Neil Kell

ACKMA Journal No. 15. June 1994. Pages 4 – 9.

My aim was to study recent developments in the design and installation of lighting to enhance the public education and enjoyment of show caves, developed from an expectation that answers for a range of show cave lighting needs might await discovery elsewhere, ready for direct utilisation in the Australian industry. In reality the quest for those recent developments with readily available answers was transformed into a search for the meaning behind the existence of similarities and differences, of the good and not so good in lighting, that occurs across the Australian, New Zealand, American and Caribbean arena of show caves.

Firstly, it seems fair to assume that lighting is the most critical input into the existence and operation of show caves.  It illuminates that which could not otherwise be seen, and enables access for a range of activities by those of us who find ourselves attracted.  Clearly this is seen as a successful alliance of human endeavour and technological application.  Only in the very recent history of show cave operation has there emerged the evidence and realisation of lighting as the not so benign element of cave showing that it once may have been thought to be. 

And secondly there are lessons to be learned from this, about the historical factors supporting the lighting of caves, and undoubtedly influencing change, and finally about understanding the broad ramifications of lighting the cave environment.

HISTORICAL FACTORS

For most of history, the subterranean world of caves was associated less with knowledge than with mystery and marvels.  Perceptions of caves are terrifying nether worlds of darkness, populated by intimidating mythological associations have persisted for centuries.  Despite the more intrepid explorers of the past, who refused to be daunted by intimidating obstacles and struggled to replace superstition with rational thought, the emergence of a science of caves, which has been largely a 20th century phenomenon, is yet to displace a cliche that implies caves are separate worlds, underground and disconnected from our sunlit world, in which the romantic and fanciful use of lighting and presentation is commonly accepted.

Those involved in development and management of show caves are often influenced in some way by the ideas of disconnectedness.  This may take many forms, from a narrow understanding of the science of caves, to a personal dislike of some aspect of the cave environment or the public who come to visit. Whatever the personal circumstance, it is a reality not often recognized, that can exert an influence on the directions a cave development may take.  Many present-day show cave management problems may be in some way a product of attitudes of disconnectedness and romanticism, and the fanciful use of light and presentation.

The history of the lighting of caves reveals a variety of alternative examples of lighting, as various light sources (candles, bengal fire, calcium light, lanterns, magnesium lamps, acetylene gas, and electricity) rose to, or fell from prominence largely on the basis of the unique difficulties which are involved in the practical areas of installation, servicing and operations of cave lighting systems.  Very often, unique solutions were found for problems in which the overall equipment in readily successful systems would be copied and applied in other locations.

In the USA, romantic attitudes to caves often gave way to degrees of pragmatism in the focus on development.  In the private sector, development appears to have focused on resource promotion to increase visitation and commercial returns.  Public caves to date have been free of the focus on commercial returns, however their charter for conservation and public access, combined with a management system linking increases in budget allocations to visitation increases has essentially created similar development results to that found in the private sector.  Overall, access for increasing volumes of visitors has been achieved by the construction of entry and exit tunnels, tunnels to interconnect caverns, vertical elevators, extensive walkways, seating and viewing areas and occasionally food and toilet facilities.  In the cave this has generally resulted in a style of lighting that appears to increase in uniformity in relationship to the increase in volume of visitors that can be conducted through the cave.

Within this history of show caves there exists at times individuals, and specific site developments, that have become key reference points for consideration and emulation by others in the industry.  Such key people in the area of cave lighting have had a considerable influence on the type of installation and the style of its function and effect.  Even though they may have been responsible for a relatively small number of developments, their influence can become quite widespread as the cave industry copies and adapts from successful examples.

Likewise, there are key show caves, often because of the relative significance of the site and the magnitude of investment commitment.  Many factors are involved: Public caves for example are often significant for cultural and natural resource reasons, examples are Jenolan Caves in Australia, Waitomo Caves in New Zealand, and Carlsbad Caverns in the USA.  Whereas private caves may generate a significance based on the success of developing a viable commercial operation, Meramee Caverns (USA) for example.

This process of consolidating and refining experience is an integral part of the vast majority of show caves open to the public today.  An historical perspective does not reveal a steady flow of considered assessment and review, of planned change on the path to an identifiable better aim, the reality is more a process characterised by flourishing periods of development punctuating an otherwise fairly ordinary story of survival amidst an array of difficulties. 

Elery Hamilton-Smith (1987) suggests that for Australian show caves a golden era flourished in the pre-World War 1 years, while Russ Campbell (1984) comments that in the USA the golden period may well have been the post World War 2 years into the 1970s.  In both countries much of what the visitor experienced in a show cave rests on the laurels of those golden years in which a combination of factors, such as national economic growth, market opportunities, development successes and leadership, seemed to have been focused in a manner that makes the industry today seem a little aimless in comparison.

RESISTANCE TO CHANGE

On the basis that the general form of cave lighting has shown little change for some decades one might assume there are identifiable factors at play, resisting change.  Some have already been mentioned, such as adoptive and adaptive processes, and key sites and people, which by the success of their example is often reason enough not to diverge from a seemingly winning combination.

There is a long-held view that show caves have had an unique monopoly of a visitor market. Indeed in Australia following MW, show caves were seen as important elements in the growth of tourism and the economy, at a time when the tourism market could easily be dominated by the show cave industry.  With the magnitude of capital investment of that growth period providing a sound basis for operations for the decades to come, in combination with the safety of a monopoly view, it becomes possible to reason against the need for change.

Other very practical aspects are involved.  Visitors developments in caves are likely to be very labour and capital intensive exercises, where more often than not, the developments of the past have been a series of such exercises, poorly documented, involving and overlapping in some instances for many decades.  For example, the walkway route in a cave is rarely altered and becomes as much a permanent part of the cave as the natural features; and lighting alterations are often grafted onto existing installations.  The true cost commitments in such involved cases is probably never known - the prospect for a manager to undo the evolutionary knitting together of access, walkway, lighting, and showing developments of many decades would be a daunting and costly process, requiring compelling reasons to justify the effort.  In addition the cumulative physical impacts on the cave of evolved developments are high and often irreversible, presenting the very vexing questions of reclamation and restoration that need to be considered as part of cave redevelopment.

This history of the processes of change have been much a part of those demands of furthering the development of the resource and the success of its use.  Against that experience can be contrasted the now increasing needs for change in show cave management which have to be identified via research within a range of academic disciplines, and diverse practical skills that are often unrelated and difficult to learn for a generalist cave manager.

A good example is the research into the growth of exotic plants (lampenflora) in show caves, by the Aley’s over the past 15 years.  Three American show caves (Blanchard Springs Cavern, Carlsbad Caverns and Oregon Caves) were researched in response to urgent needs to control an identifiable problem.  The results are generally applicable to all show caves with a lampenflora  problem, however, such valuable information appears to date to have received limited application in relationship to the widespread problem of lampenflora.  Clearly there are factors within show cave management inhibiting the implementation of new information and techniques, despite the fact that in this case the needs and procedures are clear, and the information is readily available.  It seems therefore, that cave management still embodies cliche ideas of the disconnectedness of caves from the world of normalcy.  If this is so it could be the single most pervasive factor  resisting change for the better in the multi-disciplinary and interconnected world of show caves.

RAMIFICATIONS OF CAVE LIGHTING

There are wide ramifications of lighting caves for public showing.  They exist in the area of the  application of lighting technology to a physically difficult environment, the cumulative impacts of development, lighting and showing in a finite and delicately interactive natural environment, and finally but probably most importantly the philosophy behind the showing of a normally totally dark environment for a human experience.

Whatever the philosophy that may have driven the development of show caves this century, there can be no doubt that the show cave industry exists almost exclusively on the technological advantage of electric lighting, which in due course has virtually eliminated that most intrinsic value of a cave-darkness.  The ramifications of this alone could well extend into the area of visitor satisfaction with the cave experience, the educative role so important to public cave operations, the success of show caves in the competitive tourism market of today, and finally the maintenance of the natural processes and value of cave resources.

Much has been written on the impact of lighting on the integrity of cave resources, particularly its promotion of the growth of exotic plants and other plant-dependent organisms (Aley 1984, 1985; Johnson 1980; Dromgoole 1979).  The lighting impacts and suggested changes most commonly addressed are:-

? Lampenflora growth: mitigated by lowering surface illuminance usually through installing lower output lamps; controlling undirected light; blocking some of the light transmission; controlling the use of the light.
? Heat transmission to cave surfaces: usually lowered by installing lower output lamps; distancing luminaries from affected areas; and controlling the use of the light. 
? Disturbance of cave animals: minimization can imply the periodic banning of access and lighting; lowering of illumination levels., redirecting the aim of lighting; and greater control of the use of lighting. 

While the above examples of problems exist across a wide range of show caves, there is very often a direct relationship to the overall design of the lighting that exacerbates the seriousness of these and other problems.  A very simple example would be to compare the light related problems of a cave guided on a periodic routine with the lighting switched on and off only as required, to a cave which is self guiding that requires lighting for mobility and viewing to be continuously on throughout its operational hours.

My study tour revealed that there are ramifications resulting from seemingly small elements of cave lighting development style.  By far the most significant example is what I have termed an environmental lighting style that lacks separate access lighting and guide controlled lighting circuits.  The combinations of this lighting style with high visitation effectively produces a lighting use and impact which is little removed from that of a self guiding cave.

Other examples which may not often be considered directly related to lighting style are:

? High visitation throughputs are encouraged by lighting designs that uniformly light the cave environment and require a minimum lighting control involvement by the guide.
? Interpretation and educational satisfaction can be diminished by a lighting design that circumvents (by the absence of guide-switched circuits) both the guide and visitors being able to interact with the environment through the control of lighting for effect and atmosphere.
? Experiential values of visiting a cave environment which is so illuminated as to largely avoid darkness.

Small differences in the styles of lighting development between Australian and American show caves appear to have had the potential to produce differences in the resultant impacts.  The Australian focus to date on installing a separate walkway lighting system in conjunction with separately guide-controlled cave feature lighting has, most likely unintentionally, placed a degree of limitation on the visitor throughput possible for that lighting, and therefore limited somewhat the severity of a suite of resource and service impacts that result from high visitation.  In general this is in contrast to the widespread occurrence of light impacts that result from the use of an environmental style of lighting and high visitation throughputs in caves in the USA.

Overall, the ramifications of the design, installation, and operation of lighting systems in show caves can be significant, and complexly interrelated.  To highlight this one need only contrast a cave showing conducted in the fashion of the intrepid early cave explorers, using hand held sources of light, with one designed for large numbers of visitors featuring the theatre of light and sound pageantry, controlled, finite, repetitive, and completely uniform outside of the potential for system malfunctions.

The study tour revealed that much of show cave lighting experienced today is an additive component to show cave development, often being the last component to be considered and installed and therefore not integrated into the development of a service providing cave experience.  One must add to this that the public perception of the use of lighting has become much more accepted as environmentally normal and therefore much less unique in how it is personally experienced.  In essence the wonderment of the use of technology to fathom darkness and participate in the process had been almost excluded from show cave experiences of recent decades.  Too often then, and unfortunately now, the focus of cave lighting has been of lighting caves with the concept of technology rather than the concepts of personal interaction, engineering as opposed to designing.

Toward the end of the study tour of some 50 show caves, a vision for the future forms of cave lighting began to evolve.  The vision is that the era of heavily engineered, permanently wired, and dis-guided cave lighting installations needs to give way to the design of cave experiences which are augmented, supported and enhanced by forms of lighting having a greater flexibility in use, and a minimal impact on the cave resource.  The forms of lighting and the methods of use will need to be much more flexible to enable the range of services provided by the resource to readily change in response to the changing needs of not only the modern tourism marketplace, but most importantly the diverse needs that grow from human interaction with cave tour experiences by both the provider and the customer.

BIBLIOGRAPHY

ALEY, T. & C. ALEY. 1984.  Control of exotic plants in Carlsbad Caverns.  Final report, Ozark Underground Laboratory, contract to National Parks Service Carlsbad, New Me)dco.  Contract No. CX 702930029. 13 1 p + map.

ALEY, T. & C. ALEY. 1985.  Control of exotic plants in Oregon Caves, Oregon Caves National Monument.  Ozark Underground Laboratory, contract report to Engineering Design Associated, Tigard, Oregon. 144pp.

CAMPBELL, R. 1984.  Cave Attractions and their place in the travel industry.  National Cave Management Symposium Proceedings, Missouri Speleology, Journal of the Missouri Speleol. Survey, Vol 25 Nos. 1-4, p 140.

DROMGOOLE, F. 1. 1979.  Plant growth and light in the Waitomo Caves, recommendations on lighting practice.  Research report, Botany Dep., University of Auckland.

HAMILTON-SMITH, E. 1987.  Cave and karst management down under.  Cave Management Symposium Proc., National Spelcol.  Soc., Hunstville, Alabama, pp 38-45.

HAMILTON-SMITH E. & HOLLAND, E. 1989.  A brief history of Australian cave lighting.  Journal of the Illuminating Eng.  Soc., of Aust. & N.Z., Sydney, August, 1989, p 13.

JOHNSON, K. A. 1980.  Control of lampenflora at Waitomo Caves, New Zealand, (in) ROBINSON, A. C. (Ed), Cave Management in Australia III, National Parks and Wildlife Service and Aust. Spelcol.  Federation, Sydney. pp 105-122.

A 32 page report of the study tour has been produced and submitted to the Winston Churchill Memorial Trust.  The report contains the study program, a general comparison of show caves management between Australia and the America's as found during the tour, lessons learned and conclusions, with special emphasis on cave lighting.