Counterweight Fly Height Adjustment

We’re taking out some of the slack in our fly lines. The problem is that the pipes stop about 6 feet before the height of the ceiling. This cuts down significantly the height of our drops and scenery.

Why fly systems need “surgery”

If a batten cannot travel high enough, curtains and scenery stay in the audience’s sightlines instead of disappearing cleanly above the proscenium. Shortening or re-terminating lift lines raises the high trim, increasing usable fly space and allowing taller drops and borders.

Any change to lift line length directly affects where the batten stops in both its in and out trims. Work like this must be planned, measured carefully, and checked under the supervision of a qualified rigging professional such as the original installer, an ETCP certified rigger, or another experienced theatrical rigger. Students can assist and learn during this work, but only when a qualified rigger is actively supervising and double-checking each step.

Working on a counterweight set

When you change lift line terminations, you are altering primary load-bearing parts of the system. Only hardware and fittings rated for overhead lifting should ever be used, installed with the correct tools and techniques specified by the manufacturer or by the supervising rigger.

A qualified rigger should plan the work, approve measurements and methods, and decide which tasks are appropriate for students to perform under supervision. While the work is happening, the batten and any attached loads must be fully supported and secured so nothing can move unexpectedly. Before the line set returns to service, the supervising rigger should:

• Confirm all connections are correctly made and properly torqued.
• Test the full travel of the set at low speed with clear communication.
• Re-label trims and cue sheets to match the new travel if needed.

Students and teachers can help with measuring, labeling, tool handling, and observation, but the qualified rigger must make the final decisions and sign off on the work.

Arbors and counterweights

In a counterweight system, each line set has an arbor that carries metal weights to balance the load on the batten. When the arbor weight matches the batten, scenery, and hardware, the set is close to balanced and can be moved smoothly by hand at the locking rail.

Many venues adopt a color-coding scheme for weights so crews can quickly see what portion of the stack is permanent (pipe, track) and what portion is show-specific (scenery, drapes). A common practice is to remove only the “show” weights during strike while leaving the permanent balance in place for the next production.

Every arbor should have keeper rods and locking plates or similar devices so weights cannot bounce or slide out as the system moves. A qualified rigger should perform or oversee regular inspections for loose hardware, damaged weights, bent guide shoes, or other issues, with students observing or assisting as appropriate.

Locking Plates

Every arbor should have keeper rods and locking plates or similar devices so weights cannot bounce or slide out as the system moves. A qualified rigger should perform or oversee regular inspections for loose hardware, damaged weights, bent guide shoes, or other issues, with students observing or assisting as appropriate.

Safety, training, and crew habits

A counterweight system is safe only when everyone involved respects its limits and follows consistent procedures. Some core habits to teach and enforce:

• Only trained and authorized crew load, unload, or modify arbors and lift lines, with a qualified rigger supervising any changes to the system itself.
• Always balance loads at the loading bridge before cues are run, and have a qualified person verify balance on new or unusual loads.
• Never rely on a rope lock to hold a badly unbalanced set; fix the weight first under supervision.
• Keep hands, tools, and bodies clear of moving parts at all times; stop immediately if anything feels wrong.
• Use clear calls, rehearsed cueing, and a single fly operator in charge of a rail, with students trained in standard terminology and responses.

Schools are strongly encouraged to bring in an ETCP certified rigger or other qualified rigging professional for regular inspections, documentation, and on-site training. Students can gain valuable hands-on experience assisting during that work, but the responsibility for planning, executing, and approving any rigging changes must remain with the qualified professional.

Here we see the locking rail, aka, the pin rail (see note below.) Behind the arbor is a set of tracks. These tracks guide the arbors during their travel up and down. With out these tracks, the arbors could clang into each. This would not lend well to smooth fly cues! Some systems don’t use track; rather, they use cable guide wires.

Locking rail, tracks, and rope locks

The locking rail is the operator’s station for a counterweight system, with each line set’s purchase line passing through a rope lock. The rope lock is an operating and parking device for a balanced or nearly balanced set, not a safety brake for a badly out-of-weight system.

Before unlocking a set, the operator should test for balance by gently “bouncing” the rope and feeling whether the batten wants to run in or out. If the set is badly unbalanced, it should be locked, tagged, and reported so the load and counterweight can be corrected at the loading bridge under the direction of a qualified rigger, not forced through the lock.

Guide tracks or cable guides keep the arbors running straight, reducing sway and friction and helping maintain smooth, predictable operation. Any unusual noise, vibration, or binding during travel is a warning sign that the system needs inspection and correction by qualified rigging personnel, with students watching and learning rather than improvising repairs.

Here is a close up of one of the rope locks. The handle is pushed up and applies a lot of pressure onto the rope. You can see the rope being sandwiched between two sides of a clamp. Take note of the thumb screw on the rear side of the clamp. This is to adjust for different size ropes. Also notice the ring that holds the handle and the rope together. You can see that fly line #3’s ring is not looped around it’s handle. Always loop the ring……

This is Dave Vick. He is a Master Carpenter/Flyman/Rigger who has contributed to our pages on knots. Take a look at the weights behind Dave. The color codes are very useful for the proper counterweighting of the line sets.
Dave says, “We use yellow to denote pipe-weight, and red to denote track-weight on our travelers & walking leg sets. Unpainted weight is goods. Makes it *much* faster, easier, and safer to strip down quickly when stripping the house for a roadshow.

“Actually, a locking rail and a pin rail are two different things. Your photo was of a locking rail. A pin rail is, typically, a 4-6″ dia. steel pipe drilled to accept either wood or steel belaying pins and used to tie off ropes. A pin rail is essential in a theatre with rope, or hemp, rigging. However, we still install them as a part of larger rigging systems for use with temporary or spot line rigging. I agree with you, that the terms are often interchanged. However, given your target audience, you may as well keep things straight.”

Thanks again Bob. We’re looking forward to receiving a couple of photos of a PIN RAIL.

Scott:  Just browsing through your site and happened on the feedback from my old friend Bob Ramsey re your use of the term pin rail.  Since I had this photo available in our files, thought I’d send it in.  This is Ricky Ryan, the fly man at the Eisenhower Th. in the Kennedy Center, tying off a line at one of that theater’s two pin rails.  As Bob said, although most of the activity in a counterweight rigged theater is at the lock rail, there is also a large need for spot lines, etc. that are controlled from the pin rails (located on either side of the stage, in this case at an intermediate level between the lock rail level and the loading rail level).  Much of what they do at the Ike on the pin rails is operate electric multi-cables that are terminated at the grid, get tied onto various pipes being used as electrics, and have a slack loop that must be operated separately from and in conjunction with the pipe’s lock rail line set. Also they rig odd

Pin rails and spot lines

A pin rail is different from a locking rail. On a pin rail, individual lines are belayed to pins, often as part of a hemp or spot-line system used for temporary or supplemental rigging.

In many theatres, fixed counterweight sets are run from the locking rail while temporary lines, cable picks, or special-use lines are managed from a pin rail on a higher level. Design, installation, and major adjustments to these systems should be handled or closely supervised by a qualified rigger, while students help with tasks such as coiling lines, setting belays, or managing slack under direction.