Sculptor Robert Glen was commissioned to sculpt these nine mustang horses which were placed in Williams Square, Las Colinas, Irving, TX. The research for the authentic "Andalusian Horse" was done in Spain, where evidence was found of the Spanish Conquistadores taking horses to Texas and Mexico in the 17th century. Some of these horses went wild and become known as Mustangs. The initial models for this sculpture were made in Robert Glen's studio in Africa. They were then cast in England and flown to Dallas, TX. The final installation in Williams Square was completed in 1984.

The Mustangs of Las Colinas, a modern-day equestrian sculpture, was planned and executed as a memorial to the evolving culture in North America. This monumental sculpture memorializes the heritage of Texas, recognizing that Texas is not only a geographical place on this continent, but that it represents a distinctive spirit and way of life of a people who are committed to the freedoms of action, initiative, and expression for each individual man and woman as no other culture before has exhibited. Texas is the land of the entrepreneur, a citizenship of individuals, a land of the free spirit.

How "The Mustangs of Las Colinas" Were Created

Robert Glen was given the assignment to create the mustang sculpture in the summer of 1976. The plan for a large plaza, the size of two football fields side by side, paved in Texas pink granite, was described to him by Ben H. Carpenter, the developer of the project. He was asked to create a band of mustangs crossing a stream of water in the middle of the plaza proportioned so that they could be viewed from any direction. The plaza would be bordered by granite clad buildings on three sides with a fourth building possibly to be added across the boulevard.

Glen spent a year of research prior to starting the actual sculpting process. He read books and historical periodicals to fully understand the background of the magnificent animals that were brought to the American continents from Spain and which sired the original wild horses of Texas and the western United States. He discovered that the wild horses presently in the preserves and parks reflected subsequent crossbreeding unlike the Spanish ancestry of the original mustangs. Glen was sent to southern Spain in search of authenticity. There he studied horses with the same pure bloodlines as those of the specially selected animals taken to Mexico and Texas centuries before. Following the same research techniques applied to his African wildlife sculpture, Glen used a number of anatomical castings, taken from dissected animals, to study the anatomy and muscular and skeletal systems prior to beginning his sculpting.

First Glen constructed a number of small scale model horses in various positions and movements reflecting the mood and motion of the concept that had been given him. During this stage he made 47 different models before a final scale model, less than 1/8 lifesize, became a three-dimensional outline for the next stage of the sculpturing process, as well as serving as a model around which the plaza design details could be further developed. The next phase of the process required that larger working models be made from which more accurate measuring could be done. This intermediate state, modeled in a pliable plasticine material, was fashioned by Glen at 1/2 of lifesize, which would be 1/3 of the final 1 1/2 times lifesize monument.

Modeling was done in plasticine, considered an improved material over clay for this type of work, to facilitate greater detailing. Since plasticine is a soft and easily damaged material Glen made molds of each of the 1/3 final size animals he had created in his studio and cast them in fiberglass. This intermediate stage, in the form of a fiberglass maquette, would ultimately be shipped from Glen's Nairobi studio to the foundry in England where the final 1 1/2 lifesize models would be completed and cast. Glen used a mixture of fiberglass and resin in which to cast a lightweight yet durable model that would endure the trip from Nairobi to England. The Nairobi studio was the site of this repetitive process for each of the nine mustang animals that would compose the completed sculpture; five mares, two colts, a young stallion, and an older stallion dominating the band of mustangs. The fiberglass maquettes were cleaned and prepared for shipment to England. Glen made finishing touches to each of the fiberglass maquettes. Prior to shipping from Nairobi the preciseness of the detailing of hair, mane, nostrils, and the muscular appearance of the surface of the maquette was carefully checked.

Each fiberglass intermediate size maquette was crated and shipped by air from Nairobi to the Morris Singer Foundry at Basingstoke, England, about an hour's drive from central London. This world famous foundry has cast the works of such famous sculptors as Jacob Epstein, Hamo Thornycroft, Barbara Hepworth, Dora Gordine, Oscar Nemo, Enzo Piatta, David Wynne, Henry Moore, Reg Butler, Eduardo Paolozzi, and Kym Chadwick. Periodically, Glen flew to England and spent several months at a time in the foundry where the final process of creating the 1 1/2 lifesize model was begun, using the intermediate size maquette as a scaling and measurement guide to be cast in bronze.

The enlargement of realistic forms such as the mustangs is a complex process dealing with the volumetric problems brought on by varying forms and densities. A three-dimensional pantograph was constructed to produce the enlarged models. Using the pantograph, a "cut out" in a light foam material was assembled and fitted to a metal frame or armature. The shape formed by these assembled "cut outs" were purposely slightly undersized so as to provide a reasonably accurate enlarged form in the shape of the intermediate maquette but providing a modeling surface upon which a final coating of plasticine could be applied and sculpted.

The plasticine coating covers the armature form which was created by the pantograph and enlarged to three times the size of the intermediate size maquette shipped from Nairobi. The completed plasticine model of the young stallion hangs suspended within a frame, awaiting the next step, preparation for final mold making preceding the actual bronze casting. Each horse, when completed, had one to one and one-half tons of plasticine on its frame and the armature weighed about half a ton. The bronze casting required that each of the final sculpted animals be cut into several sections. Therefore, the surface of the soft plasticine modeling material had to be made firm so that it could be handled during the cutting and strong enough to go through the mold-making process. Robert Glen devised a simple system of painting thickened polyester resin over the completed plasticine surface which hardened in about fifteen minutes. This also preserved in its final form the impression of hair created by delicate brush strokes applied to the plasticine surface in the final detailing process. Later in this process the cast bronze tail will be united with the other sections of the casting which compose the animal. Each portion of the final model was packed in silica sand within a sectional steel box.

The silica sand compound containing a small percentage of water and sodium citrate is set to the consistency of sandstone by permeation with CO2 gas. The reaction of the ingredients in the sand with the gas hardens into a reverse or negative mold around the model within. When the steel sections of the box are dismantled the hardening sand mold around the plasticine model is removed. These reverse sand molds are fitted together within another steel box, leaving a hollow void where the model had been located in the first steel box. This hollow void is then filled with sand, which in turn is hardened by the gas permeation technique producing a positive solid core mold of the maquette.

The internal solid core positive mold of sand is trimmed to an undersized shape in order that when it is fitted back together with the corresponding negative sand mold a gap of open space will exist between the two. Steel pins are used to maintain proper spacing of the relationship between the positive and negative molds of hardened sand. Then molten bronze, heated to a temperature of 1150 degrees, is poured into the open gap between the two sand molds. When cooled, the casting is exposed by removing the metal casing and smashing away the sand mold. Not until this point was it known that the cast was a good one.

Following removal from the sand mold box, the bright bronze metal castings were examined, cleaned, and touched up. Metal finishing removed any excess bits of bronze from the edges and each bronze piece was prepared and assembled for welding together with other sections of the sculpture. Bronze welding was used to chase all seams together for a unified surface. In one case, a tail was cast in no less than 34 separate pieces and then welded together. During this process, Glen was joined by foundry managing director David Vallance and foundry superintendent Arthur Markwell in supervising the final assembly of the castings. Bronze welding was done both inside and outside each section. The Morris Singer Foundry, whose heritage includes the casting of public monuments around the world such as the famed Lions of London's Trafalgar Square, is one of the oldest continuing sculpture foundries in the world. Founded in 1848 by John Webb Singer, utilizing British, French and Belgian artisans, it was merged in 1927 with the Morris Art Bronze Foundry and in 1973 with the Paris sculpture foundry, Susse Fondeure S.A. In addition to sand molding, another ancient and time consuming process is the assemblage and finishing of the resulting bronze castings. The few experts for large scale castings available today have studied and worked in it most of their lives. Foremost among them are the artisans at the Morris Singer Foundry.

The bright and shining bronze mustang castings were assembled in the foundry yard one by one as they were completed. The five mares and young stallion were to be joined later by the two colts and the older stallion. These bronze figures, however, form only a portion of the sculptural presentation. At this stage they are yet to be united with the granite clad environment in which they will be permanently situated within the moving stream designed to enforce and accentuate the perspective of motion and movement.

The bronze casting process itself was completed on November 10, 1981. The London firm of Evan Cook was engaged to prepare the bronze sculptures for shipment to Texas. A decision was made to make the shipment by air rather than by ocean. At the Basingstoke foundry each bronze sculpture, weighing approximately two tons, was loaded and taken to Cook's packing warehouse. There, specially designed crates for each individual horse were installed to protect them en route. They were then transported to Heathrow Airport outside London.

At Heathrow Airport the 17-ton cargo of nine bronze mustangs was loaded onto a Pan American Airways 747 cargo plane and flown across the Atlantic to Kennedy Airport in New York City. Las Colinas Corporation sent a representative to accompany the sculpture while they were in transit. In New York, the bronze horses were transferred to an American Airlines 747 freighter which flew the cargo to Dallas/Fort Worth International Airport, adjacent to Irving. Upon arrival at D/FW Airport, the cargo of mustangs was unloaded from the plane and brought overland to Las Colinas. Meanwhile, during the several years in which the sculpture pieces were being created, enlarged, cast and finished in bronze, the architectural firm of Owings, Skidmore, and Merrill had been engaged to design the complex of buildings which would surround the plaza. The complex of granite-clad, copper-roofed buildings, designed by Charles Bassett, a principal in the San Francisco office of the architectural firm, was well under construction and partially occupied at the time of the arrival of the bronze mustangs.

In a nearby staging area the mustangs were assembled in a mock-up of elevations and positioned as they would relate one to another on the plaza. Meanwhile, James Reeves, the landscape architect and planning engineer, had designed the layout plan for the stream in the middle of the plaza that the horses would be crossing. An 8,000 pound concrete plinth was made as a base for each horse. An intricate pumping system was designed to suggest the splashing of water around the hooves of the horses, crossing in midstream. Following the installation of the horses in the stream the piping for the water and fountain system was completed and the bottom of the stream bed was covered with a pebble-like finish.

The last stages of the installation were carefully supervised by Glen. Specialists from the Morris Singer Foundry flew to Texas to assist in cleaning the bronze surface of the installed horses by blasting the sculptures with tiny particles of plastic under high pressure. This process returns the bronze to the gold-brass coloration it had as it emerged from the molds at the foundry. In earlier years people tried to retain the bright new look of bronze. In more recent times, however, the vogue has been to rapidly influence the oxidation or patination of bronze sculpture by inducing with acid mixtures a specifically designed coloration or effect. It was decided not to chemically induce an accelerated oxidation on the mustang pieces, but instead to permit them to age naturally, evolving their patina over time, responding to the natural environment as God will have it. Periodically the bronzes are coated with a thin wax material to minimize an accelerated discoloration.

Finally, on September 25, 1984, eight years after the project was conceived, the sculpture was in place and the plaza was open for the public to inspect and enjoy. Assembled together at last were the nine bronze mustangs, forming the largest equestrian sculpture in the world. The plaza has become a place for public gatherings, symphony concerts, and other intellectual and recreational pursuits. The centerpiece of the plaza, "The Mustangs of Las Colinas", shall be a lasting memorial to the vanguard of the civilization of Texas.

Robert Glen thanks the Dallas County Utility and Reclamation District for its courtesy in allowing this article to be reproduced. ©1988 Dallas County Utility and Reclamation District