1930 Another attempt on Swinsto was made using rope ladders strengthened with wire to help them survive their passage along the crawl. R Hainsworth was defeated at first but eventually reached the final chamber. The first CPC Bus Meet was arranged. A survey of Lost John’s was published by the YRC.
1931 The CPC held their first meet at Gaping Gill.
1932 A first attempt was made to blow the roof off Swildon’s 1 sump. After many attempts, the first descent of Diccan Pot was achieved by the GC. The CPC published its first publication, Record of Meets Season 1932, and achieved the first Alum/Diccan exchange. Caving, Episodes of Underground Exploration by EA Baker was published.
1933 The GC made the first descent of Washfold Pot big pitch but they failed to reach the bottom of the pot. At Gaping Gill a petrol engine was used to power the winch together with an improved gantry which allowed passengers to walk directly to the chair rather than climbing down a ladder to reach it. The CPC pushed the tight Intestines route in Marble Steps. A route through the boulder choke in White Scar was discovered. Lyle Cavern (named after Lyle Martin, the first women to reach Groundsheet Junction) was discovered in Lost Johns. The Bradford Moor Cave Club was formed, it was renamed Bradford Pothole Club (BPC) in 1935.
1934 The first attempt was made to dive Swildon’s Sump 1, this was the first cave dive on Mendip but unfortunately neither FG Balcombe nor J Sheppard managed to pass the sump. The Wessex Cave Club (WCC) was formed. The entrance to Lamb Leer was re-opened but fell in again. There was an accident in Gingling Hole when a boulder trapped and broke the leg of Reg Weetman. It took 26 hours to get him to the surface and this incident led to the formation of “Central Rescue Organisation”, later renamed as Cave Rescue Organisation(CRO). Cine photographers shot 300ft of film in White Scar. The NCFC finally reached the sump in Washfold; this was probably the wettest, tightest and most awkward pothole explored at the time. NCFC members also pushed beyond the 1912 limit in Meregill Hole for a further 150m to reach the present day sump. In Derbyshire Nettle Pot was finally entered after a massive two year dig.
1935 The first descent of Rat Hole into GG Main Chamber was made by the CPC. Eli Simpson, together with Monty Grainger, finished the survey of Gaping Gill. Treak Cliff Caverns was opened to the public. A major diving exploration by Graham Balcombe and Penelope (Mossy) Powell was undertaken at Wookey Hole using Siebe Gorman bottom walking kit. The divers got as far as Wookey 7. There was an outside broadcast by BBC Radio from within Wookey Hole as part of the expedition, including a report by FG Balcombe while he was diving. Bristol Exploration Club (BEC) and the Mendip Rescue Organisation were formed. Inaugural Meeting of the British Speleological Association (BSA) occurred in Derby, Eli Simpson was appointed Honorary Recorder.
1936 The first BSA National Conference was held in Buxton. Swildons sumps 1 and 2 were dived. The present entrance to Lamb Leer was dug out. The first fatal accident occurred in a British Cave; Mabel Binks was hit by a falling rock in Alum Pot. The CPC discovered the entrance series of Langcliffe Pot. The NCFC descended the big pitch in Nick Pot, at 84m and it was the deepest underground pitch in the country at the time. Six members of BPC were trapped, by a combination of flood waters and a broken ladder, in Penyghent Long Churn for 28 hours.
1937 In a major epic of solo exploration Eric Hensler found the long crawl and streamway which are now named after him. These passages in Gaping Gill were later surveyed by a group including Monty Grainger. The BSA took a lease out on Cragdale. The passages beyond the Lakes in DYO were first entered. Work started on converting DYO into a showcave. UBSS made a film of exploring Lamb Leer, a cable-way was erected across the main chamber. Yorkshire Caves and Potholes : North Ribblesdale by Albert Mitchell was published as was the first volume of Caves & Caving by the BSA.
1938 The Central Rescue Organisation was renamed the Cave Rescue Organisation. Harry Harrison retired from being show cave guide at Ingleborough cave after 50 years. He had assisted EA Martel, who also died this year, when Martel became the his first man to descend Gaping Gill in 1895.
1939 Simpsons Pot was explored as far as the bottom of Storm Pot. A UBSS dig broke into first part of GB Cave. John Lambert died in Rowten after a fall, BBC Radio had broadcast a request for help from all potholers. The first attempt to dive Alum Pot Sump was made using a garden hose and a car foot pump.