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  ae

Science

The Transactions

of

the British

Cave

Research ssociation

BeR

olume

4

Number

August

987

Symposium on

Surveying aves

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  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.

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  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

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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

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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

"pocket

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)

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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