Sharpest Main Line Curve

[The Johnster]

I would like to add this one to the debate at Gateshead next to the Sage. Check rails on all four routes.

IMG_8885.JPG

Mike Wiltshire

 

Now that's how to bend a banana...

[runs as required]

I would like to add this one to the debate at Gateshead next to the Sage. Check rails on all four routes.

IMG_8885.JPG

Ha! One on my own home patch.and really interesting historically. Here is a screen shot of the National Library of Scotland  "Side by Side" map of the area.

the "banana" is negotiating the curve just to the south of the car park to the Sage on the right hand side.  Note there is a reverse curve from there onto R Stephenson's 1852 High Level Bridge (of approx 11 to 12 chains radius).

The Sage car park is on the site of the old terminus of the pre Team Valley mainline swinging around through NE Durham from Yok via the Fatfield bridge This connected to the Brandling Junction Railway into eastern Gateshead; The stone (neo Jacobean ?) terminus  building was still visible as part of the coal yard when we first moved to Gateshead over 40 years ago.

The eastern curve onto the HL Bridge was the site of Gateshead station still used by Sunderland trains until the opening of the Metro to Heworth in 1981.

The old 6" map shews the NER Greenfield works on the west (left side ) of the screen shot.

A wonderful resource these NLS maps!

 

dh

Edited August 13, 2017 by runs as required

[runs as required]

Please let me into your secret of how you define the centre-line of the tightest section of a transition curve ??

Sorry I've only just spotted this question - there is no secret, I ignore them, I cannot think how to get close to such precision in data readily available on the web.

 

My comparing of curve radii using data freely available to us on the web is very ‘quick & dirty’.

 

Lets look at the Retford curve

There seemed from a web search there was no statistical data available on line.

The largest scale I could find was a turn of the century 6” map on the National Library of Scotland  maps  site. I use PrtSc to dump  the screen image into Photoshop and manipulate graphically.

The  OS Six Inch 1888-1913 does not shew individual tracks on a double track route (as do larger scale ‘town maps’ e.g. Bristol where it differentiates between Broad and Standard gauge)  but denote double track as simply a ‘ladder’.  So I cannot get down to a precise location of the inner curve of double track, merely try a approx fit.

This I do in Photoshop by scaling a circle up or down until I achieve this approx fit, and measure its diameter (using the temporary line guides) in metres with the 100M blue rectangle then convert the radius in metres to chains...er...thats it!.

The blue circles visually shew the tightest of the curves (the easterly one).

My home spun method is a long way from the precision of calculating and setting out transition curves – in fact Retford appears to have a short straight between transition curves (either side of the signal post) .

 

If anyone has a quicker way of finding such information without expensive software - it might be a useful thread to start.

 

For example, I merely use a very crude piece of paper with marks on it to move across screen shots of contours to plot a line with a ruling grade of (say) 1 in 30 when I'm playing at being Locke or (on a road) Blind Jack of Knaresborough - how on earth did he do it?

 

dh

[Southernman46]

Thread divert .................

 

Now it's not tight but the combination of radius and cant on the Down Main through Farnborough Main at 90mph is sweet enough to make a Track Engineer's bollock's tingle

 

 

 

Just me then ..................

[The Johnster]

Thread divert .................

 

Now it's not tight but the combination of radius and cant on the Down Main through Farnborough Main at 90mph is sweet enough to make a Track Engineer's bollock's tingle

 

 

 

Just me then ..................

 

You need to get out more, mate...