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TOURIST CAVE MANAGEMENT IN SOUTH AUSTRALIA

P. Macrow : Senior Ranger (Southern), National Parks and Wildlife Service of South Australia
A. R. Gobby : Superintendent of Field Operations, National Parks and Wildlife Service of South Australia

DESCRIPTION OF TOURIST CAVES IN SOUTH AUSTRALIA

All the tourist caves in South Australia are on reserves dedicated under the National Parks and Wildlife Act. Two reserves, Naracoorte Caves in the south-east of the State and Kelly Hill Caves, on Kangaroo Island, are managed by the Service. The third reserve, Tantanoola Caves, near Millicent, has been managed under licence for many years by the District Council of Tantanoola and latterly by the District Council of Millicent, but this arrangement is currently under review. All reserves have extensive cave formations which have been explored mainly by the Cave Exploration Group of South Australia, but at Kelly Hill and Tantanoola only one large cavern is open to the public. At Naracoorte, however, three separate systems, Blanche, Alexandra and the Victoria Fossil Cave have been developed for tourists.

Information on the number of visitors at each of these reserves in recent years is as follows:

 19721973197419751976
Naracoorte (total - 3 caves)3552447522593146541467078
Kelly Hill Cave1300017068174491699618001
Tantanoola Cave36800471554080843000not available
* Estimate only - incomplete figures available

With extensive limestone areas in South Australia, there are numerous other cave systems in the State, particularly on York Peninsula and the Nullarbor Plain. Parts of the Nullarbor Plain at present under Pastoral Lease for grazing, are currently being acquired for dedication as a national park, and since there are a number of caves easily accessible from the Eyre Highway, control of the use of those caves, either as caves for recreational cave exploration or more formal tourist development will fall to the National Parks and Wildlife Service.

As is the case in most caves throughout Australia the novelty of subterranean caverns and the beautiful calcite deposits found in them are the main attractions for visitors to caves in this state. The exception is the fossil chamber of the Victoria Fossil Cave at Naracoorte. The fossil chamber is a large cavern with a bed of silt, rich in fossil remains, which composes the floor on the periphery of a collapsed dome in the centre of the chamber. A palaeontological excavation conducted by scientists from Flinders University in Adelaide has continued for several years and tourists are able to visit the active dig site, sometimes when excavation is in progress. The significance of the fossil deposit and the scientific work being carried out is explained by specially trained guides. The silt deposit is 30 metres long and in places up to 15 metres wide and is at least 3 metres thick. The bones are of animals which inhabited the area up to at least 30,000 years ago and include examples of rodents, small marsupials, the marsupial lion, Thylacoleo and the giant kangaroo Procoptodon. These bones probably accumulated when the animals became trapped in shafts or holes in the limestone end were deposited in the bed of silt built up by running water. Because of the unique nature of the fossil deposit, the interest it evokes from visitors and the opportunities it presents for explaining to people some of the principles of natural history, considerable attention has been paid to the development of the Victoria Fossil Cave and the Naracoorte Caves reserve as a whole. This has, however, not been to the exclusion of the other aspects of appeal in tourist caves at Naracoorte and on other reserves in the State, such as the calcite deposits, history and above-ground natural history on the reserves.

POLICY ON MANAGEMENT OF CAVES ON RESERVES

The preparation of formal written policies for management of caves on reserves is still taking place, but the following is a summary of current thinking within the National Parks and Wildlife Service. The National Parks and Wildlife Service has no jurisdiction over caves on other lands throughout the State, so these comments refer only to caves on reserves.

Consideration is being given to the classification of reserves into three groups, with appropriate policies for management of caves in each class.

Tourist Caves: Those caves developed for intensive visitor usage by the general public, usually by provision of free-walking access, lighting, protection from vandalism, guided tours and for public safety.

Wilderness Recreation Caves: Caves open to the public, but where facilities such as those provided in tourist caves are not developed. These caves provide for people to whom caving is a recreational pursuit and who wish to go cave exploring without a guide, crawl through undeveloped passageways and enjoy the attractions of this pastime. These caves may also be used by cave exploration, youth and education groups, to introduce and train people in caving. Management will aim to provide for public safety, maintenance and removal of litter, and the monitoring of damage.

Conservation Caves: These are caves where the primary objective of management is to conserve the features within them for present and future generations and hence, access to them may be strictly controlled by requiring persons to submit a proposal for scientific or exploration work to be carried out to gain entry. Details of the information gained would be required on completion of the visit. Management will aim to preserve these caves and to collect resource information.

In addition to these cave classifications it may be necessary to declare an area of particular scientific or aesthetic interest within any cave a prohibited area, where access to both staff and members of the public is not permitted, except with special permission after due consideration.

MANAGEMENT PRINCIPLES

1. Implementing cave development programmes

In South Australia we are attempting to improve the effectiveness of management as well as carrying out major redevelopment of tourist caves. In the current year funds in the order of $300,000 are being spent on the redevelopment of the Naracoorte Caves Reserve and $50,000 on the Kelly Hill Cave. Much of this money has been spent above ground on an interpretation centre, roads and carpark at Naracoorte, and a new cave entrance building, walking paths and picnic facilities at Kelly Hill Cave. However, the Victoria Fossil Cave at Naracoorte is being completely redeveloped by providing a new second exit, upgrading existing walkways, and re-wiring. Significant redevelopment has taken place in other tourist caves. The management principles outlined in the following sections have evolved and are continuing to evolve at this development work proceeds.

It must be mentioned at the outset that in South Australia management is made easier than is sometimes the case in other States because of the following circumstances:

Before development work is commenced in a cave it has been found essential to carefully think through and plan all aspects of the management of the reserve. For example, it is considered that visitors should be able to see a cave which is as natural as possible, whilst still providing easy access and to enable the public to capture the feeling of timeless "other worldliness". Therefore, in-depth interpretation which requires the use of audiovisual aids, models, charts, signs and so on is done above ground. Consideration is given to the layout of walkways to ensure that it is possible to cope with the present and expected future visitor numbers, and in many instances "walk-through" visitor routes have been planned. Furthermore, the facilities to cope with visitor numbers such as toilets, roads, carparks, visitor buildings, kiosks and landscaping, are provided.

For development work within the caves planning depends upon the production of a detailed plan of the cave system with vertical elevations. Contract arrangements were made with the Cave Exploration Group of South Australia to provide these, since they have a record to show that they have the mapping skills required and excellent plans have been provided by them. These have been used primarily as a basis for planning walkway routes and the electrical system layout.

A written specification for the walkways including width, head clearance, grade and the way in which the route is to be selected and approved is then prepared for the Ranger-in-Charge of the reserve (and the development project). In practice the general route of the pathway is plotted on a map. The detailed location of the walkway is selected on the spot by the Ranger-in-Charge and pegs driven into the cave floor to mark one side of the route. The height of the peg is set to indicate the amount of excavation of the floor, since material is excavated to a constant distance below the top of pegs. Pegging the route in this manner enables it to be checked before construction begins and since the pegs remain in place throughout construction, are a simple guide for workmen, ensuring that excavation is carried out as planned.

Development within caves has proved extremely labour-intensive. Casual labour has been employed for the work from the district and the size of the gang varied frequently, depending upon the accessibility of areas in which to work and other factors. It is essential that unskilled labour is constantly supervised and therefore it has been necessary to employ a competent overseer who is a tradesman (a qualified builder) to act as Site Foreman. Whilst the permanent Ranger-in-Charge of the reserve is responsible for the development project overall, our experience is that he is too fully committed on planning, arranging for supplies, equipment and contracts, and with the responsibility of the continuing management of the reserve, to be able to adequately supervise the construction labour team. In this respect we have found it important not to underestimate the additional workload a development project places on the normal permanent staff and to overcome this additional staff must be employed to prevent problems arising at the onsite planning, supervisory and managerial levels.

2. Principles for determining cave development priorities.

The first priority for development work in South Australian tourist caves is to maintain and upgrade the development within caves already open to the public. As it is no doubt sometimes the case in other states, the development of the present tourist caves in South Australia has been an ad hoc approach over many years, with scant regard to proper planning or maintenance. Since all the caves in the state require considerable redevelopment of wiring, switching and lighting systems, walk-ways, steps and people barriers, signs and interpretive facilities. Routine maintenance of the features within the caves, particularly the cleaning of formations, is required. However, although the present tourist caves have become "run down" over the years, they still remain tourist attractions and provided the redevelopment and maintenance work is done, will remain so. Therefore, the opening up of new tourist caves which is frequently suggested, is being deferred until redevelopment work in the present tourist caves is completed.

3. Visitor Barriers and Feature Protection.

In most of the caves in South Australia the practice in previous years was to allow people to move close to features of value and interest and provide protection by wire netting screens supported by galvanised iron pipes. The current emphasis is to redesign walkways and areas where people may go so that features of value are out of reach. This is achieved whenever possible in ways which retain the natural appearance of the cave, for example, by lowering walkways so that overhead calcite formations are out of reach, or by forming rock barriers with a natural appearance. Where necessary a single 4cm galvanised pipe railing, approximately 0.9 metres high, is used, welded onto vertical pipe supports of the same dimensions. The pipe is bent to fit various configurations. Where the pipe forms a barrier to stop people approaching an area of interest, a single strand of 8 gauge wire is run between the rail and the ground to discourage children from straying beneath it, but where it is simply a handrail, no wire is run.

Regulations under the National Parks and Wildlife Act to control undesirable activities in caves are currently being reviewed and greater emphasis will be placed on increasing public awareness of them. Guides will be retained in all caves (it is not proposed to introduce the self-guiding principle) and the combination of better planning of areas accessible to visitors, regulations and staff surveillance, has kept vandalism to minimal levels.

4. Electrical Wiring Systems and Display Lighting

The principal aim in planning the illumination of the cave is to provide light for the following specific purposes:

  1. General feature lighting. Light will usually be directed to illuminate a specific area in the best way possible.
  2. "Back lighting". Illumination of parts of the cave to show the extent of passages, to enlarge small areas and reduce feelings of claustrophobia.
  3. Footlighting of walkways and illumination of low overhead clearances to enable people to see where they are going with safety.

The objective is to have all lights and cables concealed and to ensure that any artificial barriers or other features are not highlighted, so that all scenes are able to be photographed without lights, cables, or barriers visible.

Different electrical systems have existed for many years in the tourist caves, including 32 and 110 volt DC and 240 volt AC systems. Cave electrical systems must now meet Electricity Trust of South Australia requirements under the electrical wiring code. It is now specified that all wiring underground must be 110 volt AC and this has a number of advantages:

  1. 110 volts is safer than 240 volts because a shock is less likely to be lethal.
  2. Because all fittings and fixtures are designed to meet safety standards for 240 volts there is greater safety when they are installed in a 110 volt system.
  3. Because 110 volt systems are used in many other countries (particularly North America) a wide range of fittings and varieties of illumination is available.
  4. There are fewer problems with an AC system arcing at switches in humid conditions compared with a DC system.
  5. There is less voltage drop with an AC system and hence lighter cable is required. Transformers are installed above ground to convert the 240V 3-phase grid system supply to 110V. In a large cave system (Victoria Fossil Cave) 400 metres of walkway, two 100 Amp capacity transformers are used, but in a smaller cave (Alexandra or Kelly Hill) either two 50 amp capacity or one 100 amp capacity transformers are required.

The accompanying schematic diagram (Figure 1) provides details of the new system being installed in the Victoria Fossil Cave at Naracoorte. The most important features of this new system are that although it meets the standards laid down and has permanent switching boxes, there is flexibility to experiment and rearrange the scene lighting to get better effects and to have various switching systems. Electricity may be directed from the main switchboards to any part of the system from either transformer. The low intensity walkway footlighting may be left on if required without illuminating formations, thus reducing algal growth, but can also be switched on and off in stages to "lead" parties of people through the caves. Scene lighting will generally be switched on only as required to introduce visitors to the caves in stages and to reduce algal growth. The master "on/off" switch at the entrance and exit door is set in a box which may be locked and can be used to turn off the whole system. This provides added security because the lights cannot be turned on by persons gaining unauthorised entry.

5. Walkways and Passage Development

At present all tourist caves in the State have only one entrance so that visitors must leave by retracing their steps and it is difficult to establish a one-way movement of people to simplify operations on a "walk-through" basis, rather than guiding visitors in groups. Where possible consideration is being given to establishing a second exit. This is now being done at the Victoria Fossil Cave at Naracoorte by the construction of approximately 130 metres of new walkway. In many instances the existing walkways in tourist caves have low head clearance, are narrow, and have steep grades or numerous steps. In the Victoria Fossil Cave there were approximately 260 metres of walkway with these problems; these have been largely restructured. This work has involved extensive tunnelling, excavation of floors and walls and removal of overhead rock.

The specifications for walkways are as follows:

Width of tread one metre with 0.1 metre on each side for drainage where possible; head clearance 2.2 metres for the full 1 metre width of the walk-way; Grade to be a maximum of 1:5 and steps to be eliminated wherever possible; Concrete surface, 7 cm thick.

The new exit for the Victoria Fossil Cave was created by the excavation of a large trench on the surface (a gently sloping hillside) to produce a vertical face 3.7 metres high and 2.5 metres wide. An inclined tunnel was driven from this face into the cave system. The trench was excavated by ripping with a Caterpillar D8 bulldozer, blasting and removal of material with a large 4-wheel drive rubber-tyred front-end loader, and a back-hoe. The trench slopes so that water drains away from the face in which the new entrance has been cut, and will be landscaped so that it appears to be a natural sinkhole, as found in limestone topography.

Several types of equipment have been used in tunnelling and the construction of walkways. Electric 25lb Bosch "demolition" model jackhammers with a chisel or moile point operated on 240V power were used initially and although they are an effective unit it is considered that electric jackhammers lack the hitting power for major tunnelling and their weight is a problem for workmen holding them whilst doing overhead work. Better results have been obtained from the 18lb air operated jackpicks using 4-inch spading, chisel or moile point bits, due to the greater hitting power of compressed air operated jackhammers and because they are lighter. These are operated from an air compressor on the surface with air supplied through up to 150 metres of ¾ inch high pressure rubber hose. More than one unit may be worked off the end of one hose. Other tools used include an air operated rotary drill to drill holes for blasting or to cut sections off by drilling a row of holes, and a heavy air operated road making jackhammer which has been used for floor excavation.

Debris is either redistributed to fill cavities which contain no features of value, or removed by wheelbarrow through the cave exit, where there are no steps. In an area where the materials had to be moved too great a distance by wheelbarrow, a vertical borehole 55cm in diameter and 20 metres deep was drilled and material winched to the surface in 12 gallon oil drum buckets.

Casual labour is used for excavation work with continuous supervision by a site foreman. Generally, two or three men only work as a team when tunnelling on a face, but when employed on improving existing walk-ways a gang of no more than 4 men has proved to be the optimum size. More than one gang may operate in different parts of the cave at one time.

A significant problem in undertaking walkway development work is estimating the time required, and hence the cost, to complete proposed work. Even with experience in this work, these estimates are difficult due to unpredictable variations in the hardness of rock, discovery of unknown cavities, the effect that staff morale has on productivity and other factors. Estimates can only be made on what experience is available and the specifications for work varied to remain within the budget. A further problem is staff safety. Throughout the operation inspectors from the Department of Mines have been involved and precautions such as propping and shoring have been taken when appropriate. Safety "hard hats" and protective clothing are essential. Nevertheless considerable reliance is placed on the Ranger-in-Charge, the Site Foreman and workmen to assess the safety of rock formations within the cave, since expertise is gained in working in local rock formation

6. Staffing and Guiding Methods

Staff are employed in various ways to most effectively manage cave reserves.

(a) Permanent Ranger staff are employed to provide local management, administration, supervision and planning functions and to carry out work which requires various trade, man management or technical skills. Although they are responsible for cave guiding and indeed train new guides, an attempt is made to keep time spent guiding by these persons to a minimum. These staff members form part of the Ranger career structure.
(b) Maintenance staff (wages employees) are employed to carry out maintenance functions of cleaning, rubbish removal, facility and ground maintenance.
(c) Cave guides are employed on a casual basis by the hour by the Ranger-in-Charge as visitor numbers require and may guide tours, sell tickets, or carry out minor maintenance work. A number of casual cave guides who are usually local residents, are trained, issued with uniforms and are made wardens under the National Parks and Wildlife Act. In fact an easily varied roster system is prepared over seven days of the week and whilst some casual cave guides are employed almost fulltime, others normally work certain days of the week or at certain periods of the year.

The training of casual guides is evolving. For each cave there are written notes detailing various subjects which guides may cover when at various locations within the caves, cave history and the best way of moving a party through the cave by the manipulation of lighting and other means. At the Naracoorte Caves these instructions are being recorded on a tape and a tape recorder has been provided to be used as a training aid. When guides are employed, there is a one week training period during which time they accompany other guides and guide tours under supervision. Cave guides are encouraged to take an active interest in developing their knowledge and a variety of talks which may be given to different groups. The Ranger-in-Charge accompanies his guides from time to time to check on the standard of guiding and help guides in developing their communication skills.

Visitors who wish to inspect the caves buy tickets for tours which are conducted at specified times, usually every half hour or hour. A loudspeaker system is then used to assemble a group which is taken through the cave by a guide. The size of the group is limited to a number determined for each cave (usually about 40 adults) and this is controlled by limiting the sale of tickets. Guides are encouraged to concentrate on the history, formation of the cave and information regarding fossil deposits and respond more to group interest and encourage dialogue, rather than to attempt to impart a large amount of information. They are also encouraged to vary their talk as much as possible and to use initiative in meeting group demands.

In caves where an entrance and exit is developed it is proposed to continue to guide parties through them on days when visitor numbers are low. However, when the number of visitors reaches the level when perhaps three guides are continuously employed it is proposed to allow people to walk through the caves on a continuous basis and the guides would then remain in certain areas of the caves to provide information and surveillance. This "walk-through" approach with guides present to do interpretation work differs from the "self-guiding" approach, where guides may not be present and interpretation is done by other means. The management of caves in South Australia is evolving as the information given above may suggest. In addition to the topics discussed there are other aspects such as interpretation and the development and maintenance of visitor facilities above ground which it has not been possible to cover. Nevertheless it is felt that more progress is being made towards the development of cave reserves which provide in all aspects a high standard of recreation facility for visitors.

Figure 1