Hmm, why?

The report said: “Navy surface ships would use high-energy solid state lasers initially for countering small boats, UAVs [unmanned aerial vehicles] and potentially in the future for countering ASCMs [anti-ship cruise missiles] and ASBMs [anti-ship ballistic missiles].

“They would be short-range defensive weapons. They would counter targets at ranges of about one mile to perhaps eventually a few miles.”

Why short range? Ah, yes, obviously, silly me. Since the days of the big battleships much of a naval battle takes place beyond the horizon, out of the line of sight…..

16 thoughts on “Hmm, why?”

  1. What if they miss and incinerate a passing albatross fifteen miles away ?

    Haven’t read the story yet as on the phone, but the problem for a long time was that a laser had to be on the target for several seconds before it would ignite. Although the aiming mechanism was always quite small the power plant below decks had to be huge, took up too much space and also meant that the ship had to be stationary. Have they solved, what seemed to be insoluble issues ?

  2. Isn’t the problem that the beam disperses (and loses power) over distance due to particles in the air…?

    More of a problem in a battle situation where the air is full of smoke and other debris (including chaff)…

  3. Bloke in North Dorset

    Bloke in Cyprus,

    “ Isn’t the problem that the beam disperses (and loses power) over distance due to particles in the air…?”

    Yes. Which is why the biggest payback on fibre optic telecoms research was in the purity and structure of the glass. Not just to allow greater distance to be used but also higher bandwidth modulation schemes.

  4. It’s not just crud in the air. A high power beam will heat the air it travels through, decreasing the density locally and changing the refractive index. That change tends to make the beam diverge, reducing the power in any one spot. Also, as hot air rises there will be more of an effect in the upper part of the beam than the lower which will bend the beam, screwing up the targeting. Laser weapons work better in the vacuum of space than in the atmosphere.

  5. Germanium! Glass is, after all, just a certain state of metal oxides. Add GeO2 to the mix and get better transmission of light through it (Or is it Ge2O3?). Night sights, fibre optic cabling and catalyst for PET production the three major uses…..

  6. I often used to think, watching Star Wars, Galactica and stuff, that if the Death Star misses, some poor bastard a few light years away happily minding his own business on his ranch on Tatooine is going to get barbecued.

  7. That you can see the beam in the photos is why range matters. You’re looking at energy being dissipated on the way to the target. And it’s the thing they always get wrong in SciFi movies. Seeing the laser beams. In vacuum you wouldn’t, or if you did, very faintly. And also why those dinky laser pistols will never happen. The emitter has to be hotter than the target. With attenuation, a lot hotter.

  8. . . . if the Death Star misses, some poor bastard a few light years away happily minding his own business on his ranch on Tatooine is going to get barbecued.

    Luckily, energy falls off and dissipates in space too – otherwise we’d be continuously fried by the stupendous maelstrom out there. There are natural energy beams that cause damage over hundreds of light-years but nothing pointed at us. There also don’t appear to be any supernova capable stars near enough to wreck our ozone layer. Goldilocks, etc.

  9. . . . if the Death Star misses, some poor bastard a few light years away happily minding his own business on his ranch on Tatooine is going to get barbecued.

    Inverse Square Law: from a point source the intensity of radiation is inversely proportional to the square of the distance.

    It spreads out so the intensity of a light a mike away is considerably less than a yard away from its source, for example.

  10. I thought that the main thrust of research in boat based offensive weaponry was directed at improving Rail Gun technology.
    I struggle to see how lasers would be a better option unless you`re using them to blind the optical sensors of incoming ordnance (or the eyes of offensive pilots).

  11. Also, whats the point of having defensive weaponry on a boat, that is effectively neutralized the moment you hit fog – a not unheard of occurence at sea – or so I believe.

  12. BlokeinBrum, the US Navy defunded rail gun development this year in favour of hypersonic missiles. They’ve been on about doing this for years, so presumably there’s an insurmountable in the way. Or they just want more transgender admirals.

  13. The best defence for naval craft is being a submarine. In a future serious war all surface ships are mere targets.

    The Bismarck showed that it’s no good being the best battlewagon if air-launched torpedoes bugger your rudder.

    The Italian fleet at Taranto. Repulse, Prince of Wales. The US battleships at Pearl Harbour. The Japanese carriers caught with their pants down at Midway.

  14. Bloke in North Dorset

    “ Germanium! Glass is, after all, just a certain state of metal oxides. Add GeO2 to the mix and get better transmission of light through it (Or is it Ge2O3?). Night sights, fibre optic cabling and catalyst for PET production the three major uses…..‘

    Yep, it’s pretty complicated stuff, hence the research, I was being lazy calling it glass, the term used on the ground.

    You think I’d know better on here 🙁

  15. The best defence for naval craft is being a submarine.

    If you sit still and don’t do anything. Once you manoeuvre and engage you’re vulnerable. The German U-Boats suffered a 75% casualty rate, the worst of WWII.

    Even the super stealthy Swedish subs that a few years ago could get through the US screen to “sink” the carriers were detectable when they fired. And the yanks can most likely detect them now, which is why they exercised.

  16. I would have thought a rail gun would have several advantages over lasers as well as missiles. The majority of ship launched missiles cost around $1m – $3m a pop and are liable to go boom if hit in situ by enemy weaponry. See what happened to the Hood after it was hit by the Bismark.

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