• Tuesday, November 12, 2019

Indian Navy gets its biggest offshore patrol vessel

Discussion in 'Indian Defence Forum' started by RPK, Sep 3, 2013.

  1. Dash

    Dash SENIOR MEMBER

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    Even I have the same question...!!!
     
  2. kurup

    kurup ELITE MEMBER

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    My actual question was even if they uses a chute to land on water , how do the ships recover them from the ocean ?? using cranes ??

    Anyway here is the ScanEagle Launch and Recovery .

     
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  3. Capt.Popeye

    Capt.Popeye ELITE MEMBER

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    Cranes and Hoists are part of a Ship's outfit. They are used to lift anything from the ship-side, stores, supplies , Ammo whatever. In the old days Warships carried a Seaplane for Recce/Scouting. The Seaplane used to be launched off a catapult and on return would land on the water. The Warship would manuever close and the Seaplane would be recovered by the Ship's crane and replaced on the catapult.
     
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  4. kurup

    kurup ELITE MEMBER

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    Thank You sir .

    Can you explain how this skyhook recovery system of scaneagle uav shown in the video works ???
     
  5. Capt.Popeye

    Capt.Popeye ELITE MEMBER

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    well; I just took a look at the video right now. What I can see is that the recovery system is suspended /attached to the end of the "articulated" recovery arm that has been extended for the purpose. Then the UAV is flown into it. Though it is not very clear in the video, I'd guess that it is LOOP at the end of the recovery line with a "slip-knot". Something like a "noose" that you would use if you were a "hangman" :D
    The UAV operator flies the UAV into the LOOP and snags it. The KE of the UAV will then cause the "slip-knot" to close around the body and wings of the UAV and tighten. Then reeve-in (roll-in) the recovery line like on a fishing rod. Swing and articulate the arm onto the deck. Voila!
    One other way that it could be done is to have a hoop on the end of the recovery line with a netted sleeve (like a drogue) and fly the UAV into it like putting a basketball in to the basket hoop.

    Both methods above will be suitable for small and light UAVs only. Larger and /or heavier ones will need to be chuted down and most likely "ditched" into the sea. Then the Ship will launch a RIB/Zodiac into the water who will hook on the hook of the crane/hoist and then recover to the deck.
     
  6. Dillinger

    Dillinger PDF THINK TANK: ANALYST

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    How challenging are well-decks in terms of naval engineering and then manufacturing?
     
  7. Capt.Popeye

    Capt.Popeye ELITE MEMBER

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    As much or as little as designing amd building the rest of the ship!
    It is just another compartment on a Ship , albeit larger than nearly any other; save for the Hangar Deck/Space on a Carrier.
    What makes this compartment viz. the well-deck different it that it can be opened to the sea (by means of the openable gate) and then periodically flooded and then evacuated of Sea Water. Not much else, but then it has to be designed and built to handle those conditions.

    How is the Well-Deck operated? The Gate opening is operated open. Simultaneously Tank Compartments in the stern (rear) of the ship are ballasted with SW. This will cause the Ship to trim by the stern and sink the rear-end of the Ship and allow the SW to enter the well deck. After the ballast tanks are done, the SW in the well-deck itself will also cause sinkage till the bouyancy balance is achieved. The watercraft can the enter or exit the well-deck as required and the process of flooding the well-deck reversed on completion of the operation.

    The additional measures required in design and construction of the well-deck then consequently be some additional strenghtening, enhanced surface coatings to prevent accelerated corrosion due to prolonged exposure to SW and most importantly methods to drain the well-deck as efficiently and swiftly as possible which means larger pump capacities and/or more pumps.
     
  8. Dillinger

    Dillinger PDF THINK TANK: ANALYST

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    Well now that India is looking seriously at its Amphib. capability we are going to see a lot more of that, pity though that NDB doesn't seem interested in designing a LHD or LHA, we are going to end up with another acquisition.:frown:

    Although the CBG and accompanying LHDs really are the 3rd dimension of warfare, area dominance of the airspace over the blue sea/littoral from far off and beyond the horizon operation of LCACs and helos dropping in troops and heavy vehicles.
     
  9. Capt.Popeye

    Capt.Popeye ELITE MEMBER

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    You know; it is sometimes easier and even cheaper to buy a design "off the shelf". Not to mention the time-saving factor. Only for a technology or Eqpt. that has greater Strategic Implications is it worthwhile to design ones own. So much easier (and wiser) to buy e.g. a Mistral or Dokdo design.
     
  10. Dillinger

    Dillinger PDF THINK TANK: ANALYST

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    Athlas 26000.:taz: True, it is not a particularly bad situation, beneficial in many ways since NBD needs to do its due diligence wrt other surface combatants. :agree: