Many lighting guidelines for large arenas can be applied to similar but smaller facilities.
While many of us are excited by the sights and sounds of sporting, entertainment, and theatrical events held in an arena, we very rarely pay attention to an important part of the facility's infrastructure: lighting. Yes, we'll probably never be involved in the design or installation of lighting for such large facilities as the America West Arena in Phoenix, Ariz. (home of the Phoenix Suns), the Rose Garden in Portland, Ore. (home of the Portland Trail Blazers), or the Spokane Veterans Memorial Coliseum Arena in Spokane, Wash. However, many of the guidelines used in these facilities can also be applied to similar but smaller projects.
Let's take a look at these lighting guidelines and see how and where they are applied.
Arena bowl lighting
Arena bowl lighting is comprised of several systems that create a lighting environment unique to the event in progress. These systems are as follows.
* Event lighting system.
* Catwalk lighting.
* Temporary lighting systems.
* Portable spotlights.
* Theatrical effect lighting systems.
* Still camera strobes.
* House/emergency lighting.
* Suite/skybox lighting.
* Advertising/score boards.
* Aisle lighting.
* Exit signage.
The event lighting system is a fixed system that provides illumination for regularly scheduled events, including sporting events, conventions, and floor exhibits. This system delivers specific levels of horizontal and vertical illuminance in consideration of the numerous viewing angles of players, performers, and spectators, while also addressing television broadcast criteria and minimizing objectionable glare. Lighting uniformity criteria is explicitly specified and field verified. The appropriate combination of horizontal and vertical illumination and uniformity criteria defines the ability of the event lighting system to reveal the three dimensional image of an object, e.g., a ball or a player. This lighting effect is know as the modelling effect of the system.
As the event lighting system is required to illuminate differing event types from day to day, you should ensure that the necessary flexibility is incorporated into the lighting equipment, fixture layout, branch circuit zoning, and lighting control system. The event occupying the largest playing area (width/length/height) and/or the highest illumination level determines the overall extent of the system.
The event lighting system is used on a partial basis for events with smaller playing areas, utilizing fixtures designated to meet each event type's specific lighting criteria.
Event lighting systems typically consist of 150 to 250 special purpose floodlight type lighting fixtures.
Light sources. Metal halide (M-H) has become the lamp source of choice for arena event lighting systems. This lamp source is significantly more efficient than incandescent sources and renders colors more effectively than high pressure sodium (HPS) sources. M-H lamps have a flicker factor of less than 0.1, reducing the undesirable stroboscopic effect, which is particularly noticeable during slow motion replay television broadcast.
M-H lamps are available in color temperature ratings from 3200K to 5600K, and with color rendering indexes as high as 70. M-H lamps may be operated with instant-restrike type systems; however, evidence of superior field experience and a minimum five year warranty is recommended in considering the use of this type of control.
Lighting fixtures. Lighting fixtures used for the arena event lighting system have a substantially constructed housing, an optical reflector, a gasketed glass lens, a ballast, aiming angle marking and locking devices, mounting accessories, and an SO cord with a twist lock plug. Optional accessories include glare control devices, instant-restrike hardware, and motorized shutters.
There are two general classes of event lighting fixtures: heavy-duty floodlights and general purpose floodlights. Heavy-duty floodlights have a substantial housing, usually die cast aluminum, with a removable optical reflector.
General purpose floodlights are typically spun aluminum bowls, with the bowl used as the reflector. General purpose floodlight systems are less expensive than heavy-duty systems; however, the savings usually come in exchange for less precise optical control. This can result in uniformity ratios that do not meet minimum criteria, which can cause problems for television broadcasters. In general, heavy-duty fixtures with precise optical control should be used for network television quality venues.
A typical event lighting systems consists of 150 to 250 M-H lighting fixtures rated at 1000W each. Designing a specific quantity and type of lighting fixtures in a specific layout on catwalks poses difficulties, as performance of different manufacturers' lighting fixtures varies widely. Instead, it has become common practice to prequalify manufacturers who are asked to submit a price based on the application of their fixtures to the illumination criteria dictated by the project specifications. This would require each manufacturer to perform computer generated illumination analyses to verify compliance with the specifications. The electrical drawings indicate the perceived "worst case" design; that is, the system with the most lighting fixtures. It's important to furnish each prequalified manufacturer with complete architectural and structural drawings so that interference from obstructing structures, scoreboards, acoustical elements, banners, etc., can be accounted for.
Instant-on control. You should give early consideration of the necessity for instant-on control in the event lighting system. The need for this feature can increase the cost of the system by 50 to 100%.
M-H lamps take 5 to 10 min to reach full light output upon application of voltage from a cold start. When the lamp is turned off, it takes 15 to 30 min for the lamp to cool, restrike, and return to full brightness. Several NBA venues feature a black out of the event lighting system during player introduction to highlight a theatrical effects display.
One way to achieve instant-on control is through the use of an instant-restrike type system. This consists of a fixture-mounted control circuit and igniter that imposes a high voltage spike on the lamp, causing the lamp to instantly produce light output. The less time the lamp is off, the less time it takes to return to full light put. (See Table.) The actual performance of these systems varies from poor to very good, and only systems with proven field experience should be considered. This system requires a special lamp, which will have a shorter life than a conventional M-H lamp (published data is difficult to find).
Another way to achieve instant-on control is through the use of a fixture mounted motorized shutter system. One manufacturer's system uses a simple worm gear type motor mounted on a box on the outside of the fixture housing to open and close a single piece, external shutter. The shutter acts as a glare shield in the open position.
When the lights are signaled to go off, each shutter closes, creating a near black out condition (1 to 2% of the light leaks from the back of the fixture). If a shutter fails to close within 3 sec, that fixture's lamp is automatically extinguished and will restrike upon restoration of voltage after the cool down/restrike cycle.
Dimming systems, continuous or out-stepped type, are generally not used for event lighting systems. Event lighting systems are designed to meet each event's illumination criteria with all lamps at full brightness. Also, dimming M-H lamps produces an undesirable color shift that affects the color rendering of the viewed objects.
Because event lighting fixtures need to be readily accessible for aiming, adjusting, cleaning, and relamping, catwalks are provided. Through analysis of the physical structure of the arena and the dimensions of the viewing fields for each type of event, various catwalk layouts are prepared and reviewed, with the one best satisfying the illumination, access, and economic parameters of the project being selected. Lighting catwalks extend parallel to the long direction of the playing court.
It's important that catwalks be far enough away from the court edge to reduce the potential of objectionable direct glare to courtside spectators on the opposite side. Cross connector catwalks are provided to enable access as well as providing for additional mounting positions. Smaller arenas may have a single catwalk on either side of the court to provide a more economic lighting solution.
Catwalks are provided with intermittently mounted linear or compact fluorescent type fixtures for access and maintenance lighting. Fixtures are break resistant and are mounted 5 to 7 ft above the catwalk, approximately every 30 linear ft. They should be connected to the emergency power system as a separate lighting control zone.
Temporary lighting systems
Many events require the use of supplementary or temporary lighting systems that travel with, and are installed by, the event staff. Major concert tours travel with scaffolding and rigging for extensive lighting and theatrical dimming systems. A dedicated power transformer (typically 500-750kVA), with distribution and separately metered power connect/disconnect service points is provided to support these systems.
A series of disconnect switches fitted with cable lug and modular theatrical plug-in fittings is provided at selected locations. These are usually configured as two 400A and four 200A connection points at both sides of the stage. Additional connections may be provided for side stage, center stage, and exhibit floor booth temporary lighting connections. At the catwalk level, a 100A connection for boxing lights (usually mounted on the underside of the scoreboard), and two 200A spares at mid catwalk locations should be considered.
Platforms are located on the lighting catwalks for portable type spot lights. These lights are plugged into special purpose power receptacles, and a connection for a spotlight portable headset intercom system is provided. Spotlight platforms are typically provided at 8 to 12 locations on the lighting catwalk. The house usually owns two to six spotlights, with unused platforms available for temporary, event spotlight use.
Theatrical effect lighting systems
Theatrical effect lighting systems are often custom-designed for a specific team or venue. The lighting instruments and controls are factory-fabricated and mount as a unit or units on the lighting catwalk. The system is turned on from the control booth after the event lighting system has been turned off. A minimum allowance of 200A, 208V, 3-phase, should be made in the power distribution system for these systems.
Still camera strobes
Still camera photography requires a much higher illumination level than that provided by the event lighting system. As this higher illumination level is only needed for the short period of time while the camera's shutter is open, it's impractical to increase the event lighting system illumination level for this purpose.
Instead, a series of high power strobe/control units is installed on the lighting catwalks for remote activation from still cameras located on the event floor. A dedicated control wiring system is provided to connect the strobe/control units from still camera connection locations on the event floor.
Cleaning/maintenance/set up lighting
It's necessary to provide a reduced level of lighting (approximately 30 footcandles, horizontal) for cleaning and event set up activities. As such, you may consider using the event lighting system on a partial basis for this purpose. The event lighting system fixtures can be programmed to rotate usage so that lamp life balance is preserved.
If the event lighting fixture zoning does not permit this, a separate system could be provided. This is usually a general purpose high bay type M-H downlight fixture. You should avoid the undesirable color rendering effects of HPS sources in this application.
The house/emergency lighting system provides an instant-on source of general illumination (10 to 20 footcandles) in the arena bowl and is used extensively during spectator arrival, departure, and event intermission periods. The lighting fixtures consist of 500W tungsten halogen, general purpose floodlights mounted on the lighting catwalks. Illumination for the upper deck of seating is provided with either tungsten halogen or M-H (with quartz restrike circuit for instant on emergency lighting) sources. Down light type fixtures over the seat rakes should be avoided as they are difficult to access for relamping and maintenance.
In the event of a power failure and the successful start up of the emergency power generator, the house/emergency and aisle lighting systems are automatically turned on at full brightness. The house/emergency lighting system should remain on until after normal power is restored, and the event lighting fixtures have completed their cool down/restrike cycle and have returned to full brightness.
Suite and skybox lighting
If the project in question has suites and/or skyboxes, their interior lighting systems normally will be exposed to the view of the arena bowl. As such, you should be conscious of potentially objectionable glare created by these systems.
These lighting systems should be capable of being remotely controlled so that during a bowl black out condition (e.g. concert special effects), they can be turned off. Undercounter lights (at the bar), restroom lighting, and back hallway lights should be unswitched for courtesy/emergency lighting during purposes the black out period.
After the house lights are turned off and the event begins, it's necessary to maintain an illuminated path along the exit paths leading from the seating decks. This usually consists of aisle lights integrally mounted in the seats at every row, at alternating sides. Additional, supplemental aisle lighting may be provided using projector type spotlights, which should be mounted on the lighting catwalks and focused on aisle paths below.
Low wall-mounted compact fluorescent step lights are provided in the vomitories leading from the bowl. Aisle lighting should be connected to the emergency power system and controlled as a separate lighting control zone.
Exit signs are required at the vomitory egress points. Be careful not to specify a low light level type sign as higher brightness provides an enhanced life safety function with little affect on arena bowl lighting performance. In addition, exit signs should not be turned off during an event for any reason.
Scoreboards and advertising boards
Lighting contributions from the main scoreboard, spectator scoreboards, video replay screens, and advertising boards can be a significant source of feature and supplemental fill lighting. Arena bowl lighting systems should be designed to avoid washing out or creating objectionable glare that would diminish the ability to see scoreboards and advertising boards installed within the arena.
Power system considerations
Arena bowl lighting systems are typically supplied at 480/277V, 3-phase, 4-wire, from panelboard clusters located in the quadrants of the catwalk level for the event lighting system fixtures. Panelboards can be mounted either in dedicated electrical closets or directly on the catwalks (if adequate clearance is available).
Dedicated transformers and panelboards, connected to the emergency power system, supply 120/208V power to house/emergency and aisle lighting systems.
Prewired connector wireways are provided on the catwalks beneath the event lighting fixtures, with an individual twist lock receptacle for each lighting fixture.
Twist lock receptacles are provided to connect aisle lights in the retractable seating decks to the building power supply and lighting control system.
Lighting control system
Arena bowl lighting control is effectively accomplished utilizing a programmable lighting control system. The system consists of lighting relay cabinets (LRCs), a personal computer (PC) interface, and manual and automatic control devices. Most systems use mechanically held relays, although reliable systems that use electrically held relays are available. You may consider integrating lighting control into the building management system. However, if the arena is sufficiently large, it will benefit from full feature software applications available with dedicated purpose systems. In addition to the arena bowl lighting systems, this system controls all other arena interior and exterior lighting systems.
The PC interface, located in the engineer's control center or control booth, provides the primary point of access to the system. LRCs are connected to the PC interface using twisted pair type data cabling. Programming information is down loaded to the LRCs, allowing each LRC to operate as an independent system in the event of the failure of the data connection. Basic software allows the programming of each relay or group of relays to respond to either a time of day schedule or a manual or automatic control device.
Optional software applications that enhance arena operation are available at reasonable cost. System monitoring software applications may be used to record lighting use patterns, which may be summarized and presented to assess lighting energy use by specific operating entities such as food service or retail tenants.
Lighting relay cabinets are provided at the catwalk level, adjacent to lighting circuit breaker panelboards, for control of event lighting systems. A separate relay should be provided for each event lighting fixture to gain the maximum flexibility of control.
Supplementary lighting contactors should be provided for control of house/emergency and aisle lighting systems and connected to the emergency power system.
The arena bowl lighting systems are controlled to match varying arena operational scenarios. Each operational scenario has an associated combination of lighting relays in a predetermined position (ON or OFF) during a specific period of time.
Basic operational scenarios include event set up, spectator arrival, event in progress, event break down, cleaning, power failure, and arena closed.
Manual and automatic control devices are wired to the LRCs and programmed as switch inputs. Switch inputs may be readily reassigned to other lighting system zones or schedules through the PC interface, enhancing flexibility. Modular switch banks are provided to allow finger tip control of event lighting system preset scenes such as basketball lights, hockey lights, etc. Additional switches are provide for house/emergency, catwalk, suite/skybox, advertising boards, and aisle lighting systems. Switch banks are strategically located at the security control center and the lighting and sound control booth.
The individual components of an arena bowl lighting system combine to create a whole that is greater than the sum of the parts. The end result is a lighting system that becomes a part of the performance, contributing significantly to the success of the event. Early planning and participation by the architect, lighting designer, electrical engineer, contractor, owner, and operating personnel is critical to the outcome of the project.
The design team must be creative and flexible in reaching the overall final solution. For example, before selecting the event lighting systems for the Rose Garden, four sports lighting fixture manufacturers were invited to provide a mock up of their proposed lighting system. Representative lighting fixtures were installed on the catwalk of the existing arena for a side by side comparison. Members of the design and construction team were present to evaluate each presentation. Final proposals were submitted and the system best satisfying the lighting performance, operational, and cost requirements of the project was selected as the fixture of choice.
RELATED ARTICLE: WHAT IS AN ARENA BOWL?
The term "arena bowl" is defined as the volume of space encompassing an event floor and aerial space, spectator seating decks, vomitories, access aisles and circulation paths, spectator and press suites, skyboxes, and catwalk levels. Seating for up to 20,000 is provided for NBA/NHL facilities (such as the America West Arena and Rose Garden) and from 7000 to 12,000 for municipal style buildings such as the Spokane Arena.
Randy J. Meyers, P.E. is Principal with Flack + Kurtz, Consulting Engineers, San Francisco, Calif.