Marking survey-stations

[Glenn Baddeley]

Hi Mike & other surveyors,

Also in Australia (down in Victoria) we use stainless steel self-tapping screws
for permanent survey markers in caves.  There are no problems with 
corrosion or rusting !
The drill hole for the screw is about 10mm long and 3mm in diameter.
A small tag about 20mm x 30mm attached to the screw using a pre-punched
3mm hole in the tag. The tag is a strong water-proof 'poly' film and white 
in colour.
Its easily written on using an ordinary HB lead pencil. I don't know 
exactly what it
is made of, although I could find out.  These white tags are very obvious 
in a cave and easy
to remove, although if they are only used for major survey stations (that 
may need
to be recovered in the future) about every 100+ metres through a cave there is
no real need to remove them.

An alternative is a piece of aluminium sheeting ~0.5mm thick, drawn on using a
a stylus (eg. a 8cm nail).  I've seen these 20+ years old in a dry cave 
with no noticeable
degradation.

Cheers,
Glenn Baddeley
Victorian Speleological Association Inc.

At 03:42 PM 23/10/2003 +1000, you wrote:
>Roger Johansson wrote:
> > I don't know is this list is still active bur I hope so since I need some
> > advice from experienced surveyors. What is the best way to mark permanent
> > survey-stations?
>....
> > Is there any better way to do this? And should one be able to remove the
> > station-markers in the future when the survey is considered to be finished?
> > Leave nothing but footprints they said..
>
>In Australia we have used in the past small copper pins hammered into 
>drilled holes
>in the bedrock. Diameter was 3 or 4mm. They last forever and can be hard 
>too see
>unless you know roughly where they. This to some extent advantageous as 
>thet are not
>even noticed by the average caver or rabid environmentalist (i.e. the ones 
>that
>insist that you cant have any permanent survey markers so you end up 
>resurving the
>cave several times). From a map though with the permanent stations marked 
>you can
>relocate them. For the number and size of copper rivets used there in 
>*most* caves
>there would be no concerns about copper metal contamination. generally 
>copper is
>biologically undesirable but in most caves its an alkaline environment so 
>it wont
>leach out.
>
>Mike
>--
>
>Mike Lake
>Caver, Linux enthusiast and interested in anything technical.
>
>--
>Cave-Surveying http://lists.survex.com/mailman/listinfo/cave-surveying