Cambridge Underground 1978 pp 6-10

THE BIRKS WOOD / REDMIRE SYSTEM

Introduction

Towards the end of 1976, progress in Birks Wood Cave had terminated in a 10m waterfall after nearly 1000m of passage had been explored. It was felt at the time that it would be no easy task to scale the waterfall and this opinion only reinforced itself during the long, wet winter. The beginning of 1977 saw most of the people concerned with Birks Wood otherwise occupied in Goyden, so it was not until summer that our thoughts again turned to the cave.

Two years ago, Rob, Bob and Nick had had a rather embarassing encounter outside Redmire Pot with Colin Edmunds and Richard Stevenson. They had heard through the grapevine (Andy) that Colin was going to dive Redmire, and as Rob had had the same idea for several weeks they decided on a preempt - fully justified they thought! Unfortunately it failed by one day, and some less than complimentary things were said about Andy by both parties. On that trip, Colin Edmunds had dived the terminal sump in Redmire and reported that it got too tight after approximately 5m. As a result, Redmire had been ignored during the exploration of Birks Wood, but the prospect of the final waterfall in Birks Wood was sufficiently daunting to make us reconsider it.

So it was in July that Rob and Julian carted an excess of gear up to, and then down Redmire. Rob kitted up and dived first using a base fed line. After a while the line went quiet and a couple of minutes later Rob returned with a broad grin on his face. The sump was only 10m long and popped up into a narrow streamway similar to the one before the sump. Some brief repairs to Julian's demand valve were necessary before he could follow through, but soon both were forging off into the unknown. 40m from the sump the lip of a 10m pitch was reached, which with no ladder, could not be descended. The passage could be senn to continue at the far side of the chamber into which the pitch dropped.

That evening Rob and Julian drove over to Ribblehead to collect some ladder and after an early breakfast at Bernie's in Ingleton returned to Wharfedale. Most of the diving gear had been left in the pot the previous day so the trip to the sump was uneventful. On the other side a ladder was rigged from a bolt and the pitch descended. At the bottom they were surprised to see the passage heading off in both directions. It had always been imagined that the system would lead on down from Redmire, gaining inlets until it met the end of Birks Wood. Instead, Redmire appeared as a small inlet to the main stream, and the inlet from Smegmire came in upstream of Redmire. This only occupied their minds for the briefest of moments, as both had developed a healthy appetite for exploration.

Downstream the passage developed into a fine streamway with some excellent helictite displays high up on the walls. An interesting zig-zag section along cross-joints was passed, and after a total of 300m of passage from the pitch, a 2m free climb was reached; 20m beyond this the stream disappeared over the lip of a pitch. Peering over the edge, the chamber below was immediately recognised as the wet and windswept end to Birks Wood. 15m of ladder was fed down the pitch and Rob given the honour of descending it first. On reaching the boulder strewn floor he immediately went to look for the end of the line rigged through sump 7 to confirm the connection. This he found and when he had ascended the pitch Julian went down to have a look around. Not wanting to spend too long underground, the pair started out, noting two inlets on the way back. The passage upstream of the Redmire pitch was briefly looked at, but it rapidly degenerated into a narrow rift. Carrying two ammo cans, weights, and a 15 cu. ft. bottle each, the trip out of Redmire was slow and it was raining heavily when they surfaced.

The following weekend Rob, Julian, Andy and Nick descended after putting an ounce of fluorescein down Smegmire. On reaching the bottom of the pitch into the main passage the stream was bright green and a quick look upstream confirmed that it was entering the Smegmire Inlet. Continuing on down, sump 7 was free dived and the ladder collected from the 10m pitch in Birks Wood. This ladder had been underground for 11 months, but still seemed to be in reasonable condition. Returning, Rob and Julian started to take photographs while Andy and Nick had a look at the two inlets. The one just upstream of the 15m pitch got too tight after 20m, whilst that halfway back to the Redmire pitch was still going after 50m of large bedding passage. By this time it was becoming increasingly obvious to both parties that the stream was rising. Both hurried back and met at the Redmire pitch. This pitch was very wet indeed, but the main pulse did not come through until they were at the sump. Whilst kitting up here, the water level rose 6" in five minutes. Emerging from the sump the chamber on the near side was deceptively calm, indicating that the duck had sumped. Realising that the trip out of Redmire was going to be fairly desperate, most of the gear was abandoned at the sump. The chamber at the bottom of the 10m pitch could hardly be seen for water, and there was no sign of the ladder. Only by ducking through the wall of water could its bottom be located. The climb was merely wet until the top 2m where the sheer volume of water sweeping over the edge nearly swept two members of the party off the ladder.

Andy's light packed up in sympathy with Nick's, which had been refusing to function since the sump. In the low wet crawl at the top of the pitch one had to raise one's body out of the stream as far as possible to avoid sumping the passage in front. Shortly after, the narrow crawl leading through to the entrance chamber was reached. Rob had a go first with his helmet on and nearly drowned himself. The prospect of sitting out a flood a mere 30m from the entrance in such a cramped and windy spot did not appeal, so another attempt was made. By removing one's helmet and jamming one's head as far into the roof as one could it was possible to pass the corner. The entrance chamber was crossed by three large streams entering at roof level, but luckily the free climb up to the entrance crawl was not too difficult. It was four very relieved cavers that emerged from the entrance. Walking back over to Smegmire where the rucksacks had been left, five single streams were seen to be sinking where normally there are only two minor sinks.

The gear was retrieved the next weekend under more settled conditions. There then followed a break of several months whilst Nick and Julian disappeared in search of sun, beer and caves in Austria, and the weather settled down a bit. Nick and Rob managed to survey parts of the extension and all of old Redmire in October, but shortly afterwards the weather closed in again, and that is the position at present.

Besides the survey, there are a number of odds and edns to be tidied up. The inlet upstream of where the Smegmire water comes in needs pushing to a conclusion as does the inlet on the Birks Fell side of the cave. The large chamber above the pitch where Redmire and Birks Wood join also needs investigating. The final prospect is that of modifying the end of Smegmire Pot to give an entrance to the system for non-divers. All these however will require more settled weather.

Brief Description of the System

From the other side of the sump at the end of Redmire, a narrow twisting streamway leads, after 40m, to the head of a fine 10m pitch (Red Aven) into the main passage. Upstream over a mound of boulders, the Smegmire stream comes cascading out of the roof down a pitch that must be in the region of 20m, while the main passage quickly closes down to a narrow high rift.

survey to Red Aven - 12k gif

Downstream from the pitch the passage develops into a pleasant walking streamway - 3 to 4m high by 1m wide. This continues for about 300m past a series of Z-bends along cross-joints and an incredible collection of helictites. Luckily these are high on the walls and unlikely to be affected by the passage of normal caving traffic. A short crawling section once more pops up in a walking streamway till a 2m cascade is reached. Here the passage turns sharp left, and 10m further on the stream disappears over the lip of a 15m pitch. This marks the end of the part of the system explored from Redmire, and the beginning of Birks Wood. Above it is a large chamber which has not been fully explored and from which most of the boulders at the foot of the pitch must have come. Climbing down through the boulders a low wet crawl ends in a sump. This is 5m long and an easy free dive. On the far side a duck leads to a canal (Vizier's Vent). After 100m of hands and knees crawling the cave starts cutting down again to the head of a 10m pitch. 300m of varied rift and stream passage follows before a rather unpleasant horizontal traverse is reached. Down through a narrow slot and a short climb brings one into an aven chamber.

From here 100m of tight rift passage with a well decorated roof leads to sump 6 in Birks Wood. This is a low 1m free dive under a flake of rock and emerges into a cross-joint. A succession of cross-joints and sandy floored bedding planes (which may sump in wet weather) follow, until shortly before sump 5, the stream disappears down a slot. At the top of the 3m climb down into sump 5 a passage leads off over the sump, but again this has not been followed to any conclusion. The sump itself is 25m long and is static at both ends, although the main water can be seen disappearing down a passage to the right of the sump, later to emerge in the airbell at the end of sump 4. One in fact surfaces in what is termed sump 4A and a 3m climb brings one to a narrow overflow passage. This continues for 50m till one drops down a rift and a low bedding on the right brings one out into the main stream again. About 30m upstream is the downstream end of sump 4. This is 20m long and surfaces in a small airbell. From here a larger airbell can be seen but not reached. Downstream from the junction sump 3 is quickly met. This is 15m long and a comfortable size (1.5m square). Crossing the large airbell, at the far side sump 2 leads off. This is only 5m long bit is very constricted and pops up in a tiny airbell. From here sump 1 is a 10m dog-leg emerging into the short crawl in Birks Wood Cave described in Northern Caves Volume I as becoming too narrow. In fact the crawl continues above the sump for a couple of metres before getting too tight. A short duck and a sump or dry bypass lead to the canal in Old Birks Wood and from here 30m of easy going brings one to the entrance which is normally a 2m sump.

Survey - 11k gif

Although a through trip has not yet been attempted, it should not prove to be too difficult. The lines in Birks Wood, in particular that in sump 5, will need checking before this is done.

Julian Griffiths


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