“Losing Games: Conservation Issues of Outdoor Statuary as Playground Equipment”

American Institute for Conservation, Objects Group, Buffalo, NY, June 1992, with Providencia Velazquez

Speakers: Mark Rabinowitz
Authors: Mark Rabinowitz and Providencia Velazquez

ABSTRACT

A number of bronze sculptures in Central Park in New York City are subject to an unique and difficult set of circumstances that severely effect all decisions associated with their conservation and preservation.  These sculptures; “Alice in Wonderland” by Jose DeCreeft, “Balto” by F. G. R. Roth, “Hans Christian Andersen” by George Lober and “Group of Bears” by Paul Manship must act in dual and contradictory roles as both works of art and playground equipment.  The conventions we hold for the use of these two functions are diametrically opposed and would be considered incompatible if the requirements of each type of use were to be fully accepted.  Instead, these sculptures occupy an ill-defined middle ground in which neither use can be fully honored nor ignored.  We would like to explore the consequences of this contradiction as it effects these monuments and our attempts to conserve them.

What identifies a bronze sculpture as a successful piece of playground equipment turns out to be more subtle that we expected.  A number of circumstances collectively contribute to create this condition.  A playground bronze does not exist solely by the intentions of its creators but rather is marked by a confluence of conditions.  Identifying these conditions will become important when we recognize that our only practical means of conservation for some of these works may lie in adjustments of their environments rather than treatments to their surfaces.  The sculptures we are studying share several characteristics; animal subjects, physical and thematic accessibility to children and siting commodious to the other users of playgrounds, the children’s caregivers.  These element together confirm the playground status.  Other works share one or some of the same qualities but without having all of them they do not enter into this use category.  I will present examples from the Central Park collection that remain close to but outside of this group.

“Alice in Wonderland” by Jose DeCreeft, should be the first work we study.  Since its dedication in 1959 this sculpture has been known as the most famous and beloved in the Park.  Despite being out of character with the rest of DeCreeft oe,vre, it is his best known work.  An unauthorized version exists in Singapore as a testament to the success of this sculpture.  It is unusual to find it without numerous children climbing all over it.  DeCreeft stated that he wanted that use and that he tailored his artistic style to increase its appeal to children.  Its advancing state of wear is evidence of his success.

In an article published in Art in America from November 1967 entitled “The Playground Explosion”  Jay Jacobs wrote that “Alice” was “from every standpoint one of the most atrociously misconceived devices in existence.  In a piece that almost screams for color, children are treated to the anachronistic patination of the nineteenth century pigeon perch.  The climbing surfaces are dangerously slippery, sizzle like short-order griddles in summer and are cold enough to freeze the ears off a bronze rabbit in winter.  The spiky protuberances on the upper left are ideal for the snagging of clothes and the poking out of wide young eyes, the whole lamentable enterprise is at once too literal to stimulate the imagination and too ‘unreadable’ for a literal piece.”

To be fair to Mr. Jacobs I won’t go into the playgrounds he admired, few of which still exist and none are as well used as “Alice”.  What is intriguing about his discussion of this work is that although his conclusion has not stood up, his description is accurate.  This piece has safety problems, is uncomfortable and lacks those qualities of color, simplicity and an interactive nature which we have come to expect from playground equipment.  Yet these faults have not lessened the attraction of this work.

Several possibly severe problems have developed from the heavy use of “Alice” over the 33 years it has been outdoors.  Most upper surfaces are worn to bright metal by abrasion from constant climbing.  Other protrusions that serve as hand-holds and foot-rests are also bright.  The metal color can seem incongruous on areas such as Alice’s nose while not otherwise detracting from the appearance of the work.  Beyond effecting the patina of the cast, the abrasion from wear has removed substantial detail from the surface.  The mushroom caps, Alice’s fingers and much of the dormouse are now smoother and slimmer approximations of their original shape.  This substantial loss of surface detail obviously effects the visual characteristics of the work, 5/16″ high ridges that continue to run across the main mushroom cap in protected areas now no longer exist in places.  It may also be undermining the sculpture’s structure as well.  The caps of several of the smaller mushrooms are deformed as well as worn.  Depressions up to 3/4″ deep exist, effecting both appearance and the loss of water shedding form.  Finally, the skin of the bronze is worn through entirely in at least one small location.

We used an ultrasonic caliper manufactured by Panametrics of Waltham, Mass. to attempt to quantify the amount of metal lost through abrasion on this and the other sculptures beyond the observable superficial details.  The ultrasonic caliper measures the echo period of an ultrasonic pulse through a transducer held to the surface of a material to gauge its thickness.  It can be calibrated to adjust for the differing transmission speeds of diverse materials by means of mechanical comparisons and is accurate to 1/1000 of an inch.  It is widely used for checking thicknesses of packaging and container walls, tubing and pipes, in situations where destructive testing methods are undesirable.

As we had no benchmark measurement from which to begin, and as thickness of castings can vary greatly from point to point, we only looked for two results; measurements below the accepted minimum thickness for a large bronze casting and adjacent or nearby pairs of points to compare highly worn areas with seemingly unworn ones.  We hoped to discover points of possible failure, either locations approaching being worn through entirely or locations that threatened structural collapse.  None of the castings studied have internal armatures, they rely instead for their support of the cohesiveness of their enclosing form like the shell of an egg which can only withstand stresses when intact but is easily crushed once the integrity of the shell is broken.  The entire weight of the Alice figure is carried by the arch of the main mushroom cap, an area that appears highly worn.  We hoped to  quantify to amount of material lost over time in order to project future failure.

Several foundries stated that a thickness below 1/4″ .250, would be susceptible to structural failure on a large bronze.  That minimum depends on location though.  Clearly, a non-bearing complex shaped surface can be thinner than a load bearing smooth one.  The mushroom cap under Alice would require the additional thickness for support, approximately 3/8″ .375, or more.

The conditions of a cast bronze sculpture are not ideal for the use of this measuring tool.  Several constraints had to be overcome; The transducer head that was capable of performing this operation worked only when in contact with a flat smooth surface of at least its own diameter of 3/8″, a situation that was common in the highly worn areas but difficult to come by on unworn surfaces, limiting our comparisons

The caliper most accurately reads thicknesses of parallel inner and outer walls, askew walls deflect the sound waves.  Although the inner surface tends to reflect the outer face of the bronze there is no guarantee that the faces are parallel.

An alloy, such as bronze, can have varying degrees of density as  there is no absolute dispersion of the individual elements within the metal nor is there any guarantee of consistency of alloy from one pouring to another much less from one sculpture to another of a different foundry.  These differences can effect the accuracy of the readings.

Panametrics calibrated the tool to a casting sprue provided by the Modern Art Foundry, the founders of “Alice.”  Robert Spring, the current owner who assisted under his father as an apprentice in the casting of “Alice” said that the alloy was similar to that of “Alice” and would be similar to other castings but this could not be confirmed.  The engineers at Panametrics could not give a number for possible variations but suggested that the effect would be slight.

To attempt to overcome these constraints we proceeded as follows:
We measured as many points on unworn surfaces as possible while limiting measurements on the more easily read worn surfaces to either areas comparable with the unworn ones or areas of maximum wear.

To overcome the possibility of variations in the underlying surface such as highpoints, pits or slopes we made at least 15 independent measurements within a 1″ radius we established an average within a standard deviation for that circle.  This then reflected the best estimate of the general thickness of that location.

For “Alice” the information was mixed.  The sculpture was fabricated from many separate castings welded together.  Adjacent castings could more than double in thickness across weld seams from .222″ to .471″.  Comparisons between highly worn and unworn points seamed to suggest that metal loss beyond the decorative ridging already measured at approximately .3″ maximum was in the range of .1″ to .15″.  Average thickness of the main mushroom cap was .345″ and of the smaller caps was .282″.  The minimum readings on the main cap was .222″ and .174 on the smaller ones.  These numbers suggest that we are nearing the critical thicknesses for structural integrity.

“Alice” is sited at the north end of the Conservatory Waters, a formal pond used for sailing model boats.  The sculpture is in full sun centered within a paved terrace ringed with shaded benches.  The view of the water is unobstructed from the terrace.  In all it is an ideal spot for parents to rest while their charges enjoy the statue.  As stated, DeCreeft intentionally departed from his normal style to produce a work appealing to children.  Margot Gayle in her book on Manhattan Outdoor Sculpture states that the characters resemble Tenniel’s original drawings but they are actually closer to the Disney animated version of those drawings than the original except for Alice which is based on DeCreeft’s daughter and the Mad Hatter which is said to resemble George Delacorte, the donor.  Finally, the work is mounted on grade and is easily climbed on by even small children who, if not able to mount the mushrooms can squirrel themselves away in the grottos and hollows underneath.

“Hans Christian Andersen” by Georg Lober makes an interesting comparison.  It was installed in 1956, three years before “Alice”, within a terrace on the same pool.  It also includes an animal character, the Ugly Duckling, is simply modeled and physically and stylistically accessible to children.  The terrace also has benches and wastebaskets and can be seen as pairing the “Alice”.  This work, although also worn through children’s use, appears less so than Alice.  It is obvious that the duck and the most readily reached areas of the figure, Hans’ lap and right arm and the opened book, are much more worn than other parts of the statue.  The fact that the primary element is figurative rather than animal may effect its appeal to children.  The site is always shaded and group is pushed to the back of the terrace, allowing for an unappetizing space behind it that is often occupied by homeless people.  The stature was designed to entice a child to snuggle up to the author under his right arm and affords many less purchases for climbing than “Alice”.  Thus fewer children can climb this work at any one time, lessening its draw as a play center where part of the attraction is that there is always a group of raucous kids.

Ultrasonic testing confirmed that the wear was on the superficial features only an was not approaching structural levels.

“Balto” by F. G. R. Roth is a much earlier work.  Installed in 1925 to commemorate the heroic deeds of the sled teams that carried antitoxin to the residents of Nome, Alaska and stopped a deadly outbreak of diphtheria, it was not intended as a play feature.  The original application to the New York City Art Commission had the statue placed on a 4′ high pedestal.  This installation was rejected and instead it was to designed to match the installations of the “Tigress and Cubs” now in the Central Park Zoo but originally mounted on a rock in a wooded area and naturalized into its environment, and “Still Hunt”, a crouching panther which has continued to be mounted on another rock outcropping since 1870.  This type of installation was favored by Olmstead and Vaux as less intrusive tko the bucolic character of the Park.  “Balto” is prominently sited near the zoo while “Still Hunt” is hidden on a higher more shaded outcropping distant from most pedestrian use.  Unlike “Alice” and “Hans”, neither offers open area or adjacent seating although “Balto” is in open sun and close to benches along paths to the Zoo.  The children are allowed to sit on his back only a short time before moving on to a more comfortable spot.  The “Still Hunt” has almost no signs of climbing wear, the siting being enough to discourage climbers.

“Balto” is however very well used by children.  He has suffered extensive wear loss over the self-base and his back.  Like “Alice” there has been substantial loss of details in the modeling.  Ultrasonic testing showed that this work was a much more consistent as well as thinner cast than “Alice”.  Overall average thickness was .253″ with no variation greater than + or – .08″.  The average thickness for highly worn areas was .219″ and for relatively unworn ones .275″ indicating a loss of .056″ beyond surface details.

If this loss is less than that of “Alice”’s it would be surprising since “Balto” has been outdoor almost twice as long.  This supposes that children’s wear is a constant which increases only over time.  This may not be true.  In earlier days the park was more actively policed than today and the lack of other bronze sculptures specifically for children may have lessened the use to which “Balto” is now put.  Historic photos of “Balto”: and of “Tigress” suggest that this wear may be a more recent occurrence, perhaps encouraged by the existence of “Hans” and “Alice” as playgrounds.

Interestingly, the color difference between the bright metal upper and patinated underside is similar to that on a small bronze by Roth of a bear in the Metropolitan Museum.  Perhaps Roth intended it to acquire this coloration.  It is unlikely that he intended the accompanying metal loss.  The questions of artistic intend as regards patination that must be addressed in outdoor bronze conservation are particularly acute in this type of situation.

“Tigress and Cubs”, an Animalier work of 1860 is another highly worn work.  The detail loss it extreme on this work which has now been moved within a fenced off area to discourage future wear.  For both of these pieces the wear has worked against the intent of the artist who desired naturalistic representations of animals.  Yet the use of these works has changed to encompass children’s play.  “Balto” is now clearly seen as a play feature,  its use acknowledged in children’s books.  Even the fence hasn’t kept children away from “Tigress” who sneak under it to get at the work.  We must accept this use but can question at what point it becomes abuse.  Do we agree that these works are sacrificial?  Does respecting the integrity of the object mean respecting its use even if that includes its own destruction?

“Group of Bears” by Paul Manship, put out in 1991 is the most recently installed sculpture in the Park.  It’s installation as a central play feature within a newly restored playground provides a chance to study the abrasion of such a work from the beginning.   It has proved itself worthy of such study.

The work is a posthumous recast of a bronze from the 1940’s in the Metropolitan Museum, itself a recast of bears modeled for the Rainey Gates of the New York Botanical Gardens in the Bronx.  It was installed in Central Park in June, 1991.  Certain problems with both the cast and the installation became immediately apparent.

The casts was made in several sections and assembled.  The welding seam lines where the plates were joined correspond to the high points of the form, the backbones of the horizontal bears for example.  These areas also receive the most climbing wear.  Wax coatings and original patina were gone within days exposing these joints of differently colored metal.  The exposed seams combine with the bright metal to further disrupt the appearance.  The work was repatinated four months after it was installed in an attempt to remedy this but naturally the patina remained vulnerable to continued wear and was again worn away within days.

This aesthetic issue that results from the construction was compounded with a structural one.  The foundry fabricated the work as they would have any other sculpture.  Like “Alice” the hollow bears and base do not have any substructure.  The base was provided with only two mounting points along its rim.  The piece was not engineered for the live loads of numerous climbers.  This stress has been sufficient to deform the self-base, collapsing it inward until the bears touched together.  The whole rocks forward and back on its mounting points, partially due to having been incorrectly installed and partly due to the deformation of the rim.  In addition, there is internal movement between the bears, threatening the possibility of future metal fatigue.

The group is as yet much less used than “Alice” despite the site providing a similarly attractive play setting.  Of course it is not yet as well known, which may alone account for this.  However, the bears provide only four or possibly five spots for kids to climb on at the same time.  The design then may limit not only the number of climbers but their duration as they seem to tire of the sport quicker without that mass of bodies.

The other play feature on this site is a slide and sandbox.  Sand from the sandbox collects in the soles of the kids’ sneakers and is carried to the statue.  You can imagine the result.  Fortunately, the cast is of a silicone bronze, which is now often used by foundries for its casting properties but has the additional advantage of being harder and more durable than red brass or other bronze alloys.  Never-the-less, sand has been ground into the self-base, exacerbating the loss of coating and coloration and causing scratches and metal loss through abrasion.  This wear is also visible on the ears and noses which also receive substantial wear.  The lines of the ears, which were crisp when the work was delivered, are already softened by this wear.

Because the “Group of Bears” is a recent piece, our conservation choices are broader.  John Manship, the son and biographer of the artist and the person who authorized the cast, endorsed the re-fabrication of the bronze in order to better withstand its wear.  Paul King Foundry, the founder, has approved the design of a substructure and has entirely repatinated the piece once, providing formulas and techniques for reproducing the coloration.  The donor who gave the work to the Park has chosen to continue to monitor the work for another year before performing any reconstruction.  It is not difficult to assemble a group to advise on this who have the highest level of skill and knowledge about Manship’s work in general and this piece in particular.

Future replacement might be possible should it finally become necessary.  The original will remain protected in the Metropolitan Museum, a block away.  The molds from which this cast was made have been offered to the Park on the condition that they only be used to reproduce the work should this one be destroyed.  And, as this is already a posthumous recast, the question of the sanctity of the original object is not as much of an issue.  We will not be losing an irreparable work of art should this work become worn out.  The very substantial expense of such a replacement should it be needed has not been addressed.  Nor has the very high level of maintenance required to preserve the visual character of this work while it wears.

This option is much less available for the other works.  No other originals exist for any of them.  The fact that these works are so well used by children dissuades us from restricting that use.  We don’t want to take candy from babies.  In certain cases, it might be appropriate to adjust the settings in order to slow the use/decay.  The gate between the “Group of Bears” and the sand box can be kept closed, requiring the kids to travel farther before getting to the bronze and thereby losing more of the sand on their shoe soles.  Reconstructions of the settings, or removals of the works to less accessible sites are more drastic solutions.  The “Tigress and Cubs” is now within a chain fenced enclosure and is no longer used for play.  This kind of solution must be tempered with the intentions of all involved.  The donor for the “Bears” prefers that they wear rather than that the children’s use be restricted however he imagines replacement after a period of centuries rather than decades.

In the case of “Alice”, soon we will have to begin to plan for the reconstruction of the worn and deformed elements, especially as the abrasion continues to weaken the integrity of the bronze shell of the mushrooms.  With no proper model available, and the difficulty of re-fabricating this large work obvious, we will probably have to settle for the best approximate of the original we can re-create.  In “Alice’s” case, this may not seem to unduly interrupt the artistic intentions of the work, which are subsumed to it use.  But this can not so readily be said about “Balto”.  Should reconstruction finally become necessary for him we will have to accept that the unique artistic quality of the work is compromised.

We believe that the conservational requirements of outdoor sculptures in playgrounds can be included in their commissioning.  If the “Group of Bears” had been properly conceived originally as a playground feature rather than solely as a work of sculpture many problems would have been avoided.  New works are under consideration for the Park that will be subject to the same set of circumstances.

The whole concept of the appropriateness of sculpture for this use can be questioned.  If the use of “Balto” has changed due to its association with the other works than we must wonder about that association.  If, however, it’s partial fulfillment of the playground requirements has allowed it to both be enjoyed well and survive longer than it may be the preferred choice for such installations.  Installations more like “Hans” than “Alice” can be designed to allow for play while diminishing the period of time each child is on the work.  Coatings might become available that more effectively protect the surfaces without either increased toxicity or reduced visual characteristics however, the reduction in the responsiveness of the bronze to the children who climb on it may actually be seen as a reduction in the quality of the work.  Part of the difficulty of this problem for the conservator is that the more we achieve success at preserving these as works of art, the more we may fail as preserving them as children’s property.  And, as there is little enough that we have specifically for children, it seems wrong to remove something that is already their’s.  Suggesting that the “Alice in Wonderland” is problematic feels like a heresy.  Perhaps our best role is acceptance of the temporary status of these works while we attempt to avoid such problems in future installations.

We are fortunate in that we work together with the planners and designers  of Central Park.  We have established a set of guidelines for future installations and which address these questions.

1. If possible, a material more structurally resilient and abrasion resistant than bronze should be specified.
2. If bronze is specified it should be of the hardest silicon alloy.
3. Bronze sculptures intended to be used as playground equipment must be constructed to structurally withstand such use.
4. Welds and seams should be located so as not to be visually intrusive when expected patina loss occurs.
5. The installation shall not encourage the abrasion of the bronze un-necessarily.  This includes the design of both the work, which may allow for climbing without emphasizing it, and the siting, which if not outfitted as a playground, will likely reduce the number of children and amount of time they are on the work.  Sandboxes should be isolated from the installation as providing a source of abrasive.
6. Policy and provisions should be made for the eventual repair or replacement of worn areas, including patination and coatings formulas and the preservation of molds or plaster originals.  Measurements should be kept to monitor metal loss.
7. Funding for the higher level of maintenance expected for these works should be included in their donation.

Mark Rabinowitz, Bronze Conservation Coordinator, Central Park Conservancy

Providencia Velazquez, Bronze Technician

The Bronze Conservation Program of the Central Park Conservancy is an in depth commitment to preserving the bronze sculptures in Central Park.  We monitor conditions, perform and maintain conservation treatments and act as a repository for information on the sculptors, their works and the conservation histories of our collection.