Light Beam Stands Guard on Prison to Quell Jailbreak (Jul, 1930)

They really didn’t think these things out too well, did they?

Light Beam Stands Guard on Prison to Quell Jailbreak

A LIGHT beam as a prison deadline—a beam that when interrupted by a felon bent upon making his get-away operates a machine gun pointed directly at the victim —is the latest addition to prison jailbreak safeguards. The apparatus, consisting of a beam transmitter which shoots a small invisible ray along the prison wall, and a beam receiver which picks up and records any breaks in the light, and at the same time fires a machine gun, is being installed in many prisons housing intractable criminals. And owing to its deadliness, its reliability, its silence and invisibility, the contrivance is doing much to cut down the prevalence of prison breaks.

The beam transmitter is an instrument, similar in most ways to a motion picture machine, and has mounted on it a machine gun of the Lewis type. The transmitter projects a small beam alongside the wall close to the top which is picked up at the other end of the wall by the beam receiver, otherwise known as the “Electric eye.” The heart of the receiver is the light sensitive lube, shown in the insert in the photo at the top of the page, which registers the projected beam. At any interruption of the beam impulses are set up in the tube which are amplified to an intensity that they actuate the firing mechanism of a machine gun mounted atop the transmitter.

The machine gun is trained along the path of the beam, and when a prisoner, attempting to climb the wall to escape, crosses the path of the beam, the electric eye operates instantaneously, firing the machine gun and thus cutting down the would-be jail-breaker.

  1. Eamon says: January 15, 20091:49 am

    The 1930’s laser-fence.

  2. Paul says: January 15, 20095:38 am

    To get around it, all you’d have to do is hold something up in front of the beam and cause the gun to fire until the ammo is depleted.

  3. nlpnt says: January 15, 200910:20 am

    …which would make enough of a racket to bring every guard in the place to the spot.

  4. Dowser says: January 15, 200910:49 am

    Another way would just to shine a flash-light at it and sneak through un-detected and without making any noice.

    But what was “They really didn’t think these things out too well” all about?

    Btw, the nasty thing about this solution was probably that it was deployed on the east-german side of the Berlin wall for quite som time.

  5. Charlie says: January 15, 200911:23 am

    Dowser: Just that as a general rule you don’t trust in the infallibility of machines to decide when to kill people. What if a guard fell off of a wall? Or a maintenance tech forgot, or didn’t know it was there?

  6. Dowser says: January 15, 200911:25 am

    Well, he should not be there… 🙂

  7. Tim says: January 15, 200911:49 am

    Birds, squirrels, falling leaves… all quickly mowed down by the unblinking eye!

  8. Dowser says: January 15, 200912:09 pm

    Don’t forget about fog, rain or snow, they will all be swiftly handled by the relentless robo-guard!

  9. Myles says: January 15, 200912:21 pm

    I’m impressed. We could install these in our homes and turn them on at night. Then we wouldn’t have to pay for police or monitoring services.

  10. Charlie says: January 15, 200912:56 pm

    Myles: Or childcare! Though blood can be a bit hard to get out of the carpet.

  11. Myles says: January 15, 20093:00 pm

    Charlie :). Looking at the diagram, things probably also get interesting when the bulb burns out.

  12. LightningRose says: January 15, 20095:10 pm

    This reminds me of the old saying, “The early bird may get the worm, but the second mouse gets the cheese.” 🙂

  13. Eamon says: January 15, 20096:38 pm

    Does anyone know if it was ever actually used? The article says it was being installed in many prisons but who knows if that’s true.

  14. Dowser says: January 15, 20097:23 pm

    Myles, it might be a problem to get your newspaper delivered if you don’t remember to turn it off in time, but sure! 🙂

    Eamon, as I mentioned before, it was used for period to “protect” the no-mans-land on the east-german side of the Berlin wall.

    And it seems like Israel is going in the same direction:…

  15. Brandon says: January 15, 20097:44 pm

    Look at the ways its pointed…if it started to fire, yes you might hit someone climbing up the wall, but you would almost certainly hit the side of the prison and maybe even get a few bullets into that little window…haha.

  16. Mike says: January 15, 20097:53 pm

    a machine gun, is being installed in many prisons housing intractable criminals.

    so how many do you think were actually installed?

  17. Torgo says: January 15, 20099:08 pm

    Technically the gun should be at the receiver, not the transmitter. That’s how I have mine hooked up. 🙂

  18. rsterling78 says: January 15, 20099:58 pm

    Wouldn’t moths be attracted to the light at night and interrupt the beam?

    And wouldn’t topping the wall with razor wire be a bit more practical?

  19. Dowser says: January 15, 200910:11 pm

    No problem, the moth don’t stand a chance against a lead slug!

  20. docca says: February 27, 20098:55 pm

    “Oh no, my ass has been detected!”


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