Jamaican Caving Notes
|Mar 01, 2003|
WINDSOR CAVE - LOWER STREAM PASSAGE:
Field notes: R. S. STEWART
Cavers: R. S. Stewart, I. C. Conolley, M. Taylor
The weather had recently been quite dry and it was decided that advantage should be taken of this by trying to extend our knowledge of the lower stream passage in Windsor Cave. It had been a full year since we'd had the opportunity to spend any length of time far into this often dangerous area. In June, the streamway was under 15 metres of water. During our Aug 30, 2002, excursion, although the phreatic zone was much lower, we'd seen fountains of water rising from the floor of the entrance to the passage, and we weren't comfortable with being any great distance from the escape to the second drop. In November of 2002, high water levels made any thought of it out of the question. The basement of Windsor Caves seemed to be a good way to get ourselves up to speed on the first day of this expedition.
A necessary trip to Falmouth delayed our entry to the system until 14:30 EST. We made good time to the first drop, noticing that conditions through the large breakdown chambers that lead to the first pitch continued to be quite wet. At the top of the first drop, we tied and tossed a 30m rope, then went down using mixed descent techniques amongst the three of us. When we were all down, a quick move brought us to the top of the second drop. We tied and tossed another 30m line, and then we all rapped in using figure-8 descenders on harness.
After we had gone down into the low passage that leads to the main streamway, I began taking compass bearings and distances that Ivor recorded en route. Our intention was to thoroughly map one leg of the stream complex and thereby begin a systematic determination of the exact layout of the whole thing. The direction chosen was the southern branch of the main river passage. This begins at the second T junction, to the north of where the entrance passage appears to first intersect the main streamway, (i.e. the first T junction). We have named this second T junction "Photo Junction" having taken a photo of very particular phreatically eroded formations on the walls of the passage. The passage begins by trending to the east, and then curving in a southerly direction, (this section is not shown in JU).
The passage was followed, with control points being set at every turn, through an ever narrowing series of crawls, until just after a chamber to the left that is partially blocked by a mud bank, it becomes too tight and mud-choked to continue. The partially blocked chamber encountered just before this is of great interest. Although without shovels it would be difficult to enter, by squeezing my head through I was able to see that it resembles the drop chamber at Duppy Cave, the west pit at the bottom of Windsor First Drop, and generally other shafts that I've seen that are both risings and sinks depending on the conditions. Marks on the clay/mud slopes of the funnel shaped chamber showed the typical flow patterns seen elswhere. Unfortunately, I wasn't able to see the entire chamber, or even the bottom of the funnel itself. There is, though, reason to suspect that this chamber, in additon to the choked passage where we'd stopped, and also the flow from the Bamboo Bottom Passage, carries the water that bursts out at the resurgence near the Main Entrance. The branch that we had taken is shown in the JU map as ending in a sump some distance before we were forced to stop, indicating that water levels were higher when that particular passage was previously explored.
In June I had seen the river crashing from the Bamboo Bottom passage down into the second drop chamber. This was not a regular rainy season occurence. I know this from having had left a piece of paper on a stal in the mid-90's that survived for two full years. Yet every year the resurgence gushes forth. It is apparent that there is a lower level flow through the southern ends of the lower streamway that transfers the water during most years. I suspect it to have two sources: the southern most branch, i.e. south of the first T junction, and the chamber that I had poked my head into. The mud-choked end of the explored passage suggests an origin in the small drain passage that heads north close to the second drop chamber. This has been seen to be taking water during several excursions when flood risk stopped as from going much further. This would explain the perfectly defined mud bank that prevented entry to the funnel chamber. I've never crawled down this passage as it looks totally nasty. A map has not been made from the control points and vectors yet. This should be done soon with WinKarst.
Time was getting late, closing in on 18:00, and we had a long trip ahead of us to get back out, so we decided to stop our survey after the completion of the targeted branch. We made our way back to the base of the second drop, and Ivor clipped in and ascended the rope first. It was still early days for Malibu and the Jumars, so the idea was that by him going second he could observe Ivor's technique and then be coached by myself at the bottom. The plan worked well enough and we soon had Malibu at the top. I followed, and after a short pause to haul rope, we moved back to the base to the first drop.
The ascent up the first drop was a pain, as usual. The thing is so muddy that it's murder on Jumars, and although it's often climbable by hauling oneself up the slope hand over hand on the line, the mud on the rope makes this a real effort. What to do? In this case, as usual, strain the muscles and save the Jumars. At any rate, we all got up, hauled rope, then headed out.
It was interesting to note the absence of bats through the roosting chambers due to the time of day; it was about 19:30, over an hour after sunset, and they were all out and about, feeding and doing whatever else bats do during their working hours.
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