OGOF HEBOG - Numbers I and II


Traditionally the route to Pant Mawr Pot from the Ystradfellte side has been to park at the locked, top, moorland gate and then to follow the footpath that strikes N.W. past the ruins of Pant Mawr Farm. Today it is probably quicker to follow the forestry road which leads north from the moor gate towards Nant-y-moch. A little under half a mile south of the forest itself the road cuts a old drystone wall which runs E-W. This is followed west to the pothole. An old track runs parallel and to the north of this wall for most of its length. About 6-700in along this track, immediately on the southern edge are the two caves called Ogof Hebog I and II although, strictly, they should be called Numbers I and II since they are NOT two parts of a single cave separated by a Bump. The name Hebog, which means falcon, was coined by Jon Young. because he noticed a Merlin overhead when he found the first of these caves.

History of Discovery

According to the Godre Pentre log book Jon Young noticed the potential of these sites when out walking and looking for caves on 16th February 1988. Number I was a hollow in a small quarried outcrop of rock which showed some parting in the bedding of the limestone with indications of solution. Number II was a similar site but with the secondary indicators less pronounced. Number I was the site first worked on.

By 26th February Jon had single handedly dug into the cave and on that day explored the first 2Oiu or so to the beginning of a tight(ish) rift, partly obstructed by a boulder with a Pipistrelle (?) bat hibernating above it. The cave was therefore left alone until the bat had gone. By Friday 22nd April it had vacated its roost and explosives were used to open up the way forward. On the 30th, Jon and friends returned to explore an estimated 20m to another boulder obstruction. On the 1st May an attempt was made to blow this up; on the 2nd the debris was removed and another charge set, still without effect. More digging and banging is recorded on 7th May and then on the 14th Jon Young and Clive Jones (SWCC) finally managed to "atoxise" the obstruction. This allowed them to climb down into a chamber orientated along a fault with a large inlet visible at high level and draughting fissures in the floor. On 15th May a party containing Jon Young, Chris Fry, Chris Grimmet, Adrian Paniwnyk and Paul Stacey started excavating the floor along the fault line and installed a pulley system to help in this work. Whilst this was being done a bolt protected climb was made up to the inlet passage; traversing precariously positioned boulders Dalmatian Chamber was reached. At the present time it has not proved possible to make headway in the digs at the lower points in the cave. The pulley system and other tools have therefore been removed.

Whilst waiting for the bat to leave site Number I the entrance to Number II was dug by Jon Young, Chris Fry, Adrian Paniwnyk and Paul Stacey on 18th March 1988. They explored and surveyed about 40in of cave which ended in a tight, mud filled tube a little way beyond a mud/sand floored chamber. This was dug on 7th May and then again on the 8th by Chris Fry, Paul Stacey, Sarah Tindall (SWCC) and Adrian Paniwnyk. At this stage the diggers were sure that they were almost through. On 14th May ten minutes digging gave access to an open continuation of the tube, about 7m long with another passage going off to the left. On 21st May Chris Fry, Chris Crowley and Martin Hatton dug in both of these passages. Work on the left hand one was stopped when it became obvious that there was a very clear aural connection with the surface. Digging in the main passage continuation is becoming difficult due to the narrowness of the tube and limited spoil tipping space.

According to memory there were more trips than just those recorded above and certainly more explorers. However we can at least be sure of the above since it comes from the contemporary log book account and it probably highlights all of the major events in the discovery and exploration of these two caves.

Description of the Caves

Number I

N.G.R. SN 896 158
L = 60m

A low grovel over fallen roof slabs leads immediately into a descending walking passage with slight vadose features, abundant patches of moonmilk decorate the ceiling and walls for most of its 20in length. The ceiling gradually lowers at the end of the passage and degenerates into a very low crawl heading south and then east. Passing an acute bend bearing left, and after several metres of side-ways wriggling through a thin layer of mud, a small inlet joins the crawl from the left. The crawl continues until the passage enlarges slightly and passes over a drop to continue, this time north, until it reaches a very tight rift known as Angela's Rift. This has yet to be pushed to a satisfactory conclusion.

A 5½in climb which is awkward on the way down, and even more so on the return journey leads into a chamber of larger dimensions with a roof height of several metres. A dig in the floor of the chamber has left a 5m blind drop with a small inlet flowing away at the bottom. A precarious manoeuvre across to the other side of the chamber leads to a rose protected climb up a slippery slope and into a boulder choke in the roof. Another boulder choke may be entered in a rift running north from the chamber, this is highly unstable but draughts well.

Dalmation Chamber is a large collapse area with well formed walls possibly aligned with a fault line. It is over l0m long and 3m wide and with a roof height of over 1½m it is the largest single void in either of the Hebog caves. At each end the chamber closes down to roof collapse but the chamber/passage show signs of continuing in each direction.

Number II

N.G.R. SN 895 157
L= 45m

The entrance is a slightly muddy, body-sized hole which is best entered feet first. This drops into a vadose canyon-type passage which quickly rises from stooping to easy walking height. A few brisk paces leads into a quite nicely decorated chamber over 2in high, a similar width and perhaps twice as long. Tapes have been put down to protect the calcite floor and the roof displays a fair number of straws and small stalactites.

Going left in the chamber leads along another vadose passage which bends left again after a few metres and ends in a choke to the surface.

The main way on is across the chamber; a low crawl leads almost immediately into larger, walking-size passage with a muddy floor. This meanders left, right, left and right again. At the end it has dropped to crawling hei9ht before turning sharp left into a bedding-plane chamber. A dig at the end of this now provides a damp squeeze into a continuing, down dip, crawl way. Part way along this there is a small, bell-like chamber where another passage enters from the left. This can be followed past left and right meanders to a sharp right turn at which point it becomes too tight to follow. Sounds from the surface can be heard at this point but verbal communication is not possible.

Paul Stacey
Martin Hatton