Submarines of the “GUPPY” Class

After the Second World War, the U.S. Navy developed innovative ideas about submarine warfare, giving birth to the “Guppy” submarine.  With its design they had achieved improvements for the time in the snorkel system, battery capacity, and submerged speed.

The Peruvian Navy became interested in the acquisition of these submarines because they were no longer used by the Americans and passed to reserve service, due to the incorporation of nuclear submarines.  In 1973, after long conversations, the purchase of this class of submarines became a reality, which after being reactivated were incorporated into the Peruvian Navy, assigning them the names “LA PEDRERA (ex-USS POACHER) and “PACOCHA” (ex-USS Atule).

This submarine is 306 feet in keel, 2400 tons submerged displacement, could reach surface speeds of up to 18 knots and submerged, 10.5 knots.  The 5/8-inch thick shell allowed submersion to operating depths of 412 feet.

The primary fire control system, comprised of an analog-type computer, allowed it to shoot conventional torpedoes from 10 torpedo tubes, distributed 6 at the bow and 4 on the stern, respectively, which were used according to the tactical situation.  This system was improved thanks to integration of systems that permitted firing of electric torpedoes and wire-guided electric torpedoes, depending on the needs of the moment.

The propulsion system was made up of two electric motors, fed by batteries.  On the other side, four diesel engines connected to their respective generators made charging the batteries possible in port or at sea, during surface navigation or snorkel operation.