lørdag 16. juni 2018

A new Spade incident...


We sailed into the Limfjord (Jutland, Denmark) from the east, and would have to go through two lifting bridges before reaching the planned marina. A nice southeasterly wind brought us in to Aalborg at the right time for an hourly opening. But alas, a boat race was going on, and all traffic was stopped for more than an hour to come. So we had to find a place to stop and wait, and chose to drop the Spade in the vicinity of another sailboat which was also waiting. In the process, i came quite close to shallow water, so I did not want to back the anchor in as we otherwise always do. We were on watch to keep an eye of things anyway.

After a short while we recognized the unpleasant condition of anchoring in opposite current and wind. The current lined us up with the stern towards the wind, and the wind pushed us over the anchorchain. If the wind is strong enough and when anchored in shallow waters, this may easily keep scratching the anchor chain into the hull and keels. So we decided to try to find a place to tie up instead. As the Spade came up, it was like a mirror of what happened to us in Des Haies  in the Caribbean in 2015 (see previous post under this tab).









This is scary. It is the third time the Spade comes up with the chain wrapped around it, and in a condition that prevents it to reset. The two first times, there had been definite boat position shifts and drifting. But the anchor had been backed in.

It must be recognized that this last time is a bit special. The anchoring technique was really poor, I did not slowly drift back while the anchor chain came out (being cautious and preoccupied with assessing shallow water behind). Thus much of the chain was probably placed very close to the Spade. In addition I did not back it in. Had it not been for the previous incidents, I would not have reacted much to what I saw. Now however, I see a big problem with the two side "wings" (vinge) of the Spade. Due to these, the anchor chain will not slide free if the anchor is pulled or lifted. The Spade is effectively rendered useless, and the boat is free to drift. 

It seems like some second  and third and even more thoughts have to be made before anchoring with this anchor in shifting winds or currents. I believe the seabed has to be soft enough to bury the anchor so deep that the chain cannot creep under the "wings". This excludes rocky or hard clay seabed, maybe even seagrass, which normally might be OK under fairweather conditions. Unfortunately, in many parts of the world you can not see the bottom or your anchor through the water.

Spade anchors have shown good properties during tests regarding directional resetting. But this is with one strong directional reversal pull.

So is it time to change the anchor? It seems to me that Spade and Rocna are the overall winners of most anchor tests. We cannot use a Rocna due to the roll bar. And it seems the Rocna also has such wings, but maybe smaller. Maybe the Vulcan is a good alternative.

At least it is time to be even more conscious about seabed and anchor penetration when anchoring in shifting wind and current, even under light conditions.

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