Lt. John Lehmann is a naval intelligence officer assigned to the Navy & Marine Corps Intelligence Training Center and a former nuclear trained enlisted submariner.
Fall 2009: USS FLORIDA (SSGN-728) is at periscope depth several miles off the coast of a hostile nation. Her embarked SEAL platoon has been ashore since the previous evening gathering vital intelligence and will return to the boat once darkness falls. Before the SEAL platoon can exit the area and return to FLORIDA via their Advanced Swimmer Delivery Vehicle (ASDV), they are detected by hostile forces and call for fire support. Due to the clandestine nature of their mission, tactical air assets are not suitable for this operation. FLORIDA receives the call for support and the coordinates of the attacking force. The coordinates are entered into the fire control computer, the OOD orders “ahead standard, broach the ship.” FLORIDA ‘s bulk rises out of the sea, missile tube number eight is opened and twelve G PS guided I 55mm projectiles are fired from the boat’s single 155mm vertically mounted gun. FLORIDA shuts missile tube eight and slides beneath the waves. Total exposure time, less than three minutes.
The development of revolutionary technologies and weapon designs enables the US Submarine Force to explore many new and exciting missions previously unavailable or prohibitive in nature. The Vertical Gun for Advanced Ships (VGAS) originally designed for ODO (X) can be incorporated into the OHIO class SSGN conversion. This package will provide Marines and Special Operations Forces (SOF) with a highly mobile, stealthy, rapid-fire platform capable of delivering massed, precision fires onto point and area targets. The SSGN platform is ideal for this mission as it is invulnerable to counter battery fire, coastal defense, ASW capabilities of our near term adversaries.
The current OHIO SSGN design has facilities for up to I 54 Tomahawk cruise missiles (7 per missile tube/22 tubes) and 66 SOF personel for Swimmer Delivery Vehicle (SDV) Operations.1 A combination of the above may be carried as each missile tube is operated independently of the rest. Modifying United Defense’s 155mm vertical gun and inserting the unit into one or two missile tubes would greatly enhance the overall mission capability of the vessel, without appreciably diminishing long-range cruise missile firepower.
Equipped with the 155 mm gun, the OHIO SSGN can deliver long-ranged, precision fires onto targets over 75 nm distant. The OPS equipped, land attack guided projectile has a planned CEP of 20 to 50m. Equipped with a variety of warheads, including DPICM2, the sub can deliver an astonishing volume of fire. Utilizing a fully automated magazine, a sustained rate of fire of 12 rounds per minute, per gun, is achievable.3 Direct, secure communications links with forces ashore will enable the boat to answer fire support requests immediately upon receipt of relevant coordinates. For the first time, SOF personnel will have an indigenous means of supporting fires.
By the very nature of the OH 10 SSGN platform, multiple guns can be carried in multiple missile tubes. The guns would be spread out within the 24-tube cluster to minimize the axial torque placed upon the vessel during a rapid-fire mission. Determination of the SSGN tactical load out would depend upon mission requirements and available assets. Installation or removal of the gun modules could be accomplished at forward bases. By utilizing the same ammunition as the DD 21, the OHIO SSGN could rearm virtually anywhere.
The Marine Corps’ doctrine of Operational Maneuver From the Sea (OMFTS) stresses the use of rapid, decisive action with firepower and maneuver from the sanctuary of a secure sea base. The OHIO SSGN equipped with the 155 mm vertical gun supports this concept; it is a secure, stable, long endurance platform possessing .massive firepower. Incorporated into the naval surface fire support (NSFS) plan, the OHIO SSGN provides the Land Force Component Commander (LFCC) with a readily available, high volume, supporting fires asset. Outfitted with multiple 155 mm guns, the SSGN could provide more direct NSFS than an entire Expeditionary or Carrier Strike Group.4 Since the demise of the battleship, the Corps has been lobbying for increased numbers of gun tubes available for fire support. The OHIO SSGN easily fills this requirement.
The incorporation of unmanned aerial vehicles (U AV) capability into the platform greatly enhances the overall fire support capability of the gun equipped SSGN. UAVs bring the advantage of real-time target acquisition, validation, and damage assessment to an already highly capable asset. A properly configured OHIO SSGN has sufficient capacity to control the UA V during the mission, but must pass over control of the UAV once it leaves line of sight.
The Navy abandoned the vertical gun concept for DDG (X) due to its unique ballistic profile. Because the projectile has to tum in flight, it has a severe minimum range restriction. Threats within this myopic zone were a danger to DDG (X), which theoretically could not protect itself. In effect, DOG (X) would need two gun systems, the vertical gun for long range and an additional gun to be used in the surface direct fire mode. The OHIO SSGN does not have this vulnerability, as it would not need the gun to deal with surface threats. In fact, the OHIO SSGN retains all the built in capability of its original submarine design, without the ballistic missile, and could use torpedoes and mines in traditional submarine missions.
Coastal threats to the SSGN are minimized or negated easily by the mobility and stealth inherent in the vessel. Once the boat completed a fire mission, she would dive deep and move 3-5 nm away at a high rate of speed; defeating any counter-battery fire. The short exposure period of the masts, sail, and hull when broached, would not provide sufficient time for coastal defense cruise missile (CDCM) fire control radar to lock on and launch. Even if a CDCM were launched by an alert crew, once the sub dove, the missile would loose target lock. Finally, the inefficiency and inexperience of our adversary’s ASW forces enables this platform to operate with near impunity. If ASW units detect and prosecute the ship, the OHIO SSGN retains its full self-defense capability.
Expeditionary forces in the 21″ century will have to face the new and unique challenges of the evolving battlefield using new technologies in a revolutionary manner. Our forces, going into harm’s way, need every advantage to ensure victory. The combination of Tomahawk, artillery projectiles, SOF, torpedoes, and mines; coupled with the inherent stealth and survivability of the submarine, makes the OHIO SSGN the multi-mission platform of the early 21st century.