BAN SAN and LUONG XA
After numerous tales of “fantastic passage in romping streamway” and numerous km of surveyed passage I finally made it on a trip. The plan, to return to junction 106 and explore a huge inlet, which possibly linked with Nguom Ban Sien. Then, if time allowed exit the cave and look for the continuation.
Martin, Duncan and Deb accompanied me for the trip as we dutifully followed behind the original explorers who were intending to take a photographic record of the cave. At the start point for the photos we were released, armed with directions we were like unleashed animals racing along fantastic stream passages until an exit was seen and the start of our inlet.
Described as ‘massive’ with a 100m echo we were excited to discover that the inlet was just that. Faced immediately with two leads Deb headed off on a recce leaving the male trio to continue the survey. Following the left wall we soon entered a high chamber with a steep boulder slope to the right and ahead. With accompanying whoops of joy we struggled to illuminate our surroundings.
Deb had rejoined us and again dutifully climbed high up the boulders to investigate the far wall and a black space that we could just make out. At the far end of the chamber the stream appeared from an uninspiring low muddy crawl. Above appeared to be a steep slope passing a fantastic stalagmite reaching over 25m. Our slope continued steeply until it stopped abruptly at a calcite wall with a passage beckoning above. Here the stealth rubber boots and 10m of 8mm rope were put to the test and with combined tactics the quartet stood staring into a large gour filled chamber. Cringing at every footstep as we crunched across the gours we continued surveying through an almost total blockage of stals into another chamber, sadly a terminal chamber.
Our descent of the climb was speeded up by a hand over hand absail. We now had no choice but to follow the low muddy crawl. After passing through a number of stagnant pools we were almost relieved to reach a sump.
With plenty of time still left we headed for the previously seen exit, our intention to head into the Doline and to hopefully find a continuation to the system. We were greeted with a spectacular sight, steeply vegetated slopes forming the sides of a long narrow cultivated doline with the river lazily meandering along the side. Ahead lay a small wooden house built in the customary way on stilts. The loud cries from a cockerel warned of our approach as mother hens hastily gathered the chicks into close supervision. From inside the dark room, wrinkled yet smooth faces stared curiously out at this bizarre picture of 4 wetsuit clad westerners passing through their property. The faces soon turned into warm smiles as we greeted them with a smile, wave and hellos.
Deb was soon testing her Vietnamese as she asked for information on other caves. Excited jabbering and arm pointing confirmed that caves lay ahead. Skirting the banks of the river we followed its course hoping to discover a large entrance. A solitary lady was tending a horse grazing on the meagre pasture, her friendly smile and wave greeted ours. Possible sinks were checked but none were caves, this became more frustrating when the river totally sank leaving only a dry bed to follow. A group of men watching over their buffalo’s appeared cautious at our approach but soon burst into laughter at our attempts to greet them. Luckily Debs Vietnamese was better and after a short conversation they confirmed a cave lay ahead. On we went and 25 minutes after exiting the cave we met a second active river flowing towards us and joining with our riverbed. Ten minutes later we stood, marvelling at the entrance in front as the streamway noisily cascaded over a dam on its course into the cave. Time was pressing but with a cave ahead we reckoned we could leg it back in less time.
Climbing down the dam led into fine streamway and cascades.A short swim led to walking size passage and a junction on the left. Surprisingly both passages are downstream! To the right the main passage continued steeply down cascades. A grandstand view of the cascades could be enjoyed from a massive calcite formation on the right, which also proved the easier route. A second junction on the left was passed with water emerging from a choke and passing through a hydro generator. We decided that water had been deliberately diverted into the first inlet and flowed to this second inlet to run the generator, though this was never proven as time prevented a full exploration.
The main way continued through a duck to large mud filled chamber and a sump. A climb up over silt banks led to a small phreatic passage containing stagnant pools and numerous ‘rats’, the cave was left at a particularly unpleasant stagnant pool, with a surveyed length of 464.9m.
With time pressing we did in fact ‘leg’ it, almost running at times, returning to the jeeps at the pre-arranged time, just. A large welcoming group had congregated at the jeeps, watching, fascinated at our pale bodies as they emerged from our wetsuits. The loudest laughs were for Duncan who, without shame bared all.
We had surveyed another 2.4km making the main river passage a respectful 4.0km long and the cave 5,471m. We had surveyed another of our aims on this trip.