Pinetree Pot
A significant Mendip system discovered and explored by the MCG.
Pinetree Pot is a significant cave system located in the Mendip Hills. Its discovery and ongoing exploration have been a central focus for the Mendip Caving Group (MCG) since its initial excavation in 1959. This page provides a comprehensive overview of the cave’s history, physical characteristics, and exploration efforts.
Discovery and Early Exploration
Initial Digging and Breakthrough
The depression housing Pinetree Pot was first noted by Antony J. Knibbs on September 7th, 1959. After securing permission to excavate, work commenced in October 1959. Early excavation involved the removal of brown mud and rocks, and as the shaft deepened, a specialized pulley system was constructed to aid in hauling material.
The breakthrough occurred on Whit Monday, June 6th, 1960. With the shaft at 14ft deep, a promising cavity was heard, and after further effort, a small passage was revealed. Arthur Spain was the first to crawl into the newly discovered passage, reporting a sizeable shaft beyond.
First Descents and Key Passages
Following this, a party of four – Peter Dyer, Pat Walsh, Mike Rennie, and Antony J. Knibbs – made the first descent. They descended the first 36ft pitch, christened Pine Pitch. At the bottom, they found Rumble Pitch, a 15ft drop, and a muddy by-pass known as The Wallow.
Continuing on, they reached a tortuous section deliberately misnamed Easy Street. Further explorations revealed Moonlight Grotto and the Back Passage Route. By July 1961, after significant improvements to the entrance, Pinetree Pot was officially opened to all properly equipped cavers.
Geological Formation and Hydrography
The cave is situated in a tributary valley to Velvet Bottom and was likely formed by water sinking from a surface stream. The presence of rounded rocks and quantities of gravel consisting mainly of crinoid fossil remnants supports theories of water percolation. While initially speculated to feed a rising 1.5 miles away, current understanding suggests the water resurges at the Cheddar Risings.
Continued Exploration and Digging
Pinetree Pot has been the site of considerable digging efforts starting in 1993, driven by the hope of discovering larger passages. These digs aimed to find a continuation of a phreatic network, guided by draughts and geological theories. Diggers consistently faced challenges with mud, water inundation, and CO2 buildup.
Efforts continued throughout the 1990s, and the dig had reached 100 feet long by 1997. It was hypothesised that this passage was linked to Shakeholes on the north-eastern edge of the Pinetree pot, but work hear became more and more arduous, with the digface filling with water five feet deep after heavy rain and work ceased.
Survey
The cave has been surveyed multiple times by the MCG to document new discoveries and inform digging efforts. This 1962 is a beautiful example but does not contain the latest extensions.
Gallery
Access Information
Access to Pinetree Pot is via the MCG. A key can usually be obtained easily from the club cottage. Please ensure you sign the logbook before your trip.
Arrange a Visit