Langford Lane & Marlingford - GWR 1940s Oxfordshire

[The Great Bear]

As long as the signal structure is clear of the loading gauge all is more or less well but the arm must be clear whichever position it is in (which it is).  What concerns me a bit more is whether the signal is properly in rear of the fouling point on that diamond/slip - usually it would be back level with the point toe of the other line which feeds across the diamond/slip and it looks a bit too far forward for that (although it could be the angle of view?).

 

Thanks, one to look at home. Fouling point being where things would hit each other http://www.rmweb.co.uk/community/index.php?/topic/61551-your-layout-track-plan-mistakes/?p=789185

 

How far close to this can the signal go, is there margin for safety? The crossover is slightly longer, the point on the up line a bit futher...erm...up because I set the spacing of the tracks is a bit wider, so toe might be too far back. Will also try and relate to photos etc of real thing tonight.

[The Stationmaster]

Thanks, one to look at home. Fouling point being where things would hit each other http://www.rmweb.co.uk/community/index.php?/topic/61551-your-layout-track-plan-mistakes/?p=789185

 

How far close to this can the signal go, is there margin for safety? The crossover is slightly longer, the point on the up line a bit futher...erm...up because I set the spacing of the tracks is a bit wider, so toe might be too far back. Will also try and relate to photos etc of real thing tonight.

Officially all you need is to be clear of the fouling point although it seems to have been common practice to 'add a bit' as I've explained above. But I have known signals on the Western to be right up to the fouling point so don't worry about it too much.

 

However there is a little operational awkwardness you need to bear in my mind because the Western almost invariably 'locked two back' which means that if the crossover was set against this signal (and thus locking it) the next signal in rear would also be locked and you couldn't run a train towards this signal until the correct route is set in advance of it.

[The Great Bear]

Officially all you need is to be clear of the fouling point although it seems to have been common practice to 'add a bit' as I've explained above. But I have known signals on the Western to be right up to the fouling point so don't worry about it too much.

 

However there is a little operational awkwardness you need to bear in my mind because the Western almost invariably 'locked two back' which means that if the crossover was set against this signal (and thus locking it) the next signal in rear would also be locked and you couldn't run a train towards this signal until the correct route is set in advance of it.

OK, thanks. The "two back" locking seems eminently sensible.

[The Great Bear]

A bit more experimenting to try and improve things, the road/canal bridge and also the points entering the goods yard. I find doing the mock up very rewarding: nice to get a tangilble taster of where things are heading.  (Taking pictures of them and posting on here helps me think about things to try and improve the end result plus I am getting to grips with new phone's camera.)

 

A

An alternative arrangement to the points/trap arrangement at entrance to the goods yard. (The geometry of the double slip didn't fit as well, didn't give enough diverge away from the bay line, Mike). I think this looks better and hopefully is ok way of doing it - I noted from the SRS signal diagram of Kidlington the prototype appears to have similar arrangement but with trap points to rear of the y on both branches. I'm not sure that both are needed, the setting of the points as shown in the photo trap things from the bay line, though I'll await the expert opnion!

 

 

 

The masking tape is the canal and you can see I am testing the turning circle of a narrow boat (taking this mock up business too far pehaps!) This arrangement avoids the pronounced kink in the road and fits better, don't need to widen the baseboard over my (messy) workbench.

 

I think things are heading in the right direction. I will sleep on it then get on with laying the track in goods yard over the weekend.

 

Thanks for looking,

 

Jon

[gazmanjack]

Have you thought about only modelling the canal at only half to 3/4s the width ? Would it matter if there was no canal edge on the front of the layout, but just the water to the edge ? The arched road bridge will only have to be a 3/4 model. The front of the road bridge (edge of board) could be modelled up in clear perspex as to hold the bridge up and avoid knocks. This would save the tightening up of the railway tracks under the road bridge.

 

Cheers, Gary.

[The Great Bear]

Have you thought about only modelling the canal at only half to 3/4s the width ? Would it matter if there was no canal edge on the front of the layout, but just the water to the edge ? The arched road bridge will only have to be a 3/4 model. The front of the road bridge (edge of board) could be modelled up in clear perspex as to hold the bridge up and avoid knocks. This would save the tightening up of the railway tracks under the road bridge.

 

Cheers, Gary.

 

Thanks, Gary - some interesting ideas for me to consider.  How to treat the edge of the canal and the bridge has always been something I've been unsure about. I will flick through my collection of magazines, modelling books to see what's been done on other layouts to see how they look when finished with completed scenery. I can remember one layout which had something what I was looking for but haven't a clue where I saw it, in print or on here.

[The Great Bear]

An alternative arrangement to the points/trap arrangement at entrance to the goods yard. (The geometry of the double slip didn't fit as well, didn't give enough diverge away from the bay line, Mike). I think this looks better and hopefully is ok way of doing it - I noted from the SRS signal diagram of Kidlington the prototype appears to have similar arrangement but with trap points to rear of the y on both branches. I'm not sure that both are needed, the setting of the points as shown in the photo trap things from the bay line, though I'll await the expert opnion!

 

Realised what I've shown isn't that sensible and am going to go with the two trap points, like the prototype as that means the switch between the goods shed line and avoiding loop can be hand operated, easier for shunting. (Because of the bridge, this area is out of sight of the signal box anyway.)

[The Stationmaster]

Realised what I've shown isn't that sensible and am going to go with the two trap points, like the prototype as that means the switch between the goods shed line and avoiding loop can be hand operated, easier for shunting. (Because of the bridge, this area is out of sight of the signal box anyway.)

You need to trap both because something could runaway from either road towards the passenger line - the logic is as simple as that.  And no problem putting a hand point there - quite common on the Western in fact.

[Ruffnut Thorston]

When it comes to canals...don't forget that the water needs to be wide enough for two boats to pass each other, plus a bit of space either side to allow for the sloping of the banks.

 

The water space through the bridge on a narrow canal would be around 7ft 6 inches...the boat being 7ft wide.

 

So, it could be a good idea to only model "half" the canal width...

 

(From a canal enthusiast.... )

 

Some Canal Info here...

 

LINK 1

 

There is also some info, including some narrow boat models in the "Workbench" thread in my Signature.

Edited August 13, 2013 by Sarahagain

[The Great Bear]

When it comes to canals...don't forget that the water needs to be wide enough for two boats to pass each other, plus a bit of space either side to allow for the sloping of the banks.

 

The water space through the bridge on a narrow canal would be around 7ft 6 inches...the boat being 7ft wide.

 

So, it could be a good idea to only model "half" the canal width...

 

(From a canal enthusiast.... )

 

Some Canal Info here...

 

LINK 1

 

There is also some info, including some narrow boat models in the "Workbench" thread in my Signature.

 

Thanks, Sarah. Lots of useful info for me to explore and consider. I've just remembered I've had a copy of "Inland Waterways of Great Britain" on the cupboard next to my desk at work, this I'm sure has similar info in it. I haven't personally ended up looking at it in relation to my work project (we go over a few, including the Oxford canal) but may well in relation to my own project.

 

All the best,

 

Jon

Edited August 13, 2013 by The Great Bear

[The Great Bear]

Following my thread on signalling for Begbrooke with lots of interesting discussion and helpful advice from the usual suspect(s) I have decided to make a change to the layout at the far right of the scenic section. Rather than have a double slip which joined the branch back to the down mainline I'm going to move this connection to the far side of the bridge. This is nearer to the prototype (Kidlington), makes signalling a bit simpler and allows a much longer train to be held in the branch whilst a faster train passes.

Revised track plan here, showing that a 20 wagon freight will just fit with revised arrangement.

 

 

Changes to track layout underway then no excuse to not start the scenic work!

 

Thanks for the interest

 

Jon

[The Great Bear]

Here's the final(?) signal diagram to go with the plan above:

 

[The Stationmaster]

Here's the final(?) signal diagram to go with the plan above:

 

I reckon that is pretty 'final'Jon - well done

[The Great Bear]

 

I reckon that is pretty 'final'Jon - well done

 

Thanks - I did have some help from the GWR signalling department, both past and present  , though!

 

Now for the interlocking and, no doubt, more questions...

[Twright]

This is an excellent layout and I look forward to the completed layout. 

[The Great Bear]

It's taken this to finally get to grips with the routes through the crossover and double slip, which levers will do what and how lock the different points*. Nice if nothing else to get points even if still controlled by Powercab for now with the 'proper' numbers not something arbitrary.

 

*subject to "approval"

[phixer64]

Only caught up with this, really clever how you have incorporated a smaller layout into a new larger layout, will be watching with interest. Also good idea with the cardboard knock ups.

[The Great Bear]

I've now started on the scenery for the layout. Work in progress are the bridges then I'm going to move on to the earthworks and the buildings. The station buildings I'm going to do last as they're the most complex, so I'm going to start on the goods shed and then the signal box.

 

Here's the CAD drawing for the goods shed which I hope to start making this weekend. In the absence of a drawing for the protype the dimensions have been scaled from photos. I'm not sure about how the platform was arranged inside it, but what I've done makes sense to me, allows for a cart to be backed in and gives a storage area in the corner?

 

I think it's going to be a bit smaller than I first thought when mocking things up, which would be a good thing.

 

[westerner]

It must be good to able to expand. I'd love to be able to add the terminus at Kingsbridge (perhaps re-named Kingscombe) that would be the terminus for Wencombe. Unfortunately that would mean drilling through the wall into our bedroom. Somehow I don't think I'd get away with it??!!??!!

[class"66"]

Some realy nice work here guys...

[The Great Bear]

Well the goods shed construction still hasn't started. It's taken a lot longer to get from the pretty picture to some fabrication drawings with all the bits to be be overlaid on card, printed and so on. As an engineer, I should have realised this wouldn't be a 5 minute job. Duh.
 
Meanwhile a piece of headscratching has been the brickwork for the skew arches for the road bridge.
 

 
Not an immediately obvious shape, well to me, anyway. I'd like to say I've used some fancy mathematical method to work this out like the Victorian engineers did like those described here but I'll fess up that the above resulted from trial and a lot of error and will still need a bit of fettling in-situ.

Thanks for the interest

Jon

[The Great Bear]

Well the goods shed construction still hasn't started. It's taken a lot longer to get from the pretty picture to some fabrication drawings with all the bits to be be overlaid on card, printed and so on. As an engineer, I should have realised this wouldn't be a 5 minute job. Duh.

 

So here's the main parts:

 

 

Having posted I'll probably find something missing. Hopefully it will fit together reasonably smoothly with few last minute alterations!

 

Thanks for the interest shown

 

Jon

[nickwood]

You've come a long way in the three years since you started Jon and I like the way that you are incorporating your initial work. Excellent stuff.

[The Great Bear]

Rather than the goods shed, I've built the road bridge by the station

 

In the prototype at Kidlington the original bridge had three spans, the side spans being brick, the centre being an iron girder. The bridge is at around a 45 degree skew. The bridge was rebuilt in the 1930s when the road was widened and realigned and replaced with a single span concrete structure. I've gone with the original design as to me was more interesting (the branch line sneaking through the side span) and also allows me to run an earlier time frame should I wish.

 

The bridge from old photos looks similar to the one by Hatton station, this design being fairly common on the the Oxford-Birmingham line though some have had centre spans replaced I think.

 

The centre iron girder span, I have assumed to be like the bridge over the canal at Heyford

 

So here's the model:

 

The side brick arches, showing the skewed arch

 

The deck being built, showing the beams and the jack arches

 

Finished (apart from the road over it) bridge

 

 

The dark stone colour for the girders hopefully is right, that's how I read the notes in Great Western Way and the B&W photo I have of bridge shows relatively dark shade.

 

 

Now onto the earthworks...

 

All the best

 

Jon

 

[artizen]

Yes the darker shade of the bricks should be right. That normally indicated that the builders used engineers' bricks which were more waterproof than a normal house brick and stronger. Same reason they always used white glazed bricks in urinals - they could take the punishment!

 

No doubt someone on here will be able to confirm why the bridge had different bricks in the structural part of the centre span.