drastic measures were required. What could be
better than a clean start? What could be more effective than a “general purpose” digital
computer to do all the processing and display necessary to keep the operator abreast of what was
going on? The complex hardware mods to analog integrators and resolvers would then be achieved
by a very simple matter of programmming; SMOP became a major, new buzz word.

Tracking through the SUBACS article, lets see what arguments the author used which we used for
the 117/BQQ-5.

Central processing could make a total system out of any conglomeration of subsystems. All we
had to do was hook the subsystem to the central processor and – SMOP, it was integrated. This
was even better than designing a total system. It permitted the addition of new systems and
deletion of old ones as they became obsolete.

New weapons, sensors, improved threat and new missions lent themselves beautifully to SMOP-ing.
Required additional computer capacity could be accommodated through doubling the density of existing memory modules and adding more.

As the amount of information increased and threatened to overload operators, this was resolved through the use of a continuous mode which did everything needed to the data as it showed up and an operator selected mode enabled him to deal with the problems one by one in his own set priority. Another mireacle of SMOP. And so it went; 117/BQQ-5 occupies a fraction of the footprint of its predecessors. Removing the complexities of analog systems would make reliability soar. Removing displays, computers and a remarkable new buzz word “graceful degradation” would overkill combat system availabiity requirements. And there was absolutely no later technology available. Life
cycle costs would obviously be lower as SMOP not only alerted the operator/maintainor to a problem
automatically, but also showed him what to do about it. A widespread conviction grew that
training facilities would not be required and that adequate training could be achieved on the
job — but cooler heads prevailed. Commonality, modularity of software, simplicity of power
supply, standardization and orders of magnitude in cabling reduction hung over 117/BQQ-5 like
halos over a newly canonized saint. And it was standardized — even to using the surface fleet’s
AN/UYK-7. There it was, a wholesale replacement for older submarine combat systems with features
that would overcome all predecessor problems and an open-ended accommodation for new requirements. But what went wrong?

Scarcely twelve years later the 117 /BQQ-5 requires a wholesale replacement by SUBACS with
features that will overcome all predecessor problems and an open-ended accommodation for new
requirements. Was SHOP the villain? Or perhaps it was something else. The more naive among us
believed that the 117/BQQ-5 would provide a new tool that would exploit the full operational
capabilities inherent in SSN637s, and 688s against any mission in real time.

Realizing the submarine community’s hesitation to do business with a new and untried system, an
iterative appraoch was selected. The first of three phases called for a digital system, side by
side with the old analog hardware under the nomenclature of FCS MK113-10. The second phase
would integrate the interface with AN/BQQ-5 at a central computer complex. The third would see
elimination of the analog position keeper with an additional digital driven display substituted.
This insured an all digital attack center.

It appeared, at least in the author’s view, that emergent SSN higher speeds, greater depths, multi-weapons and high rates of vast volumes of data would drive submarines toward automation. This has not been the case. Manual processing of combat data, with all its time late and proneness for operator error, continues to be the mainstay. The analog line of sight display on the face of the MK75 console (Position-Keeper) was to be the attack center’s focal point, but it became overly complicated by a strobe, tangent to a time-bearing curve, in order to get “bearing rate”–a similar job being performed by one of the troopers with a grease pencil and fifty dollars worth of clear plastic. The 117/BQQ-5 was not permitted to absorb the combat data processing load so it had target motion analyses techniques added to it which for the most part paralleled the number of
manual plots already in existence. Upon learning that the MK75 Position Keeper display would be
replaced by a digital driven display, a cry went up for software that would restore the old timer
in video. At the initial 117/BBQ-5 installation review, in the SSN 700 class mockup at Newport
News, but for knock-down, drag-out arguments by members of the Navy Material Command, TRIDENT’s attack center would have very much resembled the one in GEORGE WASHINGTON.

Impetus for 117 /BQQ-5 did not originate with the operators. This was reflected in the lack of
confidence shown in the equipment when it was deployed. The operators had scarcely the time to
remain proficient in existant SSN combat techniques much less to adjust to the “digital revolution.”

So what then of SUBACS? Is the operational community aware of its benefits? Is there a clear understanding of how things will be done more efficiently with this new investment; longer
detections, better ranges, bearings, courses and speeds, quicker solutions along with
absorption of a bulk of the tactical load plus incorporation of clear imagination into how this
equipment can best exploit SSN capabilities in their missions? Without these things, the khakiclad
wearers of the bearing-rate amulet must be expected to continue their principal preoccupation with the exchange of memos in the attack center and by the mid 90’s SUBACS will face “wholesale replacement by yet another system with features to overcome predecessor problems and open ended accommodation for new requirements.”

Capt. D.M. Ulmer, USN (Ret)

Naval Submarine League

© 2022 Naval Submarine League