PDA

View Full Version : Anybody know anything about Orienteering? Especially in N Europe?



Nicholas Scheuer
08-22-2009, 09:21 AM
I was discussing compasses with the Norwegian husband of my wife's cousin in Drobak, Norway when we were over their on vacation last week.

He had a couple of extra Silva Orienteering compasses and insisted on my taking one. I was very surprised to discover that its asmuth dial is divided into 400-degrees, not 360.

Our host is an avid and experienced recreational boater, and has participated in the sport of Orienteering, but was inable to explain the reason why his Silva Compass was noted for 400-degrees.

As we have European participants on this Forum, I am hoping someone will be able to explain this (to me) earth-shaking practice. I mean, if a compass isn't divided into 360-degrees, what good it it? Knowing APPROXIMATELY what direction your're going?

I e-mailed my question to Silva, but have not yet received an reply.

Then there are the Norwegian navigation boys; they're not "red right returning" from the sea! They don't have green "cans" and red "nuns", neither. Everything is spar bouys, but that is a minor quibble. Norwegian charts are noted for passing green spars to the south or west, and for passing red spars on the east or north. So, proceeding north up the Oslo Fiord from the sea, green bouys are on one's right.

Moby Nick, Rockford, Illinois.

mizzenman
08-22-2009, 09:26 AM
Never seen one even if i use orientering-compases for small boat navigation.

But had a calculator that used the 400-degrees system called 'gradients'. I was told it was used by architects

Pirate-at-heart
08-22-2009, 10:49 AM
Why 400 degrees?

In the modern era, the 360-degree system took hold. This system is still in use today for civilian navigators. The degree system spaces 360 equidistant points located clockwise around the compass dial. In the 19th century some European nations adopted the "grad" (also called grade or gon) system instead, where a right angle is 100 grads to give a circle of 400 grads. Dividing grads into tenths to give a circle of 4000 decigrades has also been used in armies.


Most military forces have adopted the French "millieme" system. This is an approximation of a milli-radian (6283 per circle), in which the compass dial is spaced into 6400 units (Sweden uses 6300) or "mils" for additional precision when measuring angles, laying artillery, etc. The value to the military is that one mil subtends approximately one metre at a distance of one kilometer. Imperial Russia used a system derived by dividing the circumference of a circle into chords of the same length as the radius. Each of these was divided into 100 spaces, giving a circle of 600. The Soviet Union divided these into tenths to give a circle of 6000 units, usually translated as "mils". This systems was adopted by the former Warsaw Pact countries (Soviet Union, GDR etc.), often counterclockwise (see picture of wrist compass). This is still in use in Russia.

Courtesy - wikipedia

P.I. Stazzer-Newt
08-22-2009, 11:00 AM
I've used the ordinary 360 degree type but silva do many special purpose scales.
http://www.roostersailing.com/articles/compass_article.htm

http://gwydir.demon.co.uk/jo/units/angles.htm << scroll to "Gradian".

Can see no real problem and several advantages to using 400 in place of 360 - back bearing? just add 200, tack through a right angle? - just add 100.

In practice you take the direction from the map using the compass base as a breton plotter, the calibration becomes simply a matter of convenience.

Andrew Craig-Bennett
08-22-2009, 11:05 AM
The Elder Sprog does orienteering and uses a Silva compass divided into 360 degrees.

Nicholas Scheuer
08-22-2009, 11:18 AM
So, if a US Marine Company Commander in Afghanistan has his platoon spread out along a ridge for the night, and a Swedish Artillery outfit is providing support for his flanks, it sounds as though a prudent Marine would advise the Lieutenants on both flanks to sleep light and be ready to haul ass, just in case the Sweeds' compasses result in some of their rounds falling a bit close.

Is NATO really like this?

Moby Nick

Pirate-at-heart
08-22-2009, 11:21 AM
yeah, the last thing the marines needs is swedish artillery (http://www.fmv.se/WmTemplates/Page.aspx?id=1373) bearing down on them. but I think that all militaries currently use the same system. Its all computerized nowadays anyway.

downthecreek
08-22-2009, 11:26 AM
Then there are the Norwegian navigation boys; they're not "red right returning" from the sea! They don't have green "cans" and red "nuns", neither. Everything is spar buoys, but that is a minor quibble. Norwegian charts are noted for passing green spars to the south or west, and for passing red spars on the east or north. So, proceeding north up the Oslo Fiord from the sea, green buoys are on one's right.

Moby Nick, Rockford, Illinois.

Most of the world (other than N and S America, Japan, Caribbean and Philippines, I believe) uses the IALA "A" system of buoyage, rather than the IALA "B" system that you are used to.

With IALA "A" red cans are left to port on entering a harbour and green cones to starboard. These can also be spars of the correct colour and with a topmark of the relevant shape. As well as lateral buoys, this system also uses cardinal buoys. These show by colour, topmark and light characteristics whether the danger they mark lies to the north, south, east or west of them and, thus, how they should bear when you pass them. In many cases, a combination of lateral and cardinal buoys is used. Where cardinal buoys are used in places other than harbour entrances etc. they are placed with reference to the direction of the flood tide. Going with the flood tide is "returning". It is well to know where the direction of the flood tide changes.... :)

From what you describe, Norway is also using a kind of hybrid system, combining elements of lateral and cardinal.

mizzenman
08-22-2009, 11:26 AM
Well, we are able to comunicate the US in their own language, so it would surprise me if we were unable to adapt to their compas system ;)

mizzenman
08-22-2009, 11:36 AM
Then there are the Norwegian navigation boys; they're not "red right returning" from the sea! They don't have green "cans" and red "nuns", neither. Everything is spar bouys, but that is a minor quibble. Norwegian charts are noted for passing green spars to the south or west, and for passing red spars on the east or north. So, proceeding north up the Oslo Fiord from the sea, green bouys are on one's right.

Moby Nick, Rockford, Illinois.

In Norway as in Sweden, green is on the right side when sailing towards the harbour.

When sailing up the Oslofjord you are progressing towards Oslo harbour, so green to green is correct. I have never heard that it has anything to do with North/South or West/East

The Norwegian way of marking skerrys with bare iron poles is kind of anoying

bobbys
08-22-2009, 12:11 PM
I had to use a Compass and depth finder only in my Dory.

I found out the hard way its not a good idea to place a hammer near the compass while its foggy and im lost.

Captain Blight
08-22-2009, 12:28 PM
So, if a US Marine Company Commander in Afghanistan has his platoon spread out along a ridge for the night, and a Swedish Artillery outfit is providing support for his flanks, it sounds as though a prudent Marine would advise the Lieutenants on both flanks to sleep light and be ready to haul ass, just in case the Sweeds' compasses result in some of their rounds falling a bit close.

Is NATO really like this?

Moby NickI know for a stone fact that the range card on the M60A3 tank, and the M1 Abrams as well, is graduated in mils. By and large, the US Army has adopted the Metric System for all its crew-served weaponry (though i have no idea if this holds true in the Navy): Ranges measured in meters, maps printed with 1 Km grid squares, and bearing from the tank turret measured in mils.


FWIW the lostest I ever got was when I was in college, where in ROTC we did a canoe orienteering session. The maps were a copy of a copy of a copy of an out-of-date survey of the Lemonweir Flowage. Nothing but swamp as far as the eye could see, which was about 25 m. But for blind dumb luck I'd be there still, subsisting on sphagnum and carp.

BarnacleGrim
08-22-2009, 01:51 PM
With a 400 grad circle a one grad arc around the earth would be 100 km long, just like a one degree arc is 60 nautical miles long. You can navigate with kilometres instead of nautical miles.

Oyvind Snibsoer
08-22-2009, 02:11 PM
As Mizzenman points out, red to port and green to starboard when entering a port.

More generally, there is a defined "main direction" of navigation. When sailing in the main direction, as above it's green to starboard and red to port. The main direction is generally northward along the coast, and into fjords and harbors. The charts show the defined main direction as an arrow with a red and green circle. In areas where the main direction may be ambiguous there will be a local symbol in the chart that shows the direction.

The "green spars to sout and west, red to east and north" is the old system that was replaced with IALA A during the late 80's and through the 90's.

Dunno what the problem with iron spikes on skerries is. They have an iron "flag" on the top that points to the safe side. Agreed, they're not easy to spot at night, but most have been retrofitted with a reflective band.

mizzenman
08-22-2009, 05:10 PM
Well that explains the mystery of the two systems!

I remember there used to be 'brooms' (kvast) in Swedish waters. Completely imposible to discern if one was aproaching towards an island full of shruby vegitation

MiddleAgesMan
08-22-2009, 05:36 PM
Did you not find it odd that in the EU there are only 10 metric hours in a day? ;)

P.I. Stazzer-Newt
08-23-2009, 02:42 AM
Did you not find it odd that in the EU there are only 10 metric hours in a day? ;)

Borrocks.

However I have seen a proposal to revert to the 12 hour day system - where the period from sun-up to sun down is divided into 12 equal length "Hours".

As a mid-latitude euro-peon I would get to spend longer in bed during the winter but work harder in the summer when the hours are longer - all in all, as long as its broad.

Northern Norway and the like may have to make special arrangements such as they already do for Ramadan.

Nicholas Scheuer
08-29-2009, 05:31 PM
Keeping red to west or south, and green to east and north may be an "old system, replaced in the 1980's and 90's", however, it's still in full effect within the Oslo Fiord near Drobak.

Moby Nick

downthecreek
08-30-2009, 03:07 AM
Well that explains the mystery of the two systems!

I remember there used to be 'brooms' (kvast) in Swedish waters. Completely imposible to discern if one was aproaching towards an island full of shruby vegitation

That takes me back.....sailing amongst the Danish and Swedish islands many years ago - lots of channels marked with these. Interesting to watch the big ferries navigating the channels with a searchlight sweeping ahead for the next "broom".

In my home waters many of the small channels are marked with "withies" - which are simply tall, thin branches planted in the mud. Some still have clusters of twigs on top. It is said that some of these withies stand where withies have stood since Roman times. The Romans were very fond of the oysters they cultivated here (and so am I :))

The main problem with withies is that it is sometimes hard to spot them near high water when they are mainly immersed. That's when you are least in need of them, but they are better not hit....

WX
08-30-2009, 04:04 AM
When this thread first started I was going to suggest you ask a German as they had a lot of practice travelling around Europe last century.
:D

Oyvind Snibsoer
08-30-2009, 12:19 PM
Keeping red to west or south, and green to east and north may be an "old system, replaced in the 1980's and 90's", however, it's still in full effect within the Oslo Fiord near Drobak.

Moby Nick

Can't be, and especially not in that heavily trafficked area. Red to port and green to starboard are IALA A lateral marks. IALA A cardinal marks are yellow and black, and represent the cardinal points of the compass.

http://images.brighthub.com/91/D/91D815F4ACD1C34F501CAD3C1C8D1B03BCF2E191_large.jpg
Red to port and green to SB when sailing into a harbor

Black over yellow and/or two triangles pointing up: Hazard is south of the mark. Keep north.

Yellow over black: Hazard is north, keep south.

Yellow/black/yellow - Hazard is east, keep west.

Black/yellow/black - Hazard is west, keep east.

http://images.brighthub.com/97/6/976D87AE95FE1B696F8550ED2F196395345FFCC5_large.jpg

In the OLD Norwegian system, however, there were only two cardinal marks, red and green and signaled safe water to the north/east, south/west respectively - or perhaps it was the other way around, can't remember I wrote previously that IALA A was introduced in the late 80's etc, but it was actually done in 1980-81.

While the IALA lateral marks are used around the coast, the cardinal marks are less common and mostly used for floating buoys. Where a marker can be placed in solid rock, iron spikes, or sometimes rock or even wooden cairns, with a "flag" that points to the safe side are preferred.

http://www.fosnaporten.no/foto/2005/08/04/_8552lk_makepastotteisjoen.jpg

Nicholas Scheuer
08-30-2009, 12:33 PM
Sorry, Oyvind, I misposted. I meant to type, "Keep TO west and south of green, and keep TO east and north of red". n The word "to" makes all the difference.

Near Drobak we passed through both north-south and east-west channels.

Oyvind Snibsoer
08-31-2009, 08:25 AM
http://oyvind.smugmug.com/photos/635522888_FHbdp-XL.png

Here's a map of the Oslo Fjord near Drøbak. There's quite an assorted collection of markers here. I shall now proceed to bore you to death with a description of them.

Starting in the NW end of Håyøfjorden (Håøyfdn), there are several slanted lines with a black dot. These are the iron spikes that mizzenman finds annoying. One of these annoying spikes, on the NW end of Stedgr(unnen), also has a white flashing light with a Quick White characteristic.

On the SE end of the Stedgrunnen there is a cardinal mark, showing that safe water is to the south.

WSW of Stedgrunnen, there is a white marker with a flat top. Except that it is not white. This is the symbol for a red lateral marker. Green lateral markers are black with a pointed top. IRL, the physical markers also hav either a flat top (red) or pointed (green). This hails back to the days before cmposites, when all markers were made of steel. In case the paint had flaked off a green marker and rust had colored it red, you could still distinguish a green from a red marker by looking at the top. Anyways, this particular marker should be kept to port when going in the main direction, which is north towards Oslo.

Due east, across the sound from the red lateral mark, there are some peculiar lights that I believe are indigenous to Norwegian waters. These are indirect lights, and they have been specifically developed to enhance the safety of fast moving vessels. These lights have both a beacon and a light that shines down and illuminates a triangular box. In the simpler form, it may just be a regular streetlight that illuminates a small patch of the shore. The great thing about these indirect lights is that it is much easier to judge the distance to them on a dark night, than to a single point of light. They are typically only used in confined waters such as these.

The green lights on the indirect lights are, again, lateral markers. Keep to SB when sailing north.

http://www.kystverket.no/arch/_img/9046578.jpg

South of Oscarsborg, there is a pecuilar, crescent shaped shallow area. This is Drøbaksjeeteen, a passive defensive military installation. Oscarsborg is a coastal fort that protected Oslo. In order to prevent the enemy from circumventing the fort by going west, an underwater wall was constructed. The top of the wall is one meter below the surface. Two passages have later been cleared for smaller vessels, but there are numerous groundings here every year by skippers who have not yet learned to read a map. If they actually have one, that is... The two openings are clearly marked with red and green lateral markers.

Apart from that, Oscarsborg is best known for sinking the German cruiser "Blücher" on April 9, 1940. On board Blücher were the troops that had been assigned to arrest King Haakon and the cabinet. Thanks to the sinking, the king and his cabinet escaped and eventually made their way to London.