Aug 10, 2021

Safety first when dressing your streetscape in catenary lighting.

By Chip Israel

Once relegated to Christmas Tree and used car lots, catenary/festoon lighting is now strutting its stuff in a wide range of applications. Today, it’s not unusual to see a strand of warm 3500K lights strung over a bar, residential backyard, retail village or even a trendy urban street that call to mind European streets, which can be can be too narrow for poles.

Tools of the Trade: Catenary Lighting
An example of a catenary system and typical detail sheet for exterior festoon mounting.

With the new systems, weight and wind loading has also increased, adding to the complexity. As lighting professionals, we have an obligation to communicate with the rest of the design and installation team about how and where we want our lighting installed. For festoon or catenary lighting, you must be aware of a few simple facts:

  1. Water and electricity don’t mix, so running them over a swimming pool is usually prohibited.
  2. Many cities mandate a minimum height of 12-16 ft for lighting strung over roads or fire lanes to provide access to first responders and fire trucks.
  3. Larger fixtures and shades can act like sails and could swing wildly in windy conditions, resulting in metal fatigue. Many times, a secondary, lateral support or tieback system is needed.
  4. Architects hate any penetrations into their buildings that could ultimately compromise the waterproofing and result in a future leak.
  5. Trees move, so connecting festoon lighting to a tree can be problematic and dangerous to the tree, so work with your arborist. Falling or trimmed branches can also damage the system.
  6. Some municipalities or even OSHA may require a device that can lower the festoon lights. This is especially convenient in areas with occasional typhoons so the fixtures can be quickly lowered, protected and then reinstalled.
  7. The tighter the catenary line, the more the horizontal stress or forces increase exponentially, so the connections to buildings and poles must be carefully designed for structural reasons.

Tools of the Trade: Catenary Lighting

Contributor(s)

Chip Israel

Chip Israel

Chip Israel has been a lighting designer for over 35 years. In 1992, he founded LIGHTING DESIGN ALLIANCE, a full-service architectural lighting design firm, where he built a highly-select team of lighting design professionals who now serve a variety of clients worldwide. As CEO... More info »