Hemp Rigging System Tips

Discussion in 'Collaborative Articles' started by gafftaper, Aug 13, 2011.

  1. gafftaper

    gafftaper Senior Team Senior Team Fight Leukemia

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    A member posted a message asking for advice using hemp rigging. Below is an edited version of that original post:

    Is there any way to safely operate such a system? My real question is, how do you safely load a batten with such a system? There is no loading rail! Do I really just load up the batten, have 3 guys pull it up by hand, tie it off and then clip some sandbags on?! That seems like a horrible idea. Also, a few of the battens are not level. How do I fix that? Each lineset has some sort of black clamp box that holds the 3 lift lines even with each other and has a place to clip on sand bags (would love to know what that thing is called) but I can only access it when the pipe is all the way out. Do I really have to empty the batten, lift it all the way and then manually adjust while having some one next to me manually hold the lift lines?

    Any general pointers as well as checks I can do make this ancient system as safe as possible are much appreciated. I realize its ancient, but I figure there must be a safe way to use it if it was the norm for many years. To my younger eyes this thing seems like a death trap, but I'm hoping that thats only because I've only been taught proper procedures on newer systems.


    Several people responded explaining that the black box on the hemp line is called a trim clamp, easy trim clamp, trimming clamp, line lock, or clew. Easy Trim Clamp / Carriages, Clews, Trim Clamp, Rigging & Hoists / Rope & Rigging Hardware / Home - Mutual Hardware
    Many agreed that step one should be to buy this book: Amazon.com: Stage Rigging Handbook, Revised, 2nd Edition (9780809317448): Jay O. Glerum M.A. B.A.: Books

    Then Mpowers and Footer responded with lengthy posts. I have edited them together a bit to make a more cohesive answer.
    -Gaff


    Hemp House 101.
    First: Hemp house operated properly, can be as safe as any other rigging system.
    Second: Hemp house operated poorly, can be the most dangerous place in the world.

    So! Obvious point is: Learn to operate it properly and pay attention to any and ALL safety rules. Don't take short cuts. Don't try to rush. In the theatre, we're always in a hurry, but don't ever get in a rush. Rushing causes hands to get careless, skip steps and miss signs and warnings.

    First a few simple rules:

    Basic:
    1. Don't guess, Make sure the action/weight/move will work before trying.
    2. Never take a chance. Rigging is NOT play. Mistakes kill people.
    3. Jokes, horse play and gags are all fine, but NOT when rigging and moving/hanging over someone's head.
    4. Never rush.
    5. Never guess.
    6. never rush.
    Are you catching on to a theme here???

    1. Check the system daily. Everything. Look for any damaged gear, leaking sand bags, slipping Trim Clamps or sundays, frayed lines, in and out trim spikes , etc. ad infinitum.
    2. Check trim and level of every line set every day, Trim, level and move to spike as needed. Especially important if you system is rigged with natural fiber lines.
    3. Keep the pin rail area clean and neat. Do not allow rope loops and free ends to lay on the deck. Do not allow gear, head set cords, chairs stools etc. on the operating area of the rail.
    4. Never try to rig alone.
    5. Plan the hang/strike in advance.
    6. Get all equipment, gear, hardware in place before starting.
    7. make sure you have the right number of crew for the job at hand.
    8. Learn basic hemp/pin rail techniques, under over under 8 is the standard tie off. Light loads will hold with just under 8, but it is poor practice to use this tie off on anything more than an empty batten.
    9. Learn how to "ride" an un weighted load to the deck.

    To clarify the "under over under 8" I hope the following explanation helps. On a "standard" hemp house pin rail with belaying pins through holes (best) or welded to a 4" to 6" diameter pipe (OK but not as versatile or easy to use). To tie off a line or a group of lines, the line(s) is first brought past the rail on the operators side, below the rail and around the lower pin. Next it is brought up and across the rail and around the top part of the pin. Now the line(s) are brought down, across the first set of lines and again around the lower pin. Finally the lines are brought up to the top pin again. Now the operator makes a loop in the line(s) and turns the loop over so that when it is placed over the pin, the free end of the line(s) are under the rest of the rope. The last flip is the "8". When wrapping lines for a tie off, always wind in a criss cross fasion so that each wrap goes over and across the one before. After completing the "8" snug each of the lines individually.

    re: #9. To let in an un-counterweighted pipe, leave the last wrap around the bottom pin (or two wraps for a heavy load) and let in the lines slowly, hand-over-hand, using friction around the pin to control dissent. You're not taking any weight yourself, just applying pressure to control the friction.

    For Hemp house rigging you will need some method of over hauling line sets. Block and fall, capstan winch, chain hoist rigged for over haul.

    Standard method of Loading a line set. This method assumes the line sets are rigged in sets with a wood or pipe batten parallel to the plaster line and not spot rigged at various points.
    1. With the pipe at an "out trim" position (and making sure it's level), attach a clew, trim clamp or sunday to the group of lines.
    2. Attach a block and fall, chain hoist either manual or powered, or some other type of over haul line.
    3. Pay out the line to the deck.
    4. Attach load to batten.
    5. Using over haul, raise load to out trim height. Tine off lines to a pin.
    6. Attach sand bags as needed. Remember, the scenery must be heavy or the scenery won't go down/in. You can't push on rope.
    7. Check and set trim spikes. Check for smooth running. Adjust level.
    8. When the in-trim is set, leave it tied to the rail. Pull the line set out to the out trim and tie a new hitch on an adjacent pin.

    For lighter loads, you can let the line set into loading height, attach the load, then pull it out to out-trim with enough people to make it safely manageable (and someone belaying the lines around a pin). This can help the work-flow of a load-in, as you can get all the soft goods in the air (for example) and then have time to attach trim clamps and sandbags as hard scenery is being assembled on stage.

    Basic unloading.
    1. Move sand bags to rail.
    2. If load is too heavy to "ride in" attach over haul to clew/sunday/trim clamp.
    3. Remove sand bags.
    4. Lower batten/scenery to floor.
    5. Remove scenery.
    6. Raise batten to grid (or begin next loading sequence) Tie off and remove over haul.

    If at all possible buy a 1/2 ton chain hoist. Electric if you have power to run it, manual if not. A manual chain hoist is slow but reliable. Hemp houses without a loading rail are 10x more dangerous then a counterweight system without a loading rail. Because the normal operation of a hemp system requires the system to be batten heavy, you can run into some very sticky situations. Bull lines and such can alleviate some of these problems but not all. With a chain hoist you can safely take the weight of the load, remove the counterweight, and in a controlled fashion bring the load into the deck. Same thing goes for the loading of the batten.

    A word about overhaul of any kind. Make sure the anchor point(s) are adequate for the up load that will be imposed. Remember a block and fall or chain hoist make it easier to pull the load, but the lower hook is still experiencing 100% of the load in an upward direction. Capstan winches and the Tiffin overhaul winch rely on a rail a few inches above the floor to "snub" the toe of the winch. This rail takes 100% of the load minus the weight of the winch itself.

    Other options do exist for getting a load out. There is always the brute force approach. It can work as long as a the line is always in some sort of hitch on the rail. I walked into a situation several years ago due to a "Hey, we need a hand getting _______ out onstage and can't figure out how to do it". They were trying to pull the load out using a come-along (which can work but is painfully slow and dangerous) and an electric bumper winch (which is not rated for overhead lifting and had overheated and blown itself up prior to my arrival). After seeing the situation, I went down to the other theatre I was working at, grabbed a chain hoist, secured it to the rail, tied a sunday off to the lines at the grid and attached the hoist. Soon there after had the load in the air, properly trimmed, and safely in weight. No one broke their back. We did not snap any cables on the come along. Most importantly, the load was secure the entire time. Its not the way our grandparents did it or even our fathers, but its the way it should be done with modern practices.

    As for how to level a load:
    Hold firm on the clamp, usually requires a helper. Gently pull the rope that is less tensioned. Continue until all ropes are equally tensioned.

    A bit more on trim clamps:

    1. After installing the clamp and getting the bolts finger tight, squeeze the clamp and slide it a couple inches up the lines, then tighten again. This pushes the internal "teeth" into proper position. Repeat as necessary. The clamp can only slide up, not down.

    2. Methods to trim a loaded, locked and weighted line set (in addition to the above). Grab only the line that needs to be "shortened." Let the pipe start flying in a couple feet, then give that line a good tug, stopping the pipe. The one-way action of the clamp should pull that line through an inch or so. Repeat. You can also use a sturdy stick between the fly deck and the clamp to resist your pulling the line through.

    3. Common nomenclature is to refer to the lines in the line set by their relative length (the line that's attachment on the pipe closest to the pin rail is the "short," then "mid short," "mid long," and "long" (depending on the number of lines in the set). When trimming, someone on deck calls out "the short is long," meaning that that line should be played through the lock to "shorten" it.

    4. Remember, an EZ-Trim clamp is just that. A trim clamp, NOT a clew. The triangular "loop" at the bottom of a trim clamp is designed to hold the sand bags, not to attach a single haul line to control and tie off the load. Conversely, a clew http://www.jrclancy.com/gccmain.asp is not a trim clamp. A clew is designed to take a large number of lines, join them so that one or two larger haul lines can be used to move the load.

    I hope this helps. You will learn more about rigging in a hemp system then any other system out there. You really get to "feel" the load. We really can't be more specific on-line. Your best bet is bring in an experienced rigger to truly asses your system's safety and do some training. Don't be shy/ashamed to admit any lack of training or knowledge/experience. Hemp systems can be operated very safely. However, in the wrong hands they can be deadly. They need constant care and attention.There was a time in my career when I had better knowledge of 5th position plie' than a rope. Don't be afraid to ask for information/advice/help from people with more experience. The only stupid question is the one you don't ask. You will be respected more for asking than for trying on your own and screwing up. Don't be afraid to learn and don't be afraid to admit you are new at rigging. Rigging leaves very little room for mistakes, VERY LITTLE. Build a flat and make it an inch tall. It can be fixed. Paint a prop the wrong color. It can be fixed. Sing off key, embarrassing but "everyone lives" (Dr. Who reference for anyone that wants to guess) mistakes in rigging can injure or kill people. Very experienced riggers are hurt or killed every year because they forget the basics. "I've climbed this ladder a million times, I don't need to clip in." (30 year experienced Stage hand who fell to his death at a Florida concert) , "This is the way we've always done it"(just before the run-a-way at the Galliger that ruined a million$$ of Blue Man Group gear and canceled the show.)

    Ask the question. Don't rush. Take your time. Don't rush. Plan ahead. Don't rush. No safety step is wasted time. Don't rush.
    Old adage...."Safety is NO accident!"

    Please feel free to ask questions in the forums or PM Mpowers or the other experienced riggers on this list for help. The only dumb question is the one you don't ask.
     
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