7382 conceptual redevelopment for show caves

A CONCEPTUAL RE-DEVELOPMENT PLAN FOR THE SHOW CAVES OF PHONG NHA – KHE BANG NATIONAL PARK IN THE QUANG BINH PROVINCE, VIETNAM EXECUTIVE SUMMARY This document has been prepared as a broad overview of critical problems observed during a visit to the caves and some recommended actions to overcome them The Phong Nha (and Tien son) cave are the principle attractions to the Phong Nha-Khe Bang National Park which was declared to be a World Heritage Site in 2003 In 2008 the visitation was in the order of 300,000 people but visitation to these truly spectacular caves can only be sustained if urgent action is taken to change how people move through and behave in the caves Some of the key problems identified and proposed solutions include  Crowding of boats within the cave Install a suspended walkway above the river between Biky Grotto and Fairy Grotto to facilitate a ‘boat in – walk out’ system  Crowding of people and a lack of effective crowd control Introduce a system of a maximum group size of 15 and ALL groups to be supervised by a park employed guide who has completed a crowd management training course  Undefined walkways Immediately install a rope handrail barrier system to define limited walkways in each cave to protect the cave sediments  Visitors walking on the sediments and speleothems on the cave floor Design and install walkways suspended above the cave floor  Lampenflora damage from inappropriate cave lighting Apply chemical treatment to kill lampenflora and subsequently design and install a new lighting system to minimize ongoing lampenflora growth The estimated costs for immediate works to prevent further degradation of these world heritage caves is in the order of US$D30,000 to 40,000 plus human resources provided by the existing park staff The total projected cost (US$D500,000 to 850,000 plus labour) for the redevelopment of visitor access infrastructure is a very broad estimate with a reliability factor of +/- 25% Brian D Clark (PSM – Aust) Former President and Life Member of Australasian Cave and Karst Management Association 1- INTRODUCTION The Phong Nha (and Tien son) cave are the principle attractions to the PNKB national park which was declared to be a world heritage site in 2003 The primary role of an area established a national park is to protect the natural and cultural features within the park they are an important part of the heritage (what our grandfathers give to us we must cherish and pass on to our grandchildren) of the people of the nation As part of their heritage they must be permitted and even encouraged to come and understand their heritage When we nominate an area as a world heritage site we are saying that is area is not just important to the people of the nation it which it is located, but important to all the people of the world, and all the people of the world should come to see and understand their heritage As managers of these areas we must provide an appropriate level of access for people to use and enjoy the area, but the only activities we allow are those which help the visitors to understand the values, purpose and significance of the park, and those activities must be provided in such a way as the impact of the visitors is maintained at a sustainable level The access and activities provided at Phong Nha (and Tien Son) Cave at present is not sustainable Just as there is no doubt that over the coming years the visitation by both Vietnamese and international visitors to PNKBNP will increase, there is no doubt that the damage currently occurring in these caves will increase to the point that the desire to see their beauty will decrease as it is progressively destroyed The typical solution to such a problem in some areas has been to find new and more beautiful caves to turn into tourist attractions, but then in time, these too are destroyed by mass tourism This is not the way to manage our heritage Visitation (at current and increasing levels) to these truly spectacular caves CAN be sustained IF urgent action is taken to change how people move through the caves and IF urgent action is taken to control how people are behaving in the caves 2 -THE CURRENT SITUATION The core visitor area comprises a boat landing area at a picnic area where local hawkers sell refreshments and souvenirs, the access stairs to Tien Son cave, the river cave passage of Phong Nha and the two dry passages – Biky Grotto and Fairy/Royal Grotto a walkway from the Phong Nha cave entrance past a pagoda of indeterminate age and up to Tien Son cave or down to the picnic area appears to be unused in recent months Figure attached provides a (not to scale) schematic plan view of the area 100% of visitors go to Phong Nha and an estimated 60% also go to Tien Son but there does not seem to be any structured pattern dictating which cave visitors go to first Visitation is highly seasonal with some serious peaking problems of 10,000 per day during national holiday times Access to the river passage and Biky Grotto is closed from time to time during the wet season in August which fortunately coincides with the (present) low level visitor season The lighting system within the caves is having a serious impact on the cave environment due placement of lighting points, the type of lighting used and the absence of an effective switching system to ensure that there is only lighting when there are visitors in that part of the cave at the time The quality of site interpretation by guides is – as it is in many areas around the world – highly variable and in general seems to be a happy blend of cultural and natural values with a strong leaning towards fantasy All of these elements belong in the presentation but it must be remembered that the geological values are the confirmed world heritage values, the biodiversity (both above and below ground) values are the primary national park values so there must be a stronger emphasis on the geological interpretation of the site The quality of crowd control and behaviour control is also variable During recent visits some guides were seen to actively and aggressively intervene when tourists were smoking in the cave or climbing up onto cave decorations while others simply ignored such behaviour some guides endeavoured to maintain contact with and control of their groups – which were generally too big – while some groups appeared not to have a guide at all A pre visit briefing about what visitors should and should not, must and must not, while in the cave was not observed All of the dry cave areas are severely degraded by the absence of a defined walkway which results in under-supervised visitors walking and climbing over every possible part of the cave floor While some of this impact no doubt predates the current tourism use of the cave it should not be allowed to continue to degrade and in fact it could and should be rectified to restore the caves to their once superior and outstanding glory Figure SCHEMATIC PLAN VIEW OF PHANG NHA CAVE VISITOR USE AREA = picnic area and toilets = pagoda = river = fairy grotto = royal grotto = Biky grotto = tien son cave river limestone 2.1 - IDENTIFIED PROBLEMS AND PROPOSED SOLUTIONS 2.1.1 - Crowding of boats within the cave The boat ride along the river passage is an outstanding experience (which could be improved with a revision of lighting to support an interpretation of the formation of the limestone and the development of the cave) but in peak season there is a significant problem with crowding both at the picnic area and at Biky Grotto A solution to this is discussed in section 3.3 – proposed redevelopment 2.1.2- Crowding of people and crowd control The biggest threat to the cave and the experience provided is overcrowding within the cave and a variety of strategies need to be investigated to resolve this in terms of spreading the visitation out over time and space but the overall problem is directly linked to the sub-problems of crowd control by the guides, the size of tour groups, the absence of effective barriers, the absence of defined and essential site-hardened walkways 2.1.3- Undefined walkways 2.1.3.1- Biky Grotto This is a 125m long section of a dry passage running parallel to but above the existing stream passage of Phong Nha The section of the cave open to visitors has some useful features for guides to further explain the sedimentary origin of the limestone and the deposition of calcite formation It also has extensive deposits of important sediments which are being trampled In the immediate term it is very important to set the standard of behaviour for the rest of the cave tour here by defining a walking path and a no –go area, and this can be done for just a few hundred dollars All that is required is approximately 85 pieces of 10mm mild steel rod about 1500mm long and some 250/300m of 28mm diameter polypropylene rope installed in the cave as shown below in Figure steel rail barrier to be removed additional lighting needed in this area The next most important action, which also requires minimal funding but a little more hard work, is to demonstrate that much of the damage done can be undone It won’t ever be as ‘good as new’ but it will look a lot bet than it does and it will demonstrate that people care about the welfare of the cave Cleaning will require at least two stages The equipment required for the first stage is an electric powered water pump with sufficient power to lift the water from the river level to the top of the ramp and 100m of 30 to 50mm canvas fire house this is a high volume – low pressure task of washing the sand and clay off of the floor of superior examples of or rim-stone pools and lower sections of the cave walls and calcite formations which have been impacted by the deposition of mud and other materials Mobilizing the materials down to the river will take a large volume of water and mechanical stimulation of heavily in ground soil particles will be necessary This is best achieved by wetting the area and scrubbing with a stiff bristled brush or broom The second stage will require a low volume – high pressure pump to blast the surfaces where the soil particles and other artificial discolorations have become resilient to mechanical mobilization by brush alone The cleaning will cause turbidity in the river so it may be desirable to undertake this during a period of reasonable water flow This section of the cave need not be closed to visitors during this process A short training program will be required for all guides to understand the importance of the project and their responsibility in ensuring that ALL visitors remain outside of the roped area With some further minor work to repair the existing steps these actions will restore and protect this part of the cave indefinitely with the current level of visitation However, the international standard for show cave management requires that visitor walkways should be suspended above the cave floor wherever possible and as the visitor levels to Phong Nha are likely to increase in the very near future it is recommended to install a suitable walkway in Biky Grotto as soon as possible Key points must be selected for groups to stop and admire the cave features and provide opportunity for interpretation by a guide and / or in situ signage 2.1.3.2 – Phong Nha dry passage ( Fairy Grotto to Royal Grotto) This truly spectacular section of cave provides an excellent opportunity to present the basis for the parks inscription on the world heritage list It has numerous and excellent examples of karstic features to demonstrate the genesis of the limestone and the caves - but they too are being severely impacted by visitation, primarily due to the lack of a structured walkway and an inappropriate lighting system Protection and improved presentation of this area requires more or less the same treatment as Biky Grotto The immediate very low cost requirement is to define an acceptable route and place a rope and steel post barrier which all guides and staff working in the cave must rigidly enforce Cleaning of the speleothems can commence using the same technique of high volume/ low pressure followed by a low volume / high pressure treatment for ingrained materials left after the first treatment The cave need not be closed during this process but care should be taken to direct the water runoff or provide a series of temporary raised walkways to keep visitors away from the wet areas At the point where the access way passes up and over a series of severely impacted rim-stone pools near the end of the Royal grotto section there is an alternate exit point (see # in Fig.3) which will need be used while the concrete and soil in-fill is removed and these important features restored to their original beauty and a proper set of stairs and a viewing platform is installed as part of the next stage which is essential for the projected increase in visitation Development of the next stage – installing a 2400mm wide – walkway with several platforms at selected viewing areas – will make partial closure of the cave necessary Figure provides a conceptual outline of the walkway and staging of the development As mentioned above the first section to have a walkway of acceptable standard should be the last 50m in Royal Grotto which will not affect the current pattern of use – except that the visitors will not see this part of the cave That is a not a problem because, except for those who have seen it before, the visitors will not realize that part of the cave is closed The next section to be installed should be from the alternate exit stairway to a very narrow section about 50m into the cave This will require that visitors are brought into the Fairy Grotto to this point and then retrace their steps to exit from the Fairy Grotto The cave to that point still provides an excellent experience for visitors The third section will be the remainder of the cave (about 200m) which will have to be closed to visitors during the installation when visitors should be brought in from the existing exit point and taken along the new walkway before retracing their steps to exit via the old alternate exit point The need to close sections of the cave and have visitors go back the way they came will increase the problems of crowding in the short term so it will be very important to institute a policy that all visitors MUST be accompanied by a park employed guide and that groups are kept to a maximum of 15 people In addition it is recommended that the construction works are well planned and that all equipment and materials are on site, that a suitable trained and properly supervised labour force is available and that the work is scheduled to commence at the end of the peak season Figure conceptual walkway and platforms # 2.1.3.3 - Tien Son Cave Tien Son must also be saved from the ongoing destruction of it’s values and beauty by installing a raised walkway along a selected route through the cave, remembering that visitors don’t have to see the whole cave from a few metres away Exactly as is required for the other dry sections of Phong Nha cave the immediate step is to prevent ongoing damage by roping off a designated pathway Because of the more intimate or closer proximity of many speleothems to the vaguely defined existing route through the cave many of them are being subjected to visitors touching them This is particularly bad as the fatty acid which is transferred from the hands to the speleothem generates a reaction which eventually discolours them A raised 1800mm wide walkway with enlarged viewing platforms at selected sites should be provided and then an intensive cleaning program initiated to restore the natural beauty of the cave The walkway should be of a nominal length of around 100 to 150m and the cave tours could continue to be provided as they are now (except that all visitors must be accompanied by and supervised by a park employed guide) or the tours could be provided on a ‘self timed’ basis to provide a new dimension to the visitors experience of PNKBNP Under this concept visitors would be permitted to walk through the cave at their own pace and appreciate the cave in their own way Park guides or ‘hosts’ should be stationed at regular intervals along the walkway to answer visitor’s questions Every attempt should be made to reduce the noise in the cave Visitors must be briefed to minimise noise and guides not permitted to use megaphones 2.1.4 -Inappropriate lighting The existing lighting system presents an environmental threat to the caves ALL lighting installed within a cave results in the growth of ‘lampenflora’ – plants which grow under artificial light The initial stage of lampenflora is the discoloration of the cave walls, floor, ceiling and speleothems with algal growths which turns much the cave green, grey and eventually black In many cases the algae is replaced by mosses and lichens and eventually, as was seen in the show caves of HNKP, ferns become established While the initial thoughts might be it is only a question of aesthetics it is not All plants generate carbon dioxide in the contact point with the cave, and carbon dioxide causes rapid dissolving and degradation of the limestone and the speleothems on which the lampenflora is growing The provision of artificial lighting is a function of management and it is inappropriate for a function of management to be so damaging to the cave The very definition of ‘show-cave’ is that they DO have artificial lighting, but the management of the lighting system can and must be managed to minimize the growth of lampenflora the primary issues are:  the amount of light  the type of light used (Florescent vs incandescent vs LED)  the placement of lights within the cave  the duration of time that lights are on At present the best practice in show cave lighting to minimize lampenflora growth is to use low voltage and minimal wattage such as 12volt dichroic halogen lamp system controlled by a manual switching or movement sensor control such that the lighting is only on while visitors are in the area of the lights However the emerging trend is to use recently developed ‘ultra-bright’ LED fittings which can be designed with variable shaped beams which facilitates the design of spectacular cave lighting options Also emerging as a trend is the installation of computer controlled switching systems which provide development of pre-planned and fixed dramatic lighting effects where visitation is rigidly confined to only group being in any given section of the cave at any given time For caves experiencing a higher density of visitation the most appropriate system is to have various sections of the cave controlled by motion sensor activated lighting If nothing triggers the motion sensor for a nominated period – say 10 minutes – then the lighting in that section of the cave turns itself off This would be the system recommended for implementation at Phong Nha and Tien Son caves and it should be considered as an immediate action which could be added to the existing lighting system at very low cost When funding is available to further improve the lighting an LED based system is strongly recommended and it is proposed that while the traditional use of coloured lighting be maintained in some of the caves, at least one significant area should be redeveloped in line with the trend towards using lighting which brings out the natural colour of the cave Again, the new super-bright LED lights are the best for this purpose 2.1.5 - Uncontrolled behaviour in the show caves On visits to the caves during March it was noted that most but not all groups are accompanied by a guide and it was noted that security staff where stationed at key points in the caves A notable problem was the lack of a readily recognizable staff uniform for guides As visitors arrived at an area they simply swarmed over every possible horizontal surface of the caves with much shouting and yelling, smoking and spitting, throwing rubbish and touching the speleothems Barricade fences were simply ignored as people climbed over them A disturbing problem was the cultural practice of climbing up onto speleothems to place ‘good luck’ money or simply to have a photo taken Some guides and some security staff did try to prevent some of this behaviour while others simply stood back and ignored the problem It is essential that visitors receive information about some key behavioural requirements which are common to most show caves around the world and certainly are requirements in world heritage caves These include not smoking in the cave, not spitting in the cave, not littering in the cave, not touching cave formations, not making excessive noise and remaining on the defined pathway at all times This should be included in symbol signage panels provided at the main entry point to the park, it should be verbally presented in the boat before visitors arrive at the cave entrance area and it should be repeated as symbol signage in the picnic area At the very first briefing stop point in each cave the guide must remind the visitors again It is very important that a park staff training program be developed and delivered so that staff understand the serious consequences of uncontrolled behaviour to the cave environment SCOPE OF WORK AND COST ESTIMATE The following is a summary of the scope of works required (in priority sequence), the equipment/resources required and where appropriate, an indicative cost estimate to complete each element of the proposed works, noting that these are subject to a more detailed process of measurement and quantity survey 3.1 Immediate requirements 3.1.1 Development and delivery of a training course This is considered essential for all staff to understand the consequences of unmanaged behaviour in the caves a preparation of the training course including course materials and assessment i allow persons (for 30 person days) for development of the course content and structure (allow days for instruction and assessment), a training manual and power-point presentation Say USD5,000 b course delivery and assessment i assuming 200 staff are targeted for retraining then the program will need 10 groups of 20 participants = 400 person days for staff plus 50 to 60 person days for planning, delivery and reporting by course co-ordinators Say USD10,000 = total USD15,000 It is strongly recommended that successful participants are rewarded for their participation and success This could be simply financial or ideally it should be emotional as well For example all successful participants are recognized by being presented with a ‘cave warden’ badge to be worn a readily recognizable uniform, which need not be more than a simple vest with the park name and the wearers position printed on it (Park Guide or cave Guide/ boat operator/ cave security etc) Allow USD15 per person x 200 = $3,000 3.1.2 Provision of behaviour modifying signage Signage in parks is always a problem Not enough signage and the excuse is always “There’s no signs to say not to and nobody told me It’s not my fault!” Too much signage and nobody reads it because there’s too much of it What languages should it be in? Before entering the Phong Nha cave all boats should be required to stop at the picnic area where a series of panels signs (repeated in three or four stations spread around the perimeter of the picnic area to facilitate access during busy periods) must be installed to provide a brief overview of the geological process which formed the Phong Nha karst, an explanation of what World Heritage is and what the rules are for people to follow while visiting the caves Importantly the rules should not simply be expressed as ‘don’t this and don’t that’, but a brief explanation of the reasons for the rules must be provided It is not enough just to put up signs The Guides must direct their group to the signs and use them in their essential pre-visit briefing The signs must be prepared in Vietnamese and should be repeated in English (the common language of European tourists) and possible in Mandarin The panels must also have the international symbols depicting no smoking, no eating, no touching, no littering 10 The symbol signage should be repeated at the entrance to each point where visitors are entering a different zone of the caves (Biky Grotto, Fairy Grotto and Tien Son Cave) Assuming each of four stations will comprise two panels (nominally 1800x1000mm in portrait format) to explain the origin of the limestone and how the caves were formed, one panel to explain world heritage and one to explain the rules for entering the caves, this one repeated at sites within the caves, then a total of 19 panels are required If a set is to provided in English and another in Mandarin then a total of 27 panels is required at an estimated production cost of USD10,000 to 15,000 for scripting, translation and graphic design and a unit cost for production in an all weather format of between USD150 to 250 Installation materials should be no more than USD500 and labour costs of around 15 person days A total of $17.5 to 25,000 3.1.3 Interim definition of walkways in the caves The dry passageways currently being accessed by visitors are (approximately) 125m in Biky Grotto, 300m in Fairy/Royal Grotto and nominally 150m in Tien Son Cave All require definition of the approved walkway by the installation of a rope barrier A total length of around 1250 to 1500m of 28mm polypropylene rope is required at an estimated USD500 to 750 together with about 500 units of 1500 x 10 to 12mm galvanized steel rod at USD1,500 to 2000 = total of $ 2,000 to 2,500 plus labour costs in the order of 50 person days 3.1.4 Reduction of lampenflora impact The total show cave area should be divided into distinct zones – Biky, Fairy and Royal Grottos and Tien Son cave – and the lighting in each zone controlled by a motion sensor or sensors The sensors have an adjustable timer which can be set for a predetermined number of minutes -say 10 minutes The sensors can also be programmed to reset themselves every time someone triggers the sensor it resets itself to turn off in ten minutes after the last person has been detected These can readily be installed as a retrofitted item in the existing system Biky Grotto, Fairy and Royal Grotto each require sensors wired in a ‘two-way’ switch configuration to allow flexibility in the direction of the traffic flow Tien Son Cave requires sensors each controlling on third of the designated pathway Each cave or section of cave should have a low wattage emergency light installed in key areas which are not sensor activated in the event that a sensor malfunctions so that visitors are not left in complete darkness The estimated costs for sensors and standby units is US$1,000 to 1,500 plus US$300 to 500 for switch wiring, US$500 to 750 for 15 units of emergency lighting = total of $1,800 to 2,750 plus approximately 20 person days for installation by technically competent staff/contractors As soon as the work has been completed all areas of the caves showing lampenflora growth should be treated with a mist spray of to % calcium to kill the lampenflora Several treatments over a period of to days may be required and the treated areas then washed liberally with water pumped from the river Allow a total of US$300 to 500 for chemical (calcium hyperchlorite) plus 150 for high quality backpack 15Litre capacity spray units and person working 20 days each to apply the treatment = 80 person days In the large scale trials of calcium hypochlorite carried out in the Glow-worm and Ruakuri Caves it was found that the concentration of hypochlorite needed for effective control depended on the composition and density of the lampenflora to 11 be treated where the lampenflora consisted only of a thin covering of algae, then a 2% solution* was strong enough to clear the surface If however, the lampenflora was made up of a dense matt of mosses and algae then a 4% solution* was necessary The only major problem noted concerning the use of Calcium hypochlorite is the strong chlorine smell evident immediately after treatment The actual concentration is very low but human sensitivity to this chemical is such that decided irritation is noted This problem is only serious in unventilated areas of the caves, e.g the Organ Loft of the Glow-worm Cave However, 12 hours after treating the Organ Loft area with four litres of 4% hypochlorite only traces of chlorine could be detected, and after 36 hours the smell was undetectable (as judged from Cave Guides comment) In summary, the costs for immediate works to prevent further degradation of these world heritage caves is in the order of USD30,000 to 40,000 plus human resources of :  200 staff released to attend a two day cave visitor management training course  supervisor and semi-skilled persons (carpentry) for days to install signage  supervisor and semi-skilled persons for 10 days to install post and rope barriers  electrical technicians for 10 days each (plus unskilled support staff) to install the sensors and emergency lighting system  supervisor and unskilled ( but cave visitor management trained staff) for 20 days to treat the lampenflora which, despite having a cost estimate reliability factor of +/- 30% (subject to prevailing local prices and regional loading due to the tyranny of distance from supply) is respectfully recommended as a relatively low cost to halt the ongoing degradation of these world heritage caves at the present level of visitation The author of this report (to GTZ et al) believes that any international financial support for, or local/international investment in, the PNKBNP must address these issues before any further development is even contemplated if PNKBNP is to avoid the reality of its demotion to the ‘world heritage in danger list’ sometime in the next years 3.2 Proposed redevelopment The PNKB caves which have been opened to tourism ARE very special, and there is no doubt that there are other caves within the park and its buffer zone which can be used to boost tourism development in Quang Bhin province However, it is vital that the existing show caves be redeveloped in accord with international best practice standards to facilitate increased visitation while protecting the caves from degradation before any steps are taken to develop any new show caves Only when this has been achieved and lessons learned from the exercise should there be any contemplation of development which will sacrifice the sites world heritage values to the demands of mass tourism in such sensitive areas 12 3.2.1 Reduction of boat crowding Crowding of boats at Biky Grotto and the Royal Grotto exit point is a growing problem which can be solved and in doing so, the cave tour experience vastly enhanced By constructing a walkway (approx 400m long) suspended from the cave wall between Biky Grotto and Fairy Grotto and instituting a system of the boats dropping passengers at a floating wharf then departing from the cave to wait on the far bank of the river boats will remain in the cave for a minimal time and the visitors walk back to Fairy Grotto, enjoying a completely different view and appreciation of the cave, after they have inspected Biky Grotto Figure – a schematic plan view of the walkway with section view of the construction method Biky Grotto 1800m m 1000mm 2000mm Fairy Grotto average water level = 100x50 x 2mm (or 2.5mm) galvanized steel C section = 50x25 x2mm galvanized steel box tube = 50x50 x 2mm galvanized steel box tube = 150x12mm galvanized bolt chemi-grouted into limestone non-slip decking of inertestimate material to be of selected price and availability A very broad theoncost of local materials and labor is US$350 to 500 per meter plus US$35,000 to 50,000 for detailed design specifications and project supervision With an estimated 400m length of such walkway required allow US$175,000 – 250,000 13 3.2.2 Raised walkways to accommodate increasing visitation There is no ‘once size fits all’ answer to installing cave walkways and there is no perfect solution to the choice of materials used The only timber suitable for in cave walkways is Borneo Ironwood as all other timbers quickly rot, cause fungi to grow or introduce mobile organic materials to the cave ecosystem and as its supplies are almost exhausted it is not recommended Some cave specialists view stainless steel as the only durable and environmentally suitable material for structural support members but it is extremely expensive compared to galvanized steel which has some very minor potential negative impacts Walking surfaces need to be environmentally inert, hard wearing, easy to work and noise dampening Several options can be explored but the recommended is a combination of expanded steel mesh, plastic/ wood waste composite planks or one many products depending on local availability The walkway should be elevated above the floor from 300 to 1800 (or more) mm to provide an easy gradient (1:15) slope throughout the cave Where the topography of the cave precludes a graded ramp then steps (with a consistent height of riser) must be used and continuous step runs of more than 17 steps avoided The walkway must be installed with 900mm high hand rails on both sides On level or moderately graded ramps a 28mm polypropylene rope with intermediate runs of 15mm polypropylene rope (see fig 5) provides a low cost and sufficient handrail for but on steps of 12 or continuous steps a fixed metal pipe rail with a non-slip textured surface is more appropriate in a high use cave The walkway should be between 1800 and 2400mm wide in a cave with high visitation with selected viewing platforms of around 15 to 25m2 Aesthetically the walkway should be gently curved, rather then a series of connected straight sections, to reflect the natural elements of the cave Figure – elevation and plan view of nominal walkway structure 14 3.2.2.1 Biky Grotto walkway The gradient of the floor of Biky grotto precludes the use of a ramped walkway as it is too steep Subject to a detailed survey of the elevation it is proposed to install a repetitive ‘step and runner’ system as indicated in Figure A Figure – a sectional view of the proposed ‘step and runner’ walkway 28mm polypropylene rope hand rails with x 15 mm barrier ropes an approximation of the natural floor gradient in Biky Grotto with 50mm galvanized steel square section with selected non slip surface proposed pattern of 2.4m long walkways linked by an even pattern of to steps (this is of course subject to further engineering study and design) The walkway should be 1800mm wide and designed to facilitate a ring-route of one-way traffic with a briefing platform at the beginning, a large platform at the top with or traverse points as shown in figure 6.1 An indicative cost for approximately 300m of 1800mm walkway is in the order of USD250 to 300 per linear meter and 125 to 150 per m2 for associated viewing platforms plus detailed design and project supervision costs of between USD20,000 to 25,000 At 300 meters the cost will be in the order of USD125,000 to 150,000 15 3.2.2.2 Fairy Grotto and Royal Grotto This spectacular (approximately 300m) section of the Phong Nha Cave will require numerous viewing platforms(nominally units) each capable of holding 15 to 25 persons at a time Where possible the 1800 to 2400mm wide walkway linking the viewing platforms should be level or ramped with a moderate grade (1:20) Where this gradient cannot be achieved stairs must be used An indicative cost is USD175,000 to 225,000 3.2.2.3 Tien Son Cave The existing visitor route through Tien Son Cave must be revised and a ring route of a nominal 125m length constructed along the same lines as the dry passages in Phong Nha Cave at an indicative cost of USD80,000 to 100,000 3.2.3 Upgrading the lighting to reduce lampenflora and to enhance the presentation of the caves The first strategy to consider in the redevelopment of the show cave infrastructure is the mode of light switching and there are several different switching options for show caves including:  manual switching of individual lights or groups of lights  sensor controlled switching of sections of a cave  programmed computer controlled switching of individual or groups of lights The first gives the guide maximum and flexible control options to dramatise the tour and it provides the optimum capacity to minimize the duration of illumination – one of the key strategies to reduce the impact of lampenflora - but with the present and projected levels of visitation to the PNKBNP show caves is not practical The second is a simple system which requires the on switch for the lighting in a section of the cave to be triggered by a person moving into range of the sensor A timer then tens the lighting off after a preset time of say 10 to 12 minutes (allow times the average time it takes for a person to casually pass through and enjoy the cave scenery in the designated area), except that each person that passes into the sensor range resets the timer to the preset time For example, a person arrives at the base of the proposed steps in Biky Grotto where there is a single light illuminating about 10m of the walkway As the step onto the first step a sensor turns on a series of lights which illuminate the left hand side of the passage all the way to the top where there is a viewing platform The average person takes minutes to walk from the entry point to the viewing platform so the timer was set for 10 minutes after which the lights go off As the person reached the viewing platform a second sensor is activated to light up all the area around the platform for say 15 minutes After 10 minutes the left hand pathway lights automatically turn off However if after minutes have elapsed another person steps onto the first step they will activate the sensor is reset for another 10 minutes It is important to install a master switch to ensure that power to the cave can be isolated at the end of each day to ensure that the low level manually controlled lighting is not accidentally left on overnight nor a malfunctioning sensor switching lights on and off during the night when it is not needed Such a system is very suitable for the style of group management and visitor level in the caves of PNKBNP The third is a variation on a sensor controlled system but provided for the ability to dramatic effects of lighting is cycled through a preset program of one group of lights turning on then slowly dimming to off 16 as another group showing a different perspective of the same area is turned on, gently changing the scenery to greatly enhance the enjoyment of the experience of the cave visitors The next strategy is the selection of light type Fluorescent lighting is probably the worst and incandescent lighting the next worst, save that 12volt Dichroic halogen lamps (20w, 35w, 50 w or even 75w) combined with a sensor activated system are lower in impact the 120 or 240volt incandescent fittings PROVIDED that the placement of lamps in proximity to active speleothems is very carefully planned The latest generation in cave lighting has evolved very recently with the advent of ‘super-bright’ LED light specifically developed for show cave lighting While a little more expensive in terms of capital cost the much lower maintenance and operating cost makes this a very viable option Assuming a total illuminated passage length of 1200m (600m wet and 600m dry) in Phong Nha and 150m in Tien Son Cave an indicative cost to redevelop the lighting with a sensor switching system is USD 55,000 to 60,000 for materials plus lighting design plan consultant (say USD5,000 to 10,000) = USD 60,000 to 75,000 including contingencies plus electrical technicians and support crew for 60 days = 240 person days 3.2.4 New product development Other caves in the park CAN be used for tourism growth but new products should target a low volume/high return international market rather than further catering to a mass domestic market A simple example would be hang Toi and hang E, which are suitable for adventure tourism which would involve small groups (maximum with competent local guides) ‘rafting’ through the caves in wet suites and buoyancy devices This should be promoted as an exclusive experience with no more than one group permitted to be in the cave at a time Duration of the experience within the cave would be to hours and such a product would sell at around USD25 to 30 per person with a minimum groups size of ($100 - 120) and a maximum of ($200 - 240) income per group with capacity to accommodate up to groups per day in each cave Another example is ‘Paradise Cave’ which could be used for low volume/high cost adventure tourism using torch lights Some low key external site hardening to protect access to the cave from causing erosion is required and ‘track marking’ within the cave is required to prevent degradation of speleothems and cave sediments This requires selection of a route (nominally to 1.5 km long in this particular cave) through the cave to a significant feature and then installing a series of 300mm high 10mm fibre-glass rods in the cave floor at to 15m intervals on one or both sides of the selected route A heavy duty (say 50kg breaking strain) monofilament fishing line is then tensioned between the rods to support a series of small reflectors placed at to 10m intervals to make it very clear which area of the cave can be walked on and which must not Once the track marking has been completed it can be promoted as an exclusive adventure caving experience product operational guidelines similar to those proposed for hang E and hang Toi – except that Paradise Cave could be sold for a 50% premium over the indicative cost of the tour to these 17 Gating of this cave to prevent unauthorized access by non-park employed/approved guides is recommended There are numerous articles available for the design of cave gating but for this cave it an environmentally and economically suitable solution would be the use of a series of expandable eye-bolts installed in the rock with a network of 5mm stainless steel cables The estimated cost to track mark and gate this cave is USD1,500 to 2,000 plus semi-skilled labour of persons for 10 to 12 days (after route selection) Development of caves in the buffer zone is a desirable possibility BUT the standards of protection, behaviour and interpretation provided must be equal to and consistent with the standards required in the park As custodians of these natural wonders it is our responsibility to teach the local and global community that we must all work together to protect our heritage from inappropriate use whether it is within the protected area or not SUMMARY OF ESTIMATED REHABILITATION AND REDEVELOPMENT COSTS Development and delivery of a training course Provision of behaviour modifying signage Interim definition of walkways in the caves Immediate reduction of lampenflora impact Chemical to kill existing lampenflora 400 meter cantilevered walkway to reduce boat crowding Raised walkways to accommodate increasing visitation Upgrade the lighting USD 15,000 USD 17,500 USD 2,000 USD 1,800 USD 300 USD 175,000 USD 380,000 USD 60,000 New product development USD to to to to to to to to 1,000 to 20,000 25,000 2,000 2,750 500 250,000 475,000 75,000 1,500 The total projected cost of between USD500,000 and 850,000 plus labour is a very broad estimate with a reliability factor of +/- (and more likely minus) 25% Labour cost have not been included as it is very highly recommended that existing staff are used rather than allowing external contactors to work in the caves 18 ... of the caves The first strategy to consider in the redevelopment of the show cave infrastructure is the mode of light switching and there are several different switching options for show caves. .. limestone and how the caves were formed, one panel to explain world heritage and one to explain the rules for entering the caves, this one repeated at sites within the caves, then a total of... visitors receive information about some key behavioural requirements which are common to most show caves around the world and certainly are requirements in world heritage caves These include