UKC

Looking to purchase a semi-technical axe for alpinism (e.g. Grivel Air Tech Evo, BD Venom, Petzl Summit Evo).

How important is a T rated axe? I understand that a T rated shaft is strong enough to belay from (400N force?).

Looking to do routes from PD-D+. I will pair the axe with a technical hammer (Grivel Matrix) when I'm on steeper ground.

Cheers.

In reply to blue_sundown:

To me, it ain't... if you belay solely from an axe, the snow will most likely fail before the axe bends.

For walkin' you'll prolly have poles. For easier snow ascents, I have two BD Whippets (ie. self arrest skipole, but then again I use it also when skiing). But a lightweight axe might also do.

Then proper tools for when ya need them.

In reply to blue_sundown:

Having tried to pull out a basic ice axe from a snow belay and failed with 3 of us hanging on the rope, I would be more concerned about the snow quality.

Due to weight limits etc I just take 2 technical axes to the alps, vipers. Depending on the route I would carry 1 or 2.

HTH Davey

In reply to HeMa:


A T-rated axe is useful in crevasse rescue to place on the lip of the crevasse to reduce rope drag - a B rated axe would be more likely to buckle when used this way. Of course it's debatable whether you think this is a good reason to have a T-rated axe.

In reply to planetmarshall:


I kind of doubt that...

In reply to blue_sundown:


It's worth being clear on exactly what a T and B rated axe means:
http://www.needlesports.com/images/AttachedDocs/Ice-Tools%20EN%2013089.PDF

In reply to blue_sundown:

Is the Air Tech Evo the only similar type axe around?
I like the DMM Raptor, but it's too heavy.

In reply to blue_sundown:

Can't see that you would regret a pair of air tech evos - they are so light and having the T rating is a bonus.

In reply to blue_sundown:

Depends on the snow, I've certainly made ice axe belays in neve that can withstand more than two climbers weight in my opinion. If your belay can't take 200 kg it's mostly psychological in my opinion!

In reply to alan.rodger:
The evos strike a good balance in my opinion.

In reply to planetmarshall:
If you have to use an ice axe belay for crevasse rescue and intend to winch using a pulley system 250 N / kg is too low a breaking point. As you winch the force on the anchor will be much more than double the climbers weight!

The problem is we don't know which test the axe failed to make it b rated rather than t. I suspect most b rated axes in good neve are strong enough for crevasse rescue, in most circumstances. I. Generally if you intend to climb you should be aiming for a t rated axe shaft whilst walking b rated is fine. Obviously there is some middle ground / cross over.

More info here http://www.needlesports.com/images/AttachedDocs/Ice-Tools%20EN%2013089.PDF

In reply to CurlyStevo:


If you ignore friction (which is of course a bit silly, but will probably not change the answer by more than a factor of 2 and probably less unless the rope gets stuck), then for slow hauling (no bouncing, again probably a factor of 2) the force on the anchor should still be around the climbers weight? Or when you say 'much more than double the climber's weight' do you just mean 'at most a few times the climber's weight', or are you (possibly quite validly) arguing that friction, bouncing etc are more significant than I am guessing?

If you are referring to the multiplication of forcing in a 3-1 or 6-1 haul system (for example) this is to multiply the small force you apply up to the hauling force on the order of the climber weight; it won't change the load on the anchor (unless you get the rope stuck and haul really hard).

In reply to needvert:



Wow I've never seen that before. the test for torquing the tip of an axe is pretty low.

In reply to CurlyStevo:

>snip<

No it won't the load is the load. In a theoretical 3:1 frictionless setup, hauling against the load will reduce the load on the anchor by 30% hauling against the anchor will increase the load by 30%.

In practice friction at each re-direct and over the edge etc screws that up but the principle is the same.

In reply to blue_sundown:

I would recommend BD Venoms those beauties are just amazing. Have 57/64 pair love every second with them.

In reply to SteveD:
Yeah I realised my mistake too late. Using the typical crevasse rescue pulley systems (3:1 and 6:1) The greater the mechanical advantage of the pulley system the greater the force on the anchors however in stasis (without the use of an ascender / prussic or lets say before some rope runs back through the system and it engages) the force on the anchor should only approach the weight of the climber not exceed it. Of course in reality to actually move them up say on a 6:1 pulley system it's likely a force on the anchor will exceed that created by body weight, can't find any actual experiments being carried out in this area to see test results.

In reply to CurlyStevo:

It is all pretty complex but with a 3:1 pulley, if you are pulling up (against the load) you are taking 1/3 of the weight, (not sure what happens at the pulley due to the 'pulley effect') also you are accelerating the load so the force on the anchor will increase but whether that increase cancels out the 1/3rd of the load that you have taken or not, I don't know.

I think that 'go gently' is the rule and watch your anchors carefully!

In reply to SteveD:

I own both e-climb Cryro and Petzl Sum'Tec.....i'd say the Petzl Sum'tec are brilliant for what you want and available in a few varieties at different lengths, depending on how tall you are and what you are most likely to use them for. They are a great Alpine axe and light enough for high altitude.

In reply to stratandrew:

I disagree the cyro is a jack of all trades and master of none. I'd get the grivel evo with its rubber handle and curved pick (better for ice axe breaking) over that for alpinism any day. For slightly more technical routes pair with a climbing axe and anything at all pushy I'd ditch the alpine axe and just take two tech axes (and suffer the reduced functionality on easy ground but make the hard ground easier). That's my 2 p worth anyways.