Sunday, July 21, 2019

Light is Right

Light has long been used as a weapon. Some of the first experiments were in the form of searchlights used as dazzle weapons at night. The British developed a series of tanks called Canal Defence Lights, or CDL's. The story of these tanks is a long one, and spans from the First World War to the end of the Second. What every version of the story I've seen has missed is the experiments carried out in 1928 by the Experimental Mechanised Force on Salisbury Plain.
The EMF tried out a night attack, they had obtained several lorries, to which they fitted powerful mobile search lights, which were able to shine forwards. These were placed within the advancing tanks, at a distance of about 70 yards between vehicles. The searchlights emitted a cone of light each, these cones widened and met about 80 yards ahead of the formation. This made life extremely difficult for the defenders who had a very hard time drawing a bead on the attacking tanks. The CDL's would go on to service in many theatres of the Second World War, although never as dazzle weapons.
 You might wonder what got me thinking about CDL's. Well earlier in the week I saw a news story about laser weapons, and it started an interesting discussion, and backtracking through laser weapons of course leads to dazzling, and thus to the CDL's.

For most of my life, when people have talked about lasers and armoured warfare things have generally been very hypothetical and seen as far in the future technology. Well it appears we're on the cusp of entering the laser weapon period of warfare. The pace of technology has made weapons more viable. So, I thought a quick article about that would be interesting.

Laser weapons, as dazzlers, have been claimed to have been used in anger already, however, as you might expect the incident is surrounded in mystery and claim or counter claim, and conspiracy tin foil hat wearing nuts can get quite shouty over it. So, for the next paragraph or two, please apply the word allegedly to everything I say.

The Strait of Juan de Fuca lies between Canada and the US on the Western coast of North America. One of the waterways off it is the Puget Sound which houses a major US naval base, where a portion of the US Navy's submarine fleet, including ballistic missile submarines, are located. As you might imagine this is a rather security sensitive location. On the 4th of April 1997 a Russian merchant ship, the Kapitan Man was lurking in the area. It is highly likely it was engaged with espionage, as an earlier inspection found sensors that would only be used for submarine hunting, which were promptly confiscated by the US Coast Guard.
The Kapitan Man
As the straights lie between the US and Canada both countries cooperate on their security, and the Russian spy ship was obviously going to need investigation. A Canadian CH-124 (Canadian name for a Sea King) helicopter, with a US Navy Observer were investigating the merchant when they both suffered intense pain in their eyes and temporary blindness. It was concluded at the time that bother pilots had suffered laser burns to the eyes, although subsequent events have cast doubt on the situation.

So, what are we looking at in regards to laser weapons, how much power is needed? Well a friend, Maddest Cat sent me this link. It is an interview with a Rheinmetall employed engineer who is working on lasers. In it there are two very useful paragraphs. These are:

'In the class up to 20 kW, optronics can be neutralised out to a distance of five to ten kilometres. We've proven that we can combat aircraft and UAVs up to three kilometres away. We can render medium-calibre munitions and munitions in munitions boxes harmless at up to two kilometres. If we consider combating mortar shells, we're talking about the 100 kW power class, and to combat aircraft we need to be thinking about a power class significantly above 120 kW, because we need to assume distances of four kilometres and more.'

and:

'The efficiency level problem has become a lot less urgent with the transition from gas lasers to solid-state lasers. Previously, we were attaining efficiencies of five to ten percent for gas lasers; today we're achieving efficiencies of close to 30 percent. In other words: To generate 1 kW of laser power today, we need only a little more than 3 kW of electrical power, which represents a huge reduction with respect to the requirements for the carrier platform – particularly as you always have to consider that the energy for the electrical lasers is only required when the laser is actually beaming.'

So, what does this mean? Well simply put a laser loses power the further away it goes as energy is dissipated. A bit like the effect of electric heater, at point blank range it can burn your skin, at 3 meters it can keep you comfortably warm, and at a mile you won't even feel its effect.
In this scene the Terminator asks for a 40 watt (not kilowatt) plasma rifle... what's he going to do, club him to death with it? My desk fan is 30w!
In the first paragraph you'll note that he talks about destroying mortar shells with lasers. Shells generally have a significant thickness of metal, certainly more than is traditional considered as a target for lasers, such as drones, missiles and planes. Why do I consider it important? Well from shells its one small leap from penetrating thin armour plates, like on non-MBT's. then we have a viable anti-tank weapon. But what of power?

That's where the second paragraph comes in, technology has advanced so that we can get quite the power output. A 500hp engine can power a 100kw laser, using the ratio above. You'll note that the above article was written in 2016, when the Germans were looking at a 10 kW laser.
RHM's 10Kw laser on Boxer.
Well the British have just started looking at a 50 kW laser. Not only that, it's multiple 50 kW lasers focused on a single point, which actually uprates the energy of the weapon, although adds its own complications. It's called Dragonfire, it is ready and being developed even as we speak.
Dragonfire turret, coming soon to a MBT near you?
What it means for warfare is anyone's guess. History is littered with people who have made pronouncements only to look very silly, very shortly afterwards. Case in point is the individual who proclaims the tank is now officially obsolete and useless. A hobby of pundits, that started sometime circa 1917, and has carried on until today and every time it has been proved wrong. But we could easily see anti-tank laser weapons in but a few years.

At sea, however, life becomes vastly more interesting. Imagine two lasers on either side of the main mast of a ship, this would give them a nicely elevated position, with unimpeded coverage. As many ships have two masts, they could mount four laser cannons. With such an arrangement you could theoretically have near, if not actually 100% effective coverage, and anything small enough, surface or air, which enters the envelope is instantly destroyed. At current missiles are the major way of achieving surface ship kills, these would, theoretically, be impossible to get through the laser screen. Before you begin to get all excited about the re-appearance of the big gun battleship, remember the shells from these could be intercepted as well. Which will leave what as the main form of surface to surface ship killing? Torpedoes don't have the range or speed; ramming and boarding actions are horribly impractical and risky (although you could likely get a good SF book out of this environment!). Possibly the answer is more lasers. Of course those only have LOS capability, Equally the size of the laser you'd need to burn through a major warship at LOS range is quite staggering... for now!

A quick heads up, I am moving house in a couple of weeks, so packing and even internet availability may well get in my way of doing articles and the like. This means I have no idea what content (if any) I will be able to get up. This period of disruption will likely last for the next 3-4 weeks then everything should settle back to normal.
Update on the day of posting the article, which is written a week in advance: The fun and games continues with my car breaking down yesterday, meaning I had to waste four hours awaiting recovery, and I don't know if or when it'll be fixed. Equally the move date is all over the place due to the silly people in the house I'm moving into being utter Admin Vortexes, who appear to be so bad they couldn't achieve getting sunburnt in a heatwave!

Image credits:
aviationweek.com