Subs Slip Through the Net

By Rear Admiral William J. Holland, U.S. Navy (Retired)
  • Continuous radio connectivity . Unless operating in surveillance or reconnaissance, submarines must spend some time away from communications depth and thereby will be unable to send (but still will receive) messages at any great distance.
  • Transmission of large amounts of data . Antenna size constrains data rate.
  • Sharing of magazine contents with others . Magazines are small and limited in variety of munitions.

Because radio-frequency energy penetrates water to a very shallow depth only at very low frequencies and because the amount of information communicated is a function of antenna size, submarines can never expect to be able to pass information at the same rates as surface ships. This inherent limitation was not evident when satellite exchange was limited to the FLEETSAT ultra-high frequency satellites; the submarine information exchange system (SSIXS) was able to accomplish everything that surface ships could do. But when, after Desert Storm, major surface ships began to exploit the Defense Satellite Communications System (DSCS) operating in the super-high frequency band, small surface ships and submarines became permanently disadvantaged.

These DSCS nodes need large antennas because the power output of the space-based transmitter is small and because the rate of information transfer is large. The designers of the space segments of these systems—rarely the same people responsible for the earth segment—always are under pressure to reduce the large capital cost of their units, and they invariably tend to marginalize the power of the space platform to save money. This in turn translates directly into the size of the antennas on the earth segments—present DSCS terminals have 8- to 25-foot-diameter dishes.

Submarines are not the only disadvantaged customers in this store. Small, mobile army units also face some of the submarines' difficulties, and Special Forces commands have antenna-size constraints that are in some ways even more restrictive. U.S. Central Command is working on low-cost, low-bandwidth alternatives to some Global Command and Control System functions. U.S. Pacific Command has developed a software program (Elvis) that transmits incrementally changing static pictures (snapshots) of continuously changing displays.

Even a casual observer will recognize that the submarine always will operate at a disadvantage compared with the transmission and reception capabilities of forces operating on the earth's surface. For the great majority of its operations, however, when the submarine operates truly independently in its classical missions, the command-and-control schemes and their supporting communications are perfectly adequate. Only when the submarine is part of the task force, involved in rapid collaborative planning, or engaged in activities that demand transmission of real-time information to high command, would the present command, control, and communications arrangements be deficient.

Knowledgeable people believe that at present, this might be a maximum of 15% or so of the submarine's operating time. As the force size decreases and fewer submarines are available for missions involving task force support, it is reasonable to expect that this percentage will decrease. But however small the number, it can never be considered marginal because surveillance information and warning delivery in real time may be crucial. In judging the technical characteristics needed in these situations, the character of the mission is significant. In this regard, experience is plentiful and such missions can be described as having the following traits:

  • Time away from periscope depth will be very limited so radio connectivity will approach 100% of the time on station.
  • The amount of information to be transmitted will be small and sporadic but important; spurts of large amounts of data, e.g., pictures or even live video, may be useful.
  • Most of the information needed by the submarine to conduct or plan this mission can be tailored to meet its needs outside of the sub itself. Access to large data bases may be useful, but transmission to the submarine will be selective. User pull technologies (like a web search engine) allow selection of information to be provided when needed, so that it can be passed efficiently.

The techniques developed in the Outlaw Shark projects, when the submarine force was creating processes to exploit over-the-horizon targeting of Tomahawk sea-attack cruise missiles (TSAMs), have direct application. In that design, off-board sensors would detect and locate targets. This information was aggregated on Shore Targeting Terminals at the Submarine Operating Authorities and made available to be transmitted automatically when a submarine established communications with the Operating Authority. Characterized as a "surrogate control room," centrally based command personnel can exploit information technology to sort, filter, store, and retrieve information from the network. Passing the vital, repackaging the important, and shelving the mundane all can be done by teams at the appropriate command center with a resultant improvement in effective use of information by the ship.

Similar surrogate schemes have been demonstrated in other circumstances. Commander Seventh Fleet, then-Vice Admiral Archie Clemins, conducted a major exercise in the central Pacific from his command ship, the Blue Ridge , with only a single meteorologist on board. Normally there are more than 20 weather people on board the command ship for such a major operation. But they were left ashore in Guam, at their regular stations, where they possessed all their normal sources of meteorological information. Their one representative on the command ship was adequate to present the information assembled and analyzed ashore.

In another example, the Joint Force Air Command Center for a major operation in Southwest Asia was located at Barksdale Air Force Base, Louisiana, instead of working out of tents in the desert. At their home station, these several hundred people planned and developed an air campaign that was implemented by fewer than 40 folks in a command cell forward.

Both of these evolutions had the advantage of vast communications capacity between the forward and home base centers, but the experiences demonstrated that while large messages were transmitted to the forward command stations, the messages sent back to the home bases were small.

The lessons of these demonstrations have direct application to submarine employment. They show that the utility of force employment need not be constrained by intermittent connections or limited capacity. In fact, these designs are even more important where vast radio capacity is not available.

In addition to communication difficulties, command and control in the network-centric design has several other aspects that make life difficult for submarines—primarily because of the task force commanders' inexperience with and lack of knowledge of submarines. Position is a prime example. With the advent of the global positioning system, the task force commander knows exactly where everyone is—everyone, that is, except the submarine.

Submarines customarily operate in large areas and at radio silence—so even if one is at communication depth, it is not reporting its position regularly, as are other units. This large patrol area and lack of regular communication creates an ambiguity with which task force commanders rarely are comfortable. This uneasiness can be assuaged somewhat by knowledgeable and articulate submarine officers on their staffs, but even the most daring commanders acknowledge that they like to hear from submarines now and then, just to reassure themselves that the submarines are there.

The capabilities of submarines in reconnaissance are not well understood, this aspect of their operations having been tightly compartmented for many years. Commanders without firsthand knowledge and today that is every carrier and cruiser destroyer group commander, not to mention joint task force commanders from other services—do not understand what submarines can and ought to do, what is reasonable to expect, and how long reaction times might be.

Knowing what the enemy is and where he is located are the most valuable pieces of all, but the decision on whether the submarine should shoot or report always will be difficult and must be carefully thought out. Commanders would prefer to delay this decision or to overlay it with conditions in order to have it respond to the moment. To preauthorize firing requires more preplanning than the force or theater commander is willing or able to invest.

To further complicate the command-and-control problem, most of the techniques and processes involved with submarine operations as part of a task force are done so seldom that little experience exists within the command hierarchy. Thus, it is of great importance to have a structured process, to automate where useful or repetitious, to provide guidelines and explicit instructions for those on the fringes who will have the least experience, and to develop a cadre of experts in the center of the command-and-control function who practice together regularly. It will become critical as the occasions to practice grow more infrequent and the real-world issues become more serious.

If submarines are to be useful in the information age, command and control, together with its supporting communications, must be treated as a system in which processes, not equipment, are the most important component. Operators should not specify technical solutions and technicians ought not suggest requirements based on inventions. To do this requires the devotion of adequate intellectual resources; leadership and management are not enough.

C41 is complex and difficult. To grasp its many facets requires education, experience, and most of all, persistence-officers and senior civilians who have repeated tours in C4I related areas. Missions not threats must drive requirements and enough intellectual capital must exist so that processes reflect reality and technical opportunities can be seized with enthusiasm and vigor.

Rear Admiral Holland served most of his active duty in submarines. He is president of the Armed Forces Communications & Electronics Association Educational Foundation. 



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