ABSEILING WITH A MARCHARD / AUTOBLOCK KNOT
TivissaRocks (a company of mountain guides and climbing instructors), is going to start a series of blog entries explaining different maneuvers and progression techniques used in climbing, both in sports climbing and multipitch climbing.
Before going into details, we want to clarify: climbing is a dangerous sport and we recommend you not to use the manoeuvres explained in this blog if there’s any question regarding the correct use. We recommend that you contact us at firstname.lastname@example.org, we will treat each specific case and will offer a beginners or advanced climbing course in world class destinations for climbing such as Margalef, Siurana, Montserrat, etc. We encourage you to present your case or experience and what climbing skills you would like to improve or learn, we will make sure you gain the knowledge to climb safer.
One of the most dangerous maneuvers in multipitch climbing is abseiling. We tend to focus most of our attention on getting to the top of the route and the ascent, the grade of each pitch or the necessary equipment we will require and often forget to carefully study the line of abseils once the route is finished or in the event that we need to escape the route.
We strongly recommend you to read the relevant guidebooks and reviews carefully, look for the most updated information about the route and the descent, both in guides and internet blogs, as well as asking other fellow climbers. Above all, take into account the length of the rappels/abseils and the length of the ropes that you will carry.
Here in TivissaRocks we can explain the simplest and safest way to rappel/abseil with a double rope:
First of all, the equipment you will need to use:
• A Tube belay device type like Pivot, ATC, Reverso, etc.
• Belay Sling: Recommended type: Multichain. (ATTENTION: The “Daisy Chain” is NOT a belay sling/personal anchor system)
• Double rope, it is important that both ropes have the same diameter. It is necessary to control the length, we always recommend to use 60 meters as it is the most common length.
• Cord for Machard or Autoblock knot: its length will depend partly on the diameter of the ropes; we will not specify the length, but we can confirm the cord must give at least three turns to the ropes when making the Machard. 5 or 6 mm diameter.
• Locking carabiners: It is recommended that the ATC carabiner type is HMS.
You might be wondering ….Why should I use an autoblock knot / Machard knot ?? Why not to use a shunt?
The Shunt is a good option for safety when abseiling, and it works on a single or a double rope, but it only works for abseiling, while a thin cord you use on a machard knot can be used for anything else like, for example, to link it to a tree during the route, and more importantly, it weights much less.
To put up the abseil, we will start passing the end of one of the ropes through the anchor rings, or through the ring if there is a chain at the anchor linking the two points, remember that we always have to rappel/abseil from two points.
We will take the end of the other rope and to bring them together we will make the DOUBLE OVERHAND FLAT knot, also known as the “european death knot”, but here we will use it double.
Among all the types of knots that can be used to put a double rope together, this one (made correctly) is without a shadow of a doubt the one that will provide us with more advantages: in addition to its simplicity and its easy checking, its resistance and versatility, it’s the most recommended knot for abseils since it has less chances of getting caught in a fissure or a tree thanks to the flat part that is left on one side of the knot. It is important to allow at least 40cm tail rope next to the knot. Here you can find some reasons, pros and cons about the knot on Climbing Magazine.
Important: We must remember in which side of the anchor the knot remains and what side of the rope we will need to pull down to get the ropes back.
We will take the two rope ends opposite to the knot and we will ALWAYS coil the whole rope, picking it up in one hand or placing it neatly on our feet, checking that no knot is made at the moment we throw the rope down.
WATCH: How to put up the abseil
Once the rope is ready, we proceed to perform the Machard / Autoblock knot:
1. We begin by putting the safety carabiner on the harness loop and the Machard cord inside the carabiner, we make a minimum of three turns to the ropes with the cord and we place the end of the cord back to the carabiner. We will do the Machard knot first, since the rope might be heavy, then it will be easier for us to insert the ATC device if we take in some rope and leave a loop between the anchor and the Machard.
2. To place the ATC device correctly, we need to allow some distance in between the machard knot and the ATC, and also, the ATC device must be above the Machard. This is where the multichain becomes most useful, since it gives us many options and sizes to put the ATC. The ATC device must be placed in a way that when the Machard clinches around the ropes to stop them, they do not touch each other (Machard and belay device).
WATCH: How to attach the Machard and the belay device
The Machard /Autoblock knot is meant as a backup to your brake hand. This knot slides over the rope during a safe, controlled rappel/abseil. In case the abseiler loses control and there is a sudden drop, the autoblock will clinch around the rope and stop the fall.
Before we start abseiling, we must check everything twice, there is only one life.
While rappelling/abseiling we must be careful and untangle the ropes if they have not fallen fully to the bottom, never continue abseiling if you are below the ropes or you may have to climb up again to untangle and retrieve the rope. You should also watch not to skip the next anchor.
In future entries we will explain more useful techniques and maneuvers in climbing, as well as the best climbing destinations and other interesting aspects of climbing; Do not forget to visit our website: