[pct-l] Testing of Bear Cannisters / URSACK

[Ken Powers]

Matt,

Personal experience: A well known cinnamon bear at Cathedral Lake in 
Yosemite was scared off from an neighboring campsite at dinner time. It ran 
toward our unoccupied campsite. When it saw our Garcia sitting about 50 feet 
in front of our tent it immediately made a U-Turn and went back to toward 
other campsite. I have heard of other people stating similar experiences. 
California bears know they cannot breach the canisters.

The bear canister that was defeated by Yellow-Yellow was a Bear Vault. The 
Bear Vault can be compressed by squeezing the sides and popping the top off. 
The Garcia cannot be compressed. It's sides are more rigid and it is shaped 
with a wider middle with a ridge. Good engineering!

There are no physical hinges on a Garcia. The lid is recessed into the top . 
The lock is flat and operated by a quarter or similar sized flat object. 
The lid unlocks, pivots open on the heavy plastic supporting the lid. I'll 
take your word that there exists a weak point. I don't see a point weak 
enough for a bear to open the canister.

You mentioned that the larger the object the easier it is to gnaw on. I 
submit that there reaches a point where that is no longer true. The size of 
the Garcia is so large a gnawing bear has trouble getting any purchase on 
the canister. The rounded edges and slanting sides give the bear little to 
gnaw on.  People who have gnaw marks on their canister are proud of them and 
are excited to show them off. The marks I have seen are merely heavy 
scratches - not even near to damaging the structure integrity of the 
canister. And most of them are on the top near the "weak point".

The biggest problem I have heard of in using a Garcia canister is that a 
bear bats them around until they roll down an hill - perhaps into running 
water. The owner has trouble finding his canister the next morning. Many 
people paint bright colors on their canister to help find/identify them.

I have no interest in Garcia or any other canister company. But I do believe 
these canisters a worthwhile in protecting our bears.

Ken

----- Original Message ----- 
From: "Matt Thyer" <matt_thyer at hotmail.com>
To: "'Scott Bryce'" <sbryce at scottbryce.com>; <pct-l at backcountry.net>
Sent: Wednesday, April 28, 2010 3:14 PM
Subject: Re: [pct-l] Testing of Bear Cannisters / URSACK


If you get a chance give a dog a chew bone that's too big for it to fit all
the way in its mouth.  Dogs will gnaw at the side of the bone until the
tooth-on-bone friction abrades the surface of the bone enough for them to
gain leverage on the now roughened surface.  While they're gnawing they'll
usually hold the bone between the front paws and the ground.  This action
does not require them to possess an opposed digit and the action is
generally easier the larger diameter the bone happens to be.  Most of the
abrading action is the work of the canine teeth, but they can and do engage
teeth further back along the jaw including molars.  The upper jaw is rested
on the top of the bone and the bottom is leveraged against this fulcrum
until the surface is weakened.

The top of the Garcia Bear looks a lot like the bottom of a big femur.  The
lid has a pair of recessed locks and a stationary hinge, but there's still
weak points where the lid sits within the canister's upper portion and where
those milled aluminum recessed locks are.  Now imagine a big bear head
resting in the shade of a long needled pine tree with a Garcia Bear
canister.  It would rest its upper jaw on top of the canister and begin
gnawing at the wall and top of the canister until it created a weak point
which it could exploit.

A hinge is a type of bearing that connects two solid objects, typically
allowing only a limited angle of rotation between them.  The recessed milled
aluminum "locks" are actually hinges in disguise.

I've been thinking it would probably be helpful to categorize encounters at
some point since there are a lot of variables that might result in a
problem.  It's extremely hard to be objective about encounters because
reporting is, as best as I can tell, completely anecdotal.  Something like a
range from "Bear sighted in area, but ran away" to "Bear broke into camp
entered <brandX> canister."  As I sort through encounter reports I'm seeing
what appears to be a lot of successful bears, but I'd wager that most bear
encounters aren't even noted which makes it impossible to calculate efficacy
of canisters.

2 cents,

MT


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