And this from an engineer??? Oh wait, forgot, an Aggie engineer.

Huh? I am NOT Mexican if you are trying to insult me!!!!!!

You are talking modern stuff. I seriously doubt if these kind of people have this kind of equipmet, let alone know how to use it. I still come back to asking how this was done prior to optics and lasers.

So far this is the first thing that makes any sense to me.

 

I know some of older guys will know this.

Has anyone ever saw the Great Escape with Steve McQueen??

The movie is about them tunnelin out of a POW camp during WWII.

It's based on a true story and is a really good movie.

Anyways, I've also wondered how they could measure it so close.

 

What'chew talkin' about Willis?!?! I'm not a stinkin' engineer!!

I don't think he was talking about YOUR family. I think he was talking about the families of the people digging the tunnels.

Trial and error....or maybe they have periscopes.

 

OK, consider this... It wouldn't be really hard with an old antique brass transit from a pawnshop and a long tape measure to come up with the cross-border distance without ever setting foot on the other side...
I'm no surveyor, but I think I could come up with the range value(distance A to B)after a while without using ANY funky math or expensive electronics.... Mark out a long line exactly perpendicular to the A-B line on your side of the border and call that A-C.
Walking downborder from A towards C, occasionally stop and take a sight back towards A and B using the ancient transit to determine when the bearing angle from A to B = exactly 45degs... Mark this as location C... Distance you walked from the stake at house A to transit's current location C = the distance from A to B.
I figure with a little preplanning, this could even be done at NIGHT!

Remember, these folks are NOT short on $$$$ and people resources! They have access to weapons, sophisticated electronics and communications equipment that our LEO's only WISH they had the budget for.

K.

 

COMPASS....

Start the tunnel where the goal is at due north or south. That way, you can always either dig the way it is pointing, or the opposit way it is pointing. Every ten or 15 feet, set up a reference point, and use the sight that are on most compasses and make sure they line up. Of course user error does factor into this scenario, but would be the way I would navigate it, if all I had was a compass. All you need then is a flashlight, and dig straight in line witht he compass.

Note to self: fly to mexico, and attach a magnet to every compass that I can find, that way when they start digging, they will be down there till death they do part....

 

Bearing angle with a cheap compass would be one thing.. But digging and keeping to the correct elevation is another! I guess when you start seeing roots, you know you are a wee bit too close to the surface...
I guess a very long roll of plastic tubing to make a Water Level would suffice...

K.

 

I'm telling you, it's trial and error...kind of like a bunch of prairie dogs. They dig and dig and dig and then a head pops out to see where they're at. Adjustments are made and then they dig and dig and dig some more.

 

"Look honey, there is another Mexstan (oops, I meant Mexican) with his head popped out of the ground...I hope they see that cliff before they dig through."

I wonder if their leader is Wiley Coyote?

 

Mess with the compass in my truck and I will stick a Mexican on you!!!! After that NO compass will help you find your way!

 

I don't need to dig any tunnels - especially northbound. Why would anyone want to go and live in the states when Paradise is right here? Oops, maybe this should be posted in the political arena?