Royal Australian Navy Discussions and Updates

[ASSAIL]

What's a yard?
Whose Moses and where is the Nile?

Thanks for the reply.

I was wondering as to the separation distance for ASW assets to "high value unit.

Cheers

Regards S

NATO ships use “Tactical Miles” or 2,000 yds. A nautical mile is 1,980 yds (based on the angle at 42deg South or North.

 

[Meriv]

Comic gold. I need cheering up after we lost yesterday Comedy great Sean Lock. If you had suggested putting two 127mm guns on a Arafura it would have been even funnier!

Look i understand size and deck penetration. If not wrong the last pages have been about increasing the scale and tonnage of your OPV.

With the ending result that you would have an Anzac class again. (Correct me if I'm wrong).

So no i wasn't thinking of the Arafura. In that case I would have proposed the 76 sovraponte that has not penetration and is lighter.

No i was simply giving an input on the multipurpose that the 5inch is becoming and how it is a cheap GP solution from a point of view that steel is the cheapest component.

 

[kato]

A nautical mile is 1,980 yds (based on the angle at 42deg South or North.

The nautical mile has never been defined as 1980 yards.

A nautical mile historically is the approximation of one arcminute of a meridian of Earth, in Imperial countries historically defined as either 6,080 ft (admirality mile) or 6,080.20 ft (US nautical mile). For people who live with modern SI units, one yard is three feet.

Both definitions were superseded in 1929 with the formal worldwide definition of a nautical mile as 1,852.01 m by the International Hydrographical Society. The US Navy dropped its separate definition in 1954, the UK declared the Admirality Mile obsolete in 1964.

The "2000 yard mile" ("tactical mile" is a modern term) originally stems from an approximation of rounding the travel time of an electromagnetic wave to only seven digits accuracy (with 1/1000th precision) due to lack of computing resources in 1970s US ships, which due to compatibility to such systems has persisted since then.

 

[ASSAIL]

The nautical mile has never been defined as 1980 yards.

A nautical mile historically is the approximation of one arcminute of a meridian of Earth, in Imperial countries historically defined as either 6,080 ft (admirality mile) or 6,080.20 ft (US nautical mile). For people who live with modern SI units, one yard is three feet.

Both definitions were superseded in 1929 with the formal worldwide definition of a nautical mile as 1,852.01 m by the International Hydrographical Society. The US Navy dropped its separate definition in 1954, the UK declared the Admirality Mile obsolete in 1964.

The "2000 yard mile" ("tactical mile" is a modern term) originally stems from an approximation of rounding the travel time of an electromagnetic wave to only seven digits accuracy (with 1/1000th precision) due to lack of computing resources in 1970s US ships, which due to compatibility to such systems has persisted since then.

Thanks kato, I’m a bit rusty but a “tactical” mile is not that modern, we were using it in the 1960s when I first signed up.
Introducing a metric system of measurement into navigation never made sense to me as nautical miles were always defined by an angular measurement and changes with latitude.
For those not familiar a nautical mile is the distance on the earths surface resulting from 1 minute of angle subtended at the earths centre, ie 1 deg = 60 nms on the earths surface.

 

[spoz]

Well, I was using a 2000 yard mile, a ten cable mile, for tactical manouvering in the late 60s when the only electronic aid to navigation in our part of the world was radar and LORAN C (and the world was analogue except for Ikara). Probably because it was a convenient approximation, but I was a junior officer so nobody ever bothered to tell me why, just to do it!

(A cable being 200 yards for those who have never had to use a Stuart’s Distance Meter)

 

[kato]

(A cable being 200 yards for those who have never had to use a Stuart’s Distance Meter)

Cable lengths are even worse as a unit, as apparently they can't even agree whether it should be 100, 101 or 120 fathoms. And then one would still have to decide which definition of a fathom to use, and if 1 fathom = 2 feet is used then off of which foot it should be based.

We should just measure everything in basic units. Instead of one nautical mile just make it 1.14661 * 10^38 planck lengths... (which makes me note that a US land mile is reasonably close to 10^38 planck lengths...)

For those not familiar a nautical mile is the distance on the earths surface resulting from 1 minute of angle subtended at the earths centre, ie 1 deg = 60 nms on the earths surface.

Although Earth isn't precisely a nice round sphere - i.e. one minute of angle of the Equator is not identical to one minute of angle of a meridian. And yes, both variants were used for the definition of a nautical mile at some point (the difference is something like 20 meter per nm, hence not trivial). The 1929 definition simply expressed it based off of a mathematical model of Earth as an ellipsoid - in normal metric units.

 

[Stampede]

NATO ships use “Tactical Miles” or 2,000 yds. A nautical mile is 1,980 yds (based on the angle at 42deg South or North.

Thanks ASSAIL

I was been a bit cheeky but the tactical mile was good info.
Old enough to still look at small measurement's in feet. Painters drop sheets and furniture reflect this so inside the house still think imperial
Out side have transitioned to metric.
No canons in the back yard so no need to get a range fix.

Cheers S

Ps- Mirror Mr Conservative re Sean Lock.
He had a good style and will be missed.
Same age as myself.
Life is a random walk.

Keep smiling

 

[t68]

Comic gold. I need cheering up after we lost yesterday Comedy great Sean Lock. If you had suggested putting two 127mm guns on a Arafura it would have been even funnier!

To be honest I’d love to see a twin mount again in the hunters, also why they dropped from 8’ to 5’

 

[ngatimozart]

Although Earth isn't precisely a nice round sphere - i.e. one minute of angle of the Equator is not identical to one minute of angle of a meridian. And yes, both variants were used for the definition of a nautical mile at some point (the difference is something like 20 meter per nm, hence not trivial). The 1929 definition simply expressed it based off of a mathematical model of Earth as an ellipsoid - in normal metric units.

Actually the earth is oblate if you want to be precise.

 

[ASSAIL]

Cable lengths are even worse as a unit, as apparently they can't even agree whether it should be 100, 101 or 120 fathoms. And then one would still have to decide which definition of a fathom to use, and if 1 fathom = 2 feet is used then off of which foot it should be based.

We should just measure everything in basic units. Instead of one nautical mile just make it 1.14661 * 10^38 planck lengths... (which makes me note that a US land mile is reasonably close to 10^38 planck lengths...)


Although Earth isn't precisely a nice round sphere - i.e. one minute of angle of the Equator is not identical to one minute of angle of a meridian. And yes, both variants were used for the definition of a nautical mile at some point (the difference is something like 20 meter per nm, hence not trivial). The 1929 definition simply expressed it based off of a mathematical model of Earth as an ellipsoid - in normal metric units.

Well had you navigated at sea you would know to use the scale on the chart adjacent to your current position.
Yes the earth is not a sphere and that’s why a nautical mile is taken as that at 42deg latitude standard..

 

[swerve]

Old enough to still look at small measurement's in feet. Painters drop sheets and furniture reflect this so inside the house still think imperial
Out side have transitioned to metric.

We had some tiling done in the kitchen a few years ago. There was some there already, & we'd managed to match the colour, but then realised that the old tiles were 6" & the new ones were 150mm. Doh!

We were debating ripping off the old tiles when the tiler suggested offsetting the new ones. That worked out OK for the small bit we needed, but it's something to beware in future.

 

[t68]

Well had you navigated at sea you would know to use the scale on the chart adjacent to your current position.
Yes the earth is not a sphere and that’s why a nautical mile is taken as that at 42deg latitude standard..

Yes if I remember correctly different navy use different standards or terminology, going from memory with the Melbourne/Evens disaster. The investigation brought up up chains or something relating to distance

All confusing to me to use to just seeing kilometres being the land lubber that I am.

 

[ASSAIL]

Yes if I remember correctly different navy use different standards or terminology, going from memory with the Melbourne/Evens disaster. The investigation brought up up chains or something relating to distance

All confusing to me to use to just seeing kilometres being the land lubber that I am.

There are no differences in terminology relating to manoeuvre of Ships operating together in NATO (or the then SEATO) exercises.
They all train for and use standard NATO publications.
The Melbourne/Evans problem was one of competence compounded by an overstretched USN manning smaller escorts such as Evans with poorly trained ROTC Officers.

 

[DDG38]

"MIDN Triffit pretends to know how to use a sextant before loading up the DefenceTalk forum and getting proper naval measurements from the boffins on the RAN thread"
-actual caption (sorry couldn't help myself )-
"Midshipman Laura Triffit uses the sextant on the bridge wing of HMAS Brisbane, as the ship sails off the coast of Queensland during Exercise Talisman Sabre 2021." Image Source - ADF Image Library

 

[t68]

There are no differences in terminology relating to manoeuvre of Ships operating together in NATO (or the then SEATO) exercises.
They all train for and use standard NATO publications.
The Melbourne/Evans problem was one of competence compounded by an overstretched USN manning smaller escorts such as Evans with poorly trained ROTC Officers.

Ah roger, thought it was something of an English thing being such a dominant heritage from the RN, I vaguely recall reading a transcript from the investigation into Melbourne/Evans and the need to enquirer about the distance of a chain from when if I recall it was Captain Stevenson giving evidence

 

[alexsa]

In the grand scheme of things though, is a hull-mounted sonar going to make an appreciable difference in detecting possible sub contacts? Both frigate classes are to be kitted out with towed and variable depth sonars, either of which I would have thought would be significantly more effective.

I have a degree of respect of the sonars fitted to UK vessels and the S2150 Particularly. They are very capable on a quiet platform and form part of a multi-static system. All the bits are there for a reason.

CMRE - The Multistatic Sonar Systems (nato.int)

 

[Stampede]

We had some tiling done in the kitchen a few years ago. There was some there already, & we'd managed to match the colour, but then realised that the old tiles were 6" & the new ones were 150mm. Doh!

We were debating ripping off the old tiles when the tiler suggested offsetting the new ones. That worked out OK for the small bit we needed, but it's something to beware in future.

Worked in the furniture trade for some years and are familiar with such stories.
Trust you like the end result

Regards S

 

[Depot Dog]

I have been reading with interest the posts on upgrading the Ararfura OPV. I think anything beyond OCV is just fantasy.

internal reviews happen on a constant basis, might happen, may not, it all gives guidance on a way forward, and by studying and debating these internally you can come up with different solutions to the problem, should always be encouraged to stave off group think.

Tac Talks: Putting the ‘War’ back into Minor War Vessels: utilising the Arafura Class to reinvigorate high intensity warfighting in the Patrol Force | Royal Australian Navy

Royal Australian Navy

www.navy.gov.au

Cheers

His article is a modest upgrade deriving force multiplier results. He is proposing containerised missile capability. He talks about utilising third party sensors and using the missile sensors for targeting. This negates the need for such sensors and radars to be fitted to the OPV.

Straight away the navy doubles the missile capable platforms. This gives the navy leathality and takes some pressure off the 11 surface combatants. Yes there is coin to spend. Training, personal and equipment. It is alot less than some of the proposal idea floated in this forum.

This idea was floated in the 2009 defence white paper. 9.20 states the capabilities of the OCV. It talks of containerising mine, hydrographic and oceanographic capabilities. To me this concept is possible still in the minds of defence planners.

With an uncertain future, modest ideas like this make sense.

Regards
DD

@Depot Dog You are in the dog box for posting a fanciful post. You will be unable to post in the RAN Thread for two days. C/ref my notification here.

 

[DDG38]

Meanwhile in the working Navy :
"HMAS Ballarat has returned to Fleet Base West, Western Australia, on 22 August 2021, following a four-month Regional Presence Deployment to South East and North East Asia and participation in Talisman Sabre 2021." Image Source - ADF Image Library

 

[Redlands18]

I have been reading with interest the posts on upgrading the Ararfura OPV. I think anything beyond OCV is just fantasy.



His article is a modest upgrade deriving force multiplier results. He is proposing containerised missile capability. He talks about utilising third party sensors and using the missile sensors for targeting. This negates the need for such sensors and radars to be fitted to the OPV.

Straight away the navy doubles the missile capable platforms. This gives the navy leathality and takes some pressure off the 11 surface combatants. Yes there is coin to spend. Training, personal and equipment. It is alot less than some of the proposal idea floated in this forum.

This idea was floated in the 2009 defence white paper. 9.20 states the capabilities of the OCV. It talks of containerising mine, hydrographic and oceanographic capabilities. To me this concept is possible still in the minds of defence planners.

With an uncertain future, modest ideas like this make sense.

Regards
DD

deleted this entire conversation needs to die