expoweb/years/1982/41svy.htm

100 lines
5.0 KiB
HTML
Executable File

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0//EN">
<html>
<!-- from Cambridge Underground 1983 p 15 -->
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf8" />
<title>
1982: Cambridge Underground report
</title>
<link rel="stylesheet" type="text/css" href="../../css/main2.css" />
</head>
<body>
<h3>Stellerwegh&ouml;hle-Schnellzugh&ouml;hlensystem : The survey</h3>
<p>Andy Waddington
<p>During the period 1976-1981, surveying has not been the strong point of
CUCC expeditions to Austria, mainly because of the limited man-weeks
available, and the amount of exploration to be carried out. In 1982, when we
were virtually certain of finding an end to Schnellzugh&ouml;hle, it was
considered essential to complete a survey of the system, since it was highly
unlikely that a descent would be made later, merely for surveying purposes.
This task was expedited by the fact that the 1982 expedition was in the field
for almost four weeks.
<p>The survey now published includes survey material from previous years, of
those parts of the system that were not rigged in 1982, mainly in
Stellerwegh&ouml;hle. The survey from Stellerweg entrance to the start of the
big rift was carried out in 1980, and was to grade four in all respects
except one, namely that one of the compasses used had been left on top of Rob
Shackleton's fridge and had recalibrated itself. Calibration in Austria
showed it to have a 134 degree error, which has been allowed for in the data
processing, but it is not certain that this calibration was constant at all
times, so only grade three is claimed. The whole of the Big Rift down to the
junction with the rest of the system at Junction chamber was surveyed only by
measuring pitch lengths and so only grade two is claimed.
<p>A surface traverse from the two entrances of Stellerwegh&ouml;hle to the
entrance to Schnellzugh&#246;hle, and extending to other entrances in the area was
carried out to grade five, and is in close agreement with data from previous
years. The survey from Schnellzugh&ouml;hle to the Confluence was all to
grade five, and agrees with the surveys done in 1980-81 to lower grade. From
the confluence to the 12' climb (Another pitch), the survey relies on 1981
data to grade three; in view of the agreement of other grade three surveys of
previous years with the 1982 data, this is considered reliable. From the 12'
climb to the bottom of the system, all surveying was done in 1982 and is to
grade five.
<p>Thus, of the 898m surveyed depth, all except a small portion is to BCRA
Grade five, and though there are no closed loops, we feel confident that the
depth is within plus or minus ten metres of that stated.
<p>Calibration of instruments on the surface suggested a magnetic deviation
of only 1.25 degrees. Since true north is difficult to determine accurately
from local maps, which have no grid lines, and since the deviation is
comparable with potential instrument errors, the survey has been drawn to
magnetic rather than true north. Calibration of instruments between two fixed
points on the surface will enable any additions to the survey to be
accurately aligned in future years.
<p>Data reduction was by the FORTRAN computer program SU 4.32 which is
implemented on a dual processor ICL 2982 (not at Cambridge), and the
centre-line plot was drawn using GHOST software on a Calcomp drum plotter.
Survey detail was sketched onto the centre line plot and then traced and
inked. The survey was originally drawn at a scale of 1:800, ie. on A0 paper,
and reduced to its present scale for publication. Passage detail in the grade
five parts of the survey were estimated and recorded in the cave, and drawn
directly from the original sketches. Passage detail for the main route in
Stellerweg was copied from the original 1980 survey drawn by Julian
Griffiths. This involved an increase in scale, and so the detail in this area
is probably not as accurate. Grade one survey data in areas near the
Purgatory Bypass were estimated and recorded in the cave and drawn from the
original sketches, while the Big Rift in Stellerweg was drawn from sketches
made in 1980 from memory with measured pitch lengths.
<!-- A.E.R.Waddington, February 1983. -->
<hr />
<!-- LINKS -->
<ul id="links">
<li><a href="../1983/41svy.htm">The truth</a> about the 1982 survey
(from CU 1984)</li>
<li>1982 Expedition info:
<ul>
<li><a href="log.htm">Logbook</a></li>
<li>Main Expo report, Cambridge Underground 1983:
<ul>
<li><a href="report.htm">CUCC in Austria</a> - Phil Townsend</li>
<li><a href="41gd.htm">Stellerweg Guidebook Description</a> by Pete Lancaster</li>
<li><a href="41camp.htm">The Underground Camp</a> by Chas Butcher</li>
<li><a href="newbit.htm">New Discoveries</a> 1982 by Mike Thomas</li>
<li><a href="bats.htm">The Bats of 115</a> by Dave Brindle</li>
</ul></li>
<li><a href="bcracc.htm">BCRA Caves &amp; Caving Report</a></li>
</ul></li>
<li><a href="../../pubs.htm#pubs1982">Index</a> to all publications</li>
<li><a href="../../index.htm">Back to Expeditions intro page</a></li>
<li><a href="../../../index.htm">CUCC Home Page</a></li>
</ul>
</body>
</html>