UUVs, Fire Scouts and buoys and why the Navy needs lots of them.Jan Musil, Center for International Maritime Security
29 July 2015
This article, the second of the series, lays out a suggested doctrine of use for the UUVs and Fire Scouts that have already been developed. It is an incremental strategy, primarily calling for using what the Navy already has in hand, adding use of buoys in quantity combined with appropriate doctrinal changes and vigorously applying the result to the ASW mission.
In getting this program underway the U.S. Navy can utilize existing sensors, whether for prosecuting ASW, developing sonar projections of the water below, including occasional deep diving missions and whatever else we find a need for the UUV to do. In practice though, generating useful results is far easier to accomplish if the UUV is routinely, though not exclusively, used with a tether so the data generated can easily be transmitted back aboard for analysis and use.
Utilizing tethered UUVs with a suite of frequencies to listen and broadcast on opens up some interesting opportunities for the ASW mission. By significantly expanding outward the range of ocean area being searched the U.S. Navy can realistically anticipate creating the possibility of being able to establish a rough range number to a detected target. Spread the sonar emitters out far enough and the use of parallax kicks in and if there is just a little difference in vector to the target from two widely separated hunters they now have a working range number. This range estimate will almost certainly be nothing close to accurate enough to fire on, but it will certainly indicate a distinct patch of ocean to direct any orbiting P-8s or other airframes toward. Finding a needle in haystacks is a lot easier if you have a solid clue as to which haystack you should be searching.
Particularly if the Fire Scouts are simultaneously dynamically moving dipping sonar equipped buoys around the ocean in conjunction with the UUV equipped buoys. For discussion purposes let’s say a Fire Scout starts its day by moving one UUV equipped and four dipping sonar equipped buoys, all transmitting locally to an ISR drone or ScanEagle just overhead, in relays, across the ocean. As the hours pass an enormous amount of ocean can be searched, further and further out from the task force, yet the buoys will be able to keep up with the task force as it travels, even in dash mode. With only one buoy in the air at a time, each one only being moved hundreds or a few thousands of yards at a time, there will be a constant stream of much better data generated for the ASW team than the existing use of sonobuoys can provide. And the deployed equipment will be able to reliably function on station for many more hours than a manned helicopter team can provide.
Perhaps not at a 24/7 rate nor for days and days on end, but a task force with 15 Fire Scouts and 60 buoys
deployed, potentially separated by many miles, has added multiple alternatives to the ASW teams quiver.
It is suggested above that 15 Fire Scouts dynamically rotate 60 UUV or dipping sonar equipped buoys across the ocean. 15 and 60 are merely suggestions though. The real point is that to derive the greatest value out of the newly developed UUVs and Fire Scouts the Navy needs to be thinking in terms of a dozen plus helicopters and scores of buoys at a time, regardless of the particular mix of equipment and sensors dangling beneath them. Again, think and operate in quantity.
At this point a brief description of the buoy noted above, to be deployed in scores at any given time, is in order. A set of eight hollow, segmented and honey combed for strength where necessary tubes, say one foot in diameter, made of a 21st century version of fiberglass can be configured in a square. Stacking the ends of the tubes on each other log cabin style, but deliberately leaving the space between each pair of tubes empty creates as much buoyancy as possible, but very deliberately reduces freeboard. Whether the resulting buoy is equipped with a dipping sonar or UUV, both the sensors and the equipment needed to operate the tether, reel for the line and so forth is going to get soaked anyway. Simultaneously, we want a minimum of tossing and reeling about in various sea states as the sonar or UUV does its job or as a helicopter drops down to utilize a hook to grab the buoy and gently lift it clear of the water. So if the waves and swell are moving between the pairs of tubes, this will substantially reduce the buoys unavoidable acrobatics in the water, vastly easing the helicopters task in relifting it for redeployment.
So long as the pyramid resting on top of the buoy containing the motor driving the reel and its power source has a double sealed compartment and the necessary electronics, radar lure and antenna are in a triple sealed compartment above it; both routinely riding above the waves, limited freeboard is actually an advantage. At this point all that is needed is to add an appropriately sized circle of steel for the helicopter to snag each time it moves the buoy and we have an extremely practical piece of equipment to deploy, in large numbers and at a rather low price, across the fleet.
In years to come the Navy can incrementally add the ability to transmit and receive on different frequencies to measure the difference in time back to the emitting sensors thereby creating additional ways to monitor the underwater environment, detect targets and potentially be less intrusive when operating amongst our cetacean neighbors. By doing so we can build a much more sophisticated picture of surrounding water conditions as well. Knowledge that good computerized analysis of the data and developing a doctrine of best practice to utilize this knowledge of water conditions will leave the mission commander’s CIC in a position to make much better informed decisions on where to deploy their search assets next.
Sounds great doesn’t it? But as always there is a problem or three lurking about that need to be dealt with. For now we have reached the point where we need to consider the question used as the title for the article. Where is the U.S. Navy going to put them all?
In the next article we examine two new ship classes that can be used by the fleet to go to sea with the various types of drones, UUVs, Fire Scouts and buoys suggested, in quantity, as well as the needed sailors aboard.
Jan Musil is a Vietnam era Navy veteran, disenchanted ex-corporate middle manager and long-time entrepreneur.