Post on 07-Aug-2018
8/21/2019 BCRA 14-2-1987
1/52
ae
Science
The Transactions
of
the British
Cave
Research ssociation
BeR
olume
4
Number
August
987
Symposium on
Surveying aves
8/21/2019 BCRA 14-2-1987
2/52
ave
cience
The Transac t ions
of
the
Br i t i sh
Cave
Research covers
a l l
aspects
of
spe leologica l
s c i e n c e
inc lud ing
geology,
geomorphology,
hydrology,
chemistry ,
physics ,
archaeology
and biology
in
t he i r
appl i ca t ion to
caves .
I t a l so publishes
a r t i c l e s
on t echnica l ma t t e r s such as explora t ion
,
equipment,
diving , surveying,
photography and documen ta
t ion
,
as
well
as
expedi t ion repor ts and
h i s to r i ca l
or
biographical s tudies .
Papers may be read a t meetings held in var ious par ts
of
Bri ta in , but
they may be
submit ted
for
pu b
l i c
at ion without
being read.
Manuscr ipts should be
sent to
the
Edi tor ,
Dr T. D.
Ford
, a t the
Geology
Department , Univers i ty of
Leices te r
, Leices te r LEI 7RH .
In tending authors are
welcome to
contact
e i t he r the Edi tor or the
Product ion
Edi to r who wi l l be pleased
to
ad v i se in any cases of
doubt concerning
the
prepa ra t ion
of manuscrip ts .
NOTES FOR CONTRIBUTORS
These notes are intended
to
help the authors
to prepare their material
in the most
advantageous
way so
as to
expedite
publ i c a t i
on and to
reduce
both
their
own
and
edi torial la b
ou r
. I t saves a
lot
of
time i f
the rules
below
are
followed .
All
material should be
presented
in a format
as
close
as poss ible t o that of C VE SCIENCE s ince
1985.
Text should
be
typed double
-
spaced
on one
s ide o f
the paper
only .
Subheadings within an
ar t i c le
should follow the
system
used in
CAVE
SCIENCE; a
system
of
primary, secondary ,a
nd i f
neccesary, t e r t i a ry
subheadings sh ould
be
c lea r ly
ind icated .
Abstrac t :
All mater ia l
should be accompanied
by an
a b s tra c t
s t a t i ng the e s s e nt ia l results
o f
the invest igtation for use by abstract ing l ibrary
and other serv i ce s . The abstract may a l so be
publ i shed
in
CAVES
AND
CAVING.
References
to previously published work
should
be given in
the
standard format used in
C VE SCIENCE. In
the text the
statement
referred
to should
be
fOllowed by the relevant author s
name and date (and
page number,
i f appropriate) in
brackets .
Thus: S
mith
, 1969, p . 42). All such
references c ited in the text should be given in
fu l l in alphabet ical
order
at
the
end. Thus:
Smith, D.E.,
1969. The speleogensis of the Cavern
Hole. Bul let ing Yor kshir e Caving Assoc . Vo l . 7,
p.
1-63
. Books should
be c i t ed by
the
author ,
date
t i t l e publ isher and where published .
Periodical t i t l e s should be abbreviated in
standard
s ty l e
or
where doubt ex i s t s
should be
written out in
fu l l .
Acknowledgements:
Anyone
who
has
given a
grant or helped with the
inves t igat ion, or
with
the preparation of the
ar t i c le ,
s hould be
acknowledged
br ie f ly .
Contr ibutors
in
Univers i t ies and other ins t i tu t ions are
reminded
that grants towards the co s t
of
publicat ion may be
availab le
and
they should make the appropr iate
enquiries as early as poss ible . Expedi t ion
budgets should include an element
to
help
publ icat ion and the ed i t or should be
informed
at
th
e
time
of submission.
I l lus tr a t ion : Line
diagrams
and drawings must
be in BL CK ink on e ither
clean
white paper or
card or on tracing
paper
or such materials as
kodatrace. Anaemic
grey
ink and penci l wi l l
not
reproduce I l lus tr a t ions should be designed to
make maximum use of page space. Maps
must
have
bar scales on ly . I f photo - reduct ion i s
contemplated a l l
l ines and
l e t t
ers must be
large
and
thick enough
to
allow
for
the ir
reduct ion
.
Letter s must be done by
s t e n c i l
l e t raset
or
s imi lar methods, not
handwritten.
Diagrams should
be numbered
in sequence as
f igures
and referred
to in the
t ex t where necessary,
by insert ing
Fig. 1)
e tc in
brackets . A fu l l l i s t
o f
f igure
capt ions
should
be
submitted
on a separate
sheet .
Photographs are
welcome.
They
must be good
c l ear black and
white prints
with sharp
focus
and
not too much contrast ; prints about 15 x 10
cm
(6
x 4 inches) are best ; i in doubt a se lect ion may
be
submi t ted.
They should be numbered in
sequence but normally not referred to in the
te x t .
A fu l l
list
of
pl a t e
captions with
photographer credits where
re l evant should be
submitted
on a
separate sheet .
Tables : These should not
be
included in the
te x t
but
should
be
typed, or c lea r ly handwri t ten ,
on separa te s heet s .
They
should
be
numbered
'in
sequence
and a list of capt ions i necessary,
should be submitted on a separate sheet .
Approximate locat ions for tables plates and
f igures should be marked in pencil
in
the
manusc r ipt margin, unless already
clear from
the
t ex t .
Copyright: I f
any t ex t ,
diagrams o r photos
have been
published elsewhere it
i s
up to the
au thor to c lear any copy r i ght or
acknowledgment
matters.
Speleologica l expedi t ions have a mora l
ob l i g a t i on to
produce repor ts
contractual i n the
cases of rec ipients o f
awards from the
Ghar
Parau
Foundation) .
These
should be concise and cover
the r e su l t s
o f
the expedi t ion
as
soon as
p o ss ib le
af te r the return
from overseas
so
that l a t t er
expedi t ions are
informed
for their planning.
Personal anecdotes should
be
kept to a minimum,
but use f u l advice such as locat ion of food
suppl ies
medical
services e t c . may be in c
lude
d.
Authors
may order reprints of
their
contr ibut ion
for the ir own private us e . The orde r must be
not i f i ed to t he Editor a t the
time
of submission.
I f
you have any
problems
regarding
your
material
please consul t
e ither of
the Editors in
advance of submission.
8/21/2019 BCRA 14-2-1987
3/52
ave
Science
TRANSACTIONS
OF THE
BRITISH
C VE RESE RCH
ASSOCIATION
Volume 14 Number 2 August
1987
Contents
Symposium
on
Surveying
Caves
Surveying Caves
Paul Hatherley
49
Cave Surveying in Br i ta in - an His tor ica l Re v i ew
Bryan El l i s
52
Review of
Cave
Surveying Techniques
Steve
Worthington
56
Cave
Surveying in
Di f f i c u l t
Condit ions
Dave Brook 60
Cave
Surveying
on Expedit ions
Tony
White 61
Surveying
In and Beyond Sumps John
Cording ley
66
App l i ca t ions
o f
Computers to Cave
Surveying
A J Bennett 69
Network Traverse Closure
with
a
Micro
Computer D J Irwin 72
Using
a Spreadsheet to Reduce Survey Data Bryan
E l l i s
75
Cave
Surveying
with the Topof i l
Steve Foster 79
Aeria l
Photographs
for Cave
Studies
D
J Lowe 81
Arc haeo log ica l
Surveying
in Caves
C 0 Hunt I P
Brooks
G M
Coles
and R D S
Jenkinson 83
Hydrology and Cave Surveys
John
Wilcock
Geology
and Cave Surveys
D
J Lowe
Cov er: Fool s Paradise
in
Gingl ing Hole , Fountains
Fe l l s
This
photograph
i s
taken from the
f i e l
d
guide
to the caves and
karst of the Yor
kshire Dales
which i s number 1
in
the
BCR
Cave Studies
Ser ies
By Martin Davies .
Editor : Dr .
T. D
. Ford Geology Dept . Leices te r
Un
i
ve
r s i ty Leices te r
LE
I 7
RH
85
87
Product ion Editor :
Dr
. A.C . Wa
l tham
Civ. Eng. Dept .
Tren t Po ly techn ic
Nott ingha
m
NGI
4
U
Cave Science
i s
pub l i shed by the Br i t i s h Cave Research Assoc ia t ion and i s i s sued
to
a
pa id
up members of
the
Assoc ia t ion .
1987 subscr ip t ion r a t e s a re :
I ndividua l - EI 0.00
In s t i t u t ion or
Club - E12 . S0
Subsc r ip t i
ons
should
be
sen t to
the Membership Secre
t ary:
D.
Stoddard
23
Claremont Avenue
Bishopst
on Br is to l BS 7 8JD
Individua l
copies and
back numbers of Cave
Science
a re obta inable
from
:
B. C. R. A.
Sa
l e s
20
Woodla nd Ave nu e
West
o
nz oy
l a nd
Bridgwater
Some r
s e t
TA7
OL
Q
Copyr
ight
the Br i t i sh Cave Research Assoc ia t ion 1987 .
No
pa r t of th i s
publ ica t ion
may be
reproduced
in any othe r pub l i ca t i on used i n adve r t i s i n g
s tored in an
e l ec t ron i c r e t r i eva l
system or o the rwise
used fo
r
commercial
pu r
pose
s withou t the pr ior
wri t t en conse
n t o f t he
authors and of the Assoc ia t
i
on
.
ISSN 0263 -7 60X
8/21/2019 BCRA 14-2-1987
4/52
8/21/2019 BCRA 14-2-1987
5/52
CAVE
SCIENCE
Vol. 14,
N o . 2 ,
August
1987
Transac t ions of the Br i t i s h Cave Research Association
Symposium
on
Surveying
aves
FOREWORD
Paul
HATHERLEY
The
Br i t i sh
Cave
Research
Association held
a
cave survey study weekend a t the Univers i ty of
Sheff ie ld and
in
Peak Cavern
on the 15th
and
16th
of March
1986.
The following
papers were
presented:
Cave surveying as
it
used
to be
Survey method and
ca lcula t ion
•
Surveying under
d i f f i c u l t
condi t ions and divin ing
Archaeological surveying in caves . .
.
Hydrological surveying
Surveying
in and beyond
sumps
. . .
Geology and
cave
surveys
•
Draughting techniques and the
Peak
Cavern
Survey
Use of
computers
in cave surveys
.
Expedit ion surveying
.
The surveying
of Daren
Cilau
Surveying aves
Paul
HATHERLEY
B
S
D
C
J
J
D
J
A
A
D
El l i s
Foster
Brook
Hunt
Wilcock
Cording
ley
Lowe
Beck
Bennet t
White
Ramsey
The
cave surveyor
in Great Bri ta in
performs
a
thankless t ask , with
few
s po r t i ng cavers
apprec ia t ing the hard work
which
goes in to the
production of
a
cave map. Since the Daren Cilau
breakthrough of
1984,
surveying
t r ips
by one
small
team of cavers commonly exceed
f i f t een
hours
(Ramsey,
pers comm).
However, surveying
can be
rewarding, i f not enj oyable.
Some
cavers in the
USA
take
cave
surveying very
ser ious ly
and
the
high
prof i le
given to
surveyors
i s i l l u s t r a t e d by
t he i r 'Compass and Tape' ,
a
quater ly newsle t te r
devoted to the
ar t
and science
of
cave mapping.
The pr inc ip le of
surveying
a
cave
passage i s
to
measure the
dis tance ,
di rec t ion and angle of
inc l ina t ion
along
s t r a igh t
l ines ( legs) between
f ixed points
(s ta t ions) . The
spa t i a l
re la t ionship
between s t a t i ons can then be calcula ted by
simple
geometry to
provide
co-ordina tes and these points
are
plo t ted
a t a
su i tab le sca le on
a
drawing
medium.
Measurements are a l so
made from
the
cent re l ines and a t
s t a t i ons to
the f loor ,
walls
and
roof of
the cave and
information
such as f loor
depos i t s
are
also
recorded.
These
de ta i l s
are
drawn around the cent re l ine to form the
f ina l
map. The layout of t h i s
map
var ies but in Great
Bri ta in it wi l l tend to
follow t ha t of
an
engineer ing drawing, with plan,
e levat ion
and
sec t ions
on the same sheet
.
I t i s not proposed to descr ibe the
techniques
employed
in
a
cave
survey beyond the above
summary
as these are covered elsewhere
in
t h i s i ssue and
in 'Surveying Caves' (El l i s
1976)
which
wi l l soon
be re-publ ished as a th i r ty- two page
booklet .
A
competent
team
of
two
or three
surveyors
can, in
normal
circumstances, take su f f i c i en t
measurements to
record the cent re
l i ne
and passage
de ta i l s
of severa l hundred metres of passage
in
a
few
hours.
I t i s imposs ible to be spec i f i c about
Footnote': 'Compass and Tape' from the Survey and
Cartography
Section of
the
National Speleological Society.
Edited
by
J .
Ganter,
RD1
Box 71B
Port Matilda, PA 16870 USA
Available
f r
om
Lance
Lide, SACS Treasurer, PO
Box 2601,
Li t t l e Rock,
Arkansas
72203
USA
-
$4.00 for
4 issues.
49
The
idea for t h i s specia l cave survey
ed
i
t ion
of Cave Science or ig ina ted from t h i s
study
weekend.
Grateful
thanks
are
due to the authors,
many of
whom have
cont r ibuted
to
both, and also
thanks are
due to
Charlot te Roberts
who
organised
the study
weekend
in Sheff ie ld .
I t is hoped to
repeat
the cave
survey
study
weekend in
the not
too dis tan t future
and tha t the
fol lowing
papers
wil l s t i
m
ula te fur ther
discussion. I t i s also hoped to include papers
on
computer
appl ica t ions to cave surveys and
t he
design and use of
radio
loca t ion devices, in
fu ture edi t ions of Cave Science
-
extensive topics
which have hardly been
touched upon
here.
the ra te
of
cave
surveying
s ince it wil l vary with
the survey Grade
(see
below), loca t ion
of
the
passage,
the ease by which the
pa s s age can
be
t raversed and
the
temperature
and
presence of
water
(Brook, White
t h i s
i s sue) .
I t
is t h i s
lack
of apprec ia t ion
of
the environment
in
which cave
surveyors
work that
can lead to cr i t i c i sm by the
surveying profession.
Whils t
t h i s
c r i t i c i sm i s
j u s t i f i ed
in terms of the
inaccuracy
of cave
surveys,
it i s to ta l ly unjus t i f
i e d
when
the
reasons
for
a
cave
survey are examined
.
The bes t surveyor i s not the
one
who
i s
ex
t
re
m
ely
prec ise but the one
who
makes
a
survey with
su f f i c i en t
prec is ion to se rve i t s purpose
without
waste
of
t ime or money . (Anon)
This statement
i s as t rue
today
a s it
was
when
f i r s t
published
in 'Surveying Caves'
in
1976.
The
reasons
for
a
cave survey were l i s ted
then
as:
Obtaining
a
general idea of the layout
of
the cave
A
source of information, e .g . tack
l e
requirements
A
route
map for f inding the way
through
t he
sy
s
tem
To
postu la te
fur ther
extensions or
connections
in
a
cave
A
convenient form in which to record sc i en t i f i c or
other
information
To
t h i s
can now
be
added the
requirement
to
record d e t a i l of expedi t ion f inds for sponsors and
the surveying of
a
cave j u s t
for
the
pleasure
of
crea t ing a cave
map.
The
word
' accuracy ' i s the
nearness of
the
r esu l t
(or
average of
a
number
of
resu l t s ) to the
t rue value.
This d i f fe r s from
p r eci s
ion
which
i s
the nearness of repeat
r esu l t s
to
each
other ,
i r respec t ive
of
t he i r accuracy
.
The science of
Land Surveying aims
to
achieve prec ise
measurements
using instruments
which
are
f ine ly
8/21/2019 BCRA 14-2-1987
6/52
adjusted and surveying
techniques
such as
t r i angula t ion which lead to
a
high degree of
accuracy
There i s no requirement to achieve such
a
high degree
of accuracy
in
a cave
survey but
the
overal l
aim should st ll be
to
make as accurate a
survey as poss ib le in the t ime avai lable to meet
one
or more of
the funct ions
l i s t e d
above.
The
graded
accuracy of
Bri t i sh
cave surveys
i s
based
on the accuracy of the inst rument reading
taken between
s t a t ions
and the maximum permissible
s t a t ion pos i t ion error , not
on
the
inst ruments or
techniques used.
The Bri t i sh Cave
Research
Associat ion
survey cent re l ine gradings are
explained
in
Tables 1,
2
and 3. The BCR grading
system assumes t ha t the
inst rument
being used
has
been
cal ibrated pr ior
to
use and t ha t the
surveyors are recording the
t rue readings.
Take a reading with both
eyes
open and then close
the f ree eye. I f the reading does not change
appreciably there i s no disal ignment
of
the eye
axes, and both
eyes
can be kept open. Should
there be a di f ference
in readings, keep the
o ther
eye closed and s ight half-way above the
inst rument
body.
The hai r l ine
now
r i ses
above the inst rument
body
and i s seen against the
target .
The
condit ion may be
so
bad
in
some
people that
t
may be inappropriate for them to
take
par t
in
a
cave
survey as
the
inst rument observer . I t
i s
thus
recommended
that
the t e s t shou
l d
be car r ied
out on
the
surface
a t the same time as cal ibrat ing
the
inst rument (see
below).
One of the main problems of using any kind
of
s ight ing
inst rument
i s
t ha t
of
paral lax. n eye
condit ion ca l led heterophoria can impair the
reading accuracy of a
Suunto
compass. A
surpr i s ingly high percentage of people suf fe r from
t h i s condi t ion without being aware
of
i t . The
manufacturers
of
Suunto
inst ruments
recommend the
following
t e s t :
Cumulative er rors in
a cave survey
can
be
correc ted i f the
inst ruments
are ca l ibra ted
immediately
pr ior to and preferably af te r
every
surveying t r ip .
Cal ibra t ion i s
par t i cu la r ly
important i f a l a rge cave system i s being
surveyed
over
severa l v i s i t s and
par t i cu la r ly
where more
than
one
se t
of inst ruments
are used. Compass,
cl inometer
and measuring
tape
cal ibrat ion
i s
eas i ly
car r ied out
on the
surface by f ix ing two
SCRA SURVEY ENTRE LINE GRADINGS
Note:
Caving organisations, and others , are encouraged to reproduce Tables
1, 2 and 3 in the ir own publicat ions; the perm ission
of
the British Cave
Research
Association
to reproduce these three tables need not be obtained,
GRADE 1
Grade 2)
GRADE3
Grade
4)
GRADES
GRADE
GRADE X
NOTES:
A SKETCH
O
LOW ACCURACY WHERE NO MEASUREMEN TS
HAVE BEEN MADE
May be used, if necessary, to describe a sketch that
is
intermediate
in accuracy between grade 1 and grade 3.
A ROUGH MAGNETIC SURVEY. HORIZONTAL AND VERTICAL
ANGLES MEASURED TO
± 2to;
DISTANCES MEASURED
TO
± 50cm ; STATION POSITION ERROR LESS THAN
±
50cm.
May be used, if necessary , to describe a survey that fails to attain
all the requirements of grade 5 but
is
more accurate than a
grade 3 survey.
A MAGNETIC SURVEY. HORIZONTAL AND VERTICAL ANGLES
ACCURATE TO
±
1°; DISTANCES ACCURATE TO
±
1
Ocm
; STATION POSITION ERROR LESS THAN
±
10cm.
A MAGNE TIC SURVEY THAT IS MORE ACCURATE THAN GRADE
5
A SURVEY THAT IS BASED PRIMARILY ON THE USE
O
A
THEODOLITE INSTEAD
O
A COMPASS.
1 The above table is a summary and
is
intended only
as
an
aide memoire; the
definitions of survey grades given above
must
be read in conjunction
with
the
additional comments made in the B.C.R.A. book Surveying Caves . The more
important comments are summarised below .
2 In all cases it is necessary to follow the spirit of the definition and not just the
letter.
3 The term accuracy, used in the definitions, means the nearness of a result to the
true value; it must not be confused
with
precision which is the nearness of a number of
repeat results to each other, irrespective of their accuracy.
4 To attain grade 3 it
is
necessary to use a clinometer in passages having
an
appreciable slope.
5 It is essential for instruments to be properly calibrated to attain grade 5 - deta ils
of calibrati on are given in Surveying Caves
6 A grade 6 survey requires the compass to be used at the limit of possible accuracy,
i.e. accurate to
± to;
clinometer readings must be to same accuracy. Distances and
station position must be accurate to at least
±
2tcm and will require the use of tripods
or similar techniques.
7 A grade X survey
must
include on the
drawing
notes
on
the type of instruments
and techniques used, together with
an
estimate of the probable accuracy
of
the survey
compared with grade 3, 5 or 6 surveys.
8 Grades 2 and 4 are for use only when, at some stage
of
the survey, physical
conditions have prevented the surveyor from attaining all of the requirements for the
next
higher
grade and it is
not
practical
to
survey again.
9 The tabular summary above must not be re-published without these notes.
50
Table 1 Grading of the survey centre line
8/21/2019 BCRA 14-2-1987
7/52
points and taking readings from one to the other
in both di rec t ions . A su i tab le correc t ion
fac t
or
can then be applied to the readings for each
p
ar t icu la r t r ip . Instrument
cal ibrat ion
is
standard prac t ice in the USA and
Canada
and
it is
hoped
that a l l Bri t i sh
cavers wil l
adopt such
good
prac t ice in the
fu ture .
A
factor
not
taken in to account
by the BCRA
grading system i s
that
of
the ef fec t
of
avoidable
mistakes such as omit t ing a survey l eg , reading
the wrong value
on
the instruments , booking
the
wrong value on
the survey
sheet
and
other
random
mistakes
due
to
inexper ience
in
the
use
of
the
instruments , bad techniques and care lessness .
Care should always be taken
when
using a cave map
for t h i s reason
a
high grade does not
necessar i ly me
an
an accurate survey.
The
majori ty of
cave maps
are
reduced
for
publ ica t ion . Misclosures which
r esu l t
from er rors
and mistakes dur ing the survey are o f ten adjusted
by
manual re
-
alignment
without the appl ica t ion of
proper ar i thmet ic
techniques.
Whils t
t h i s
may
be
acceptable where the misclosure is small or where
the cave
map
i s a t
a
scale
of
1:2000
or
grea te r ,
where
a 0.5mm
th ick l ine
equates
to one metre, the
ef fec t
of
such
inaccuracies
wi ll become
apparent
when
new
passage
discover ies complete
loops
or
connect adjacent caves and a compilat ion map needs
to be
prepared.
The
temptat ion
for manual
adjustment should
thus
be avoided. The Gaping
Gil l
cave
map
i s
a
compilat ion of
a
number
of
d i f fe ren t
surveys and the map indica ted
that
the
dis tance
from
Ingleborough Cave
was
considerab le .
In
fac t
the
dis tance
turned out
to
be a matter
of
metres.
The
connect ion
between Gaping
Gil l
and
Ingleborough Cave
i s unl ike ly to have
been
forged
without the
use
of
rad io- loca t ion equipment
to f ix
the postu la ted connect ing
point .
This example
i l l us t ra t e s two points;
f i r s t l y ,
that
many
compilat ion
maps in Br i t a in contain
gross
inaccuracies and, secondly,
that the use
of
radio- locat ion equipment
to
f ix
points can
s igni f icant ly
improve the usefulness of these
maps
without the
need to
carry
out
major re
-
surveying
of
the
caves. Improvements can
be
made
to
most
surveys
by
f ix ing severa l
poin ts using
radio- locat ion
devices
and dis t r ibu t ing
the
er rors
through
the r es t of the cave passage. I t i s
suggested
that
any
cave
maps
improved by
the
use
of
radio- locat ion should indicate
clear ly
de ta i l s
of the point locat ions and
the
er ror
dis t r ibu t ion
car r ied out .
The manipulat ion of cave
survey
data using
computers
permits
the car tographer greater t ime to
crea te an
ar t form of
the f in ished drawing.
Too
of ten a
Bri t i sh
cave map i s
drawn badly and t h i s
does not do
jus t ice
to the
hard
work done
by
the
surveying
team.
In
many
instances
maps show
i n su f f i c i en t de t a i l and the following should
always
be
included: name of
cave,
prec ise
locat ion, BCRA Grade, names
of surveyors, date s )
of
survey, a gr id preferably re la ted to the
Ordnance Survey National Grid system, a proper
north point
-
with
an
indicat ion
of
whether gr id ,
t rue
or
magnetic with date)
i s
being used,
a
proper bar sca le to allow for photo-reduct ion,
length,
depth
and
volume
see Worthington,
t h i s
i s sue) . The
surveying of
caves
i s
no
longer
j u s t
involved with the measurement of cave passages.
I t now includes the work of the hydrologist ,
geo log is t and
geomorphologist
and i f space permits
a l l
re levan t informat ion
should be recorded on
the
cave map.
Access
arrangements for v i s i t i ng
the
cave and
an
indicat ion
of
loose,
f lood-prone or
All details based
on memory
Survey in
Dan
yr
Ogof photo:
Alan
Coase)
otherwise
dangerous
passage
are also invaluable .
Last ly , reference
should always be
made on the map
to a
wr i t t en
repor t of the cave
survey
which
should provide su f f i c i en t informat ion on the
actua l survey to allow
others
to assess
i t s
t rue
accuracy and
usefulness , notwi thstanding
i t s
BCRA
Grade.
The
sk i l l s
of
the cave sur veyor are advancing
rap id ly
but independent ly throughout the
world.
The use of computers and radio - lo
cat ion devices
are
perhaps the
two aspects of
surveying which
have advanced most
in
the l a s t
decade. I t
would
be possible to ill an
en t i r e edi t ion
of
Cave
Science with papers devoted to j u s t
one
of these
t
opics . The In te rna t iona l
Union
of Speleology
IUS)
can
play
an
important role
in the future
development of cave surveying mainly by at tempt ing
to es tabl i sh world standards.
Internat ional
caving
magazines
should
promote
cave
surveying,
and along
with
spec ia l i s t
publicat ions
l ike
Compass and Tape, can
act
as a forum for future
discussion.
The
papers
in
t h i s edi t ion
of
Cave Science
give an indicat ion of
the
advances
made in
Bri ta in
since the Cave Research Group Symposium
on
Cave
Surveying
1970).
I t is acknowledged
t ha t
Bri t i sh
techniques d i f fe r
from
the r es t ot
the
world and
we
s t i ll
have a
long
way to go to
perfect
equipment, techniques and ab ove
a l l ,
presenta t ion
of
our
cave surveys to
other
cavers , sc ien t i s t s
and the general public .
REF
ERENC
ES
E
s
B . e
d
1 9
86
Su
rveying Caves. Bri t i sh
Cave
Research
As s
oc i a t io n, Br i d
ge
wa t
er .
88 pp .
Fo rd , T.O. ed) 1970 S
ymp
osium on c
ave
s urveyin g . Tr ans Ca ve
Research
G
ro
up
of
G.B
. Vol
12,
no
3.
Paul
Hather l
ey
8
Victor ia Stre
e t
Bradford B013 AR
Grade 1A
laaaA
CIa 8
CIa• •
CIa• • D
Passage
details
estimated
and recorded
in
the
cave
Measurements of detail made
at survey
stations only
Measurements of detail made at survey stations and
when
Grade
38 r3C
ever necessary
between
stations to
show
significant
changes in passage shape size
direction
etc
Table
2
Classification
of
survey
detail
Table 3 Recommended grading/classification combinations
51
Grade
5C or
5D
Grade 6D
Grade X8
XCorXD
8/21/2019 BCRA 14-2-1987
8/52
C VE
SCIENCE Vol. 14, No.2 , August 1987
Transact ions of the Bri t i sh Cave
Research
Association
Cave
Surveying
in ritain
an Historical
Review
Bryan
ELLIS
While
the ea r l i e s t
publ ished
underground
survey
tha t
I
have
traced
is one
of
an
Egyptian
gold
mine tha t was,
apparent ly, "published"
in
1320 BC,
cave
surveying did not
r ea l ly
s ~ r t unt i l
the 17th and 18th cen tu r ies and the number of
surveys published
since
then has roughly followed
the growth in popular i ty
of
caving as a
pastime.
A
study of
the Mendip Cave Survey
Catalogue
shows
that for
th i s caving area
about
25 surveys are
recorded
as
published
before the
end of 1919,
approximately 15 surveys
publ ished
in the
twenties, 40 in
the next
decade, 70 in
the for t i e s
( including the war years ) , and
over
one hundred
in
the f i f t i e s ; the r e l a t ive figures are almost
cer tain ly s imi la r for the other caving areas .
A fa i r ly comprehensive study of the
l i t e ra ture , made
with the help
of
bib l iophi les
such as Ray Mansfield, Martin Mill s and Dave
Irwin,
has fai led to f ind anything published
on
how
to
make
a
cave
survey
pr ior
to
Arthur
Butcher 's c lass i c
work
on the subject
publ ished
by
the Cave
Research
Group
in
1950. There were
plenty of s tandard works on surface and mine
surveying but nothing spec i f i c to
cave
surveying,
though it is
believed
that various manuscript
notes on surveying methods prepared
in
the
twenties or
t h i r t i e s
by C. F . D.
Long
are
in
the
possession of the Cambridge Universi ty
Caving
Club; there may well be others . This lack of
published methods has lead me to the
conclusion
that most
surveys
published
before
1950,
including
those in club publ icat ions and books, must
have
been prepared using what are by today 's standards
very crude techniques. This in tu rn means t ha t
today they
would
be classed only as grade 1, 2 or
a t the very bes t , grade 3 surveys.
Butcher opened
his
work
on
surveying by saying "Most exper ienced
cavers
car ry
a
small pocket
compass
with
them
in
a
ca
ve
. With
th i s
and ropes of known
length (or
by
pacing) a rough sketch - plan
of
a
cave
can be
made. Need any more be said ? There i s
a t
leas t
one exception that must be made to th i s
genera l i sa t ion , the survey of Ease Gil l made in
the l a te for t i e s by Arthur Gemmell; the
notes and
comments
t ha t
he publ ished
in the ear ly Cave
Research
Group Newslet ters
show that
he w
as
a very
conscient ious surveyor and appreciated many of the
problems
involved. However,
th i s genera l i sa t ion
of mine
i s
pure conjecture and i f anyone
can
pro v ide
any informat ion
to re fu te
it
or
ear l ie r
references
about how to make cave sur v
eys,
I hope
they
wil l get in contact
with
me.
Therefore
it i s my
opinion
that
cave
surveying as a science ra ther than
an a r t can
be
said to ha ve i t s or ig ins in 1950 with Arthur
Butcher 's
"Cave
Survey";
th i s
book
was
almost
cer tain ly the f i r s t in Bri ta in on the subject and
possibly
in
the
world . The
contents were
republished in vi r tu
a l ly
the same
form
in the two
edi t ions
of
Bri t i sh
Caving"
t ha t appeared in
1953
and 1962; then in 1966 a revised and enlarged
version was published in
volume
8 of the
Transact ions of
the Cave
Research
Group of
Great
Bri ta in . I t says a lo t for Butcher 's ideas
that
36
years l a te r
his or ig inal recommendations still
form the
basis of
cave surveying
in Br i t a in
and
Author' s Note.
This
paper was o r ig ina l l y prepared as a
l ightweight introduction to the more erudite papers that were
t o
be
given
a t th e Cave
Surveying
Symposium held a t Sheff ield
in March 1986 . The i n t en t ion was to provide a h is to ry of
cave surv
eying
but
t
ende
d
up
re
as
personal
reminiscence
t
has now been rewr
t ten
in
the
form o f
review. I t
i s hoped
t ha t
it
wi l l prompt the publicat ion
of
more information on
cave surveying techniques
nd instruments
of
the
past .
52
elsewhere. They were, af te r a l l , only modi f ied
and
expanded
but not
dras t ica l ly al tered
in
my
own
book
"Surveying
Caves"
t ha t was
publ ished
in 1976,
and th i s book
is s t i l l
the only
Bri t i sh
one
avai lable.
What has developed
since
19 50? The
r es t
of
t h i s paper wil l
at tempt to
descr ib
e the
major,
and
some not so major, changes
that have
taken place
in the following th i r ty
f i
ve
years.
SURVEYING
TECHNIQUES
There have been few changes made in
the
basic
techniques
used to
obtain
the data
from
which a
cave survey i s
prepared.
The
only technique
t ha t
has been
int roduced on anything
l ike
a
large scale
since 1950
i s
the one known as leap-frogging.
This
i s
where the
readings
are
taken
a l te rna te ly
in backward and forward di rec t ions along the
passage
ra ther
than
always
in
the
forward
di rec t ion . This
method i s
both
quicker
and
potent ia l ly
more accurate . I t
was cer tain ly
being
used
in t he very ear ly s ix t ie s and may
possibly
have
been introduced s l igh t ly ea r l i e r . The idea
of taking forward and
backward readings on every
survey leg ,
while
s t i l l
considered
to be
the
idea l , is one
that
has been prac t i sed only very
ra re ly .
Where
there has been
an
appreciable
improvement i s in
techniques
for surveying in
spec ia l i sed
circumstances
such as under
par t i cu la r ly arduous
caving
conditions,
o r
in
areas where
large magnetic anomalies
exis t .
Radio-locat ion i s
without
doubt a development
since 1950 but
it will
probably
surprise
most
cavers nowadays to learn
that an
electromagnetic
di rec t ion f inding device was in
use
by U.K. cavers
in
the mi d
- f i f t i e s . I f asked when th i s
technique
originated
the majori ty of
those
at tempting
an
answer would probably
quote
the
work
by
members of
the
South
Wales Caving Club in the ear ly 1960' s
but
a device was
developed
by Norman Brooks of the
Westminster Speleological
Group and
tes ted
as
ear ly as October
1954. In the following
years it
was used to
check the
St r ide bro thers '
survey of
August Hole, and the
indicated pos i t ion
of Pi l l a r
Chamber
in Ogof Ffynnon
Ddu.
The
problem
wi th
t h i s ear ly device was that it
used
glass va l ves
which required
a 120
vol t
dry
bat te ry to
operate
them and th i s made it very heavy and very f r ag i l e ;
I s ta te that
from
personal
exper ience
By the
ear ly
1960's
t r ans i s to r s
were
avai lable to rep l ace
v
a l
ves and
electromagnetic t r ansmitters
and
receivers
were designed and bu i l t
using
them.
They had the
ad
vantages of being smal ler ,
less
f rag i le
and require much lower voltages with
the
resu l t that more
powerful
and
more
portable
devices were
possib le . A
l a te r
development was
the
fac i l i ty to
t ransmit
speech in
both di rec t ions
which removed the
need
to
keep
to the
s t r i c t
t ransmission t imetables
that were
previous
ly
necessary
to
ensure
that both par t i es
were
doing
the appropriate thing a t
anyone
t ime.
One technique
t ha t
was discussed by Butcher
but
which has never been used to
any
appreciable
extent in
cave surveying
is t ha t of making
theodo
l i t e t r averses
. His in ten t ion was to
produce a more accurate survey l ine but it has
been found
to be impractical to use commercial
inst ruments
in
most
cave s i tuat ions
and
s impl i f i ca t ion of the instrument, al though t r i ed
by several surveyors , does
not give
the accuracy
that is required to produce a be t t e r r esu l t
than
that obtained
with a
magnetic
t r averse . I t has
been
a
technique
vi r tua l ly
used only
when
a
magnetic
t raverse i s impractical for some re as
on
or another.
8/21/2019 BCRA 14-2-1987
9/52
REDUCTION OF SURVEY D T
The area where the
greates t
development has
taken place in the
l a s t t h i r t y years i s without
doubt
in
means of reducing
t raverse
da ta
into
s t a t ion
co
ordinates .
This t ask which i s now
so
simple
to
carry
out wi th the a id
of
the
ubiqui tous
computer
was the
bane
of
the surveyor s
l i f e
un t i l
the ear ly
sevent ies
when e lec t ronic ca lcula tors
f i r s t became
ava i lab le . Before
then
calculat ions
had to
be
car r ied out
in longhand
using logarithm
t ab les o r a
s l ide
rule; the for tunate surveyor
might have had access to a
mechanical
(or perhaps
even an e lec t r ica l ) ca lcula tor
but
these
machines
were only capable of
performing
the four basic
mathematical funct ions, and then only
one
of them
a t
a
t ime. I t was
st ll necessary
to look
up
the
values of s ines and
cosines in
t r igonometr ical
t ab les
before car ry ing out
the mult ipl icat ions
on
the ca lcula tor , followed by a separate
s tep
where
a l l the
direct ional
changes were added together to
obtain
the s t a t ion
co-ordina te .
There was
an
al ternat ive in t ha t t raverse tables
could
be
used
to determine the
la t i tudes
and departures
in
a
single
s tep but they were cumbersome and none too
accurate . Now the lo t can be done in one s tep
using a
ca lcula tor
cos t ing
l ess
than £10. One
r esu l t
of t h i s ear l ie r d i f f icu l ty
was that
many
surveyors did not bother to
reduce t he i r
data but
simply
prepared the survey
by
plo t t ing
out
the
data
from
t he i r cave
notes using
a prot rac tor and
ru ler .
In
fac t t h i s
method
was the pr inc ipa l
one
described
by
Arthur Butcher, with only a
br ief
mention
of
mathematical reduct ion. Hopefully a l l
surveyors
today determine the co
ordina tes of
t he i r s t a t ions
mathemat ical ly for a l l but
the
simplest
of
surveys
before
s t a r t ing to plo t the
r esu l t ; there
i s
no excuse for
not
doing t h i s
nowadays.
PRESENTATION
TECHNIQUES
Butcher
considered cave
surveys as three
dimensional engineering drawings and
his ideas
and
recommendations are st ll
followed very closely
today;
they have
been
s impl i f ied but the
pr inc ip les are unal te red . This
i s
not to say
that
other methods
of
present ing surveys have not been
proposed
since
then
e i ther
for general
use
or
for
spec ia l i sed
purposes. Cut
away
block diagrams to
show
the layout of the
caves
have
been
extremely
ef fec t ive but requi re
a
lo t
of
ef for t and no
mean
amount of
a r t i s t i c
sk i l l to
prepare. Other ideas
t ha t
have
been proposed
include
isometr ic
drawings,
s impl i f ied diagramat ic surveys intended
to give
j u s t
a
rough
idea of the layout of a cave
and even route sever i ty diagrams
intended,
as the
name
suggests , only to indicate routes through
a
cave, the time
required, di f f icu l ty ,
etc . and not
dimensions or layout . None can be considered to
have
caught
on and vi r tua l ly a l l
surveys
are st ll
produced in the t r ad i t i ona l s ty l e . Programs for
use
on
simple
computers to draw
the survey
cent re
l ine
from the
survey
data have
been
publ ished but
the idea
of automatical ly
plo t t ing the passage
de ta i l
in
addi t ion
i s , in
the mid-e igh t ies , st ll
in
i t s infancy
and
r es t r ic ted
to
those with access
to large and expensive equipment.
On the quest ion of symbols to be used with
cave
surveys,
Bri ta in has
gone
in the
opposi te
di rec t ion to severa l
other
count r ies
. Over
the
years we have reduced
the number
of
recommended
symbols from the l i s t prepared
by
Arthur Butcher
and
now
publish only the basic symbols; surveyors
are
expected to
devise
the i r
own
symbols
for
more
special ised
purposes,
and
to
publish
a key on
the
survey . Some other count r ies seem to be
publishing ever longer and more complex
l i s t s
of
recommended symbols
.
CCUR CY
OF
C VE SURVEYS
There has been
a
considerable
increase in the
accuracy of surveys produced over the years . To
see
t h i s
t
is
only necessary
to
comparer
the
standard of
surveys produced in the eighteenth and
nineteenth
centur ies with
th o s e made
in the
f i r s t
53
hal f
of
t h i s century,
or
t h i s l a t t e r group
with
those prepared since 1950. In the
1960's ,
and to
a l esser extent since
then,
there have
been
many
papers publ ished discussing var ious aspects
of
cave surveying and
apar t from
the few deal ing with
the presenta t ion
of
surveys,
jus t
discussed,
most
dea l t
with improving
the
accuracy
of
surveys
by
some
means
or
another .
Topics
covered
have
included the ca l ibra t ion
of
the inst ruments used,
the
dis t r ibu t ion
of
closure
errors ,
at tempts to
improve techniques and
hence
accuracy,
the need
to
use
a
cl inometer ,
rat ional i sat ion
of
survey
grades, and
so
on.
The
majori ty of these papers
or ig ina ted from Mendip surveyors but t h i s
i s
probably only
because
with
so
few proper
caves
to
survey
they
have had to
tu rn
t he i r in t e res t to
more theoret ical
aspects I t i s in te res t ing to
note, however,
that
severa l of the points put
forward l a te r
by
Mendip surveyors, such as the
need to
use
a cl inometer
even
when
making a medium
grade
survey,
or
the fac t
that
the accuracy
of a
survey
i s not
necessar i ly
dependant on the
caving
sever i ty
of
the
passage,
were
f i r s t put
forward
by
nor thern cave surveyors in the 1940's but ignored
when "Cave Survey"
was
writ ten.
s
with
the
presenta t ion of surveys,
there
has tended
to
be
a
s impl i f i ca t ion
of
the grading
system used to
indicate
the expected accuracy of
cave surveys.
This followed
from a
real i sat ion
tha t
the
f iner
discussions
over r e l a t ive accuracy
of surveys
were only of
i n t e res t
to
cave surveyors
and most cer tain ly
not of in te r es t to
the average
survey
user s far as the l a t t e r
are
concerned
surveys are
of
low, medium
or
high accuracy,
and
no more.
One
small
change
has been
to indica te
the probable accuracy of the de ta i l
in
addit ion to
that
of the cent re
l ine; th is
i s done by
means of
a
suf f ix l e t t e r . There has been
a
change
away
from
the
s impl i f ied view
that one could gauge
the
accuracy
of a
survey so le ly
from the inst ruments
used
ra ther
than from how they were used. I t i s
very
gra t i fy ing to not ice
that
surveyors from most
count r ies around the world
now
quote t he i r
est imate of
accuracy
by means of the B.C.R.A.
grading system.
SURVEY INSTRUMENT TION
In
the f i f t i e s , being relat ively
soon af te r
the
second
World
War,
there
was
an abundance of
f a i r ly
simple
surveying inst ruments avai lable
cheaply from government surplus dealers .
These
included the mark I I I
l iqu id f i l l ed
prismatic
compass, the
Abney l eve l ,
the Watkin cl inometer
and surveying tapes a l l very sui
table
for the
making of
r e l a t ive ly accurate cave
surveys,
cer ta in ly
a vas t
improvement
on the
compass
and pacing" that ,
presumably, had
been the
norm
before.
Compasses
The ex-government mark
I I I
prismatic compass
soon became the inst rument most
commonly used
by
cave
surveyors. They
were readi ly
avai lable
in
both dry
and
l iqu id f i l l ed
versions but only
the
l a t t e r
was real ly pract ical
for
use
underground;
with the
other
t
was
necessary
to
wait
for
ever
and
a
day for the needle to s top osc i l l a t ing
.
The
pr ice
a t that
t ime
was
£4 £5
(or to put
th i s
in
perspect ive,
about the
cos t of seventy f ive
pin t s
of
beer)
so, al though
not cheap,
they were not
out land ish ly expensive, in
fact i f
one adver t i sed
in
"Exchange
and
Mart"
t
was
poss ib le to
pick
them
up
a t about hal f
that
pr ice . They
are
excel lent instruments , very robust , accurate ,
r e l a t ive ly cheap (when purchased ex-WD),
compact
and very easy to
use
in day l igh t . Unfor tunately
they had not been designed
for
use
underground.
The pr inc ip le
i s
that while looking through
a
s lo t
a t
the near s ide of the compass one
l ines
up the
dis tan t s ta t ion
with a s ight ing l ine
marked
on the
ra i sed l id ,
and a t
the
same t ime you
look
a t
the
compass card
through
a
prism
below the s lo t .
The
problems
when
using these compasses for cave
surveying are
in
i l luminat ing
the card
below
the
prism so that the
bear ing
can be
read,
and
cleaning
the
prism i t s e l f
when t becomes coated
8/21/2019 BCRA 14-2-1987
10/52
in
mud or condensat ion.
One's tongue
is
usual ly
the most
effect ive
method
of
deal ing with the
l a t t e r ,
but
at tempts
to
solve
the former
have
given r i se to some in t r iguing
invent ions
that
at tempt to prevent e l e c t r i c a l
f i e ld s
from the
i l luminat ion af fec t ing the compass. The other
problem
with the ex-WD pr i smat ic i s
t ry ing
to take
accurate bearings on survey legs
that
slope a t
more
than
about +20°
or
- 15°; but then the Suunto
instruments
a re
even
worse
in t h i s respect . One
method used
to overcome
t h i s problem was
to
f ix
a
glass
or
Perspex rod
horizontal ly
across the
s ight ing l ine so that
the
target l igh t was
re f rac ted to the prism
but it
i s very doubtful i f
th i s was any more accurate than s t ruggl ing without
it. ( Inc identa l ly , t h i s
same
idea
has recent ly
been suggested
for
use
with Suunto compasses to
overcome
the
same problem.)
The
only other compasses
even vaguely in
common
use a t th
i s t ime were
the
Si lva- type
compass (qui te a
good
inst rument for lower grade
surveys) and the ex - government 06A h and-bear ing
pr ismat ic .
The former
are still avai lable of
course;
the l a t t e r were much
l a rger
inst ruments
only
graduated
in two degree divis ions but the
prism could
be
t i l t ed
which
meant
that
readings
on
upward sloping
legs could
be made much more
accura te ly . I t also
had
bui l t in i l luminat ion .
Bulky and heavy, but accurate and a very easy
inst rument
to
use.
The
Brunton
compass,
beloved
by
the Americans, has very ra re ly been used in the
U.K.; one caving
club
who did own such a thing
considered it to be too
expensive
to
take
underground
By the
very end of
the 1960' s
the
Suunto
compass had
been
int roduced to cavers by
northern
surveyors and i t s
use
rapid ly spread to other
areas. Largely
because
of i t s
r e l a t ive
ease of
use
but aided a little
by
the fac t
that
by
th i s
time
pr i smat ics were
becoming hard to
obta in
a t an
acceptable pr ice , it soon
became the
most
commonly
used
inst rument
despi te , as
one contemporary
surveyor wrote, i t s high
purchase
pr i ce of £ 6
These
are
still
of course, the instruments
most
commonly used today.
Clinometers
The Abney
level
was
another inst rument
avai lable ex-WD a t roughly the same price as
prismatic compasses
though
they were a
l i t t l e more
di f f i cu l t to come by.
Although
ca l led a l eve l
these instruments are
r ea l ly
cl inometers . They
are
reasonably
robust and to use them underground
does
not presen t any addi t ional
problems beyond
the
obvious
one of i l luminat ion .
The pr inc ip le
of
use
i s
t ha t
one
looks through
a s ight ing tube a t
the
t a rge t
and
a t
the
same
t ime
looks
(by means of
a mirror
occupying hal f
of
the
s ight ing
tube) a t
a
sp i r i t level bubble. The bubble
is movable
and
i s
a l te red unt i l
it is
cent ra l in the f i e ld of view.
The angle
of slope can then
be read
agains t a
scale.
I t i s a
r e l a t ive ly easy
inst rument to
use
but
it
becomes progress ive ly more
di f f i cu l t
to
make accurate readings as the angle of slope
increases and, al though ca l ibra ted from +90° to
-90°,
the maximum
angle
i s
about
±45° when
used as
a hand-held instrument . Some surveyors modified
it
so t ha t
it could be mounted on a
t r ipod when
it
became an
even be t t e r
inst rument , eas ie r
to use
accura te ly
and it
could
be
used
on
l ines
of
s ight
a t v i r tua l ly any
angle.
Another
inst rument
that
was occa
siona
l l y
avai lable on the
government
surplus market was the
Watkin cl inometer .
This
i s based on a pendulum
ins tead
of
a sp i r i t level and has a
scale
ca l ibra ted
from
-45°
to
+45°,
sometimes
marked
d i rec t ly
in
tangents of the angle. I t is
used
by
looking through a pin hole on one
s ide of
the case
and
out
through
s ight ing wires on the
other ; there
i s a
concave mirror
occupying
hal f
of
the f i e ld
of
view and the sca le , f ixed to the pendulum, can be
seen in th i s .
Once
the inst rument
has
been
s igh ted on
the s tat ion
the
scale
i s
locked and the
reading
made
in
"comfort".
While
quicker
to
use
as a hand-held inst rument than the
Abney
l eve l ,
the method
of
s ight ing
i s
r e l a t ive ly crude and
the
prec is ion i s
probably
not
as
high. They were
54
u
seful when
making
surveys
where speed
had
a
higher pr ior i ty than accuracy.
s
with the compasses it
was in
the l a t e
1960's
that Suunto
cl inometers
became known to the
cave surveying
community
and swi f t ly became the
most commonly used
inst rument ; they still
are .
Vir tua l ly
the only other cl inometers
used in
the ear ly post-war
years
were
home-made
ones. A
typical inst rument consis ted
of
a 15 cm aluminium
a l loy
ladder
rung
that
had cross wires inser ted a t
one end
and
a
plug with
a pin
hole through
it
a t
the
other .
Along
the s ide
was
fastened a
semi-c i rcular school
prot rac tor
over which
moved
a
weighted
brass pointer "dr iven" by
gravi ty.
The
tube was
sighted on
the dis tan t s ta t ion , the
pointer clamped by
the
judicious
use
of a f inger
and then the inst rument moved
so t ha t
the reading
could be made During t h i s period, unt i l the
in t roduct ion
of
Suunto instruments , few
northerners bothered to
use
any form of cl inometer
when making
cave surveys.
Combined Inst ruments
Over
the
years
ef fo r t s were
made by
severa l
surveyors to
combine
a compass and cl inometer in to
a s ingle inst rument ; one such was designed by me
in the mid-1960's when a prismatic
compass
and an
Abney l eve l were r ig id ly
mounted together
in what
was
ca l led
a
Survey
Unit.
The
idea
was
to remove
many
of
the
problems
associa ted
with using the
inst ruments
independent ly. The Abney
was used
to
sight on the dis tan t s t a t ion and th i s one
s ight ing
suff iced fo r both the cl inometer and
the compass
reading
so
the l a t t e r
could
be taken on very
s teeply sloping l egs .
The sp i r i t
level
of
the
Abney
was
se t by looking from above the
inst rument
ins tead
of
through the mirror and so
it
was
possible to take prec ise readings
in the ver t i ca l
range
+80°
to -80°; the di f f icu l ty of i l luminat ing
the
bubble was also removed.
A
l a rger prism was
Survey in
a Mulu
cave (photo: Colin Boothroyd)
8/21/2019 BCRA 14-2-1987
11/52
f i t t ed
to the compass and th i s made both
i l lumination
and reading
easier . The
complete
inst rument
was used mounted
on
a t r ipod and t h i s
gave a fur ther increase in precis ion. However
t
must
be
admitted
that
outside a small band of
Mendip
surveyors t
never caught
on and
i t s demise
was
hastened by the
appearance
a few years l a te r
of the Suunto instruments .
A commercial version of the same idea i s
knowr. as the Verschoyle Trans i t . But for one
defect
t
would
probably
be
the
best
inst rument
avai lable
for
cave
surveying,
even
today. I t
cons i s t s of a 7.5
cm
diameter compass scale
graduated
to 0.5°, a sp i r i t level and a folding
sight ing
arm.
The compass scale
and
sp i r i t level
can be
seen, by means of a
prism,
a t the
same time
as looking along the sight ing arm and the two
readings
are made agains t the same reference. A
pointer
at tached
to the sight ing arm moves over a
semi-ci rcu lar scale
and the
incl inat ion i s
read
from th i s . I t
does suffer
from the same problem
as the Abney level in
that
t becomes
progressively more di f f i cu l t to make
readings
through the prism as the
angle
of slope
increases
but th i s
can be overcome by mounting
the
inst rument
on a t r ipod and se t t i ng the
bubble
without using the prism - as was done with
the
Survey
Unit.
I f
only
the compass were l iqu id
f i l l ed
t
would be close to
the
idea l
inst rument
for cave surveying.
Another
combined inst rument made by cavers
appeared on the market some years l a te r in the
sevent ies , the Topofi l . This attempts to overcome
the
sight ing problem, and a t
the
same time measure
the in te r - s ta t ion
distance, by
using a thread
pulled
between
the
s tat ions . Again, t h i s
inst rument
has
fai led
to catch on except wi th a
small band of surveyors. Why? Is
t
conservat ism
on
the par t of cave
surveyors
or , in th i s
case,
doubts
about
the
inherent
accuracy
of
the
system?
I suspect that
t
i s a combination of both
reasons.
Astro compasses, or ig inal ly used to take
bearings
of
s tars
from
aeroplanes,
were
modified
in
the
ear ly
1950's
by
a t
l eas t
two cave surveyors
who added a simple sighting tube
so that
they
could be used as a
"cave
theodol i te . As
s tated
ea r l i e r , theodol i te t raversing has never caught on
with
Br i t i sh
cave surveyors
l a rge ly
because
t
has
been
real i sed that
very precise
instruments
are
required
for
th i s type of
t raverse;
ast ro-compasses and other home made cave
theodoli tes cer t a in ly did not
reach
the
required
standard.
Length and Depth Measurement
An instrument
developed
by members of the
Universi ty of
Bris to l
Spelaeological Society in
the l a te
for t ies
was known as the
Spelaeobathometer. I t
consisted
of one hundred
fee t of pressure
tubing
f i l l ed with water and had
a
pressure gauge
a t one end d i rec t ly
cal ibrated
to
show the depth ( in feet ) of the
gauge below the
o ther
end.
I t was claimed to be accurate to
wi th in one foot
and to
provide
a
rapid but
reasonably accurate
method
of
level l ing
through a
cave. This might
be an
idea
worth
resurrect ing
Members of the S.W. Essex Technical College
Speleos also experimented with a water level in
the
ear ly
1960's but
th i s time as a s t r a igh t level
without
the
pressure
gauge.
"Fibron" tapes , consis t ing
of
glass f ibre
reinforced PVC
were not
introduced
to cave
surveying unt i l the
mid-s ix t i es ,
and ear l ie r the
only
measuring
tapes avai lable were those made of
l inen (which st retched or shrank a t the s l igh tes t
provocat ion) ,
those
known as "metall ic"
tapes
( l inen tapes incorporat ing strands of
copper
and
which were not much be t t e r than c lo th t apes) , and
s tee l tapes. These l a s t
had
the
disadvantages
that
they
rusted i f great
care
was
not taken of
them, were
prone
to kink i f one was not carefu l
when
using them,
and broke
i f they
were trodden
on.
There was also
the
poss ib i l i ty
of introducing
er rors
on
a
magnetic
t raverse
i f
the
tape
was
allowed to get too close to the compass;
but
t h i s
danger was not as great as many
thought.
55
CONCLUSION
I f the review given above i s anything l ike a
true record,
then t
can be seen that
the
vast
majori ty
(about
95 ) of the
Bri t i sh
cave surveying
development took place over a period of
approximately 25 years tha t
s tar ted
around
1948.
I t
s t a r t ed
with
people l ike Arthur
Gemme
1
and
Arthur Butcher, and was developed by
surveyors
prac t i s ing
in
the
1950'
s a n d
1960' s .
Vir tua l ly
the only
developments
since
then
have
been
in
f ie lds
of using computers to ass i s t
surveyors,
and
improvements in rad io - locat ion equipment. Is
anyone going to
dispute
this? I f so,
then
I hope
de ta i l s wi l l be brought
to my a t ten t ion
so that
the record
can
be
corrected.
Author ' s
Pos t scr ip t
Li te ra l ly as
the
manuscript of the
above
ar t ic le was being
run off
I came across
an
ear l ie r
a r t i c le
describing
how to make cave surveys. This
was
publ ished
in 1947 in
the
Bul le t in of
the
National Speleological
Society of America and
therefo re p re-dates
Butcher 's
paper by three
years,
al though t
i s contemporary
with the
discussions in the ear ly C.R.G. Newsletters.
Although r e l a t ive ly short th i s paper does
deal
with many problems of cave surveying and the
presen ta t ion
of surveys without going
into great
de ta i l .
As
my paper i s a
review
of
cave
surveying
in
Bri ta in
t
does not mater ia l ly
affect
what has
been writ ten; Butcher was a committee member of
the Cave Research
Group
and therefo re
t
i s j u s t
possible t ha t he may have been
aware of the
American paper
when
he
wrote
his own work but t
i s almost
cer tain that
general knowledge of t in
the United Kingdom would
have
been very
res tr ic ted.
Bryan El l i s
20 Woodland Avenue
Westonzoyland
Bridgwater
TA7
OLQ
8/21/2019 BCRA 14-2-1987
12/52
CAVE SCIENCE
Vol.
14,
No.2 ,
August
1987
Transact ions of
the Bri t i sh Cave Research
Associat ion
Review of ave
Surveying
Techniques
Steve WORTHINGTON
The
main
purpose
of
t h i s
a r t i c l e i s to
compare d i f fe ren t
mapping
techniques, so
that
an
appropriate one
may
be chosen for
a
par t i cu la r
cave.
Ult ra-accura te techniques
such as
using
t r ipods are not
discussed here, as t he i r
appl icat ion
i s l imi ted to a small minor i ty of
caves. Most modern mapping i s car r ied out under
time
r es t r a in t s ,
due to the shortness
of an
expedit ion
or the di f f icu l ty of a
cave; thus,
rapid
mapping
techniques are emphasised
here.
One can broadly define three reasons why
caves
are mapped:
a) to compute the length/depth
of a
cave for
record
purposes,
b)
to
produce a map of
the
cave fo r
route-f inding,
sc ien t i f i c purposes,
or
as
a
work
of
a r t ,
c)
to loca te
passages accura te ly so
that
connect ions or new
entrances
can be made
by
fur ther
explora t ion ,
digging or
blast ing .
Each of
these requirements
imposes
d i f fe ren t
demands
upon
the cave
surveyor,
and wil l be
considered
in turn.
Length and depth l i s t s
of
caves
are
becoming
increas ingly popular and provide a sa t i s f ac t ion
of
achievement and
a compet i t ive spur . In many
long
caves,
it
seems
that
the ca lcula t ion of length
i s
the main
reason for mapping.
An extreme
example
i s the Mammoth System, where the t o t a l cave
length
i s
publ ished
an:1Ually (1985: 500,506m), yet the
most
recen t
maps
are 1908 ( for
56km
of
Mammoth
Cave)
and 1964
( for 53km
of the Fl in t
Ridge
sec t ion) .
Only
computer-generated
l ine
plo t s with
no
passage
informat ion have
been
publ ished
in
recent years . I t
i s
in teres t ing
to note
that
American
cavers
of ten
record how many
survey
s tat ions
they
se t on
a
par t i cu la r
t r ip ,
ra ther
than how many
metres
of
passage
they
mapped: t h i s
a t t i t ude rewards ef for t ra ther than luck, and it
encourages
the mapping
of co ns t r ic ted passages
with shor t legs . The ca lcula t ion of
the
depth
of
a
cave
i s
r e l a t ive ly
simple,
though with l a rge
entrances
(e .g .
Sotano de l as Golondrinas,
Mexico)
the choice of
datum
i s o f t
en arb i t rary .
with
long
cave systems, the data i s usua l ly
fed in to
a
computer,
which
wil l
generate a
prec ise
surveyed
length.
But
with
l a rge
data
bases
it
becomes increas ingly di f f i cu l t to
keep
t rack;
for
ins tance ,
in
Holloch
(Switzerland)
the
current
length of l33,050m follows a
purge
of
over llkm
of
data from the resurvey of passages; thus the
length
of the cave
had
been overest imated for many
years .
Having
carefu l ly
el iminated
a l l
dupl ica te
surveys
from
your
data ,
do
you now
have
an
accurate length? Not a t a l l .
You
f i r s t
have to
decide
whether
to
follow the pr inc ip le
of
cont inui ty
or
the pr inc ip le
of
discont inui ty
(Caving In te rna t iona l , 3 p35). To fo l low
e i ther
method
s t r i c t l y
would
be so tedious that
I
doubt
whether e i ther
has
been implemented in
an
extensive cave, yet
in
a cave with wide passages
and chambers the
difference
could be severa l per
cent .
Next, what about
that
20m
oxbow
that
you
sketched?
You may not have produced numbers for
your
computer
to add up, but it s a passage on
your
map and
so
should be par t
of the
cave length.
Then
what
about
big
passages? Should you
zig-zag
from wall to wall to give good
passage def in i t ion ,
take the shor tes t route , follow
one
wall ,
or
map
down
the centre? The l a s t
choice i s
the most
logical for accurate
length, but
the
other methods
may
be
eas ie r to use. When you've resolved
a l l
these
problems
and
calculated
a prec ise length, i s
it
r ight?
I f
you want your confidence shaken,
ge t
someone e l se to
remap any sec t ion
of the cave,
56
preferably using
d i f fe ren t
techniques.
Most
l ikely the i r r esu l t s wi l l di f f e r by a t l eas t
1 .
Thus i f one
i s mapping a
cave to ca lcula te
i t s
length, there seems
l i t t l e
point
in
s t r v n ~
for
bet ter
than
1
accuracy
in one s
survey.
To produce a good cave map requi res
careful
drawing of passage de ta i l . The National
Speleological
Society (USA)
has encouraged t h i s
for
many years by present ing awards
a t t he i r
week-long
annual
conference for the bes t cave
maps; the r esu l t i s
that
some American
maps
achieve
the
highest car tographic s tandards
anywhere, wi th
meticulous a t ten t ion
to
the
portrayal
on indiv idual boulders and format ions.
For route- f inding purposes, a map
should emphasise
those fea tures
that
a caver is
l ikely
to
not ice,
such as deep pools , climbs, pi tches ,
ducks,
sumps
and squeezes. For
sc ien t i f i c
purposes
it i s
most
usefu l to have an accurate ,
well-drawn map, but
most
sc ien t i f i c
projec t s
wi l l
requi re
addi t ional
informat ion
in
spec i f i c par t s of the
cave.
To locate passages for connect ion purposes,
it is
useful to have an accurate map, but nowaday
s
radio- locat ion
i s
commonly used in
many
count r ies
and wi l l
give
be t t e r
informat ion than
the
most
accurate mapping.
EQUIPMENT
The
standard
method of surveying measures
dis tance ,
compass
di rec t ion and inc l ina t ion , using
three
inst ruments
( though these
may
be
mounted
together
as in
a
t opo f i l ) .
These
wil l be
considered
in turn.
Distance
may be
measured by
tape,
topof i l
or
te lemetry. Thir ty metre long f ibreglass
/
PVC
(Fibron)
tapes are most
commonly used, though
15m
tapes are
l i gh te r
and
cheaper
and
are
preferable
in most
ci rcumstances. A
topof i l
(Foster , t h i s
High-grade survey with a gyrotheodolite in
Alderley Mines (photo :
Paul Deakin)
8/21/2019 BCRA 14-2-1987
13/52
volume) may come in
one
of three forms;
t
may
j u s t measure
dis tance
e.g .
Topofil TSA (although
t i s easy
and
inexpensive to
add
a prot rac tor
and
sp i r i t
l eve l
to
the case to measure
incl inat ion) ;
t may measure dis tance and
incl inat ion (e .g.
Topofil
Dressler) ;
or t may measure
a l l
three
parameters (e .g. Topofil Vulc
ain) .
Telemetry (ul t rasonic rangef inder) (Breish
and
Maxfield 1981; Torode 1984; Mixon 1984) has
been
l i t t l e used in caves,
due
largely to high
prices
and the
del icate
nature of exis t ing
instruments,
but
improvements
in
microelectronics
assure a
more
popular fu ture for these
ins t ruments . I t
works best with r e l a t ive ly short
survey legs «10m), because t i s d i f f i cu l t to aim
prec i se ly
a t
a
d i s t an t survey s t a t ion and because
accuracy
diminishes with
distance. However,
th i s
device enables heights in high passages
to
be
measured for
the
f i r s t time, and passage
cross-sect ions and
chamber dimensions
can
be
measured speedi ly and accura te ly .
For measuring compass
direct ion ,
a Suunto
compass is most frequently used. Once
the
circumferences
of the
two windows
are sea led
with
s i l i cone adhesive,
these
l igh t , durable
instruments are water - r es i s tan t and
almost
ideal
for cave surveying. There are
two
methods
of
reading the
scale; for normal s ta t ion- to- s ta t ion
usage
the
scale with 0.5 degree gradations is
read, but the
scale
with
5
degree
gradations
is
used when al igning the compass with a
topof i l
thread or
when a pace-and -
compass
survey is being
made.
In the l a t t e r
case, i f a s t r a igh t l ine i s
engraved
along
the
centre l ine
of the
top
of the
compass
to
fac i l i t a t e alignment,
then
the sca le
can
be read
to
an accuracy of one degree. Other
types of compass such as Brunton U. S. A.) and
Topocha
ix
(France)
are
st ll
used,
but
they are
bulk ie r , more expensive
and
less
su i tab le than the
Suunto for
cave
use.
For measuring incl inat ion ,
the
Suunto
clinometer
i s
the
most popular
ins trument .
Some
topof i l s have a prot rac tor
mounted on them, and
some care
is
needed to
achieve
an
accuracy of
one
degree. Alternat ively, a Suunto cl inometer may be
aligned
along
a thread.
Mud
and
water seem to have
an af f in i ty
for
surve