martes, 23 de febrero de 2016


Desnivel publica Después de la nieve, novela finalista del Premio Desnivel de Literatura 2015.
Ganar o no ganar. Eso no es el dilema. Al menos no en Desnivel donde las buenas historias suelen convertirse en libros, y los buenos escritores, ganen o no ganen premios, nos empujan a seguir creyendo en ese algo tan difícil de definir llamado “cultura montañera”.
Acabamos de publicar Después de la nieve, novela finalista del Premio Desnivel de Literatura 2015,con la que su autor, Ricardo Martínez Llorca, cierra el ciclo inaugurado con el libro El precio de ser pájaro en torno a la pérdida y la culpa.
Un relato, una historia que nos engancha desde su primer párrafo. Después de la nieve tiene por un lado la habilidad de trasladar al mundo de la escalada en solo integral, las contradicciones, los miedos y las culpas presentes en las vidas de hombres y mujeres de todos los tiempos. Por otro, utiliza una prosa ágil, casi periodística (no en vano el narrador es periodista), sin caer en la trivialidad o detenerse en lo superficial. El resultado es un relato en el que la montaña, la escalada son la excusa idónea para sumergirnos en una historia de renuncia, de abandono, de pérdida y de culpa.


miércoles, 17 de febrero de 2016

viernes, 5 de febrero de 2016



Nylon (polyamide) and Dyneema®/Spectra® (polyethylene) are two synthetic raw materials with distinct strengths and weaknesses used in the manufacture of slings and quickdraws. Understanding the properties of these man-made fibres will guide us to best practice at the crag for using such products.
While Dyneema® has a much greater strength-weight ratio (static load) than nylon, its elasticity is far less. At DMM’s test-tower we took a look to see what implications this difference has for a dynamic loading on to a Dyneema® sling and what happens if there is a knot in the sling? You can see the comparative results betweenNylon and Dyneema® slings (all rated at 22 kN) in this video and in the table below.
Red Walls, GogarthAfter watching the video I’m sure you’ll agree that dogging a move on a sport climb while clipped to any sling is a dangerous idea and that having any slack in a belay system is best avoided – you wouldn’t want to fall off a ledge clipped into a slack sling.
Even a 60 cm fall-factor 1 fall on to an open Dyneema® sling can generate enough impact force (16.7 kN) at the anchor to pull a Wallnut 11 wire (12 kN) apart. Tying a knot in a Dyneema® sling weakens it even further leading to sling failure in a fall-factor 1 loading on to a 120 cm sling.
For perspective, most leader falls are between 4 – 7 kNs. Forces above 10kN will start to cause internal injuries – 10kN equates to 1 metric tonne in ‘old money’.
While the impact forces in the tests for the nylon slings are lower than the Dyneema® they were still high enough to snap wires. This isn’t to say Dyneema® is bad and nylon is good. On the contrary, comparing the two materials, Dyneema® has a strength to weight ratio higher than not just nylon but also steel, a significantly higher resistance to cutting and lower water absorbtion (important in winter), making it an ideal material for slings and quickdraws. It is also more resistant to ultra-violet rays and chemical attack than nylon but has a lower melting point. This is an important factor to consider when abseiling – pulling a rope through a Dyneema® sling, say as in poor abseiling practice, will generate enough heat to severely weaken the sling, if not melt through it.
It’s knowing these properties and making an informed choice according to your needs as a climber that is important. Clearly, taking advantage of the shock-absorbing capability of the rope by using it to tie directly into anchors as opposed to using a sling, will reduce the chances of dramatically shock-loading the anchors. If you do use slings then ensuring there is no slack in the system is paramount.
It is also important to bear in mind that the characteristics of slings and quickdraws are also affected by the weave and blending of fibres, purposefully used to achieve particular handling qualities. Dyneema® slings are in fact usually a blend of nylon and Dyneema® fibres.
Mean Results
Open SlingsCowstail Rope ‘Slings’
DyneemaNylonSemi StaticDynamic
Fall Factor: 1 or 2Length of SlingLength of Fall8mm11mm16mm26mm11mm10mm
FF1+ Overhand knot120cm120cm11.111.0
FF2 + Overhand knot120cm240cm11.714.3
FF1 + Overhand knot60cm60cm10.2
Sling failure
Photo: Nick Bullock grateful for a decent sling runner near the end of the difficulties on the top pitch of The Super-Duper Calabrese E6 6b, Left-Hand Red Wall, Gogarth. © Ray Wood

martes, 2 de febrero de 2016