Author Topic: Lockable Drawstring Knot  (Read 15265 times)

tylerthehun

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Lockable Drawstring Knot
« on: June 05, 2013, 02:57:50 AM »
I've been planning an extended backpacking trip and I've come across the problem of securing my backpack, which has a drawstring closure on top. I've been recommended a retractable cable lock which can be passed through the top following alongside the drawstring and secured, but this has proven to be a very awkward and time-consuming method.

What I'm wondering is if there exists a lockable knot that can be tied into the drawstring itself with an exposed bight through which can be passed a deadbolt (in this case the bolt of a masterlock), such that the knot can be neither loosed nor untied without removing the deadbolt. I haven't had much success fiddling around with it on my own. Is this even possible?

roo

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Re: Lockable Drawstring Knot
« Reply #1 on: June 05, 2013, 04:38:57 AM »
I've been planning an extended backpacking trip and I've come across the problem of securing my backpack, which has a drawstring closure on top. I've been recommended a retractable cable lock which can be passed through the top following alongside the drawstring and secured, but this has proven to be a very awkward and time-consuming method.

What I'm wondering is if there exists a lockable knot that can be tied into the drawstring itself with an exposed bight through which can be passed a deadbolt (in this case the bolt of a masterlock), such that the knot can be neither loosed nor untied without removing the deadbolt. I haven't had much success fiddling around with it on my own. Is this even possible?
You've got to admit that protecting cord with a masterlock is a little odd considering what quick work scissors can make of cord (or fabric for that matter).

What you could do is hitch a thin cord to the end of the cable lock (neck of the free end of the cable) such that when the bag is fully tightened, the end of the cable just begins to show and allows locking.
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tylerthehun

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Re: Lockable Drawstring Knot
« Reply #2 on: June 05, 2013, 05:48:54 AM »
Honestly, the cable lock could probably be cut with ordinary scissors as well, not to mention the bag itself. I'm not sure what you're describing with that hitch, but with the lock I have the extra cable spools back into the body of the lock so I can leave only as much free cable exposed as I need. When locked it's definitely plenty secure (as well as I can expect, anyway) but passing the free end of the cable in and out of the drawstring opening as well as feeding it around the loop is a real pain. Also, the extra drag added by having the cable in there makes opening and closing the bag difficult, and prevents it from opening all the way as the cable isn't long enough. The lock works fine once in place, but it really makes me work for it and fiddle with the cable a lot.

I was hoping for a deterrent that could be tied quickly onto the string and require physically cutting into it to open, which would be a vulnerability no matter how I secure the thing. The best I've come up with so far is a constrictor knot with the free end passed back through the middle, alongside and parallel to the bolt. It can be untied but it bites really hard once tightened making that very difficult, and pulling out the lock makes it fall right apart. Is there any knot that is physically impossible to untie without cutting it or removing a structural element like this? It might not exist, but I think it's an interesting idea at the least, even if it proves impractical for my uses.

Sweeney

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Re: Lockable Drawstring Knot
« Reply #3 on: June 05, 2013, 12:17:45 PM »
What you could do is hitch a thin cord to the end of the cable lock (neck of the free end of the cable) such that when the bag is fully tightened, the end of the cable just begins to show and allows locking.

I think what Roo means is if for example you put a small fixed loop at each end of your cable such that when the bag is closed only the smallest part of the loops emerges. Attaching your lock means that the loop knots (tightened and perhaps glued) are inaccessible. However when you remove the lock (but leaving it attached to one cable loop only) and open the bag you will lose one loop so you will need a thin piece of cord attached to this cable loop in order to retrieve it when you want to tighten it again. Same principle works if your lock uses the free ends of the cable rather than loops.

Hope that makes sense.

Barry
« Last Edit: June 05, 2013, 12:22:02 PM by Sweeney »

roo

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Re: Lockable Drawstring Knot
« Reply #4 on: June 05, 2013, 06:11:42 PM »
... cut with ordinary scissors as well, not to mention the bag itself.
Yes, as I mentioned with my comment about the fabric.  Unless you're just trying to keep your kid sister out, you're getting almost no security for your hassle.

You'd be better off locking your bag in a secure container/vehicle, or lacking that, just hiding it (security via obscurity).

Quote
I'm not sure what you're describing with that hitch,
The small cord attached to the cable end keeps the cable end from getting lost in the tunnel around the opening of the bag.

Quote
but with the lock I have the extra cable spools back into the body of the lock so I can leave only as much free cable exposed as I need.
If you have plenty of retractable cable length, maybe you could just crimp something larger than the grommet hole near the end of the cable to keep it from getting lost in the bag neck.  Again, we're only talking security against your kid sister.  ;)
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tylerthehun

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Re: Lockable Drawstring Knot
« Reply #5 on: June 06, 2013, 01:46:09 AM »
You'd be better off locking your bag in a secure container/vehicle, or lacking that, just hiding it (security via obscurity).
I'll be staying in hostels mostly, so I won't have the luxury of either obscurity or a vehicle, though I imagine I'll occasionally have access to lockers. I'm resigned to the fact that if somebody really wants to steal from me, it's going to happen. There's simply no way to thwart a determined thief, but I can minimize opportunity. Pacsafe nets are probably as secure as I can get in this case, but they're fairly bulky and expensive.

As silly as the knot idea might seem, I think it will be less hassle than this cable while providing at least equal security, however little. The drag induced by the cable adds a good 15-20 seconds to both opening and closing the bag, which is ridiculous, while a knot takes maybe 5 seconds to tie. The cable might have a psychological advantage in that it at least appears it might be impervious to ordinary scissors, while the cordelette is obviously no match.

I've been playing with this constrictor knot and it seems a bit more secure to do two individual knots with each side of the drawstring rather than a large one with both, and I don't need to bother with securing the free ends since the tiny knots remove almost any leverage one could get with the larger knot. I'm starting to think it's geometrically impossible to tie the knot I was originally imagining with a real rope since any slack on the free end is going to allow tracing it back through and eventually loosening it up. Friction can work to my advantage though and everything I've read about the constrictor has said to just cut it off if it jams since it's nearly impossible to remove otherwise, but since I can just pull out bolt the I don't need to worry about that. I'll probably go with this unless there's a better idea.

Dan_Lehman

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Re: Lockable Drawstring Knot
« Reply #6 on: June 09, 2013, 06:15:42 PM »
... and everything I've read about the constrictor has said to just cut it off
if it jams since it's nearly impossible to remove otherwise, but ...

That is because Ashely's too-proud assertion has been
parroted as though it's a commandment in stone (and
because copying prior books is much the method of
producing later books --with seeming blindness, at times!).   >:(

I can think in general that there might be some knotty solution
such as you seek, in which the tying would not be so surely
secure, BUT any likely tamperer would probably not have
the wit or persistence to doubt it --many people figure that
knots cannot be untied (or they parrot such assertion).

Still, I'm inclined to the worry that real thieves both exist
and know how to use knives (not scissors), and possibly
would take such a seemingly secured pack --the securing
sending a signal of valuables within(!)-- to use strong force
in a safe (for them) other location.


--dl*
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