Moorland Caver (2003)

NGR: SE 709865
Altitude: 40m
Length: 200m
Depth: 20m
Access: Ravenswick Estate
Grade: IV
Entertainment value: V+

Warning: Bogg Hall is a very wet cave; wetsuits are essential, mask & neoprene hood useful. A small rise in water levels will sump The Drain. Descend in dry, settled weather only.  Despite its short length Bogg Hall is quite a serious undertaking.

Divers Entrance: Bogg Hall Rising is a large resurgence on the East bank of the River Dove consisting of two sumps which are not free diveable:
Sump I: A dive of 9 m in a roomy bedding 3 m wide and 1 m high surfacing in an air bell formed by a cross rift.
Sump II: A further dive of 9 m surfacing in the main Sump Chamber.
( The sumps may be dived as one by following the left wall although this is not lined)

“Oh my ears and whiskers” (Dry Entrance):
Probably the best and most sporting trip in Ryedale. Oil drum entrance with locked lid (key nailed to the tree nearest the lid, please replace after use) drops down into a small earthy chamber. At the South end a short blind, excavated crawl leads off. The way on is down a narrow, partially blasted rift in the floor. It should be stressed that the rift is very narrow and larger cavers may experience difficulties, particularly on the return. If an epic is to be avoided the rift should be rigged with a handline or, better a ladder belayed to a tree outside. The rift drops into the main Sump Chamber.

Care should be taken not to step back into the sump pool as the unwary may be washed down into the sumps!
Two passages which soon reunite lead from the Sump Chamber, the right hand passage takes the majority of the water and is best avoided except in times of low flow.
The more usual route is to follow the passage to the left. Follow this wet and gloomy passage past a junction on the right (which leads via the right hand passage back to the Sump Chamber) to arrive at a “dry” blockfall chamber. Straight ahead leads into a low, wet and confused area and is best avoided. The way on is to the right into an area with about 30 cm air space. The intrepid explorer is now confronted by one of the caves main obstacles: The Duck. The Duck consists of a submerged slab lying across the passage. Although there is air space above the slab, the best (and most entertaining) way to pass it is a short, 1m, free dive under it (mask useful). It is best tackled feet first and on ones back thus: Remove helmet and hold it under the slab with the right hand, insert legs under slab, place left arm under the slab and grab the far side of it, lie back, and raise legs, take a deep breath and pull yourself through with your left arm. It is possible that the first pull might not get you through, if this happens a shove with the right hand usually does the trick. Try not to surface too enthusiastically as you will crack your head on the low roof – not recommended. From this point things start to get sporting! Turn sharp left into a low airspace (10 cm – 15 cm) canal known as The Drain. This looks frighteningly narrow but it bells out below water. The Drain is best entered feet first on ones side, nose and mouth up in the roof. A helmet is something of an encumbrance here and is best held out in front. Use the lower arm to propel oneself along the passage, blowing water out of your mouth as you progress (the return journey is easier as you are borne along by the water). This is not a place to panic – stay cool, lie back and enjoy the experience. After 10 m of very aqueous progress a small chamber provides some respite, turn right here up another canal about 5 m long. At the end of this section turn left to emerge in the River Passage, to date unique for the area. The River Passage is 1 m – 2 m high and 3 m – 5 m wide; an impressive spot. Of interest are fossils partially washed out from the walls (CARE). Good going for about 60 m passes fallen blocks and an oxbow to arrive at the terminal sump: The Font. An unusual feature of The Font is its fauna – a colony of Lampreys. The Font Chamber is quite a large rift, 15 m long, 6 m wide and 4 m high. The aven in the roof has been scaled and was found to pinch out. Water wells up from the centre of the lake from a vertical rift. This has been dived, past a ledge at – 6 m to a depth of about – 17 m. As yet no definite conclusion has been reached.

Tackle:
The Rift: Either an 8 m ladder, spreader and sling or handline, belayed to tree at entrance (optional)

History
Sump 1 was passed by Shackleton and Griffiths of the C.D.G. in 1981.
On 31-10-1981 Richard Wilsdon and Neil Hanan, passed Sump 2 and explored the cave to the Font.
S.C.C. dug the dry entrance in early 1998, the first “dry cavers” reaching the Font on 12-2-98.

Memoirs of a Moldywarp (2008)

SCC Minutes 01/02/1998