Langcliffe Pot facts for kids

Quick facts for kids Langcliffe Pot
Oddmire Pot entrance shakehole
Location	Great Whernside, North Yorkshire, UK
OS grid	SD 9958 7107
Depth	116 metres (381 ft)
Length	9.6 kilometres (6.0 mi)
Elevation	488 metres (1,601 ft)
Discovery	1936
Geology	Yoredales Limestone
Entrances	2
Difficulty	V
Hazards	water, loose boulders
Access	None
Cave survey	ULSA survey on Cavemaps

Langcliffe Pot is a cool cave system found on the side of Great Whernside mountain in North Yorkshire, England. It's about 3 kilometers (2 miles) south-east of a village called Kettlewell. This cave is part of a special area called the Black Keld Site of Special Scientific Interest. This area has one of Britain's biggest and deepest underground water systems, even though only a small part of its caves can be explored right now. Another famous cave, Mossdale Caverns, is also in this special area.

Even though a lot of Langcliffe Pot has been explored, the deepest part found so far is still 170 meters (558 feet) above where the water comes out at Black Keld. It's also over 4 kilometers (2.5 miles) away from that point. Going to the very end of Langcliffe Pot is known as one of the most challenging trips in British caving.

Exploring Langcliffe Pot

The entrance to Langcliffe Pot is in a shakehole, which is like a big dip in the ground. You squeeze through a small gap between rocks to reach a ledge. From there, you go down a 26-meter (85-foot) deep shaft. This leads into a chamber with a narrow crack-like passage. This passage soon becomes the "Craven Crawl," which is 200 meters (656 feet) of low, wet crawling.

After the crawl, the passage gets bigger and is called "Stagger Passage." This section is about 600 meters (1,969 feet) long, where you can mostly walk or stoop (bend over). You'll pass a side passage that leads to another entrance called Oddmire Pot. The main passage then turns into a deep water channel.

Hammerdale Dub and Beyond

The water channel continues until it reaches a major meeting point called Hammerdale Dub. From here, over 1,000 meters (3,281 feet) of passages go upstream, also leading back towards Oddmire Pot. If you go downstream, you'll find 1,500 meters (4,921 feet) of a rocky streamway. The water eventually disappears under a wall, but a small passage leads into Boireau Falls Chamber. Here, you can get back to the stream.

The stream then ends at a spot called Nemesis. This is a 20-meter (66-foot) deep shaft. Below it, you have to find a way through a tight and tricky pile of rocks called a boulder choke. This leads into Gasson's Series.

Gasson's Series and New Fearnought Streamway

Gasson's Series starts as a high stream passage but then becomes a low, wet section. After this, the passage continues for 100 meters (328 feet) before reaching Poseidon Sump. Divers have explored this underwater section for about 20 meters (66 feet) until it became too small.

Back at the low pool, there's a dry passage with narrow cracks and chambers. This passage goes on for over 1,100 meters (3,609 feet) before getting smaller and dropping into the large New Fearnought Streamway. Downstream from here is Dementor Sump, which divers have explored for 20 meters (66 feet) until it was blocked. Upstream, the passage ends after 230 meters (755 feet) at a blockage of rocks.

Oddmire Pot

Oddmire Pot is another entrance to this cave system, located about 350 meters (1,148 feet) north-west of Langcliffe Pot. It's a small hole in a shakehole that leads to a broken 17-meter (56-foot) deep shaft. At the bottom, "Strid Passage" continues as a crawling and stooping passage for about 500 meters (1,640 feet). It then joins up with Stagger Passage from Langcliffe Pot. There's also a hidden side passage called "The Roads" about 150 meters (492 feet) in, which is a longer way to reach Hammerdale Dub.

How the Cave Formed

Langcliffe Pot is a solutional cave, meaning it was formed by water dissolving rock. It's found in rocks from the Yoredale Series, which are part of the Carboniferous period (a very long time ago!). The Yoredale Group has layers of different rocks like sandstone, shale, and thin layers of coal, with limestone beds in between.

The upper parts of the cave formed in the Middle Limestone. The passages slope downwards towards the south-east, with sandstone forming their floors. In Boireau Falls Chamber, the stream cuts through a 50-centimeter (20-inch) thick sandstone layer, then through 4 meters (13 feet) of shale, and into the Simonstone Limestone. Nemesis Pitch goes straight through this rock, and Gasson's Series is entirely within the Hardraw Limestone. The water eventually comes out at Black Keld, which is about 174 meters (571 feet) lower than the lowest point of Langcliffe Pot. This water comes out from the Great Scar Limestone.

Water Flow in the Cave

Langcliffe Pot is part of the 20,000-hectare (49,421-acre) Black Keld water area. Most of the water in this area flows into Mossdale Beck, which then disappears into the limestone at Mossdale Scar. Langcliffe Pot gets its water from a few small streams that drain an area about 500 meters (1,640 feet) wide on the side of Great Whernside. The water then flows downwards in the general direction of Mossdale.

The water from Mossdale Caverns and Langcliffe Pot eventually join up somewhere underground. This combined water then comes out at Black Keld. Divers have explored Black Keld for about 2 kilometers (1.2 miles) but haven't yet reached Langcliffe Pot.

History of Exploration

Langcliffe Pot was first noticed in December 1935 by members of the Craven Pothole Club (CPC). They made the first trip down the cave the following April. They explored the first 45 meters (148 feet) of the downstream passage to a pool. Soon after, they used dye to trace the water from Langcliffe Pot and other streams to see if it came out at Black Keld, which it did.

Another group from the same club went down in 1954. They pushed further, exploring another 400 meters (1,312 feet) along what is now called the Craven Crawl before turning back. In August 1968, a team from the Yorkshire Underground Research Team explored over 1 kilometer (0.6 miles) beyond where the CPC had stopped. They reached a spot called the Kilnsey Boulder Crawl. They weren't very impressed with the cave, so they passed the exploration on to the University of Leeds Speleological Society (ULSA).

Over the next three months, ULSA explored and mapped the main stream passage all the way to Boireau Falls Chamber. They also explored all the major side passages, bringing the total length of the cave system to 6.4 kilometers (4 miles).

Discovering Nemesis Pitch

The next big step in exploration happened in 1970. The choke (a blockage of rocks) in Boireau Falls Chamber was dug out, and Nemesis Pitch was discovered. A week later, a way was found through the complicated pile of rocks at the bottom of Nemesis Pitch. This led to the discovery of another 2 kilometers (1.2 miles) of passages!

In June 1972, the cave system flooded while a ULSA diving team was on the far side of the Nemesis boulder choke. This trapped them inside and led to a major rescue call-out. Luckily, the team came out safely after a 44-hour-long trip. Another big rescue happened in 1974 when five cavers got trapped on the far side of the Nemesis Choke after some rocks shifted. They were also rescued safely.