Lasers and rail guns oh my

So linked at the bottom is a file by the congressional research service regarding the progress the Navy is making on laser weapons, rail guns and hyper velocity smart munitions. Not the best topic for Christmas Season but oh well.

A series of articles in the Drive and elsewhere have discussed the progress in laser weapons over the last few years. To recap, a technology that was discovered as a fairly early practical application of quantum theory evolved into an important digital communications tool where the demand for longer distance between repeaters drove the power up to a point where cutting material like paper was practical that evolved into cutting steel which provided the basis for weapons grade systems although the military R&D complex had been exploring alternative paths for decades.

Now real systems (in the sense of shooting down light weight drones or setting outboard motors on fire, as well as dazzling or spotting) are being deployed and fairly aggressive plans are being made. There still remain problems with the technology though many of them are resolvable. And like earlier many pieces are being worked on for civilian reason, not the least in the field of astronomy where light transmission through the atmosphere is important and the brain power is deep and unfettered by military R&D issues.

In the end it is not clear that at sea is the best place to locate a laser weapon but ships are (relatively) big and have (relatively) large power systems so they are a good early trial. If lasers can be of value there they are going to make it other places as the technology improves.

Rail guns…what can you say (I could say a fair amount but won’t) they are the technology of the future and have been my whole adult life. I spent a couple of years involved with them and that is enough to tell me that there are a lot of fundamental problems that appear surmountable in early hand waving but are practically insurmountable as you get closer and closer to reality.

The ‘rail’ part of the gun has most of the problems of a powder gun barrel of erosion, fatigue, stress, compounded by huge electromagnetic forces in the metal itself. Vastly more complex than a simple bang tube. The energy required is huge but not only that it has to be released in a controlled manner at several times the rate of an explosion since the energy and the power are both higher than the propellant ‘burn’ of a powder weapon. Modern power electronics can handled this but they are not light and the resultant waste heat instead of exiting the barrel in a plume of plasma is retained in the energy storage device and switching system, none of which can be dowsed with water like you can do with a gun barrel.

Every 5 years or so since the seventies the rail gun has popped up as a candidate to replace the powder cannon of the day. Each time more of the hurdles identified in the last round are knocked down. But then new hurdles appear, often more complex than those dealt with and hidden by the earlier barriers.

And at the end of the day is the result worth the price? In WWI and WWII guns of prodigious range were developed but made no difference in the end. Mostly filling in for fighter bombers when the weather was crappy or the target too diffuse to be worth risking a pilot/aircraft.

In the early days (the 1970’s) of the rail gun its potential range and rate of fire appeared very attractive especially for Naval support gunfire. 100 miles and 10 rounds a minute of lethal kinetic punch were very much of interest to the amphibious forces. Since they were powered by electricity and fuel is relatively cheap + plentiful and the rounds compact, the ‘depth of magazine’ was fantastic. And all of this is still deeply interesting. But. In the end is this really what you need? In WWII through Desert Storm this capability set would have been game changing. Today? Maybe not.

The round designed (successfully) for the rail gun, can fit in any of our current 155mm class cannons. These guns with their 52 caliber barrels can punch the round out to 40 miles or more. The round is guided and has shown the ability to shoot down a cruise missile ! So it is as accurate as you like. It’s ‘shortfall’ in modern ops game theory is that it is a bit slow for shooting down ballistic missiles or reaching the outer theater to shoot down other high performance targets. But there are missiles that can do that and the attrition cost of a missile on that sort of target is worth it.

40 miles is not 100 miles, some targets are out of reach, you cannot stand off as far or reach in as far to destroy targets. But in reality is that an issue? If you think that you are going into amphibious war against hostile beaches maybe. But you have to assume that you can destroy the enemies area denial defenses (Because otherwise why worry about 100mile standoff?) so you can get the amphibious forces in close enough to get on and over the beach at acceptable cost. None of that appears realistic today. While some kind of Eurasian Fascist Empire and air tight anti strategic defenses might create an existential threat that triggered WWIII and the concomitant bloodbath this scenario is simply not on the table now or foreseeable in the next twenty years.

For now we have Taiwan and the South China Sea as the most likely battleground for near peer conflict. ——— OK no one ever really KNOWS what is coming next, the Med, the Baltic, maybe somewhere in Oceana might go south with zingers but none of those have the deep resources required to cause an existential threat or survive an attrition campaign long enough to make the rail gun a potential player——

To continue, while T and SCS are both in their way an argument for that extended range neither is going to be resolved in any way by one weapon. Neither are any other scenarios one might game other that EFE+ATSD above and that ain’t goin to happen (yet.)

So? Lasers…full speed ahead, look to the sky, 150kW on a fighter is a game changer. Rail guns…spend some money, let the Chinese trial their barge, see if they have solved the problems, they haven’t but what do I know? Hyper (or High) velocity smart munitions,…go, go, go power rangers !

Congressional Research Service Report on Lasers, Rail Guns and Hyper Velocity Rounds, via the US Naval Institute Proceedings website.

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