Denver Zoo was originally constructed in 1896, so when the new Toyota Elephant Passage exhibit was in its conceptual stage, 116 years of  knowledge and experience went into every aspect of the new feature, from the main structures to the smallest details. The opportunity for a zoo to build such an advanced, state-of-the-art exhibit seldom comes around, and careful consideration was given to the planning and decision-making for a facility that would house the largest land-based mammals on the planet.

In this day and age, the challenges are numerous for constructing an environmentally-sensible facility that will provide a humane environment for the animals, as well as a safe experience for visitors. A decade of planning went into this $50 million, 10-acre exhibit, designed with over two miles of interconnected trails and more than one million gallons of filtrated pools. Due to its strength and versatility, steel was the logical choice as the primary building material for the numerous outdoor and indoor structures required to create this inviting, Asian-themed facility.

All the steel structures, cages, fences, and 136 massive steel gates are perpetually exposed, both to environmental and weather conditions as well as the corrosive waste produced by elephants and rhinoceroses.  Most protective coatings in these harsh, high-traffic areas would be scratched and scraped away within a short time by these massive animals.

Fortunately, Denver Zoo has extensive experience with hot-dip galvanizing (HDG), through the Predator Ridge exhibit and expansion. Completed in 2004, Predator Ridge houses over 50 species including South African lions, spotted hyenas and African wild dogs and contains hundreds of tons of HDG steel. The coatings superior performance made the decision to protect future exhibits a simple one.

Hot-dip galvanizing is the safest coating option, as zinc is an essential element for all living creatures. HDG is also the most durable option, thanks to the zinc iron alloy coating layers that are harder than the base metal. The metallurgical bond strength of HDG also minimizes the flaking and peeling prevalent with other coatings. A well-adhered HDG coating will eliminate the possibility of animals ingesting potentially harmful flakes or chips prevalent with other coatings, while withstanding the routine power washing necessary to remove the animal waste products.

Many of the steel cages, gates, doors, guard rails and other miscellaneous steel components were designed and fabricated using hollow tubes and pipes susceptible to internal corrosion. The galvanizer worked closely with the designers and the fabricator to determine the proper locations for venting and drainage openings. As a result, the HDG process will coat all internal areas, providing complete and equal protection for all surfaces both inside and out.

Aesthetics for the new display were very important, as Asian-themed colors and designs are prevalent throughout the exhibit. Versatile HDG coatings can be easily profiled to accept a secondary color coating. The resulting synergistic effect of the duplex system will greatly extend the life of both the galvanized coating and the color coat. Once the HDG coating is in place, the color options for these themed structures are endless.