UKC

Inspired by the scene in Taken 2 where Liam Neeson establishes his location by the simple measure of phoning his daughter and instructing her to throw a hand grenade out her hotel window in the middle of Istanbul and measuring the time delay before he hears the blast I am wondering if MCofS and BMC should recommend hand grenades as standard navigational equipment for hill walkers in the event they become lost.

One problem is that the method shown in Taken 2 is impractical for mountain rescue because it requires the use of mobile phones , which are unreliable in the hills. Therefore, assuming the more usual scenario where the lost walker and mountain rescue each have at their disposal only a box of hand-grenades, an O/S map, a bootlace, a pencil and the ability to measure time delays to within a tenth of a second by counting in their head is there a reliable method by which the location of the lost walker can be triangulated using the Hand-Grenade Positioning System?

In reply to tom_in_edinburgh:

Lost walker sits on whole box of hand grenades and sets them off, spreading themselves over a significantly larger area and making a box search far more efficient by increasing the target size?

In reply to tom_in_edinburgh:

would it be ok to use in the presence of unstable cornices?

In reply to Dr.S at work:

Yes, that could be a drawback.

In reply to tom_in_edinburgh:

oooh, if they use a hand grenade on the end of the bootlace, tied to the pencil, as a pendulum, they could have an accurate time measure!
http://en.wikipedia.org/wiki/Pendulum

In reply to Dr.S at work:



That would work great, unless you tied the shoelace to the pin.

In reply to tom_in_edinburgh:
I think this is a silly idea. Most walkers don't carry a box of hand grenades. The modern, light weight hiker will opt for a claymore mine every time. They are useful in setting up a secure perimeter to protect ones butties from marauding sheep or nazi cows.
The boot lace and pencil could be used fashion a tripwire. When a rescuer trips the mine, the lost walker can accurately measure the time delay and work out their proximity to the rescue party.

In reply to dread-i:

Who has the holy hand grenade?

In reply to tom_in_edinburgh:


Great idea. But where can I buy a box of them? And can also I use them when I'm leading and get annoyed with my second? (I wouldn't throw them directly at him/her, of course).

In reply to Skipinder:


On the contrary, I see the use of the grenades for avalanche risk prediction as an additional benefit of the hand-grenade location system.

In reply to tom_in_edinburgh:

Three rescuers on the boundary of the search area detonate grenades according to a pre-determined time schedule, synchronised before leaving. Say, once every 90 seconds.

If the lost person hears all of the grenades at the same time, they set off one grenade. If they hear them at different times they set off two with a short interval.

Obviously the person being found needs to know what's going on, so perhaps we could add this advice to maps and survival bags.

In reply to tom_in_edinburgh:

"Hand Grenade Positioning System"

So that is what GPS stands for! I've often wondered. Must learn to use one sometime soon.

The "Taken" films are really quite nasty though aren't they, apart from the obvious absurdity.

In reply to tom_in_edinburgh:

They'd also be handy for warding off the unwelcome attention of over eager MR teams who may feel the need to rescue you at those, 'oh so difficult pitches' wether you want to or not.

In reply to tom_in_edinburgh:

What about a RPG or a heavy cal rifle with tracer bullets.
Both also solve the unstable cornice issue although the RPG admittedly may only solve it for you and not for an unfortunate group who arent lost but are closer to it.

In reply to dread-i:

A recoilless rifle would be just the thing for rescues, as it would allow you to mark the position of other parties who suddenly find themselves in distress.

In reply to tom_in_edinburgh:

Interesting discussion.

May I ask where I could buy some grenades and ear plugs?

In reply to The Lemming:


As far as I know grenades are supplied by friendly ex-CIA operatives in a fancy aluminium suitcase with moulded plastic foam. The suitcase also contains a pistol which never needs to be reloaded and a useful selection of automatic weapons.

In reply to tom_in_edinburgh:

Any of these worth a punt?

http://www.amazon.co.uk/s/ref=nb_sb_noss_1/280-5014657-8129508?url=search-a...

In reply to tom_in_edinburgh:

You may joke but this or at least a very similar idea was one of the proposed solutions to the problem of finding longitude at sea: A network of moored ships firing cannons at known times. Hopeless of course for a variety of reasons.

If both parties have the ability to make a loud noise, measure elapsed time to a tenth and an agreed signal-response procedure then yes, it's possible with 2 bang pairs (each pair initiated by the rescue party) to triangulate the lost person's position to one of two possible points on a surface with reasonable accuracy. Our ears allow us to determine the rough direction so that's probably good enough to resolve which of the two points to check.

jk

In reply to The Lemming:
>May I ask where I could buy some grenades and ear plugs?
Have you tried Ellis Brigand, Snow and Rockets or V2 outdoor?

In reply to The Lemming:


just search online. Add in "ISIS support" and "bomb making" and a few other relevant terms and I am sure the cops will be round to deliver some grenades. Admittedly stun grenades with the pin out but they will be delivered.

In reply to dissonance:

Thanks for the heads-up.

I'll let you know how I get on.

In reply to XXXX:

The best solution in terms of minimal use of hand grenades and lack of requirement for communication or accurate watches that I can come up with is:

One mountain rescue guy with four hand-grenades starting at a known location. Walker with three hand-grenades at an unknown location. The mountain rescue guy throws the first hand-grenade to alert the walker that the location procedure is about to start at which point the walker gets ready to throw one of his own grenades. The mountain rescue guy waits a minute for the walker to get ready then throws a second grenade and immediately on hearing the explosion the walker throws one of his own. Mountain rescue guy calculates the distance to the walker based on the delay between the two bangs after subtracting the 5 second fuse on the walker's grenade (the time delay indicating twice the distance since it is there and back) and draws a circle on the map. Mountain rescue guy then walks about 1/2 km to another location and repeats the procedure (without the initial grenade because the walker is already ready to respond) drawing another circle - this narrows down the walker's location to two possible points. Mountain rescue guy walks to a third location and repeats drawing a third circle at which point the walker is located.

In reply to tom_in_edinburgh:

they were surprisingly close to civilisation and could have walked out. At least until the grenade landed in their lap.

In reply to dissonance:


Another advantage! It would make people think twice before calling Mountain Rescue.

In reply to tom_in_edinburgh:

That's the simplest semi-practical solution that can provide an unambiguous search area.

jk

In reply to jkarran:

If you are talking about area searches then surely a cluster bomb or thermobaric weapon of some sort would be more appropriate?

In reply to davidbeynon:

I like it. Some might say it's overkill but you can never be too prepared
jk

In reply to jkarran:

I think this has already been tried in the field (and at altitude) using Nitro Glycerine in an American study dating back to 2000 supported by Ed Viesturs.

In reply to Gavin:

Hmm, I think I saw a documentary about that. Now what was it called...
jk

In reply to Gavin:

Now your talking! That and a couple of opposing armies armed with a few 25lb ers up in the Karakoram. The bigger the bang the easier the recovery.

In reply to tom_in_edinburgh:

Its called sound ranging. There's a complicated formula on the Wikipedia entry for sound ranging that can be used to triangulate the location of an explosion. It was perfected in WW1 as a means of locating enemy artillery positions so they could be targeted.

In reply to dread-i:

Equip your tripwire are also quite reliable

In reply to tom_in_edinburgh:

HPS sounds perfect for when someone's practised navigating a route so much they have no idea what GPS grade to give it.