Kirkby Luneside (Original): End of the line....

[jukebox]

Jeff - can you humour me and take a quick look at the links below:

 

http://www.foscl.org.uk/sites/foscl.org.uk/files/scrca/img-720/ph/249270_2012-03-24_MRH_Masons-Hut_Context%20from%20south.jpg

 

http://1.bp.blogspot.com/-adxDOor17aI/T5R5BKZ6UyI/AAAAAAAAAjk/5qdWxfc_e50/s1600/March%2B2012%2B038.JPG

 

http://upload.wikimedia.org/wikipedia/commons/5/51/Blea_Moor_Tunnel_-_Southern_Portal_-_geograph.org.uk_-_1152943.jpg

 

I know they aren't all the North portal, but to my eye the bottom 20mm or so of your portal drawing is too vertical. Try ignoring the dimensions for a minute, and place a piece of paper over the bottom of your sketch so it cuts off everything below the box on the right that has "78" in it.

 

To my eye, that's the Blea Moor portal shape.

 

Of course, I'm 12,000 miles away, so my vision could be a smidge off!

 

Regards

 

Scott

[The Stationmaster]

Theoretically a widened 6ft shouldn't make any difference (except in the visual appearance of the 6ft) if the overall dimensions add up. Provided the track centres are correct all that happens is an overscale 6ft and an overscale cess width. If the track centres are too far apart then you will have to widen the tunnel mouth.

 

Minimum prototype track centres for double track running lines (using the 1950 figure) would be a tad under 45mm in 4mm scale (you can of course get away with much wider on ex GWR lines which were formerly broad gauge ) and the desirable minimum between structure faces at maximum vehicle bodywidth is 106mm in 4mm scale.

 

Martin or Gordon will no doubt dive in somewhere soon with information about the various centre and 6ft dimensions for 00FS (in its various versions) and someone may tell us all off for not using a super accurate track gauge - please let's not go there! The situation we face with 16.5mm gauge track is one where we have little option but to do some sort of fiddle with the 6ft and I think it inevitably has to be a compromise that allows safe running on curvature - can be less on straight of course - and a compromise or optical fiddle for appearance reasons. But it can make overbridges and tunnel mouths potentially look 'not quite right'.

[Physicsman]

That's an incredibly neat sketch, but it does capture the look of the prototype. How are you going to deal with the widened 6ft? Stetch it sideways, or make the whole thing bigger? I guess you'll have to be careful to not lose the elliptical shape of the arch.

 

Hmm, good questions Michael! I'm going to have to do 2 things. I'll have to widen the tunnel mouth, but I doubt it'll have to stretch much more than 1cm. Even if the mainline diverges to 4cm, from the 3cm I have now, it'd only add 1.6cm, which isn't too much. I'll also have to distort the ellipse a little to make sure the locos etc don't touch the walls, so a probable vertical stretch of a few mm. I'll cut out a card portal and test it before the real thing.

 

There are always complications, but that's what makes it interesting!!

 

Jeff

Edited November 28, 2012 by Physicsman

[Physicsman]

Thanks Scott. Don't worry - the tunnel mouth was only a rough sketch - but I'm aware the curve continues. Whether I'll be able to capture that, I don't know. If you look at the picture below you'll see it's not quite straight, but the continued curve is subtle!

 

 

Jeff

[Physicsman]

Morning Mike.

 

I see you've maintained your phenomenal posting record on the Forum (I've knocked in 2000 posts in the last year. you must have doubled that!), but I thought you'd deserted us!

 

The main thing, as far as I'm concerned, is the "feel", "style" of the thing. If necessary, I'll stretch the dimensions both ways to maintain what Scott described as the Blea Moor shape. If it looks right, and my locos can pass through it without hitting the roof, then I'll be happy!

 

Jeff

Edited November 28, 2012 by Physicsman

[Grovenor]

The diagram is based on the 6 foot spacing between the mainlines, 24mm in OO. However, the mainline separation on my layout is set at 30mm.

Best not to approximate to much here or you may end up changing more than needed. The prototype 6ft is between the outsides of the rails not the running edges, and also assumes a gauge of 4'8.5", rails are 2.75" wide so the scale track centres work out to 11' 2", near enough 45 mm so the 24 mm in your sketch should be 28 mm which makes the 30 mm you are using rather more accurate.

Regards

Keith

[Physicsman]

Best not to approximate to much here or you may end up changing more than needed. The prototype 6ft is between the outsides of the rails not the running edges, and also assumes a gauge of 4'8.5", rails are 2.75" wide so the scale track centres work out to 11' 2", near enough 45 mm so the 24 mm in your sketch should be 28 mm which makes the 30 mm you are using rather more accurate.

Regards

Keith

 

Cheers Keith! For once it works out the right way! Many thanks.

 

Jeff

[robmcg]

I think Keith has it... the idea of approximation is ok in my way of thinking as long as the characteristic dimensions are very close, the 6ft way being of course a bit odd with 4ft gauge track as in 00.

 

So long as it looks about right, I like to leave room for that unit of measure called a 'smidgeon'.

 

Nice plan-drawing style, but wouldn't have got very good exam marks for my physics teachers (1966-8)...

 

Rob

[Physicsman]

Yes Rob, the "smidgeon", that unquantifiable unit of "something". I'll try and make sure I leave a smidgeon or two!

 

And I quite agree - I'm not trying to mimic the prototype to the n-th degree. As long as it looks ok. Who is going to get "up close and personal" with it - probably only me!

 

Just wish the blasted turnouts would arrive so I can get it sorted. Think I'll ring Marcway tomorrow - and I need more SMP track anyway. Hope you're continuing to have fun with your sleepers, chairs and rail!!

 

Jeff

Edited November 28, 2012 by Physicsman

[Andrew P]

Hi Jeff, I hope you are well,

 

I have been busy for the last couple of days so not much in the way of postings.

 

I have just had a re-read back through the last couple of pages and I must say I am impressed with some of the more technicle postings and dimensions, that is all way beyond me.

 

I have always worked on the principal that I use a sutible size tunnel mouth and then WANG A LONG COACH through the hole at great speed , if it goes through then O.K. if not PANIC .

 

I hope all this talk of tunnels is not to BORING boom boom, get it BORING, TUNNEL, TUNNEL BORE HOLE haheheheh

 

Andy.

[Physicsman]

Hi Jeff, I hope you are well,

 

I have been busy for the last couple of days so not much in the way of postings.

 

I have just had a re-read back through the last couple of pages and I must say I am impressed with some of the more technicle postings and dimensions, that is all way beyond me.

 

I have always worked on the principal that I use a sutible size tunnel mouth and then WANG A LONG COACH through the hole at great speed , if it goes through then O.K. if not PANIC .

 

I hope all this talk of tunnels is not to BORING boom boom, get it BORING, TUNNEL, TUNNEL BORE HOLE haheheheh

 

Andy.

 

I've just put a post on your Trebudoc thread, Andy. Come on - "show us yer wiring" ... I guess you operate on the principle that if you don't get a shock, or the insulation's not melting, then it must be ok!!? Lol.

 

You do make me laugh. And your layouts, high speed coaches or not, are rather good!

 

Jeff

[Andrew P]

Hi Jeff, I have put the pics on Trebudoc, hahah

[coachmann]

This 45mm track centres, first mentioned by LNER4479 of Grantham fame and now getting an airing on Kirby Luneside, is getting to me............now stop it! I sneaked into the shed this afternoon armed with a 45mm spacer to eye up Greenfield while Mrs coach was re-setting the mice traps.

[gordon s]

Theoretically a widened 6ft shouldn't make any difference (except in the visual appearance of the 6ft) if the overall dimensions add up. Provided the track centres are correct all that happens is an overscale 6ft and an overscale cess width. If the track centres are too far apart then you will have to widen the tunnel mouth.

 

Minimum prototype track centres for double track running lines (using the 1950 figure) would be a tad under 45mm in 4mm scale (you can of course get away with much wider on ex GWR lines which were formerly broad gauge ) and the desirable minimum between structure faces at maximum vehicle bodywidth is 106mm in 4mm scale.

 

Martin or Gordon will no doubt dive in somewhere soon with information about the various centre and 6ft dimensions for 00FS (in its various versions) and someone may tell us all off for not using a super accurate track gauge - please let's not go there! The situation we face with 16.5mm gauge track is one where we have little option but to do some sort of fiddle with the 6ft and I think it inevitably has to be a compromise that allows safe running on curvature - can be less on straight of course - and a compromise or optical fiddle for appearance reasons. But it can make overbridges and tunnel mouths potentially look 'not quite right'.

 

 

I'll have to fire up Templot as it's on my other PC, but from memory the double track configuration for 00-SF is 44.67mm from centre line to centre line. I increase this to the DOGA fine measurement of 50mm to avoid long overhang vehicles crashing together on curves. With tracks on a 44.67 centre, the distance between one rail from each track is around 27.5mm.

[Physicsman]

This 45mm track centres, first mentioned by LNER4479 of Grantham fame and now getting an airing on Kirby Luneside, is getting to me............now stop it! I sneaked into the shed this afternoon armed with a 45mm spacer to eye up Greenfield while Mrs coach was re-setting the mice traps.

 

Not sure I understand it myself, Larry. The typical rail to rail separation of my main lies is 30mm, or about 47mm centre - centre. Is that what it refers to? In the end, who cares? I only maintained it at 30mm rail to rail so I knew I'd put the 2 tracks down properly!

 

Jeff

 

ps. hope you caught plenty of mice!

[Physicsman]

I'll have to fire up Templot as it's on my other PC, but from memory the double track configuration for 00-SF is 44.67mm from centre line to centre line. I increase this to the DOGA fine measurement of 50mm to avoid long overhang vehicles crashing together on curves. With tracks on a 44.67 centre, the distance between one rail from each track is around 27.5mm.

 

Ah, now it becomes clear. Thanks Gordon. I used 60" radius turnouts throughout - and the Marcway geometry led to the 30mm separation or 46.8mm track centres, which I was pleased with. However, on curves of radii less than 40" I found I had to increase this, for the reason you've given. As I said to Larry, what's a few mm between friends? Or is size really that important? (Umm).

 

Jeff

[coachmann]

I was only jesting......,she was out badger baiting. The 45mm track-centre to track centre is narrower than the Peco track centres as set by their points. It's probably too late for most of us to alter things now but it does indicate why tracks in photos of the real Greenfield appear to be closer together.

[Physicsman]

I was only jesting......,she was out badger baiting. The 45mm track-centre to track centre is narrower than the Peco track centres as set by their points. It's probably too late for most of us to alter things now but it does indicate why tracks in photos of the real Greenfield appear to be closer together.

 

Do you realise how much that last post of yours will be worrying many of your followers?

 

No, it's not because your missus might get arrested for disturbing badgers. It's the prospect of Larry ripping-up the track again to gain 2mm closer track centres! Don't do it man! Greenfield looks ace, whatever the separation!

 

Jeff

[coachmann]

Hi Jeff, I read on the excellent Grantham site ...."The other thing I do is to modify pointwork so as to maintain a standard 11' 2" (@45mm) track centre; standard Peco pointwork gives 'too wide' 50mm track centres." I'm always open to ideas and 5mm sounded worthwhile. However, I'm not ripping anything up.

[robmcg]

Not sure I understand it myself, Larry. The typical rail to rail separation of my main lies is 30mm, or about 47mm centre - centre. Is that what it refers to? In the end, who cares? I only maintained it at 30mm rail to rail so I knew I'd put the 2 tracks down properly!

 

Jeff

 

ps. hope you caught plenty of mice!

 

Notwithstanding the necessity and importance of correct, no ... 'looks right', double track separation, and the avoidance of trouble on curves, I would like to show my progress in cobbling together my own code 75 bullhead assemblage of parts. At least I don't have to worry about curves, points, and so on, it being for my diorama photos where image-editing can fix or at least alter almost any error.

 

I will use the transparent sheet under the sleepers, suitably trimmed to about 75mm wider than sleepers, to accept paint, glue and ballast.

 

Below, an approximation of things,

 

 

and now, below, awaiting a smidgeon of adjustment before a gentle book-placement.

 

 

Cheers,

 

Rob

Edited November 29, 2012 by robmcg

[Physicsman]

Yes Rob, they look very nice. I'm sure they'll find adequate employment in all those photos you take! You sound very satisfied - are you making any more - enough for a loco and a few coaches, maybe?

 

Btw, 5C in the bunker at 7am. Heater on. Give it an hour and I'll find some wiring to fiddle with!

 

Jeff

[Jason T]

Larry, you strike me as the one person for whom RMWeb isn't helping you progress with your layout

 

I suppose that some of the additional space between the rails is taken up by the incorrect gauge of OO track and when thought of in those terms, then the only way to get Greenfield looking exactly right is to model it in P4, and I am sure you don't want to go down tat road

 

I don't know if you spotted it on my thread but Jeff has had a case of "the Larry's", tearing up and relaying a section of the fiddle yard because it wasn't exactly right !

[Physicsman]

Larry, you strike me as the one person for whom RMWeb isn't helping you progress with your layout

 

I suppose that some of the additional space between the rails is taken up by the incorrect gauge of OO track and when thought of in those terms, then the only way to get Greenfield looking exactly right is to model it in P4, and I am sure you don't want to go down tat road

 

I don't know if you spotted it on my thread but Jeff has had a case of "the Larry's", tearing up and relaying a section of the fiddle yard because it wasn't exactly right !

 

You weren't supposed to tell them that!! Lol.

 

I've actually pulled up 3 pieces: 2 were joined and had a slight "wobble" - they've been replaced. The other was cut about 3mm too short and I couldn't abide the "excessive" gap between the adjoining sections (even allowing for expansion gaps). That was ripped up at 11pm last night - its replacement is due to go in this morning.

 

At that point, though, I call a halt. So there you go, Larry - it's a contagion!!

 

Jeff

[MichaelW]

Rob, I agree with Jeff, that trackwork is looking good. I hope you're pleased with what you have achieved.

 

Jason, I'd noticed that, and I'm worried that it might be catching... I lifted the track on my narrow-gauge module last night too. Maybe I should check the anti-virus on my computer to make sure it can't spread any further

 

Makes you worry what Jeff'll do today when he's fiddling with the wires...

 

Edit:

 

And now he's admitted to doing even more. Quick, isolate him in the Bunker till he recovers!

Edited November 29, 2012 by MichaelW

[Physicsman]

Oh my goodness - it's a conspiracy! They're coming for me!!!!

 

I'll put your mind at rest, Michael. I can't replace any more after the next piece as I've run out of SMP. However, I'm going to ring Marcway to check on my turnouts - and get another box... but I promise, I'm changing nothing else!

 

Was it the track on the embankment that you lifted? I thought that looked good. Btw, general question. What's the appeal of OO9 for you?

 

Jeff

Edited November 29, 2012 by Physicsman