Guidance and Warheads · 6:18am Nov 25th, 2013
Yay, weapons! This blog is about the sensors and effects of modern munitions.
dakka dakka dakka
Weapons make war work. There are lots of ways to get that accomplished, but the very basics of it are simple: ordnance on target.
Fun fact: "Ordnance" is a weapon. "Ordinance" is a piece of legislation.
But how do we put the guidance in the guided weapon? Many ways.
If it exists, we've probably built a weapon to take advantage of it. We have lasers, GPS, infrared (heat seeking), radar, sonar, optical, command, and others. There are a few major categories of guidance: active and passive. Semi active weapons are sort of halfway in between.
Active weapons send out signals and listen for the return. Passive weapons are just listening for signals the target makes. Semi-active weapons are halfway in between: listening for the returns, but returns produced from something else. "Signals" could be radar, heat, or other things.
Active weapons sometimes have "fire and forget" capability, so they can track targets themselves and whoever fired them can think about something else. Unfortunately, the target might detect the signals from the weapon and realize that it is coming. The AIM-120 AMRAAM air to air missile is an example of an active weapon.
Semi active weapons need to have a signal to follow. This means something needs to always help them along. The target might detect the source of the help, but they may not detect the actual weapon. A laser guided bomb is an example of a semi active weapon. Something paints the target with a laser beam and the bomb goes after it.
Passive weapons are hard to detect because they don't emit signals. However, in order to find the target, the target has to be putting out a signal for them to follow. An acoustic homing torpedo is an example of an passive weapon, following the sound of a submarine.
Those are the basics. Want to get more complicated?
Command guidance – something is directly controlling the weapon. This could be something like a TOW missile, controlled with a joystick through wires that trail behind the missile, or maybe a radio controlled SAM where the launching system uses radar to track the target and also the missile, guiding the missile until it hits the target.
Some weapons are pre-loaded with a set of GPS coordinates before they are launched. For example, a Tomahawk missile or Joint Direct Attack Munition (JDAM). A few of these can be updated in flight to hit something else. Unlike lasers, radar, or heat seeking, GPS is pretty much unaffected by weather. However, GPS isn’t good for hitting moving targets and can be jammed.
And some weapons have multiple kinds of sensors. If one sensor has better information, the weapon can use that. Example: the laser JDAM combination bombs.
It may surprise you that some bombs are like erector sets. You have your basic bomb body to which you attach different kinds of fins, fuzes, and guidance packages.
Bomb body at top, showing that it can have fuzes at the nose or tail. Two examples of fins are at the bottom. Retarding fins are used if you need to slow the bomb down as it falls.
Examples of regular dumb bombs on the left and their laser guided version on the right. Bottom left is a JDAM, which looks a lot like a regular bomb but with stuff strapped to it. The JDAM has become popular because of how cheap it is, reportedly $27,000. This is in comparison to a $730,000 Tomahawk missile.
Okay, so now we’ve got guidance down. How do we set the bomb off? With a fuze or detonator.
Contact- the weapon hits the target and goes off
Remote- somebody presses a button to set it off
Proximity- the weapon gets close to the target and goes off
Altitude- sometimes we want weapons to go off at a certain height above the ground
Timer- useful for setting the weapon off inside a bunker after penetrating a couple of the outside layers
Great, the bomb is going to hit the target and go off. But what will it do? There are lots of kinds of warheads.
Good ‘ol high explosive is the most common. This creates a simple shockwave that messes things up.
Sometimes, you can put a whole lot of little bombs together to sprinkle over a large area. This is called a cluster bomb. International law doesn’t ban them outright, but does frown on them. Lots of tiny bombs creates a bigger risk for a dud that could lay around for a while and hurt some unassuming civilian.
Some warheads have added features like fragmentation or shrapnel, aiming to hit the target with lots of little pieces of fast-moving metal like a shotgun. A variant of fragmentation is continuous rod, which creates an expanding metal ring from where the warhead detonated, in effect cutting through everything in a circle around it. This is most often seen in antiaircraft missiles.
Shaped charges have special, well, shapes that direct their power by aiming the force of the blast in a single direction, usually to penetrate something hard.
Thermobaric weapons use liquid or gaseous fuel combined with air. Most conventional explosives consist of a fuel-oxidizer premix (gunpowder, for example, contains 25% fuel and 75% oxidizer), whereas thermobaric weapons are almost 100% fuel. This makes them more efficient, but not as easy as conventional explosive.
Thermobaric effect. The initial little poof is the fuel being dispersed. The fireball is the result.
And of course, nuclear warheads. Other weapons of mass destruction include chemical and biological weapons. These usually carry a liquid or gas that covers the target area with bad stuff. I could devote a whole blog to WMD’s.
And then we get to one of my favorite kinds of warheads: kinetic. They don’t carry explosives, instead they just use their kinetic energy. A bullet, basically. These are good for when you want to limit collateral damage. Some defensive missiles like the Army’s THAAD and Navy’s SM-3 have kinetic warheads to shoot down enemy missiles. They actually have to skin-to-skin hit their target. Yeah, getting two missiles to collide in midair when both are moving several times the speed of sound. Surprisingly enough, the smart people have figured out how to get it to work.
Specialized kinetic warheads can be shaped or hardened in such a way to be extra penetrating. They can use exotic materials like depleted uranium to be as heavy as possible to hit with as much energy as possible.
A sabot fired by a tank. The stuff you see peeling away from the dart is packing material that lets it be fired from a conventional gun barrel.
Let me close with a bit of terminology. I dislike the term “smart bomb.” The weapon can’t think, it just does what you tell it. While it might be especially intelligent, it can’t actually make decisions and can only do what it is told. It can’t decide if the point you sent it after is a bad guy or a baby. Instead of calling them smart bombs, I prefer “obedient” bombs – because they do exactly what you tell them whether it is right or wrong.
As always, comments, questions, stuff I missed are welcome.
Thanks for enlightening as always! I swear you and The Descendant should team up and to a blog post on civil war technology or something.
1539628 That's not really my focus, but I would do what I could.
Boom
Good ole weapons
Hard science. Yum, yum.
Any updates I should know about as far as directed energy weapons go, or are they still Über expensive?
funny how you only touched on tank rounds for one paragraph.
If ya need a SME(Subject Matter Expert) on tanks, let me know
Tanks next please.
1539893
No tanks, I'm good!
A true 'smart bomb' by your definition would be a very interesting thing to see, one that had enough processing power to evaluate if the operator made a mistake that is. It would also be very tricky to do and still not really all that smart as I imagine it would only be able to interact with specific circumstances...
Well, food for thought I suppose.
Guns are for pussies. Fisticuffs is the way to go.
1539770 Same here, I love talking shop about tanks. My area of specialty is usually the WWII era tanks, though I can give a good accounting of myself in early and mid cold war tanks. Centurion's my favorite. Probably the best tank every designed and built.
Very educating.
Have you done a blog on the messed up world that is 'tanks' and all the things that are incorrectly labelled as such?
I'm no war buff, but knowledge is never amiss.
1540047
And we will name them SKYNET and everything will be dandy.
Everything I learn about military stuff seems to come from your blogs. Also, you can never have enough dakka.
1540337 I was thinking about more small scale, you know, individual devices that have no control over their lunch or activation, just the ability to stop themselves.
Because that couldn't possibly go wrong...
1540259
The centurion....wow, safe to say your the first I've heard say that.
and my experience is more first hand knowledge of modern American vehicles and tanks and Russian tanks from the T-54 and on
1540337 Ah, sorry, just found out that wasn't the whole clip. This is how it ends...
1540407 What do you mean when you say I'm the first to say that about the Centurion?
1540417
because it's slow, tall, only has a 105mm on the newer versions, had a Christie track, and only 150mm of armor(correct me if I'm wrong, I'm going off of memory here)
in it's hayday(1945 ish time period) it was a decent tank, but was soon outpaced by the t-62/64 series of tanks and the modernized versions of the t-55. The t-55 in fact had a huge upgrade to it's gun just so they could penetrate the armor of the centurion at range and the t-62/64 rolled off the line being able to do so.
I will give it this, it was a solid design. Everything on it was done well for the time period. The 8th hussars(correct me if i'm wrong again please) during Korean war, impressed alot of people by teaching them that anywhere a tank could go, we would be a devastating force. And since it was only a lighter 40 ish tons, it could(and can) go places heavier tanks cannot go. And coupled with the wide tracks the British liked throwing on their tanks only improved those facts
1540460 Well, the Israelis used the Centurion to great effect. Taking on both T-54/55's and 62's and coming out on top with them during their various wars with their Arab neighbors. Plus that L7 105 Royal Ordnance, is a deadly accurate weapon, and is in my opinion one of the best tank guns ever made.
Now I will grant you that the Centurion is hopelessly obsolete against modern battle tanks like the Abrams, Challenger, Leopard and T-90 today. But the thing that makes the Centurion one of the greatest tank designs, (Not necessarily the best, but still great,) is its ability to be upgraded and continue to come out on top of, what are supposed to be, superior opponents.
Moreover, the Centurion is one of the longest serving tank designs in the world. South Africa still uses a modified Centurion tank design to this day. In fact the Olifant, the South African upgraded Centurion, spots a 120 mm smooth bore. In addition, to numerous other upgrades to its engine, and fire control.
I might also add that a Centurion tank was used in a Atomic bomb test with a yield of 9.1kt and was placed less than 500 yards away from the center of the blast. After the test, it was discovered that the tank was only slightly damaged and that the engine had only stopped running for lack of fuel. After a quick fuel up, it was driven off the ranged and continued to serve with the Australian military during the Vietnam war.
Over all the thing that makes the Centurion so great is the fact that it is so versatile a design, and its ability to receive modern upgrades that keep it soldiering on. It has proven time, and time again its ability to go toe to toe with new tanks and still hold its own. And yes, the armor isn't anything to write home about, and I wouldn't consider the Centurion to be a world beater. But that wasn't what it was designed to do in the first place. It was designed to replace both medium and heavy tanks and in doing so, it created the modern main battle tank that we know and love today.
So this may come of as kind of a dumb question, but would an air to air missile have a IFF in it or could you trick it to track the one who fired it?
1540409
1540766 It's called Darkstar if your interested. It inspired the
rip offTV show Red Dwarf if your more familiar with it.1540501
Israel also had the advantages of better crew training and were going up against older model t-55/54's and early model export t-62.
As for the L7....ugh... I work on the MGS stryker, which has a m68a2 cannon(an American licensed L7, literally the same cannon but just made in America) and while it is accurate, it has some serious firepower issues(and ammo issues, but that's probably just us)
as for the upgrades, I've seen some stupid things done to centurions(stupid awesome not stupid stupid), Such as several countries turning the thing into basically a battle bus or slapping a modern leopard 2 turret up on top. the weirdest though was a MLRS version though....
anyways, I wasn't bashing on the centurion, and I apologize if it seemed like I was, I was just surprised to see someone who liked and supported an ole' workhorse like the centurion
1540993 Oh well, no offense taken on that regard. But yeah, as far as the Arab T-54/55's and export 62's you are right. Their training was horrible, the tanks were craptastic and all that jazz. As for the L7's firepower deficiencies yeah that's probably on us. Though I'm sure with some minor modifications to the ammo it could make it better. I mean, just look at the M-16 in early Vietnam, using ball propellant and not issuing cleaning kits to the troops in the field. Honestly, I sometimes what the Brass use for brains.
But yeah, I love the old Centurion. With a track record like what it has, who wouldn't like it?
Roll out!
badasshistory.com/badass-centurion2.jpg
1541048
well I love the ole' Abrams, which also has a wonderful track record
chivethebrigade.files.wordpress.com/2012/07/abrams-tank-920-50.jpg
And PS, the ammo issues I was talking about is more to the fact that we're shooting rounds made in 1970's and 80's, so we've had a few 'oh my fucking shit!' moments
1540513 Data links are important. As long as the airplane that fired the missile is still in contact with it, it shouldn't team-kill. If that isn't the case, then I would think that anything goes.
However, many air to air missiles only have motors that burn for a few seconds. They reach their top speed quickly, but glide after that. Therefore, many missiles don't have the power necessary to turn completely around and return to sender.
1541168 I can imagine. If those rounds are that old, no wonder you're having problems with them.
I think...I think I'ma try to stick to the weapons of old.
I know how a lot of weapons worked, and the tactics that went with them...lord I miss swords.
1541454 Ah thank you.
1541838
yeah, lets go with just a few
1542290 I take it that they tend to foul the barrel pretty quick?
1542878
yes, but I was meaning that it's like every other round that has an issue
1543127 I take it misfires are common as well? In addition to poor performance?
1543163
The most hilarious thing I've ever seen was one of out HEP (High Explosive Plastic) rounds had just enough energy to leave the barrel...to land about six meters in front of the MGS
Thank god it was a training round
1543426 Oh man, I've seen that happen before with a TOW. People just about crapped their pants.
1543431
not even talking about TOW's, we almost lost a stryker due to friendly misfire fire because of one
1543482 I was referring to what you said when the round left the barrel and then dropped to the ground because of lack of force behind it. But yeah, almost losing a Stryker to friendly fire that sucks.
1543501
yeah, I have no faith or trust in tows at all, too many of them fuck up
1543532 Agreed. Course that doesn't compare to a navy destroyers aft fire control turret malfunctioning and shooting a supply ship anchored near by.
1543537
whoops, hope noone got hurt
1543547 From my understanding the shell denoted in the ships laundry room. No one was killed but seven guys were sent to the base infirmary for chemical burns and what not.
1543551
guess they were lucky it was not a full burst
1543562 Yeah no kidding.