Cuillin and compasses

In article <[email hidden]>, [email hidden] says...

Quoted message said:

Points will be deducted from anyone who recommends a GPS, tells me which
digital camera is best to photograph the sunset, where to pitch my Argos
tent, or how to use a walking pole as a combined navigation aid, tent and
camera support.

and you are expecting exactly how many replies? 🙂

(And haven't a clue as to the question!)
--
Darren
mail to darren not ng

The message <[email hidden]>
from "NC" <[email hidden]> contains these words:

Quoted message said:

I'm planning a spring trip which includes Skye. So, some of the Cuillin
might be on the agenda. Many books tell me that compasses can be
inaccurate
on the Cuillin.

Quoted message said:

Could someone post a description of which areas the magnetic anomoly
affects
?
Is it just very rocky ground, such as the main ridges, or is it in the
peaty
glens as well ?
Is the nature of the anomoly random or predictable if planned for ?

I think it is sporadic but only on one occasion have I ever had to test
it out and that was in attempting to persuade a companion that I knew
(from previous experience) which way to go in the mist and as he hadn't
been there before he didn't. The place in question was (IIRC) one of the
summits of Bidean Druim nan Ramh. I was sitting on a boulder with the
map (useless anyway) on my lap. Happened to move the compass (out to
orient the map) and the needle moved. Moved the compass from one side of
the map and the compass rotated almost 180 degrees.

Quoted message said:

Points will be deducted from anyone who recommends a GPS, tells me which
digital camera is best to photograph the sunset, where to pitch my Argos
tent, or how to use a walking pole as a combined navigation aid, tent and
camera support.

A gps would at least reliably tell you which way is North but up on the
Ridge that is of limited value. Following a track or go-to would be
verging on pointless. It is usually pretty obvious which direction you
need to go in. What is often not obvious is how to achieve that
objective.

--
Roger Chapman so far this year 5 summits
New - 5 (Marilyns 0, Sweats 0, Outlying Fells 5)
Repeats - 0 (Marilyns 0, Sweats 0, Wainwrights 0, Outlying Fells 0)

In message <[email hidden]>, NC <[email hidden]> writes

Quoted message said:

I'm planning a spring trip which includes Skye. So, some of the Cuillin
might be on the agenda. Many books tell me that compasses can be inaccurate
on the Cuillin.

Could someone post a description of which areas the magnetic anomoly affects
?
Is it just very rocky ground, such as the main ridges, or is it in the peaty
glens as well ?
Is the nature of the anomoly random or predictable if planned for ?

I used to lead groups across the Cuillin from Camasunary to Glen Brittle
and then on scrambling routes in the Cuillin. When we reached the ridge
I used to show them how by placing a compass on the rocks and then
moving it around you could get the needle to pass through 360 degrees.
However by holding the compass high above the rocks and as far away from
them as possible an accurate bearing could usually be obtained. If you
have several people each with a compass bearings can be taken from
different points, in case one is inaccurate. If using one compass I
would take bearings from several places.

Away from rocks there's no problem - but then most of the Cuillin is
rock.

Note that much navigation in the Cuillin is route finding rather than
compass work. You know which way to go and where you want to be. The
problem is how to get there. It's one area where a good guidebook is
worth having. Noel William's Skye Scrambles is excellent. If you're
interested in easier walking in other places as well as the Cuillin then
my own book, the Rambler's Guide to the Isle of Skye, might be helpful.

--
astrecks(at)yahooyourbrain(dot)com (remove your brain to reply)

Always look on the bright side of life (De do, de do, de doody doody do)

"NC" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I'm planning a spring trip which includes Skye. So, some of the Cuillin
might be on the agenda. Many books tell me that compasses can be

inaccurate

Quoted message said:

on the Cuillin.

Could someone post a description of which areas the magnetic anomoly

affects

Quoted message said:

?
Is it just very rocky ground, such as the main ridges, or is it in the

peaty

Quoted message said:

glens as well ?
Is the nature of the anomoly random or predictable if planned for ?

Points will be deducted from anyone who recommends a GPS, tells me which
digital camera is best to photograph the sunset, where to pitch my Argos
tent, or how to use a walking pole as a combined navigation aid, tent and
camera support.

- Nigel

--
NC - Webmaster for http://www.2mm.org.uk/
Replies to newsgroup postings to the newsgroup please.

The Black Cuillin is composed of volcanic gabbro rock which contains a lot
of iron where as the eastern Cuillin ( Red Cuillin ) is granite.
Obviously its the iron content that upsets the compass. Unfortunately it is
not predictable with any degree of accuracy.

I have only ever visited the Cuillins once, and I was lucky to have
cloudless skies for the weekend, so navigation wasn't a problem.

I would suggest, like a previous poster to get hold of a good guide book.

At the risk of losing some points! Can I ask what is your objection to GPS?
If indeed you are objecting!

Jeff C

NC said:

Could someone post a description of which areas the magnetic anomoly affects?

Virtually all of the main ridge is subject to some degree of magnetic
anomoly. I've seen a compass needle actually oscillate approx. 90
degrees at one point, which was quite amusing in good weather. :-)

According to my old (1981) SMC guidebook to Skye, the only places
where compass readings appear to be 100% reliable are the Bealach Coir
'an Lochain, Bealach an Glaic Moire and Bealach Coire Lagan.

Quoted message said:

Is it just very rocky ground, such as the main ridges, or is it in the peaty
glens as well ?

I've not noticed any odd compass behaviour off the main ridge, nor
have I read of any such areas. However any large rock masses nearby
might give erroneous readings so I'd avoid taking a bearing in the
shelter of a handy boulder, for example.

Quoted message said:

Is the nature of the anomoly random or predictable if planned for ?

It's very unpredictable; the variation can alter markedly within a few
metres. However, don't let the idea of compass vaguaries put you off.
Provided you know which way on the ridge you need to go to reach an
escape route, and have planned your route(s) within your capabilities,
precise navigation isn't necessary. I'm not making light of the
serious nature of the terrain, but an unreliable compass is not the
major problem it might be on more featureless ground. IMHO the key is
familiarising oneself with the main features along the chosen route,
and much of that can be done with a 1:25k map and a step-by-step guide
to the Main Ridge as found in the SMC guidebook or the excellent
"Black Cuillin Ridge Scramblers Guide" by SP Bull (published by the
SMT/Cordee).

HTH.

Al
--
[This space intentionally left blank]

JeffC said:

"NC" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I'm planning a spring trip which includes Skye. So, some of the
Cuillin might be on the agenda. Many books tell me that compasses
can be inaccurate on the Cuillin.

Could someone post a description of which areas the magnetic anomoly
affects ?
Is it just very rocky ground, such as the main ridges, or is it in
the peaty glens as well ?
Is the nature of the anomoly random or predictable if planned for ?

Points will be deducted from anyone who recommends a GPS, tells me
which digital camera is best to photograph the sunset, where to
pitch my Argos tent, or how to use a walking pole as a combined
navigation aid, tent and camera support.

Quoted message said:

I would suggest, like a previous poster to get hold of a good guide
book.

Thanks for all the answers posted from Roger, Chris, Jeff and Alan. Useful
stuff. I'll dig out a few of the books suggested. I managed to borrow
Storer's book on Skye routes from the library (semi-picture book format, so
not very practical on a hill, but useful information from a writer of guides
I've used elsewhere).

For the main ridge routes, if I go up them, I'll probably hire a guide.

However, there are a lot of potential routes around the area, smaller
summits, interesting view points, etc. It sounds like I can trust a compass
provided I exercise a bit of caution to check that readings are not subject
to a local anomoly.

Quoted message said:

At the risk of losing some points! Can I ask what is your objection
to GPS? If indeed you are objecting!

Not objecting to one, I'll probably have one with me. But I'd have a compass
for backup of a piece of electronics; a compass is quick, cheap, light,
almost impossible to break, etc..

- Nigel

--
NC - Webmaster for http://www.2mm.org.uk/
Replies to newsgroup postings to the newsgroup please.

Roger said:

The message <[email hidden]>
from "NC" <[email hidden]> contains these words:

Quoted message said:

I'm planning a spring trip which includes Skye. So, some of the Cuillin
might be on the agenda. Many books tell me that compasses can be
inaccurate
on the Cuillin.

Quoted message said:

Could someone post a description of which areas the magnetic anomoly
affects
?
Is it just very rocky ground, such as the main ridges, or is it in the
peaty
glens as well ?
Is the nature of the anomoly random or predictable if planned for ?

Quoted message said:

Quoted message said:

Points will be deducted from anyone who recommends a GPS, tells me which
digital camera is best to photograph the sunset, where to pitch my Argos
tent, or how to use a walking pole as a combined navigation aid, tent and
camera support.

A gps would at least reliably tell you which way is North but up on the
Ridge that is of limited value. Following a track or go-to would be
verging on pointless. It is usually pretty obvious which direction you
need to go in. What is often not obvious is how to achieve that
objective.

A GPS is not likely to reliably tell you which way is north, rather it
is likely to tell you where you are to within about 15m (or less if
you have EGNOS) if the satellites are arranged suitably. Whether this
is of any use then depends on the map you are carrying. OS products
are next to useless when trying to follow the ridge.
--
Phil Cook looking north over the park to the "Westminster Gasworks"

NC said:

I'm planning a spring trip which includes Skye. So, some of the Cuillin
might be on the agenda.

That's more of an expedition than a trip, surely?

--

R
o
o
n
e
y

The message <[email hidden]>
from Dave Fawthrop <[email hidden]> contains these words:

Quoted message said:

| A GPS is not likely to reliably tell you which way is north,

If it tells you which direction you are moving in then it is also
telling you which way is North but knowing where you are to any degree
of accuracy is not worth the paper map you try and translate that
information to.

Quoted message said:

It tells you *only* which way you were traveling last time you moved.

That presupposes you are stationary.

Quoted message said:

So if you are on a ridge/path it tells you the direction of the
path/ridge. If you can/do not move it is useless.

On much of the Main Ridge you often have no more than 2 practical
choices - go forward or go back, and neither obvious. :-)

If you get into a position where you cannot move you're stuffed.

--
Roger Chapman so far this year 5 summits
New - 5 (Marilyns 0, Sweats 0, Outlying Fells 5)
Repeats - 0 (Marilyns 0, Sweats 0, Wainwrights 0, Outlying Fells 0)

As has been suggested, neither a compass nor a GPS are much use
without a decent map. Which rules out the OS maps. Harveys is the
best of a bad lot, and even that one is of most use of you know the
ridge reasonably well.

Regarding compass bearings - take a bearing, then move 50m or so in
the direction indicated. Assuming you haven't fallen off anything,
check the bearing. If it still points in the same direction then the
chances are it's correct.

--
York Alpine Club - http://www.yorkalpineclub.org.uk
Recent Photos - http://climbing.me.uk
Old Photos - http://www.simon-caldwell.co.uk
My Brother's Photos - http://www.caldwellcreations.co.uk

"Phil Cook" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Roger said:

The message <[email hidden]>
from "NC" <[email hidden]> contains these words:

Quoted message said:

I'm planning a spring trip which includes Skye. So, some of the Cuillin
might be on the agenda. Many books tell me that compasses can be
inaccurate
on the Cuillin.

Quoted message said:

Could someone post a description of which areas the magnetic anomoly
affects
?
Is it just very rocky ground, such as the main ridges, or is it in the
peaty
glens as well ?
Is the nature of the anomoly random or predictable if planned for ?

Quoted message said:

Quoted message said:

Points will be deducted from anyone who recommends a GPS, tells me which
digital camera is best to photograph the sunset, where to pitch my Argos
tent, or how to use a walking pole as a combined navigation aid, tent
and
camera support.

A gps would at least reliably tell you which way is North but up on the
Ridge that is of limited value. Following a track or go-to would be
verging on pointless. It is usually pretty obvious which direction you
need to go in. What is often not obvious is how to achieve that
objective.

A GPS is not likely to reliably tell you which way is north,

Unless of course it has an in-built compass (several models including Geko
301).

I have to say that I've found this feature to be more useful than I thought
it would. While I normally have the compass switched off, it has been
beneficial to switch it on in whiteout conditions where navigation was
particularly tricky and direction finding partularly important!

druidh

"NC" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I'm planning a spring trip which includes Skye. So, some of the Cuillin
might be on the agenda. Many books tell me that compasses can be

inaccurate

Quoted message said:

on the Cuillin.

Could someone post a description of which areas the magnetic anomoly

affects

Quoted message said:

?

The compass anomilties are only the beginning of the navigational problems
in bad visibility in the Cuillins. Difficult to understand maps, terrain
that all looks the same and difficulties in calculating distances (pacing)
add to the problems!

Keep the compass well away from the rock and it will give you a basic
direction, SW, SE etc etc (take lots of bearings regularly to rule out the
rouge ones). Since you can only follow the ridges then this is actually good
enough!

Mark your route and alternative Routes on your map in biro before you set
of.

I have found that an altimeter watch can be a big source of info in the
cuillins

druidh said:

"Phil Cook" <[email hidden]> wrote

Quoted message said:

Quoted message said:

A GPS is not likely to reliably tell you which way is north,

Unless of course it has an in-built compass (several models including Geko
301).

But that will be affected by the magnetic properties of the gabbro
too. I think I'd rather have a physical needle to look at in
situations like this. Then I could actually see it's behaviour
directly as I move it about instead of the damped and delayed reaction
of a pointer on a screen.
--
Phil Cook looking north over the park to the "Westminster Gasworks"

On Sat, 15 Jan 2005 11:11:38 +0000, Phil Cook
<[email hidden]> wrote:

| A GPS is not likely to reliably tell you which way is north,

It tells you *only* which way you were traveling last time you moved.
So if you are on a ridge/path it tells you the direction of the
path/ridge. If you can/do not move it is useless.

--
Dave Fawthrop <[email hidden]>
Subscribe to uk.net.news.announce. A low volume *civilised* newsgroup
with only the essential information about what is happening in the uk.*
newsgroups, Request For Discussions (RFDs) Call For Votes (CFVs) etc.

"JeffC" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I would suggest, like a previous poster to get hold of a good guide book.

Or better still a geological map ((Minginish, Scotland BGS sheet 70) and
keep an eye on where the gabbro outcrops.

Regards

Peter

"Peter Ward" <[email hidden]> wrote

Quoted message said:

Or better still a geological map ((Minginish, Scotland BGS sheet 70) and
keep an eye on where the gabbro outcrops.

Talking of which, is it just the area comprising the Cuillin ridge that is
gabbro or is it all over the place? I ask because I want to get some
samples for our school. Last time we were there the weather was pretty
nasty and I was feeling lazy so I didn't get up that far. Picked up some
basalt from the Storr though and some marble from, uh, around the toilet
block of the Sligachan car park.

AndyP said:

Talking of which, is it just the area comprising the Cuillin ridge that is
gabbro or is it all over the place? I ask because I want to get some
samples for our school.

No idea. But nor have they most likely, so just pick up anything
vaguely similar and claim it's the real thing ;-)

--
York Alpine Club - http://www.yorkalpineclub.org.uk
Recent Photos - http://climbing.me.uk
Old Photos - http://www.simon-caldwell.co.uk
My Brother's Photos - http://www.caldwellcreations.co.uk

"Simon Caldwell" <[email hidden]> wrote

Quoted message said:

Quoted message said:

Talking of which, is it just the area comprising the Cuillin ridge that

is

Quoted message said:

Quoted message said:

gabbro or is it all over the place? I ask because I want to get some
samples for our school.

Quoted message said:

No idea. But nor have they most likely, so just pick up anything
vaguely similar and claim it's the real thing ;-)

What? Lie to children? Couldn't possibly. I leave that kind of thing to
the teachers.

AndyP said:

Talking of which, is it just the area comprising the Cuillin ridge that is
gabbro or is it all over the place?

The gabbro is all concentrated around the main Cuillin ridge (and the
Blaven massif) from what I remember. The easiest places I know for
good examples are either Coire Lagan or Coir' a' Ghrunnda, or perhaps
around the Coire a' Bhasteir gorge on the Sligachan side.

An alternative is to drive down to Elgol, where there's a large
outcrop of peridotite above the beach below the school. This stuff is
even rougher than gabbro and looks like petrified sponge. It's
amazingly adhesive to climb on but shreds fingertips at the slightest
touch!
--
Al

[This space intentionally left blank]