26 December 2020 Survey

Trip date: 2020-12-26
Project manager: Bob Lerch
Trip purpose: Cartographic objectives in Upper Thunder River
Areas of Cave visited: Upstream Thunder
Trip participants: Bob Lerch, Joe Sikorski, Isaac Smith and Dan Lamping
Entry Time: Noon
Exit Time: 9 PM

We began looking for tie-in stations near the shaft. It turns out that the beginning of the Angel Pool Passage (T survey) was never sketched. A survey line was run through it as part of the first survey trip of the CCC, but there’s no sketch. So, we assessed how much passage needed to be drawn and found tie-ins. This will be a full day’s work in the future.

Doing mop-up work now, is a good time to remind folks exploring in Carroll Cave to be mindful of survey stations as we sometimes have to tie into old stations to add new survey. One they’re moved, though, we cannot use them. Because the cave floods sometimes survey stations get washed away. If ever flagging is found in the stream floor, or buried in mud and has been stomped on, it’s probably safe to assume it’s been moved from its original location and can be removed from the cave. But, if it’s on a ledge, piece of breakdown or on the floor, but hasn’t been stomped on, please leave it in place.

After we determined what needed to be done near the shaft / Angel Pool area, we made our way to UL1, which is a high side passage on the left side of Upper Thunder River. This area was originally surveyed with a transit by the CCC, which was called the U Survey. Later, we replaced that survey with handheld instruments, and updated the sketches, which is the NU survey. Both the original sketch and the the NU survey sketch put UL1 in one place, but the survey lines of each put it about 30-40 ft away in a different spot. After playing with the data, we determined it was likely a bad tie-in during the U survey, which was preserved in the NU. Isaac stemmed over Thunder River so we could reshoot the tie in from the NU to the UL1 survey. We’ve since entered the data and this seems to have fixed the problem.

From there we went into UL2 to the area between Convention Hall and Conference Hall to finish a sketch from nearly 20 years ago. This task was accomplished and we made our way out of the cave.

Additionally, there is now a printed reference map of the cave for trip planning purposes, to familiarize new people and in case of any potential rescue planning. It is stored in a PVC tube. The map is printed on Tyvek, making it a little more hardy than paper, but it can still stain very easily, so please use caution when laying the map out on the picnic table or on the hood of a vehicle. When we laid it out on the table to show Isaac, almost immediately, the wind blew it over. It may be worthwhile to cut a piece of plywood or something rigid to attached the map to. It would take up more space, but it would also make it easier to view.

Dan Lamping