Midget Submarines and
Diver Delivery Vehicles
The SOF Underwater Systems project provides for engineering & manufacturing development and operational systems development of small combat underwater submersibles and underwater support systems and equipment. Also provides for pre-acquisition activities (materiel solutions analysis, advanced component development and prototypes) to respond to emergent requirements. These submersibles, systems, and equipment are used by Special Operations Forces (SOF) in the conduct of infiltration/extraction, hydrographic/inland reconnaissance, beach obstacle clearance, underwater ship attack, and other missions. The capabilities of the submersible systems and unique equipment provides small, highly trained forces the ability to successfully engage the enemy and conduct clandestine operations associated with SOF maritime missions.
Combat Submersibles includes conducting product improvement efforts for the in-service SEAL Delivery Vehicle MK 8 and conducting technology development and engineering & manufacturing development for the follow-on combat submersibles such as the various types of shallow water combat submersibles. The shallow water combat submersibles uses an evolutionary acquisition approach to develop a family of submersibles, to include a new wet submersible capable of operating from existing Dry Deck Shelters, and more capable wet or dry submersibles that will operate from future large submarine shelters/systems and/or surface ships. The combat submersible sub-project leverages existing seal delivery vehicle components, develops new state-of-the-art components where appropriate, and leases or purchases commercial-off-the-shelf components and vehicles for test and evaluation and operational assessment. Combat Submersibles acquisition program for Block I will use full and open competition and competitive prototyping to award contracts to develop and produce test articles with options to produce production systems and provide contractor logistics support. The acquisition strategy for other combat submersible systems is under development. Additionally, existing contracts are utilized where appropriate for various component development and prototypes.
Underwater Support Systems and Equipment includes conducting product improvement efforts for in-service submarine support systems such as the Dry Deck Shelters, unmanned underwater vehicles such as the Semi-autonomous Hydrographic Reconnaissance vehicle, and diver equipment such as the Hydrographic Mapping Unit, Non-gasoline Burning Outboard Engines and Diver Propulsion Devices. Also provides for technology development and engineering & manufacturing development for follow-on underwater support systems and equipment.
Underwater vehicles are susceptible to detection by active sonar systems used for surveillance of littoral areas. Such systems can operate over a range of frequencies and can ensoniify at various intervals and powers and, consequently, be effective at different ranges. The challenge is to develop a small package to intercept such emissions early enough for the underwater vehicle to avoid capture or destruction. The system needs to fit in the confines of existing and future undersea vehicles, minimize the power requirements, and, ultimately, interface with existing vehicle systems such as command and control, communications. Current intercept systems require significant space and weight of rack-mounted equipment supporting very large processing systems.
The proposed system must provide sufficient source bearing accuracy and emission characteristics to allow identification and classification of the emission as a threat emission so that tactical decisions may be made. Identification and classification, while necessary to the tactical decisions, are outside the scope of this topic. (They are necessary to distinguish between threat and friendly force active sonar.) The desired system must detect a wide range of threat frequencies and should be capable of filtering out the acoustic emissions of its own platform in order to prevent false alarms. Because of the range of potential acoustic threats that need to be addressed, development of this system will not be classified.
The Navy will only fund proposals that are innovative, address Research & Development, and involve technical risk. The program office supporting this topic focuses on manned Naval Special Warfare vehicles including the Advanced SEAL Delivery System (ASDS), SEAL Delivery Vehicle (SDV). And the planned Joint Multi-Mission submersible (JMMS) and Shallow Water Combat Submersible (SWCS). However, the technology is applicable to large diameter UUVs.
The trend is that of perfecting the means for frogmen to move about in the areas of their actions and of standardizing their transportation to these areas. Preference is being given to submarines, which offer greater concealment than other naval forces and are capable of releasing frogmen and their means of movement.
The tendency in the development of midget submarines consists in reducing their dimensions and improving their tactical capabilities by improving the engines and stxengthening the hull. In 1960, the USA built a relatively small size submarine, the "Tyke" type: length four meters, width 1.85 meters, and a displacement of five tons. It had treads for moving about a short time on dry land, The power source was a storage battery.
In the postwar period, the American-produced "Nautilus", "Minisub M-3", and "Minisub M-4" guided torpedoes came into widespread use. The "Nautilus" has a cylindrical body of plastic 5.5 meters long, 0,8 meter in diameter, with a cabin 1,4 meters high, themotor is powered by a 24-volt battery, the total weight of the device was 240 kilograms, inside it two men can be positioned, On the surface it can move at a speed of up to six knots (11 kilometers per hour), submerged it had a speed of up to four knots (seven kilometers per hour), its cruising range is 10 to 18miles (18 to 30 kilometers). In 1962, a modification of this device appeared, the "T-14", differing basically from the previous one only by the availability of an attachment for towing cargo containers and by the absence of the high cabin, The"Minisub-4" guided torpedo is made of plastic, is 4,3 meters long, one meter wide, moves at a speed of five to six knots (nine to 11 kilometers per hour), and dives to a depth of 10 to 15 meters. Two frogmen can position themselves on top of the torpedo under a transparent hermetically sealed canopy.
The American "X-1" submarine and the British "X" submarine were both built in 1955, The "X-1" had an underwater displacement of 25 tons, a length of 14.6 meters, and width of 2.1 meters, and was able to submerge to a depth of 50 meters. Its underwater speed of movement was up to 12 knots (22 kilometers per hour), and on the surface, it was 15 knots (27 kilometers per hour). Its basic weapons were two shallow water mines of 300 kilograms each and it had a crew of five men. Two or three frogmen can be landed through its air-lock chamber.
The "X" type submarines had a displacement of 30 to 34 tons, a length of 16.5 meters, a width of 1.7 meters, and a movement speed on the surface and submerged of six to seven knots (11 to 13 kilometers per hour). The basic weapons were two torpedoes. Submarines of both types can cruise a distance of up to 500 miles (900 kilometers) on the surface and of up to 45 miles (80 kilometers) submerged.
The KAPPA submersible craft concept, the result of a 2003 Carderock Division Naval Surface Warfare Center (CDNSWC) Innovation Center project, may be an effective, cost efficient force multiplier that can perform covert missions in littoral regions and austere ports, assist in providing and maintaining access, and support other joint assets. The KAPPA craft concept is a stealthy, highly maneuverable craft, with a modular payload volume and flexible ocean interface that acts as part of a cascading payloads chain for improved littoral warfare operations.