*


All times are UTC + 1 hour



Post new topic Reply to topic
 [ 19 posts ]  Go to page Previous  1, 2
Author Message
 Post subject: Re: Ice Screws and Snowkiting!
PostPosted: Thu Dec 15, 2011 12:32 am 
Offline
Medium Poster
User avatar

Joined: Fri Feb 24, 2006 4:02 am
Posts: 181
Location: planet earth
Image


Top
Profile
 Post subject: Re: Ice Screws and Snowkiting!
PostPosted: Thu Dec 15, 2011 12:50 am 
Offline
Medium Poster
User avatar

Joined: Fri Feb 24, 2006 4:02 am
Posts: 181
Location: planet earth
start here
Image

Image

Image

Image

Image

So you can see more or less that the threads are really important in ice...especially dense ice like on a lake.. more or less though the weakest part of an ice screw is in the hanger ESPECIALLY for what kiter's are doing.....which tends to push the ice screws hanger beyond its range of motion.

The next few pictures show a solution to the hanger issues but also let you keep the ice screw for the emergency needs that may come up on the lake while riding. This is a REALLY OLD common sense ice climbing trick (every ice climbing knows about this) More over it has been shown through countless studies that in good ice a ice screw can be very strong...enough that a carabiner will break when the screw and hanger are properly aligned. Yet in bad ice or with loads that are not with the axis that the screw and or hanger is in line with, they can be very and surprisingly weak and dangerous. Ice screws used in the manner that the photos below show can really save your butt (especially if you land on a ice screw....or save your skis/snowboard base if you ride over one))

Image

Image

Image

Image

realize this as well. The "thread" has been for years called the "V"thread in ice climbing, a few years ago it was with good data to support...found that lining the thread to be perpendicular (NOT PARALLEL) to the load was significantly stronger. This means that the thread should ideally be looking like an "A" not a "V". in the perspective that the kite will be pulling from.

Also, consider that the ice screw IS NOT EVEN necessary to make a thread, For example, one day while teaching a snowkite lesson, on a frozen lake., I used a ice axe "adze" (think chopping axe) to carve out a trough or trench like groove about 12 inches long and 3 inches deep.....here I used water, snow, and slush to fill in the space, but before totally filling in the trench, I put a piece of 11/16 inch webbing into the base of the trench and with the cold temps, about 10 minutes later it was DEAD FROZEN and help with NO issue, three fully powered kites looping simultaneously.

Another consideration is that for lakes and thermal heat or "conductive" heat transfer from the sun INTO the hanger and tube of the ice screw is a major factor in why some days an ice screw will simply melt out of the original hole made say early in the morning only to return early afternoon to the screw that a mouse could lift out as th metal heated up and made the hole bigger.

Mind you all, this is the tip of the ice berg. (no pun intended) in regards to the complexity to ice and ice screws. But it is lay information where I am from as I teach snowkiting as much as Ice clmbing and this info needs to make it out there.

thanks for the patience

Zebulon Jakub

Image


Top
Profile
 Post subject: Re: Ice Screws and Snowkiting!
PostPosted: Thu Dec 15, 2011 5:47 am 
Offline
Medium Poster
User avatar

Joined: Wed Dec 01, 2010 3:16 am
Posts: 83
Location: Saranac Lake, NY
Awesome post Zeb! Thanks for sharing!


Top
Profile
 Post subject: Re: Ice Screws and Snowkiting!
PostPosted: Thu Dec 15, 2011 7:17 am 
Offline
Frequent Poster
User avatar

Joined: Tue Feb 24, 2009 1:43 pm
Posts: 322
Location: Iv.G.-Slovenia
I don't know what kind of kiting you are refering to? My includes riding!!??


Top
Profile
 Post subject: Re: Ice Screws and Snowkiting!
PostPosted: Thu Dec 15, 2011 7:27 am 
Offline
Very Frequent Poster
User avatar

Joined: Tue Jul 08, 2003 7:06 pm
Posts: 2309
Location: MD
that's pretty cool.

no idea what you mean by "A" vs. "V" ...but the rest makes good sense.


Top
Profile
 Post subject: Re: Ice Screws and Snowkiting!
PostPosted: Thu Dec 15, 2011 2:43 pm 
Offline
Medium Poster

Joined: Thu Dec 25, 2008 6:21 pm
Posts: 98
Thank for the information Zeb. I wish I had it a couple of years ago , I would have picked up one long screw for making the ice anchor holes and several short screws to carry while zooming arround. Its allways bothered me leaving a metal post in the ice for a snowmobile or kiter to go ripping over. Good stuff thanks.


Top
Profile
 Post subject: Re: Ice Screws and Snowkiting!
PostPosted: Thu Dec 15, 2011 4:44 pm 
Offline
Medium Poster
User avatar

Joined: Mon Oct 13, 2008 3:51 am
Posts: 173
Location: Ridgway
That type of anchor is called an Abalakov V-thread. They're even more bomber than the ice screw placement. It's best to use a 25cm screw to make them.
If anyone needs ice screws sharpened, Bill Leo at Ouray Mountain Sports 970-325-4284 has a sharpening machine.


Top
Profile
 Post subject: Re: Ice Screws and Snowkiting!
PostPosted: Fri Dec 16, 2011 5:10 am 
Offline
Medium Poster
User avatar

Joined: Fri Feb 24, 2006 4:02 am
Posts: 181
Location: planet earth
hI let me try to clear the A vs V up. But first,.....a short ice screw can and usually is in good hard solid ice PERFECTLY FINE!!!!!


A vs V.

If you kite is pulling at North. then the holes should be HORIZONTAL (X AXIS) this is "A".
If your kite is pulling at North and the holes from the V thread are VERTICAL...then it is a "V".

The deal is, they are both good for kiting. BUT< the A or horizontal holes (perpendicular to the pull of the kite) are stronger then the V or the holes that are PARALLEL to the kites pull. If this makes sense, then you would want to ask, what if the wind changes directions and pull on the v or a thread changing the orientation? Then the thread can possibly become weaker. The KN (kilo Newton) of the pull from the kite is more than likely NOT going to break the thread especially if you fill the holes with water and let the holes freeze up.

does this help......?

And like said this is AKA Abalakov thread,.....BUT the A orientation takes this to a different level, and also, filling the holes with water and or sluch to freeze later take it to an even larger degree of strength.

Hope that this HELPS....

PS from Slovenia (spelling?) Yes I like riding more, hence why the sports is called snow kiting....but here in New England we are often on ICE not snow and the kites MUST be grounded when coming in to the landing zone or leaving the launch zone, especially at ice (lake ) events.


Top
Profile
 Post subject: Re: Ice Screws and Snowkiting!
PostPosted: Sat Jan 07, 2012 6:29 am 
Offline
Frequent Poster

Joined: Tue Jul 20, 2010 5:57 pm
Posts: 392
Location: Quebec, Canada
I just found this nice paper on ice screw :

http://www.needlesports.com/catalogue/c ... 9e00a633da


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic
 [ 19 posts ]  Go to page Previous  1, 2

All times are UTC + 1 hour


Who is online

Users browsing this forum: No registered users and 3 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group