need help convert chain in inches to metric

M

misterchugg

Active member
hi all

what is 2 chain to the inch in metric?
what is 4 chains to the inch in metric?

sorry, but i cannot find the info anywhere

thanks
ron
 
Are you referring to the imperial measure? If so 1 chain=22yards=66feet=792inches=20.1168metres. length of cricket pitch between creases I believe.
Otherwise
1inch=2.54cm
 
Last edited:
Ron,

If you have a full size copy of that drawing you will be able to scale it, otherwise you have to find a known reference dimension on the drawing then figure out the scale.. If you have a scanned copy then we don't really know what size it is...

Assuming you have a full size copy,

The scale 2 chains to the inch is 1:1584


there are 22 yards in a chain so

2 chains is 2 times 22 yards = 44yards and there are 36 inches in a yard

44 times 36 = 1584 inches.. thus scale is 1:1584

so 1mm on the drawing would be 1.584m on your baseboard..

Given this you could make a series of 720 metre square tiles (one baseboard) out of the drawing (you already have scanned it so that should be easy) and use them as a guide to where to put your tracks, platforms etc. To do this you have to figure out how many pixels on the drawing make a length of 720m...

Or you can make one large planar mesh in GMax the size of the drawing multiplied by 1584 and texture that with the drawing then place that planar object into surveyor.. You can then rotate it and move it so it fits where you need it in your route..

That is a famous piece of Australian rail history you have there.. I hope you can make something of it.. One more point.. You may be able to get the overall size of it from Google Earth.. There should be enough clues left to its location and size to this day... Vulcan has a tutorial on how to get dimensions out of Google Earth.

Later Edit: I just discovered that the drawing is scanned and downloaded from the internet, so you will need to use other sources to get the size of it.. The scale calculations above won't mean much unless you can manage to print the drawing out at a size to match the original..
 
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hi peter
thanks for all that useful info.
i will save for later use.

i'm thinking i might have to bite the bullet and do a weekend run to wallangarra with the wife and 2 cameras and a long cloth 20m tapemeasure.

just need to figure out if they would let me on the main platform without any hassles

oh well, have to wait and see.

just emailed a mate overseas who has a lot of aus station stuff

hopefully he'll have something that i can use

thanks for the help
cheers
ron
 
misterchugg said:
what is 2 chain to the inch in metric?
what is 4 chains to the inch in metric?

sorry, but i cannot find the info anywhere
Click to expand...

All exact equivalents - just from memory.
• 1 mile = 5,680 feet = 1,760 yards = 80 chains = 1.609344 kilometres
• 1 inch (in or ") = 2.54 centimetres​

Change HO & OO to real miles or kilometres, & you can see just how a small ½ millimetre difference per foot makes a difference.
 
If my memory serves correct, in the days of steam on the NSWGR they used 100 chains to the mile.

Not 80 chains.

So if you are looking at old mile posts remember 100 chains = 1 mile.

Dennis
 
Ron,
I have messed around with the drawing and Google earth and I reckon if you use the drawing as is off the internet the scale is 1300 pixels for 720 metres (one baseboard).. Google Earth clearly shows the whole thing.. You could use it as the basis of your layout and use the drawing for details of signage and signalling..

Here is a link to the Google Earth Image..
http://www.members.optusnet.com.au/~villaump/trainz/Wallangarra_GE.jpg

On the image the distance between the two red dots is 720m. It also shows the orientation to North. The Latitude and Longitiude are shown so you can easily find the location yourself on Google Earth..


Hope this helps.
 
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** DO NOT follow the first quote, otherwise your measurements will be way out. **
DeRiCo said:
So if you are looking at old mile posts remember 100 chains = 1 mile.
Click to expand...

DeRiCo said:
If my memory serves correct, in the days of steam on the NSWGR they used 100 chains to the mile.

Not 80 chains.
Click to expand...
Nope, if you check some books, websites. Click on 80 chains = 1 mile - somewhere buried in one of those lengths is an external site for measurements.

Yeah, I know I should be in bed, but due to a virus. . (grrrr - ought to make the rotten, filthy, bloomin' scumbags pay & pay [insert extremely angry smiley here]!)
 
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G'day Misterchugg,

That's all very interesting guys but why didn't you ask me this question first? When converting chain measurements of curve radii, I use this simple formula:

radius of curve in Metres = indicated chain radius x 2 with an additional power of 10...

...that is to say, if the designated radius of the curve is 2 chains, then the Metre radius is 2 x 2 x 10 = 40 metres

...if the designated radius is 25 chains, then the metre radius is 25 x 2 x 10 = 500 metres...

...if the designated radius is 150 chains, then the metre radius is 150 x 2 x 10 = 3000 metres...

...is that what you were after, sir?


P. S.

...there are 1,760 yards in a mile, 22 yards in a chain, so 1,760/22=80 chains per mile...

Jerker {:)}
 
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G'day All,

Oops. My most humble apologies, guys. I have just realised that I have misinterpreted your question Misterchugg. After a second reading, I realised that you are actually referring to a "scale" when you speak of 2 chains to the inch. This, I presume relates to the scale of the drawings to which you link us - they being drawn to the rather unusual 2 chains to an inch scale, which should actually be translated into a more correctly useful topographic scale of...

1 chain = 22 yards = 66 feet = 792 inches x 2 (2 chains to the inch) for a scale of 1584 to 1...

...or 1584:1 as already noted by PEV (from whom I would expect nothing less)...


...this means, that for every meter of drawing that you have, you should have 1584 meters of real (or virtual) ground...

...thinking "inside" the box (since I'm guessing you don't really have 'meters' of drawings), for every Centimeter of drawing, you should have 1584 Centimeters (or 15.84 meters) of real or virtual distance...

Jerker {:)}
 
DeRiCo said:
If my memory serves correct, in the days of steam on the NSWGR they used 100 chains to the mile.

Not 80 chains.

So if you are looking at old mile posts remember 100 chains = 1 mile.

Dennis
Click to expand...

100 is involved but not as the number of chains to a mile.

There's 100 links in a chain and 80 chains to the mile.

7.92 inches = 1 link
100 links = 792 inches = 66 feet = 22 yards = 1 chain
80 chains = 5280 feet = 1760 yards = 1 mile

That's why you'll see railway distances in many Commonwealth (and other) countries as 'XXX miles, XX chains, XX links'.

In Australia, curve radii were also commonly expressed as 'XX chain curve' by most railway operators.

Cheers,
Dreadnought1
 
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Well I don't know what they called them in Victoria, but during my time on the railway here in NSW I have never heard them say 'links'.

I found a station diagram that shows a 12 mile post with a signal just before it that shows the number 11.97.

This would have been stated as 11 miles 97 chains when I was a young fireman on the steam.

Dennis
 
hi guys

thank you all for your help, but now i'm more cionfusded than i was to start wiht.
derico
the google earth pic is good, thanks

does anyonw know of any pics of the wallangarra station area?
it would help immensly if i dont have to go there for a weekend

cheers
ron
 
DeRiCo said:
Well I don't know what they called them in Victoria, but during my time on the railway here in NSW I have never heard them say 'links'.

I found a station diagram that shows a 12 mile post with a signal just before it that shows the number 11.97.

This would have been stated as 11 miles 97 chains when I was a young fireman on the steam.

Dennis
Click to expand...

As I wouldn't like to think we're giving Misterchugg a bum steer, I went and checked through my NSWGR archive documents which confirm that while Miles/Chains were commonly given for distances in the Imperial era, Links don't seem to get a mention (unlike in Victoria where they were commonly used). However, out of the 150 or so rail mileages I saw mentioned, not a single one was in the 80 to 100 chain range.

For example, Wyalong Central is given as 336M 71C according the NSWGR Circular 166 for the extension of the line from Wyalong to Cargelligo (dated 07/11/1917) and the same circular lists the mileage (Miles & Chains) of 11 stations and 71 level crossings on the line to Cargelligo. Again, while these stations or crossings have chainages between 0 and 79, there's not a single one with a 'chainage' between 80 and 100. On the balance of probabilities, about 20% should be in the 80-100 chain range if there were 100 NSW chains to the mile but there's not a single one.

While signal numbering isn't always exactly the same as the official mileage, I think it'd be interesting to find the official explanation of the 11.97 signal.

To finalise this (and remove any confusion), anyone out there conversant with NSWGR signal numbering and survey data who can put us all straight?

Cheers,
Dreadnought1
 
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hi Dreadnought1

oh man, this thing is getting harder and harder.
thanks for all the info.
i'll keep it all on a disk so that i know for the future.

i think a trip to wallangarra might still be needed so that i can get the distances right.

i done a search through the qr stuff that i was able to, but nowhere does it give distances.


i know there was a book?? that had all the stations in it.
not sure if it was the gazette or not.

i seen them a few times wehn i was younger, but having no idea what they were called i couldnt search for them by name.

i can find out lots of info on wallangarra apart from the sizes that i need.

as usual mr. murphy and his law put me way
behind the 8 ball to start with :D:hehe:

thanks for the help

cheers
ron
 
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