Set the stage19 June 2019
The entertainment industry demands ever-greater spectacle, which means ever-greater demands on stage lifting technology. Julian Champkin is stage-struck.
Sustaining illusion is a necessity of stage-craft. The machinery that is involved should not distract from the entertainment. Lifting apparatus for stage, concerts and entertainment venues must be safe; it must also be unobtrusive—silent, and all but invisible. Of course we know that when Peter Pan and Wendy fly off stage at the end of the pantomime they are actually suspended on wires from some kind of hoist, but the less we see of the mechanisms the happier the audience will be.
Wirral-based Hoist UK have been in the field of theatrical lifting for a decade. As well as being a distributor for Verlinde stage lifting equipment they also make and supply their own, including such specialised products as winches for aerial performers—acrobats, circus performers, and the likes of Peter Pan.
They can be used for single line pendulum flying from a single winch, which is the standard configuration for aerial performance or for single point lifting in a theatre. Alternatively, 2D bridled flying using two winches gives more control over the actor’s direction; or 3D bridled flying using four winches can give total control over altitude, attitude and direction.
Hoist UK have also recently introduced a Compact Integrated Lighting Bar Winch Solution for lifting lighting rigs, audio equipment, curtains, scenery and more. The system is based around their Pilewind winch which is integrally mounted inside a stick of either 30cm or 52cm truss, which has no internal diagonals.
The Pilewind is manufactured by Hoist UK, while the aluminium truss is produced by Truss UK, a sister company to Hoist UK.
The standard lighting bar winch can accommodate safe working loads of 125kg and 250kg, but an also Integrated Lighting Bar Winch for load capacities of up to 990kg can also be supplied.
The winch can accommodate up to six lines coming off the drum to support the lighting bar and is fitted with an integral safety gear within the gear box to act as a secondary safety feature in the unlikely event of the main gear drive failing. When the secondary gear is engaged, it locks the drive shaft preventing the load from dropping.
The Integrated Lighting Bar Winch also features six-position gear driven electrical limit switches (upper and lower working and safety limits, plus two additional limits for auxiliary switching).
The system, they say, is designed for small studios, theatres and school applications where the installation of an individual winch and pulley system is problematic and a single unit is preferred. It is also a good fit for hire solutions. Instead of fixing loads of pulleys to the ceiling, couplers can be fixed to existing trusses to suspend the Integrated Lighting Bar Winch. There is therefore no need for drilling on site, which saves time and expense.
Film and TV studios depend even more on precisely-controlled lighting rigs, individually positioned for each shoot. An installation of Verlinde hoists has hugely eased working practices at the Glavinko TV and film complex near Moscow. Founded in 2008, Glavinko encompasses a dozen soundstages including a 33,368sqft soundstage that is Eastern Europe’s biggest. It has nine fully-equipped film studios stretching over 21,000sqm and hosts popular TV shows as well as major film productions.
Even a year ago, adjusting lighting equipment and scenery in the shooting pavilions involved climbers laying lines, lifting equipment, and solving other tasks at high altitude and at risk. The procedure has a name in the entertainment industry: it is called ‘stuffing’ a studio. It took time and was expensive. Modernisation of the system was needed. 224 Verlinde Stagemaker SR5 hoists were used to do it.
“We wanted to provide the customers with the opportunity to use an automated suspension system, because ceilings in the various pavilions are very high and not everyone was allowed access to the high rigs, and yet frequent access to them was necessary for every new set-up as well as during shoots,” said Vlad Mazurov, head of the directorate for customer operations of Sofit Light, which supplied the installation.
Installation took place in difficult conditions: equipment had to be placed in pavilions occupied for shooting that could not be cleared. “In some pavilions we had to work only during intervals between shooting, and all the scenery remained in place, while climbers worked atop.
“Full installation took four months; during this time about a thousand metres of trusses and 216 hoists were mounted.”
Load capacity of the Stagemaker SR5 model is 500kg; for this project the D8 version with double brake was used. They give a lifting speed of 4m/min. A patented chain guide system is claimed to eliminate chain twisting and jamming and to give noise levels of less than 60dB.
The hoists have their assigned default locations, with switching boxes on the walls—one per two hoists, with layout to all points on the ceiling. The filming customers get a prepared layout diagram, but if they are not satisfied with standard scheme on the ceiling they can lower everything to the floor, re-arrange it to their own requirements and then return it to ceiling height.
“We were surprised by the quiet motor working of the hoists,” said Denis Chuvilkin, head of hardware at Glavinko. Site preparation for shooting now takes at least half a shift less than before, and attractiveness of the facility for its customers has grown significantly.
Unobtrusiveness, as we have said, is important everywhere in stage technology; the aim is for the audience to see only what is part of the show. To that end Columbus McKinnon’s entertainment division, CM-ET, has a new black phosphate finish available on the chains of their Lodestar and Prostar theatre hoists. Designed especially for the entertainment industry the dull black surface absorbs light, reducing reflection and visibility during performances. Despite its matt appearance the chain still has a smooth running surface, and when properly lubricated and maintained, meets the same corrosion resistance specifications as the company’s standard zinc plated chain. CM-ET’s Lodestar comes in capacities of up to 2t, and, they say, has been the industry’s workhorse for generations. The D8+ version, which goes up to 1t, has the double brakes and a clutch outside the load path, and a 10:1 design safety factor.
That last point is important. Sound stages, shoots and theatrical performances are crowded with people— actors, technicians, stage hands and the public—whose minds are on things quite other than scenery or apparatus which may be hanging over their heads. Regulations stipulate different requirements for lifting gear that suspends stationary loads over populated areas and that move loads over them.
For example, the GV-D8+ (enhanced BGV-D8) classification in Europe is not considered suitable for moving loads over people, but is suitable for suspending loads (rather than moving them) over people without a secondary safety device. The classification demands, among other things, double brakes that act directly on the drive train, a 10:1 safety factor, and clutch that is not load bearing.
For situations where movement over people is required, Globestock’s UKmade G.Guard load arrestors are a safety back-up that can be used for lighting and sound equipment. The G.Guard is a retractable, tensioned extra safety line, reel-mounted, that is attached to the load. In normal use it extends and retracts, following the movement of the load. But if the load enters free-fall the cable is pulled out of its reel at an accelerating rate; when the activation speed is reached, the braking system engages, bringing the load to a stop.
The fall protection brake includes a shock-absorbing element to minimise the forces encountered when stopping a falling load; the stop is smooth and cushioned. Stopping distances are approximately 0.0 to 0.7m; G.Guard load arresters are suitable for protecting both static and moving loads and they are available for maximum working loads of 300kg, 500kg and 1t.
“Installers’ risk assessments may also highlight the need for a secondary backup,” says Sean Harris, Globestock’s marketing co-ordinator, “in which case load arrestors are often an ideal solution. Anecdotally, we have heard of stageindustry users deploying G.Guards as a means for reducing insurance premiums.” To cater specifically for the stage industry, Globestock also offer G.Guards in a black finish to blend into the background and not distract from the performance below.
G.Guards, he says, are well suited to temporary installations, as well as permanent installations. Straight-forward single shackle fittings allow them to be fitted easily and quickly to a range of anchor types, and each unit is light enough to be carried by one person. The extendable cable is available in lengths of up to 25m, but cutting to length is not necessary: when the cable is connected to the load the equipment’s retraction spring will automatically take in the slack.
GIS has been supplying lifting gear to the entertainment industry since 1992, but their first range specifically designed for the sector was the LCH series. This, though, was very much based on their standard product lines for industrial appliciations. In 2014 GIS began the introduction of their LP series of electric chain hoists, their first to be developed from scratch for the special requirements of the entertainment industry. The LPM250, with a capacity of 400kg, was the first to be released; since then GIS have been extending the range with larger capacity models. The LP1000, with a maximum capacity of 2.5t on the two fall model, is their latest introduction, released in 2018. It is distributed in the UK by LTM, which was acquired by GIS last year; LTM describe it as giving customers a very costeffective hoist with maximum capabilities, and filling a gap in the market for small compact hoists with a high lifting capacity.
“The square profile of the manganese phosphated chain is much lighter in weight than round chain, and allows increased capacity,” says LTM’s marketing co-ordinator Alison Marshall. The square cross-section provides about 15% more capacity at the same nominal an identical nominal as round steel chain, which means that it now offers as standard the D8+ requirement of an 8:1 factor of safety. The higher crosssectional area also reduces wear and increases the lifetime of the chain. “The manganese phosphating process improves its corrosion resistance and dry running properties,” she says. “Lighter chain also reduces the weight for tours being shipped around the world, in turn reducing costs and carbon footprint.”
The final, and highest-capacity, release in the LP series from GIS will be competed next year. “GIS considers it very important to keep the electric chain hoists as compact and as light as possible,” says company spokesman Lukas Bühlmann. “For example the LPM250 reaches a maximum load capacity of 400kg but weighs only 12kg unequipped without its chain.”
This, he says, is especially appreciated by the riggers who use electric chain hoists for mobile stage constructions. The hoists often have to be lifted and placed in the working position by hand. Many of these hoists are used in outdoor applications. “Here it is of great importance that they are protected against dust and jet water,” says Bühlmann. “All LP hoists are IP65 rated as standard and have a cathodic dip coating which provides good protection against mechanical wear and high UV resistance.
“A possible second brake, which is mandatory for D8+ applications, can easily be added to the existing shaft without further modification. As no housing extension is needed for this, the external dimensions of the hoist remain the same, which again contributes to a compact design. Polygonal connections allow the LP series hoists to be disassembled and reassembled quickly. This saves time and costs, which service technicians as well as the customers appreciate.”
And small adjustments, he says, can bring big improvements. “Recently we introduced a two-part wearing plate. It has the huge advantage that the chain no longer has to be removed when replacing the wearing plate. This results in considerable time savings for hoists with high lifting heights.
“Several different options make it possible to tailor the hoists exactly to the customer’s requirements. And if a customer’s solution changes, the hoists can be modified rather than replaced in many situations,” he says.
As the ambitions of entertainment producers, and the expectations of their audiences, grow, stage technology will need to keep pace. It is a challenge that will keep manufacturers occupied for some time to come. But, as they might put it, that’s entertainment.