Oppenstein Brothers Memorial Park, Kansas City, MO
A complete redesign and rebuilding of Oppenstein Brothers Memorial Park at 12th and Walnut in downtown Kansas City, Missouri, was dedicated on April 18, 2008. The park concept is named Celestial Flyways to celebrate the natural environment of the Kansas City area.
The park was designed by Kansas City artist Laura DeAngelis and Davison Architecture + Urban Design and was commissioned by the Art in the Loop Foundation, a metropolitan organization of business and civic leaders with a continuing mission to enhance central Kansas City with public art. This project was a cooperative venture between the city of Kansas City and Jackson Country Parks and Recreation. It required two years of work, the talents of at least 150 people at a cost of nearly $500,000, much of which was donated.
The park and anaphoric star disk are clearly visible from space with Google Earth.
The park’s theme, Celestial Flyways, was inspired by the migratory patterns of many bird species which pass through the Kansas City area. The park design includes migratory bird routes with inlays of sixteen bird species. The arcs in the picture below represent the migratory bird routes. The park landscaping uses native prairie plants.
(photo by E. G. Schempf)
Green Heron inlay (photo by E. G. Schempf)
The objective of the park’s design is to give the park visitor a sense of Kansas City’s natural environment and, hopefully, a sense of history. Animal life is represented by the migratory birds. Plant life is shown with the native plants. The sky is included through a remarkable astronomical construction.
The centerpiece of the park is an interactive sculpture based on the anaphoric clock, a model of the sky with roots deep in antiquity. The anaphoric star disk in the park is very likely the largest and most accurate astronomical machine of this type ever made.
(E. G. Shecmpf photo)
This discussion concentrates on the anaphoric star disk. The other aspects of the park, which are lovely and quite interesting, will be described in a forthcoming web site.
The anaphoric star disk consists of a 10 foot (3 m.) diameter disk containing the positions of 457 stars in 50 constellations. The stars are shown by holes in the disks filled by acrylic lenses and are lighted from below. Drawings of the mythological characters associated with the constellations are etched on the surface of the disk. Park visitors rotate the star disk to a date and time with a motor operated by buttons on the base. The mechanism is not a clock since it does not run by itself. If it were a clock, the disk would rotate once in a sidereal day.
Above the rotating star disk is a grid showing the local horizon and meridian, the celestial equator and the Tropic of Cancer. The Tropic of Capricorn is the outer diameter of the disk. The meridian is accurately oriented and the horizon corresponds to the latitude of the park at 39° 6' North.
The base of the sculpture is decorated with ceramic representations of the Kansas City natural environment made by Laura DeAngelis.
The outer circumference of the base contains a calendar and the outer edge of the disk has a time scale. Park visitors set the disk by aligning a time with a date. Once set, the stars are positioned for that instant.
The sun’s annual path, the ecliptic, is also engraved on the disk in the form of a calendar. The sun’s position for a day corresponds to a date on the ecliptic circle.
The star disk can be set for the current date and time to see the current positions of the sun and stars, set to find the time of a celestial event, such as sunrise or sunset or set to any other date and time of interest. It is a very informative display for such a simple machine.
The anaphoric star disk required the experience, talent and effort of a large number of people. The overall design was by Laura DeAngelis with Dominique Davison. The star positions, constellation asterisms, ecliptic, time scale and calendar were computer produced by James Morrison. The constellation figures were drawn by Laura DeAngelis and Peregrine Honig. Detailed design drawings were supplied by Davison Architecture + Urban Design. The disk, grid and supporting structure were fabricated by A. Zahner Co. The star lenses were made and installed by Louis Rose. The base ceramic decoration was made and installed by Laura DeAngelis and Louis Rose.
Evolution of a Constellation Figure
Anaphoric Star Disk History and Design
The Celestial Flyways anaphoric star disk is based on the anaphoric clock. The name derives from the Greek anaphoros, which means rising and is specifically applied to the rising of stars. Such a display was particularly useful in the ancient world since much folk astronomy is related to seasons defined by the rising of certain stars just before the sun.
The history of the anaphoric clock dates from before 50 BC. The earliest surviving description of a machine of this type is from the writing of the Roman author and architect, Marcus Vitruvius Pollio (ca. 88 - ca. 26 BC), who in de architectura [Book IX, Chap. 8, 8-15] describes a clock (a clepsydra or water clock) in this form. It is almost certain the Tower of the Winds in Athens contained a mechanism of this type. Fragments of similar constructions dated from the first to third century have been found in Salzburg and Grand (Vosges) in northeastern France, so such mechanisms were apparently fairly widespread among Romans. Richard of Wallingford used this form of display for his astronomical clock built in the early 14th century.
Wallingford Astronomical Clock Reconstruction
The anaphoric clock was probably not the first astronomical machine, but it was surely one of the earliest and had enduring influence as a direct precursor of the astrolabe, and possibly the most influential one. The astrolabe was by far the most widely used astronomical instrument before the invention of the telescope.
The content of the anaphoric clock is defined from the stereographic projection which preserves circles and angles in the sky on the projection. All star coordinates, the tropics and ecliptic are precisely projected.
The Oppenstein Brothers Memorial Park anaphoric star disk contains 457 stars in 50 constellations. It was designed using star coordinates precessed to 2010. 2010 was chosen as the design base as it is halfway between leap years and is something of an average for relating celestial positions to civil time. Stars are represented in four sizes. The brightest stars are 0.5 inch (1.27 cm) in diameter. Each successive smaller size has one half the area of the next larger size to provide a visual sensation approximating what you see in the sky, with the smallest stars being somewhat brighter than those visible on a dark, clear night. The stars are lighted from below by bright LED lamps. Each star has a clear acrylic lens extending below the disk to channel the light to the surface.
The time scale around the edge of the disk was aligned to the exact star positions for the park’s location. The park is located at 94° 35´ West longitude, 4° 35´ west of the center of the Central Time Zone. The disk is intended to show the location of the stars at the park’s location at a given civil time. Civil time is the same at all locations within the time zone so the time scale alignment is adjusted by 18 min. 20 sec. to account for the fact that it takes a star that amount of time to travel from the time zone center to the meridian of the park.
The meridian is accurately surveyed to the precise North/South line through the installation.
Just as an aside, the stereographic projection of the horizon for the park’s latitude divides the meridian almost exactly by the Golden Ratio. The Golden Ratio is often used by artists and architects to provide an aesthetically pleasing balance. This somewhat surprising element adds to the artistic impact of the structure.
Star Disk Fabrication and Installation
The anaphoric star disk was required to meet at least the following criteria:
- It must be rugged enough to withstand both frigid winters and boiling hot summers, rain, snow, ice and hail.
- It must be safe for park visitors.
- It must be virtually maintenance free.
- It must be as vandal proof as possible.
- It must be accurate.
- It must be pretty.
This challenge was taken on by A. Zahner Co. of Kansas City. Some of the technical details of the fabrication follow. This brief description cannot begin to reflect the skill and creativity of the Zahner team, led by Bill Zahner.
The star disk is 122” in diameter, with 120” visible. One inch of the disk is covered by the calendar and grid to protect both the disk and park visitors.
The entire mechanism is designed to work without maintenance for many years. The surface of the disk is 18 gauge (0.05”) interference coated stainless steel, treated to provide a dark blue aluminum oxide surface that is very rugged. The stainless steel disk is mounted on a 0.190” aluminum base to provide rigidity at reasonable weight (the entire disk weighs 382 lb.). The disk structure is mounted on a rigid carousel to provide a firm base. The disk does not have a center support and the entire carousel/disk combination rotates on bearings around the outer edge.
The stainless steel was supplied in panels and roll cut into a variety of shapes to form the final disk. Each section of the disk surface is attached to the aluminum base with adhesive, with a gasket seal between the sections to provide for thermal expansion.
The characters associated with the constellations were etched using a photo-resist mask using a proprietary Zahner process. The star holes were drilled as the last step in the disk fabrication. Some of the star holes required drilling deep holes in the carousel beams.
The star locations and size, constellation asterisms, ecliptic and time scale were created from a PostScript program and converted to an Adobe Illustrator file that was accurately transferred to the disk with more Zahner magic. The constellation figures were hand drawn, scanned and included in another Adobe Illustrator file, from which the photo-resist mask was made.
The interior of the anaphoric star disk base provides drainage and electrical access for the lights and motor.
The ceramic tiles around the star disk base and the risers for the park stairs were all hand carved, colored and glazed by Laura DeAngelis. They required 3,000 pounds of ceramic material and hundreds of hours of firing and glazing. There is a string of LED’s around the base to light it at night. The lights are activated by a photoelectric cell so they come on in dim light. It’s gorgeous.
The following pictures show the evolution of the anaphoric star disk and, hopefully, communicate some of the skills and effort needed to bring it to life. The photos are from Chris Morrison, Robin Trafton, Laura DeAngelis and Eric Steele.
The poured concrete base. Note the curb for the carousel.
The Carousel. Note the bearings around the edge.
Curb with Carousel Installed
Installing the month caps
Aluminum Disk with some stainless steel sections
The completed disk
The disk ready for installation
The disk on a truck, ready to install.
Unloading the disk
Installing the disk. Note the special tooling designed by Zahner to slide the disk into the base.
Grid ready for installation
Installing the Grid
Ceramic Tiles around base. Note the perimeter lighting.
The completed anaphoric star disk in place and working
Even a child can use it.
Dominique Davison, the architect, is in the light blue coat.
Emily Morrison (age 5) demonstrating the Star Disk
Briefing Mark Funkhouser, the mayor of Kansas City (the tall gentleman with the goatee).
Gratuitous Picture of Laura DeAngelis and James Morrison
Following are some photos of the park by E. G. Schempf that show some details of the installation and how the park integrates into the urban setting.
- Lead Artist: Laura DeAngelis
- Lead Architect: Dominique Davison, Davison Architecture + Urban Design
- Artist’s Team: Peregrine Honig, James E. Morrison, A. Zahner Company
- Contractor: Hoffman Cortes Contracting Company with Sturgis Materials (stonework)
- Engineering: Antella Consulting Engineers
- SK Design Group, Thornton Tomasetti
- Landscape Architect: Genus Landscape Architects
- Greater Kansas City Community Foundation
- City of Kansas City, Missouri
- Oppenstein Brothers Foundations – Commerce Bank, Trustee
- Richard J. Stern Foundation – Commerce Bank, Trustee
- Muriel McBrien Kauffman Foundation
- Bank of America
- William T. Kemper Foundation – Commerce Bank Trustee
- H & R Block Foundation
- WallStreet Tower, Inc.
- M&I Bank
- Francis Family Foundation
- Lighten Fund
- Stinson Morrison Hecker LLP
- Kansas City Power and Light
- Missouri Bank and Trust
- The Arts Council of Metropolitian Kansas City – Arts KC Fund
- J. E. Dunn Construction Company
- Jackson County Parks and Recreationn
- Jackson County, Missouri
- The Downtown Council
- Downtown Community Improvement District
- Taliaferro & Browne, Inc.
- Kate Hackman
- The Art Selection Panel
On a personal note, my involvement in the overall project was modest compared to many others. It was, however, a wonderful collaboration with outstanding people. I am deeply impressed by Kansas City. It is a vibrant city, rich with tradition and very fortunate to have a core of dedicated public servants and civic leaders who continue to enrich the urban experience. You should go there if you can. It’s a terrific place.