Wednesday, April 30, 2014

Riders on the storm

29/04 day 11
Position: 65.379 N 47.100 W
Elevation: 2180 m
Total distance: 505 km
Distance today: 70 km
Hours kited 3h00

For tonight, Marc our meteorological router had announced a gentle storm. His advice was roughly: "Get the work done early, when the winds are still light, and make sure to tie down everything in time to get ready for the storm."
And while we were happy for this advice, and took it very seriously, we were at the same time a little sick of laboriously looping our biggest kites to grind little distances. So we rather did the opposite and waited for the increasing winds to get out our Beringer storm sails.
In barely 3 hours we kited about 55 km on the Beringer 8 m2 in steady winds of 50 km/h and 15 km on the Beringer 5 m2 with gusts up to 70 km/h. When we stopped, it was not without regret, as we quickly logged kilometers. But with strengthening conditions we started to worry about the resistance of the suspension lines of the sails with the heavy sleds. And most importantly, we needed to make sure we are still able to mount the tent.

The night was up to the forecast and our expectations. Despite a decent snow wall to protect the tent from the high winds, no sleep without earplugs.

The image shows Mika in the developing light blizzard. Even with better resolution, there wouldn't be much more to see. Its one of the particular things about these conditions, that we were kiting under stretches of perfectly blue sky, with the sun and clouds clearly distinguishable, while the surface is covered by a layer of thick driving snow.

The winds should weaken tonight and tomorrow, and we hope to take advantage of the wake of the storm. For the moment however (30/04) we are bound to the tent.

Beringer Skisails? These 'kites', developed by Wolf Beringer at least 30 years ago, have the particularity that the bar is directly connected to the bridles of only a few meters in length, that define the canopy, and without additional lines. Contrary to most current kites, the bar acts on the angle of attack of the canopy, rather than on the steering/brake back-lines. The direction of the Skisails is controlled by the torsion of the bar with respect to the wing. The control of the angle of attack with the bar provides direct control on the power of the wing. In strong conditions, this has the huge advantage that all traction can instantly be released. In addition, it takes less than a minute to take these Skisails down and packed. In combination with their excellent upwind performance, this makes for ideal storm sails. These advantages come at the price, that the Skisails cannot be 'worked' and looped to generate additional power in light conditions, due to the short lines and the particular steering system.

During his historic east-west crossing in 1888 Nansen already used conventional sails to aid progression. But the Beringer Skisails were most likely the first modern 'kite wings' used for a ski crossing of Greenland, when the Messner brothers stunned the world in 1993 (?) by covering the 1800 km from Isortoq to Qaanaaq, in barely more than one month.

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