1. Rigging Certification -- Loader
Purdue University Theatre
April 8, 2006
Purdue University Theatre
9/18/2018

2. Introduction Counter Wait? How to knot hurt yourself and others
Principles of counterweight systems
How to knot hurt yourself and others
Safe working practices on the weight rail
Weight loading techniques and methods
Help! I’m tied up!
Common rope types and uses
Common knots and uses
Purdue University Theatre
9/18/2018

3. Counterweight systems
Used to enable scenery to come from and disappear above the stage
Simple in concept: a system of ropes and pipes is used to move scenery up and down (known as “flying in” or “flying out”)
Weight is used offstage to balance the weight of scenery onstage
Purdue University Theatre
9/18/2018

4. Counterweight systems
Two common types of counterweight systems
Single-purchase
Double-purchase
Purdue University Theatre
9/18/2018

5. Single-Purchase Counterweight System
Parts of a single-purchase lineset system:
Head block for lift and hand lines
Loft blocks (mule blocks as needed)
Wire-rope lift lines
Batten
Hand line (purchase line)
Counterweight arbor
Lock rail
Tension block
T-bar guide rails
Loading bridge
Single-purchase systems are used in a 1:1 ratio: for every foot of movement on stage, the purchase/hand line will move one foot; for every pound of weight loaded on the batten, one pound of weight will be loaded on the arbor.
Purdue University Theatre
9/18/2018

6. Double-Purchase Counterweight System
Parts of a single-purchase lineset system:
Head block for lift and hand lines
Loft blocks (mule blocks as needed)
Wire-rope lift lines
Batten
Hand line (purchase line)
Counterweight arbor
Lock rail
Tension block
T-bar guide rails
Loading bridge
Arbor blocks
Hand line tie-off
Hand line and lift line tie-off
Double-purchase counterweight systems utilize compound rigging for both the hand lines and the lift lines; the batten will travel 2’ for every 1’ of arbor travel, and for every 1 pound of load, 2 pounds of counterweight are required.
Purdue University Theatre
9/18/2018

7. Counterweight systems
Because single-purchase systems operate in a 1:1 ratio, they must be able to travel the full distance of travel required of the batten (i.e. for a batten to descend 65' from the grid, the arbor must ascend 65' toward the grid)
Because double-purchase systems operate on a 2:1 ratio, they only need to travel half as far; however, they need to stack twice as much counterweight, which means taller (and harder to load) arbors
Purdue University Theatre
9/18/2018

8. Counterweight systems
The Hansen Theatre employs a single-purchase counterweight system
34 counterweight linesets
2 counterweight tab pipe linesets (running US-DS)
56' battens maximum live load 1450#
5 lift lines with self-levelers
T-track guided steel arbors maximum load 1850#
2 counterweight (brick) sizes:
1" (1/2 brick), 14#
2" (full brick), 28#
Note that the maximum allowable load on the batten is less than the maximum allowable load on the arbor; because of this, it is never possible for a safely loaded lineset to be too heavy to be counterweighted properly.
Purdue University Theatre
9/18/2018

9. Lift lines and Hand lines
Wire rope lines connecting the batten to the arbor
Hand lines
Provide method of operation of the lineset
The hand line is essentially unrelated to the counterbalancing of the weight on stage
A counterweight system can “counterweight” a batten without a hand line
Changing the hand lines, for example, can be done with a load on the batten. This is, of course, not safe practice, and not advised.
Purdue University Theatre
9/18/2018

10. The Lock Rail
The lock (locking) rail supports a series of rope locks, one for each hand line
The lock is intended to keep a safely balanced batten in position
The lock is never intended to hold a heavily unbalanced (“out-of-weight”) load while loading or unloading
Purdue University Theatre
9/18/2018

11. Rope Locks Purdue University Theatre 9/18/2018
Consists of a pair of jaws and a lever arm. The arm has a cam, which presses against the onstage jaw, causing it to pinch the rope between both jaws. A steel ring (through which the hand line is threaded) slips over the lever when it is up (or locked). The ring locks the lever closed and keeps it from falling open. A properly adjusted rope lock will be “self-locking”; in other words, when it is raised 2 degrees above horizontal, it will stay in position.
The pressure of the jaws is easily adjusted by means of a thumbscrew on the back of the lock.
Purdue University Theatre
9/18/2018

12. The Arbor Purdue University Theatre 9/18/2018
The arbor is the rack that holds the counterweights
Consists of a top plate, a bottom plate, a back plate, 2 guide shoes, 2 steel guide rods ¾" in diameter, a series of steel spreader plates, and a locking plate
Purdue University Theatre
9/18/2018

13. The Arbor The guide rods keep the counterweights in place
The spreader plates prevent the guide rods from spreading apart should the arbor smash into the top or bottom stops; if the guide rods were to spread, counterweights could fall out
Spreader plates should be distributed every 2' (12 bricks)
The lock plate prevent counterweights from falling out in the event of a crash, and should be locked down above the topmost counterweight
The arbor is the rack that holds the counterweights
Consists of a top plate, a bottom plate, a back plate, 2 guide shoes, 2 steel guide rods ¾" in diameter, a series of steel spreader plates, and a locking plate
Purdue University Theatre
9/18/2018

14. Vocabulary Pipe weight In-weight Out-of-weight Pipe Heavy Arbor Heavy
The weight necessary to counterbalance the weight of the batten and the lift lines
Pipe weight on each arbor is painted yellow, and should never removed from the arbor
In-weight
Refers to a state of balance on a lineset
Out-of-weight
Refers to a state of imbalance on a lineset
Pipe Heavy
Refers to an out-of-weight lineset which is heavier on stage (at the batten)
Arbor Heavy
Refers to an out-of-weight lineset which is heavier at the arbor
Flying in (coming in)
The movement of a lineset or scenery down toward the stage
Flying out (going out)
The movement of a lineset or scenery up away from the stage
Heads
Announcement used to indicate an uncontrolled, falling item
Mention pipe weight on the tab pipes.
Purdue University Theatre
9/18/2018

15. The Loading Gallery
The Hansen Theatre has two loading galleries, at approximately 50' and 60' above the stage
When accessing the galleries (or any overhead position), remove all loose articles including hardware, tools, coins, wallets, or other items that might fall from your person
All of the galleries, with the exception of the upper loading gallery, are accessible via standard stairwell
Purdue University Theatre
9/18/2018

16. The Loading Gallery
Only authorized personnel are permitted on the galleries
Unless wearing a fall-arrest harness and secured to the gallery, the guard chains must remain in place
Never load or unload weight without being specifically directed to by the fly operator
Always use proper calls when loading and unloading weight
Always stack weights on the onstage side of the gallery
Never stack weights higher than the kick plate on the gallery floor
Purdue University Theatre
9/18/2018

17. Cadence (or calls) When loading weight: When unloading weight:
“Fly rail: loading 3 bricks, lineset 13.”
When unloading weight:
“Fly rail: unloading 4 bricks, lineset 3.”
When weight is loaded:
“Fly rail: lineset 12 at seven bricks above pipe weight.”
When weight is unloaded:
“Fly rail: lineset 7 at pipe weight.”
or, “Fly rail: lineset 7 now at 3 bricks above pipe weight.”
Purdue University Theatre
9/18/2018

18. Proper Loading Procedure
Announce commencement of loading to fly rail
Loosen lock plate
Slide spreader plates and lock plate up on the arbor and out of the way (secure with a metal spring clip)
Firmly grasp brick with two hands, one on each side
Always keep two hands on the brick!
Slide brick onto arbor and around rear guide bar
Lift near end of brick up and over to clear front guide bar; lower around front guide bar
Continue in this manner until proscribed number of bricks is loaded
Slide a spreader plate down onto the stack after every 12th brick
Slide spreader plates and lock plate down
Tighten lock plate
Announce completion of loading to fly rail
Purdue University Theatre
9/18/2018

19. Proper Unloading Procedure
Announce commencement of unloading to fly rail
Loosen lock plate
Slide spreader plates and lock plate up on the arbor and out of the way (secure with a metal spring clip)
Firmly grasp brick with two hands, one on each side
Always keep two hands on the brick!
Lift near end of brick up and over to clear front guide bar; lower to rest on stack to the side of front guide bar
Slide brick from rear guide bar and off the arbor
Stack brick on the gallery (on the onstage side, never higher than the kick plate)
Continue in this manner until proscribed number of bricks is unloaded
Slide spreader plates and lock plate down
Tighten lock plate
Announce completion of unloading to fly rail
Purdue University Theatre
9/18/2018

20. Common Ropes Manila (natural fiber) Best natural fiber rope
Because it is a natural fiber, it ages and loses strength
Internal rotting
Drying and dampening from atmosphere
Stretching over time
Purdue University Theatre
9/18/2018

21. Common Ropes Three-strand twist (polyester, Multiline II)
2 times stronger than similar-sized manila
Synthetic fiber is not susceptible to atmospheric aging
Less likely to stretch than manila
Because it is twisted like manila, any fiber breakage reduces the strength of the rope
Purdue University Theatre
9/18/2018

22. Common Ropes Parallel Core (polyester, Stage-Set X)
3½ times stronger than similarly-sized manila
Continuous polyester fibers surrounded by a polyester jacket
95% of strength is in the core; minor damage to jacket does not effect strength
Synthetic fiber is not susceptible to atmospheric aging
Nearly limitless lifespan
Purdue University Theatre
9/18/2018

23. Common Ropes
Breaking Strengths for Manila, 3-strand twist, and parallel core
Purdue University Theatre
9/18/2018

24. Common Knots Effects of knotting
Knotting a rope produces bends and shear stresses, and alters the geometric cross-section of the rope
Knots thereby reduce the breaking strength
Ropes will typically fail next to the knot
Two common (and preferred) theatrical knots
Clove hitch (used for tying to a rigid object, like a batten)
75% efficient (reduces breaking strength by 25%)
Bowline (used for creating a loop in a rope
60% efficient (reduces breaking strength by 35%)
Purdue University Theatre
9/18/2018