Tuesday, 17 June 2014

Special Forces Crossbows

                While locating illustrations for my previous blog post I came across some intriguing images. Some were of Special Forces units with crossbows. Also there were statements that a wide variety of Chinese units use crossbows, including their traffic police. Possibly “traffic police” in China covers a wider range of duties than the translation of their title suggests. Slovenians, Croatians, Spain, Greece, Serbia and Turkey are all fielding crossbows, some of them having been used in action. Trying to get some more concrete information on these modern uses of the crossbow has proved elusive. Plenty of opinion and conjecture out on the web, much of it with obvious errors.

                Some personal thoughts along these lines:-

                Contrary to what is often claimed, crossbows and bows are not silent. It is more accurate to say they are quieter than firearms. There is not muzzle blast and no supersonic crack. Bows and Crossbows do store quite a bit of energy, however, and when this is released some of this is as sound. If a bow is loosed from a location close to you you will be able to hear it and may locate the shooter.

                Bows do have recoil. Some people seem to thing recoil is something to do with the explosion of gunpowder. If a bow projects a bolt of one or two ounces at a hundred or more feet per second there is going to be a kick. Incidentally, that is why the railguns Arnie shoots in “Eraser” would have been a handful. Basic physics means a high velocity projectile expelled from a weapon will create recoil whether it is projected by gunpowder or electro-magnetism.  

                In medieval times it has been authenticated that there were crossbows with ranges in excess of 350 yards. Some siege crossbows could reach 450-500 yards and had draw weights of thousands of pounds. Most modern crossbows have draw weights of around 150 pounds. Even with high tech design and materials it is unlikely they are effective at more than 200 yards, probably less. Even compared to a subsonic bullet a crossbow bolt is considerably slower with means more curved trajectory, greater susceptibility to wind effects and longer time of flight to target. All of these will affect the practical effective range.

                Both bullets and crossbow bolts kill by penetration and blood loss. The impact of a bullet often has a stunning effect that allows these more lethal mechanism to have time to take effect. This is rarely seen with an arrow or bolt. This means someone shot with a crossbow may cry out, raise the alarm or trigger a bomb before hit kill or subdues them. This is assuming the bolt has not been treated with a poison or tranquilizer.  

                Many of the bolts shown in these photos are simple ogival points as are used for target shooting. While such bolts are sometimes marketed as being for hunting they are very poorly suited to for this purpose. One of the advantages of a bolt is that it can mount an edged head that can cut through soft body armour and webbing equipment.

                What are these modern crossbows being used for. A popular theory is “sentry removal” but there are a number of objections to how practical this is. The shooter would have to get relatively close and have a good estimation of range to allow for the ballistics of the bolt. To produce an instant, quiet kill the number of suitable targets is also limited. Special forces units have access to suppressed firearms including specialist weapons such as those produced by JD Jones. Such weapons are easier to carry than a bulky crossbow and offer a number of advantages including a quick follow-up shot when needed. As an aside, it seems incredible that any competent military force still fields solitary sentries!

                Line throwing has been mentioned as an application of crossbows, which makes some sense. A related application is to project a grapple that can be pulled back through the undergrowth to trigger tripwires. A similar system is in use using a grapple launched from the muzzle of a rifle like a rifle grenade. The grapple setting off any explosives does counter the argument that using the crossbow is more stealthy! Given that the line on the grapple must be relatively robust one wonders if alternate projection systems such as Atlatl might be just as effective at casting the grapple a similar distance.

                Perhaps the most interesting suggestion for using as crossbow is the idea that a hit from a crossbow will not set off any explosives the target may be carrying or wearing. Of course, the lack of incapacitation becomes a factor here too so the bolt probably needs to be combined with a fast acting (possibly lethal) does of tranquilizer or similar agent.

Attack, Avoid, Survive: Essential Principles of Self Defence

Available in Handy A5 and US Trade Formats.
A5 Edition.
US Trade Edition.