Designed by former Cos.Mo.S engineers at Vapor Industrial, the Chilean Crocodile 250 Class (Crocodillo) midget submarine is the first such craft designed in Latin America. It is only slightly larger than the Cold War Cos.Mo.S MG110 design but is much more heavily armed and boasts Air-Independent Propulsion (AIP) which greatly increases its covert loiter capability. It is also unusual among midget submarines in that it has impulsors for the torpedo tubes allowing the carriage of non-swim-out loads such as anti-ship missiles. Load is still limited by weight so only two tubes can be used for anti-ship missiles at a time.
Representative hull section. No prototype is thought to be in actual production.
although this is the first modern midget submarine designed in Chile, the country is not new to small-scale submarine building. This is an early design from the 1860s by Gustavo Hayerman. It sank on its maiden voyage.
The design features a partial double-hull with a smaller diameter inner hull for the forward section and a full-bean single hull construction in the aft. This allows for external torpedo tubes to be buried in the forward hull. One minor disadvantage of this configuration is that these tubes can only be reloaded when the submarine is hauled out of the water. Beneath the forward hull is a sealed battery compartment tube.
One curious feature of the boat is that in many illustrations the lower rudder appears to extend too low beneath the boat to allow it to sit on the sea floor. This limits both mission profiles and special forces options as it is sometimes preferable to bottom the submarine before the divers exit or re-enter.
Despite significant differences the design heritage to the MG110 is clear. The separate sealed battery tubes under the hull is one give away. Note however the significantly more modern aft section and the moving of the torpedo tubes from on top of the hull to the lower sides.
Length: 33 meters
Beam: 3.6m meter
Displacement: 250 tons
Maximum speed: 8 kts (surfaced), 12 kts (submerged)
Operating depth: 200m
Endurance (without surfacing): 100nm at cruising speed of 4kts, 200nm with AIP in operation
Endurance (patrol): 2500nm
Armament: 4 x 533mm (21") torpedo tubes. 4 torpedoes or 2 anti-ship missiles (Exocet, Harpoon) plus 2 torpedoes.
Special Forces: 6