Also known as 'freefall abseiling', freefall rappelling is a form of abseiling that allows one to descend down a rope without a wall. This basically means that the descent is faster, and a bit scarier for the inexperienced.
The advantages of freefall rappelling are as follows:
Convenience - It allows one to descend safely in situations where there are no walls, such as caving (although most cavers would use a descender via Single Rope Technique (SRT) which is safer).
Fun - It is certainly more exciting than doing a normal abseil descent but requires greater skill. For the really adventurous, try it face-down1.
Aggressive - Most of the world's special forces units are adept in the art of freefall rappelling as it allows a very aggressive method of deployment down into buildings and onto the ground from helicopters (such as the assualt by the SAS during the Iranian Embassy Siege).
Aesthetics - Freefall rappelling looks a lot better and more impressive than plain abseiling, but only if you can do it properly. (See the film Mission Impossible 2 for a correct demonstration.)
As well as there being advantages, there are naturally, well, disadvantages.
Danger - Freefall rappelling, as with all climbing sports, contains a considerable amount of danger. This can be minimised with proper equipment and training, but it's advised not to try it unless you know what you're doing!
Skill - One needs to be experienced in abseiling, climbing, and general rope skills before attempting freefall rappelling. The person controlling your safety line must also be as good as you, preferably better.
How to Freefall Rappell
This is for informational purposes only. Please do not attempt this on your own, or without proper instruction, training, and equipment.
Two Harnesses with Leg Loops - One for you, one for your safety man or woman.
Static Line Rope - This is the rope you rappell down. It is pre-stretched, unlike climbing rope, so that you don't bounce. Check that it is long enough before use. This, like the dynamic line, should be 11mm Kernmantle.
Dynamic Line Rope - This is your safety line. It has not been stretched so that if you fall, it will stretch a little making the shock not as great. Again, check it is long enough before use.
Screw-Gate Karabiners (Krabs) - These provide the means to connect the ropes to your harness, figure of eight, and split ring. These must be screw-gate, as opposed to a snap-gate, for safety.
Figure-of-Eight - The all-important component for abseiling, this is what the static line passes through, the means by which one descends, and how you control the rate of your descent.
Split Ring - Your safety man has this connected to his harness via a krab2 to pass the safety line through. This will jam up if the safety line suddenly starts to run quickly, as in a fall situation.
Two Helmets - These are vital for your safety. Again, one for you, one for your safety man.
Tapes - These allow ropes to be attached appropriately and safely to fixed points.
Gloves - Not essential, yet recommended, a pair of gardening gloves will protect your hands from rope burn.
How To Do It
Set up the Equipment:
Put the ropes up in the correct manner using tapes and krabs if necessary.
Put the harnesses on, ensuring that the belt and leg loops are securely fastened.
Put the helmets on.
Connect the ropes to the harnesses:
Put one krab through your harness belay and another through your harness belay and your harness belt. The safety man should put a krab through his harness belay.
Tie a figure of eight on a bight3 on the end of the safety line. Clip this into the krab that is connected to your harness belay and your harness belt.
The safety man should take the other part of the safety rope (the part that comes down the other side from the point that it is fixed, the figure-of-eight on a bight being on the other side) and run it through the split ring and his krab. He should then take up any unnecessary slack in the safety rope.
Take the static line (the rope that you will rappell down) and make a loop. Put this loop through the large hole in the figure-of-eight and then pass it behind the small hole. This should firmly connect the figure-of-eight to the static line. If you are right handed, the static line that hangs towards the ground from the figure-of-eight should be on the right-hand side. If you are left handed, it should come out from the left-hand side. Now connect the figure-of-eight to the krab that is connected to just your harness belay, by clipping the krab through the small hole in the figure-of-eight.
Prepare to Rappell - By this stage you and your safety man should be in position and ready for you to rappell.
Decide which way you are going to step off the ledge (if applicable) and begin your descent.
Ensure that your safety man has taken up any slack on the safety line, but not so that it is taut.
Take up any slack on the static line so that it is taut. If you are right handed you should always guide the rope above you with your left hand and control the rate of descent with your right hand. Your right hand never lets go of the static line until you have reached the ground. Naturally, if you are left handed, the opposite applies.
Lock off the static line by moving your right hand (or left hand) behind you, close to your bum.
Check that your safety man is ready and do a final check of all your equipment and that all the krabs are screwed shut.
Step off from the edge with minimum forward momentum so that you don't swing. You will go down slightly with a bit of a jolt as the tension is taken up in the safety and static lines. Keep your right hand firmly behind your back with the static line.
As soon as you feel comfortable (when you've gotten over any shock, and stopped swinging), begin your descent proper. Move your right hand out to your side to allow rope to pass through the figure-of-eight and thus allow you to descend. If you need to stop at all, or slow down, just move your right hand with the rope back behind your back. This applies increased pressure on the static line, and allows you to stop.
At the Bottom:
As you reach the ground, be ready to land. Let your legs absorb the shock by bending them at the knee slightly. Ideally, you should land with the force as if you had done a small jump, so remember to slow down!
When you are sure you are on the ground, and that you can comfortably stand up, disconnect the static line and figure-of-eight from your harness, and then do the same for the safety line. Then move away from your landing zone so that if others are descending, you don't get in the way or get landed on.
Make sure that your safety man knows you've reached the bottom safely.
Worst Case Scenario
Not designed to put you off, this is just to make you aware of some of the dangers, and therefore hopefully prevent you from making them.
Setting up the Equipment - The most common fault is to put the harnesses on incorrectly. It is simple to put harnesses on, but just as simple to mess up. If done incorrectly, the result can range from having the leg loops bite into your legs (slightly uncomfortable), to your harness coming undone 20m-plus up in the air (slightly fatal)4. Forgetting to put your helmet on is just asking for something to fall on your head, so don't forget it.
Connecting the Ropes - This is probably the most vital stage to get right as it is the ropes that keep you from falling. Double-check the knots and that the krabs are screwed shut. If either of these fail then you can either get snagged up on the line (a situation which is hard to correct, especially under strain from your weight), or fall to the ground. The ropes themselves should be in good condition with the mantle break-free with no gaps in the core or lumps in the rope. If the rope has passed its fall rating or hour rating5 don't use it. Having the rope break is not good.
Final Prep - It is vital that you check that your safety man is ready. If he isn't ready and you step off and have a problem, he will not be expecting to take your weight on the safety, probably causing an accident for both of you. If you fail to lock off before stepping off the edge, you will go down fast and it could be hard to regain control. If you let go of the static line with your right hand, the rope will flow freely through the figure-of-eight causing you to fall. It is therefore a good idea not to wave at others. The final check is to minimise any danger of you failing to do something. Fail to remember to do this, and you could be in danger.
The Rappelling - As long as you have followed all the instructions up to here, there is surprisingly little that could go wrong. The golden rule is to always keep hold of the static line with your right hand. When you step off, be careful not to bash into the ledge/rocks etc, as you swing. If you do get into difficulties: don't panic. Panicking doesn't help when there is a lack of time before gravity looks up and demands to know why you're not down on the ground. Try to correct the problem as quickly as possible but also as carefully as possible. Tricky.
The Bottom - The actual falling part of a fall is not dangerous; it's the hitting the ground part that is. When you get to the ground, move away so that you are not in the way of anyone/anything else that may also be coming down. Remember to disconnect the lines only once you are sure you can stand up, otherwise you can jar yourself, and a twisted ankle or knee is not pleasant.
These are just reminders of what can go wrong. Do the right thing under the right supervision, and none of these things should happen. Hardly any accidents are experienced by those who prepare properly and use the correct techniques. Don't try this without correct equipment or instruction.
So that's freefall rappelling in a nutshell. It is fun and exciting, and it provides a great way to get rid of any excess energy, as well as providing a thrill. Just remember that there are dangers involved too. Always check that you know what you're doing, that your safety man knows what he's doing, and that your equipment is up to standard. For more information and training in this activity, visit your local climbing or caving club.