Tuesday, January 30, 2018

Aegis Battle Damage Resilience

While the circumstances were tragic, the Navy now has a wealth of damage control and battle toughness data available to consider related to the recent collisions of the two Burke class destroyers.

Consider the photo below.  There was not direct impact damage to the Aegis radar arrays but they were clearly affected.  You can see that the array to the right is partially unsupported and has a gentle curve or warp in it.  The array to the left seems largely undamaged although there is some involvement at the very bottom. 

Collision Damage Near Radar Arrays

The question is, were the arrays still functional immediately after the impact and, if so, to what degree?  One of the supposed benefits of arrays is resilience to damage given the modular nature of the elements that make up the array.  On the other hand, we’ve heard unconfirmed reports that the gentle grounding of the Port Royal threw the Aegis arrays out of alignment to the point that they could not be repaired.

Of course, the Navy is unlikely to release any information on this but, internally, the aftermath damage assessments should provide invaluable information about the resilience and battle toughness of the Aegis system.

The same kind of resilience and damage control information can be gleaned from the many other impaced systems and damage control practices.  There are a wealth of valuable lessons to be learned.  It would be fascinating to read an assessment, even a basic, unclassified one, of the battle worthiness of the Burkes. 


  1. It would seem pretty obvious to study what systems worked, how they degraded,etc,etc...if nothing else, a system inventory/check should be run so USN could run a simulation later thru a battle exercise and get some results.

    AEGIS has 4 panels, does the other 2 panels on the left side still work? What about computers? Which ones still work and can the crew work around a solution or just everything shut down?

    Seems like some people assume that once hit, you go back home but let's assume those ships still had to be part of a Task Force, could they still operate? Were they still able to provide something to the TF?

    I know this is a little crazy but I almost wish USN would keep 1 DDG like this, maybe not forever but before completely repairing it, why not make it safe to use but leave the AEGIS alone, if it still works and put in a crew to see how it operates and crew deals with it in it's degraded state. Can AEGIS still work, can it be worked around by a regular crew? How useful is it in it's state if facing a stimulated battle? At lot could be gleaned from these 2 ships before they are repaired.

    If we find out later that AEGIS was IN-OP, then we have a major problem on our hands, this system is too fragile to sustain any damage, too complex to repair at sea by crew and just doesn't degrade like promised.

    1. It's also an opportunity to see how much the damage affected the ship's stealth signature.

      So much to learn from this tragedy.

  2. A side note, at the recent SNA 2018 LM were advocating updating the Tico and Burke SPY-1 radars with their GaN TR/M, Transmit/Receive Modules, which use dual polarisation, polarimetric radars transmit and receive on both horizontal and vertical axis, used in their S-band Long Range Discrimination Radar, LRDR, for the BMD, a 2015 $784M contract.

    Interesting point is LM said that TR/M would allow enable them to do away with internal the SPY-1 waveguides, no way of knowing the internal damage caused to the SPY-1 by shock of collision, are wave guides delicate? Radar manufactures claiming new TR/M based radars will degrade gracefully as the undamaged TR/M's will continue to operate.

  3. One of the AESA antenna areas seems to be deformed. That all but guarantees that the signal processing is off if it's not an optical illusion / camera optics thing.

    An AESA antenna has about 100-110° effective field of view. This means that there was certainly a dead angle of greater than 30°, which might have been compensated for with cruising in s-lines.

  4. While a worthy idea, after posting that the Navy is thumbing its nose at the DOT&E, dare we really expect even an internal assessment of a weapons system?

    1. There is the potential for shock damage.Has this been assessed by shock testing? Ignoring the DOT&E for any weapons. sensor testing would seem to be a firing offense.

    2. Shock testing was done with multiple if not all Arleigh Burkes.
      Warships like that are mostly hardened against very short and very, very strong shocks as from explosions.
      A collision has a longer, relatively gentle acceleration instead.

      I suppose it's more relevant regarding permanent deformation of structure, mountings and fittings. A collision in the half rear could have caused problems with the shafts, for example. Some WW2 warships were irreparably limited in their top speed because of deformations to shaft mounts caused by battle damage.

  5. Wasnt the power knocked out for hours on that ship? If anything I would think studying that in an effort to make the ships power generation more robust would be the best course of action. Also, having some crew that are extensively trained in the electrical architecture of the ship, in addition to the other sub-systems, would seem like a very handy thing to overcome battle damage. But we know they cant even find the time to train sailors how to steer the ship so lets not get ahead of ourselves.

  6. As CNO mentioned LO being degraded and now MrTexas bringing up the fact that power was out for hours....sure seems USN could learn A LOT from these 2 accidents!!!

    Sadly, afraid everything will be repaired and forgotten.

  7. I've been looking to see if more information has been put out so far about repairs, only found that USN is going to spend $675million to repair both damaged ships and Fitz won't be upgraded to Baseline 9 AEGIS.

    1. It's reported that Fitzgerald will get unspecified new equipment installations and upgrades as part of the "repairs". Thus, the "repair" cost includes modernization costs. No idea what, specifically is going to be added or modernized nor what portion of the total cost is true repair and what is upgrades.


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