CAVING: Shedding light
There are 560 known cave entrances within 2 hours of There are 560 known cave Kuching with many more still to be found.
We’re all left in the dark from time to time but nothing will prepare you for the total absence of light in a cave system. Well lit cave entrances can be stunningly beautiful but the light soon runs out as one ventures further inside and you are in utter darkness.
Our earliest ancestors used the caves as homes and, later, as burial grounds but seldom entered into the dark for fear of the spirits and wild animals inside and, of course, the unknown. When the Chinese traders arrived in Sarawak, in the 9th Century Borneo's natives, incentivised by trade, lit their torches (a resinous wood frayed at the end), overcame their fear, and went deep into the caves to collect edible nests of the cave swiftlets.
In 1857 Spenser St John, James Brooke's private secretary, went into Gua Sireh in the Serian district to see where the nests were collected. ‘Our slight torches could scarcely penetrate the gloom that hung thickly about us’ he wrote.
And later ‘A fresher blast (of wind) blew out some of the lights and I thought for a moment that that we were about to be left in the dark’ And if they had been left in the dark that is the last we would have heard from Mr. St John!
Taang Raya. 1 x 900 lumens and Darth Vader
Carbide lamps started replacing resinous wood flares in 1900. Producing a bright white light they were indespensible to cavers until the 1990s when battery powered torches took over. Initially generating less than 200 lumens of light, battery powered lighting has advanced rapidly (thanks, recently, to the CREE light emitting chip and lithium-ion batteries) and 2000 lumens is now commonplace with 4000 lumens becoming affordable. Look out for consumer-priced 10,000 lumen torches in the next 2 or 3 years.
Illuminating the darkness isn't just about light. Cave exploration has been going on for a long time but much of the underworld contains, along with some of the seabed, the last spaces on earth that haven’t been explored. Exploration isn't just about going there - It is about documenting what you find. The first sketch map of a cave was done in the 1640s prior to the introduction of the first cave tour in 1648 (!) whilst the first measured map (or survey) was done in the 18th century in France.
Gerry Wilford from the British Geological Survey surveyed many caves in Sarawak and Sabah between 1947 and 1963 and there are 560 known cave entrances within 2 hours of Kuching with many more still to be found. Many of these cave systems have not been surveyed at all and some are completely unexplored. And you dont have to walk a mile to find them. Above the heads and beneath the feet of the 1000s of tourists who visit Fairy cave every year are unexplored passages.
When Gerry was surveying caves in Sarawak the work was done with a tape measure, a compass and a clinometer (which measures slope). Each measurement was written in a waterproof notebook and the map of the cave drawn up over a beer. Just as lighting systems have moved on, so has surveying. Nowadays we use a laser measure which transmits each measurement to an app in a smart phone and the survey (plan view) is drawn in the cave, which would leave us with the problem of what to do when we are having a beer! However, using the same data, we can build 3D models of the cave, so no time to relax!
FAIRY CAVE Natural lighting
LOBANG BATU Main entrance Natural lighting
Gerry Wilford Groyong survey from the 1950s.
Gerry Wilford from the British Geological Survey surveyed many caves in Sarawak and Sabah between 1947 and 1963
Even this isnt state of the art. The same laser technology that is employed in driver-less cars (and incidentally some speedcams) can be used to survey caves. It is called Lidar (Light Detection and Ranging). Both the cost and the weight of the equipment is coming down fast driven by the automotive industry and we will soon be mounting lasers on drones to reach those hard to reach places.
We can add to our surveying toolkit photogrammetry which is a technique which produces 3D images from a series of 2D photos. Photo-realistic 3D cave models which can be flown through, which 5 years ago would have been just a dream, are close to being a reality.
A lot of light has been shed on our caves (both literally and figuratively) but there is still a great deal more to do. But before you head underground make sure that you have the adequate equipment and that you are fit enough. Never go underground on your own and always go with an experienced caver (at least until you are experienced). Our ancestors were right – this is, potentially, a dangerous and unforgiving world and those who get it wrong face the prospect of being kept in the dark for a lot longer than they anticipated!