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  • Us navy

    Cracks plague Ticonderoga-class cruisers

    By Christopher P. Cavas - Staff writer
    Posted : Thursday Dec 9, 2010 21:44:09 EST

    Barely a year after the Navy spent $40 million to fix the cruiser Port Royal after an embarrassing grounding, the ship is again out of action, back in a shipyard at Pearl Harbor, Hawaii. But this time it’s not a damaged hull that’s the problem. Rather, it’s an issue that is plaguing all 22 cruisers in service: cracks in the aluminum superstructure.

    The Port Royal was operating in the Pacific Northwest in September when sailors discovered new cracks in the superstructure, including an eight-crack on the 06 level, one of the highest decks in the ship. Most of the cracks that appear on the Ticonderoga-class cruisers are being repaired during regular overhauls, but in this case the damage was enough to send the ship home to Pearl Harbor for yet another extended repair period.

    So far, the Navy has awarded $14 million to BAE Systems in Pearl to fix the Port Royal. The work package will include repairs to the bulkheads and deck around two gas turbine intakes; fuel oil storage tank top repairs; superstructure crack repairs; and removal and replacement of aluminum decking and plating. The work is expected to be finished in February.

    “We are dealing with a class-wide issue of superstructure structural issues,” said Cmdr. Jason Salata, a spokesman for Naval Surface Forces in San Diego. “These are things we’re seeing on other ships of this class.”

    The Port Royal situation might be the worst case to date.

    “Most of the issues are being dealt with when the ships come in for a regular availability,” or overhaul, said one source familiar with the situation. “This is the first one I know of where we specifically went in for repairs.” The work is necessary, the source added, “to restore structural integrity of the ship.”

    The problem, according to the Naval Sea Systems Command, is the aluminum alloy used in the superstructure of the cruisers, which have steel hulls.

    “There have been various degrees of crack repair on every CG [guided-missile cruiser] in the past year,” said Chris Johnson, a NAVSEA spokesman in Washington. “The decking is the most prevalent cracking area due to exposure to elevated temperatures caused by solar absorption and exhaust temperatures.”

    More than 3,000 cracks have been found so far across the entire Ticonderoga class, which originally numbered 27 ships. Twenty-two of the ships remain in service, and Port Royal, commissioned in 1994, is the newest.

    Their superstructures are made of aluminum alloy 5456, a material used on numerous U.S. warships since 1958. The alloy, according to NAVSEA, relies on approximately 5 percent magnesium as an alloying element to develop strength. Over time, the magnesium leaches out of the material and forms a film, susceptible to stress-corrosion cracking in a marine environment.

    NAVSEA has developed more than 17 alterations to deal with the cracks. In late 2008, the service began evaluating a different welding technique called Ultrasonic Impact Treatment. The Port Royal was one of the test ships for the new technique, Johnson said, and the UIT procedure was applied to specific areas of the ship in 2009.

    “With the current state of the technology, it is only practical to use UIT in small areas,” Johnson said in a written statement. “We believe it has potential, and are evaluating it as part of CG Aluminum Superstructure Task Force for future use.”

    The task force was set up this year by NAVSEA — at the fleet’s request — to develop and assess technically viable options, Johnson said. Results from the group’s work are expected to appear next spring.

    Many sailors who have served on a Ticonderoga-class cruiser have stories to tell about the cracks, ranging from descriptions of cracked masts to leaking fuel tanks next to high-wattage electrical equipment. Solving the issue is a key element in making sure the ships remain effective and safe to operate to the end of their planned 35- to 40-year service lives.

    NAVSEA noted that the aluminum alloys used on the cruisers are not on the new littoral combat ships, which are built with commercial alloys 5083 and 6082.

    “While the Navy has no current experience with this alloy, it is in wide use on commercial craft,” Johnson said.

    The Port Royal has seen little service since returning from its last deployment in June 2008. On Feb. 5, 2009, just after completing a three-month overhaul, the ship ran up on a reef just off the Honolulu airport, in clear sight of every aircraft taking off and landing at the airport, and visible from the beaches at Waikiki. The cruiser was refloated after three-and-a-half days on the reef and towed back to Pearl Harbor, where the commanding officer was relieved of his duties.

    The Port Royal’s hull, propellers and sonar dome received severe damage, and shipyard repairs continued into this year. After visiting Seattle in early August for Seafair, the cruiser caused a public relations stir when its wake washed up oysters on shore while operating near the Hood Canal.

    Despite these problems, the ship apparently has not missed a deployment.

    “Port Royal has not missed a scheduled deployment as a result of these repairs,” Salata said. “She will continue her training and deploy in 2011.”

    http://www.navytimes.com/news/2010/1...isers-120910w/

    Es una nota que interesa, ya que segun alguno este tipo de actos es aval para una logica muy digamos...sesgada.

    En todos lados se cuecen habas.

    Saludos
    Zhukov siempre quiere más soldados, más piezas de artillería, más armas de fuego. También más aviones. Jamás tiene suficiente. Pero nunca ha perdido una batalla. J. Stalin.

  • #2

    new aggresors?


    flying eagles

    Saludos

    Comentario


    • #3
      Este reportaje esta excelente.
      Ojala entiendan algo de lo que dicen en Frances

      http://www.dailymotion.com/video/xdm...reme-port_tech

      http://www.dailymotion.com/video/xdm...reme-port_tech

      http://www.dailymotion.com/video/xdm...reme-port_tech
      "No es la especie más fuerte la que sobrevive, ni la más inteligente, sino la que mejor responde al cambio."

      Charles Darwin

      Comentario


      • #4
        Mientras que otros paises tratan e conseguir el nivel de furtividad y fusion de sensores alcanzados por los aviones de la Fuerza aerea norteamericana, la US-Navy esta alcanzando un nivel de efectividad impresionante pero con una aproximacion mas inteligente.
        Tomemos el caso de la segunda guerra del golfo y el reciente ataque a Libya, cuando desde submarinos atomicos que son los mas furitivos que existen se comenzo el ataque a los centros de mando y control del enemigo, asi como a sus baterias antiaereas

        http://www.youtube.com/watch?v=7rPu3...eature=related

        Luego sus Growlers, que al ser solo 90% furtivos, facilitaron el que otros aviones no furtivos continuaran el trabajo por estar dotados de los radares sensores y capacidad de guerra electronica mas avanzados que existen, actuando a su vez de centro de comando aereo.


        http://www.youtube.com/watch?v=bIvQ4-4Q8bk
        http://www.youtube.com/watch?v=jOkR_7v0pg8
        http://www.youtube.com/watch?v=RmpyM...e_gdata_player

        Inclusive la ultima operacion de los Navy Seals, demostro que estan en capacidad de hacer incursiones en territorio hostil sin ser detectados, siendo el debut de los nuevos helicopteros mh-60 multirroles modificados con diseno de cierta tecnologia furtiva, aunque lamentablemente uno de ellos se perdio al momento de atacar la guarida de Osama, no se sabe si fue alcanzado, fue un error del piloto o tuvo una falla mecanica.





        Luego esta la introduccion de los UAVs para el 2018, que revolucionaran por completo el arte de la guerra, y ni que hablar de la tecnologia de defensa laser.


        http://www.youtube.com/watch?v=gFVxY...eature=related

        Mi punto es que sin derrochar una cantidad sideral de Dinero, la USNavy esta siendo la que esta revolucionando el arte de la guerra, y no la USAF, dotada de especializadisimos F22 colosalmente caros pero que hasta ahora no han sido puestos en combate, y al parecer tampoco lo estaran, dada su limitada capacidad de compartir informacion, como parte de todo un sistema integrado.

        Quizas no seria mala idea pensar en modificar nuestros submarinos, para que puedan lanzar misiles capaces de alcanzar centros de comando y control, como ya tienen nuestros vecinos del sur.


        Me parece que lo que esta haciendo y planificando la USNavy tiene mucho mas sentido a nivel de estrategia, integracion, furtividad inteligente, y utilizacion recursos.
        Editado por última vez por Arquitecto; https://www.defensa.pe/member/339-arquitecto en 28/05/11, 14:07:12.
        "No es la especie más fuerte la que sobrevive, ni la más inteligente, sino la que mejor responde al cambio."

        Charles Darwin

        Comentario


        • #5
          Lockheed Martin F-22 presentó un avion de combate que combina el sigilo,
          supercrucero, aviónica integrada, incluyendo fuselaje,
          materiales estructurales, radar, motor y los sistemas de cabina totalmente nuevos. El F/A-18E/F
          se basó en una célula motor y aviónica existente. Mientras que el costo de desarrollo del F-22 fue 7,2 mil millones dólares por encima del presupuesto, el F/A-18E/F fue emitido al costo previsto, concluye el informe Rand.
          "Si tuviera que retroceder en el tiempo a 1990 y le dicen que es así como su
          estrategia de adquisición va a terminar en el 2011, ¿cómo se sientiria al respecto? Mi sensación es que la fuerza aérea lo habria repensado realmente, dice Wertheim.
          "La marina invirtio en F/A-18E Growlers en lugar de limitarse a poner toda su inversión en "stealth ", añade. La Armada esperaba que la tecnología madurara un poco. Estamos viendo algunos de los problemas que está teniendo el F-22 con su fiabilidad, porque el mantenimiento es un requisito. Su fiabilidad no es lo que se esperaba.

          "No todo el mundo está convencido de enfoque de la Armada fue la correcta.
          Polmar dice que la estrategia de F/A-18E/F funciona pero ayuda el hecho que la marina no se ha enfrentado a adversarios más capaces (La USAF tampoco). "Hasta ahora no he conocido a ningún oponente que haya sido capaz de superar una formación de F-18s ", dice.

          Bombarderos de largo alcance

          Esta situación parece estar cambiando rápidamente. En diciembre, .
          los militares de USA reconocieron que China envió un misil anti-buque balístico. Tanto Rusia como China también han revelado prototipos para cazas de quinta generación para competir con el F-22 y el F-35 de Lockheed Martin. Mientras tanto, las estrategias de la fuerza aérea y de la Marina de los EE.UU. para una nueva generación de aviones de combate parecen ir en direcciones opuestas.

          La fuerza aérea está desarrollando un nuevo bombardero de largo alcance, mientras que la Armada tiene previsto
          introducir el F-35C en las cubiertas a finales de la década, junto con un sistema revolucionario no tripulado llamado posiblemente (UCLASS).
          La marina de guerra también puede reemplazar el F/A-18E/F con el FA-XX a mediados de la década de 2020 (Ya dijeron que no, se van por el SH internacional).
          Si la Marina finalmente combina el F-35C, UCLASS y FA XX-en una sola
          cubierta, las capacidades de esa fuerza seran probablemente como a la flota prevista por Dunn que selló el destino del A-6F a cargo de Garrett en 1989.
          "De eso es de lo que se trata todo esto", dice Dunn. "Cualquier pensador de la aviacion naval
          dirá que la fuerza aérea tiene la penetracion y la capacidad de permanecer si tiene las bases aereas que se lo permitan. Ellos a menudo no tienen esas bases, es por eso que la marina ha de estar siempre lista. "

          http://www.youtube.com/watch?v=u9wLK...eature=related
          http://www.youtube.com/watch?v=8dtzS...eature=related





          The Lockheed Martin F-22 introduced a fighter that combined stealth, supercruise and integrated avionics, including all-new airframe, structural materials, engine, radar and cockpit systems. The F/A-18E/F was based on an existing airframe, engine and avionics. While the F-22's development cost was $7.2 billion over budget, the F/A-18E/F was delivered on cost, the Rand report concludes.
          "If you were to go back in time to 1990 and say this is how your acquisition strategy is going to end up in 2011, how are you going to feel about it? My feeling is the air force would really be rethinking it," Wertheim says.
          "The navy invested in EA-18 Growlers instead of just putting all their investment in stealth," he adds. "The navy waited for that technology to mature somewhat. You're seeing some of the issues you're having with the F-22 with their reliability because of the maintenance requirement. Their reliability is not what they hoped for." Not everyone is convinced the navy's approach was the right one. Polmar says the F/A-18E/F strategy worked but it helps that the navy has not faced a more capable adversary. "So far we've not met any opponents that have been able to beat a formation of F-18s," he says.
          LONG-RANGE BOMBER
          That situation seems to be changing rapidly. In December, the US military acknowledged China had fielded an anti-ship ballistic missile. Both Russia and China have also revealed prototypes for fifth-generation fighters to compete with the F-22 and Lockheed Martin F-35. Meanwhile, US navy and air force strategies on next-generation combat aircraft seem to be going in opposite directions. The air force is developing a new long-range bomber, while the navy plans to introduce the F-35C on carrier decks by the end of the decade, along with a possibly revolutionary system called the unmanned carrier-launched airborne surveillance and strike (UCLASS) system. The navy may also replace the F/A-18E/F with the FA-XX in the mid-2020s. If the navy eventually combines the F-35C, UCLASS and FA-XX on to a single carrier deck, the capabilities of such a force would probably be recognisable to the fleet Dunn envisaged when he sealed the fate of the A-6F in Garrett's office in 1989.
          "That's what it's all about," Dunn says. "Any thinking naval aviator will say the air force has the punch and the stay-ability if they have the bases. They don't often have the bases, so that's why the navy has to be ready."
          Editado por última vez por Arquitecto; https://www.defensa.pe/member/339-arquitecto en 28/05/11, 15:45:11.
          "No es la especie más fuerte la que sobrevive, ni la más inteligente, sino la que mejor responde al cambio."

          Charles Darwin

          Comentario

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