A-11 Mar del Norte arose from an urgent project that resulted in an excellent ship. Her commission gave the Spanish Navy the ability to deploy task force away from any naval base. In fact, one of its main missions was to act as a “floating gas station” so that A-14 Patiño supply vessel could considerably increase its range of action and that of the combat group itself.This ship was completed in just 19 months thanks to a revolutionary integrated modular construction system created by Bazan shipyard. The ship had a cost of only 52.4 million dollars (of 1991) thanks to the use of a civil design that was adapted to the needs of the Spanish Navy. These needs were consistent with the “Altamar Plan” developed at that time. This plan included the incorporation in the medium term, of a new supply vessel in collaboration with the Dutch Navy. This program would lead to the building of A-14 Patiño replenishment ship.Originally, the vessel had a length of 123.21 meters, which was later lengthened to 126.10 due to the extension of the helicopter’s flight deck. A-11 had an hangar in which it could hold a helicopter in a permanent manner, as well as up to 23 members of the Air Unit Embarked if necessary. The helicopters perform vertical replenishment tasks (VERTREP), so they have a station of this type at the stern of the ship next to the flight deck.Marques de la Ensenada payload was about 9,300 tons and consisted mainly of about 7,450 tons of DFM F76 fuel for ships and 1,716 tons of JP-5 fuel for aircraft. In addition they carried 120 tons of solid cargo in containers, mainly supplies, spare parts and ammunition. The ship has an armament for self-defense composed by two 12.7mm M2 Browning machine guns and two 7.62mm machine guns. Ther was a space for installation of a Meroka CIWS system, but it was never installed.A-11 was able to replenish fuel to three ships at the same time, at a rate of 360 m3/h. It had two supply stations on each side, one for liquids and one for solids and a third station aft equipped with a Hepburn winch. For loading and unloading operations, this vessel had three pumps of 120 m3/h capacity. Even a system capable of distilling 18 tons of seawater into fresh water every 24 hours was installed.The ship’s crew consisted of 93 people and had space for a group of 23 more, which could be from the Embarked Air Unit or a Naval Infantry’s protection team. The ship had an infirmary with 5 beds and a treatment room although it did not have the means for long-stay hospitalizations. It also carries a pair of Hurrican semi-rigid boats (RHIB), suitable for protection and transport of the Marines when they are on board.The electronic equipment consisted of Racal-Decca radar 2459 for air/surface exploration, Racal-Decca ARPA 2690 navigation radar, satellite TV antenna, and satellite communications INMARSAT and SPAINSAT. The A-11 vessel could fully supply fuel to 14 Santa Maria class (O.H. Perry) frigates or similar vessels. This gave great flexibility to a task force, which was able to extend its permanence in the area of operations.Despite having cost a third of an AOR ship, was a very profitable vessel thanks to its enormous payload. In the first 21 months of service, the ship was a total of 320 days at sea. A-11 had installed the SIMBAD internal control system for breakdowns and load situation. This system was developed entirely by Bazan company and automatically updated the vessel’s loading and stability conditions in every moment, even in case of damage or flood conditions.(A-11 and MSC Melody ship). On April 26, 2009, A-11 responded to the request for help of Panamanian flag MSC Melody cruise ship. This ship had repelled an attack by Somali pirates the day before, when it was about 250 miles from Seychelles. The cruise ship had almost 1,000 passengers and more than 500 crew on board and was escorted for 3 days by waters near Somalia, Oman, Yemen and Djibouti. Later the pirates were captured by the Spanish Navy’s F-83 Numancia frigate, deployed in that area within the Operation Atalanta.(A-11 and MSC Melody ship). During her busy career she participated in Operations: “Maritime Guard”, “Albanian Guard”, “Enduring Freedom”, “Coherent Behavior”, “Active Endeavor” and “Atalanta”. This last operation was against piracy in Somali waters. Within that operation, she avoided the assault of two ships and arrested and delivered 14 insurgents to Kenya. The ship was decommissioned in January 2012 as it was not a double-hull vessel and caused several protests about the possibility that it could suffer an accident and cause an ecological disaster.
