Green land-bridges

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KeithW
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Re: Green land-bridges

Post by KeithW »

Greg07 wrote: Sun Aug 14, 2022 22:20 The " Miss James bridge" Image[/img]just south of the Hindhead tunnel is a green bridge of sorts. Not very wide but very green. ( this is the best photo I can find to link to ). [https://www.alamy.com/stock-photo-miss- ... 33313.html]
I believe it was a public right of way which is why the bridge was built and it has a champion in the NT who could have blocked the project if it was not built.
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Scratchwood
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Re: Green land-bridges

Post by Scratchwood »

I was walking in the Weston area yesterday, and have to say the A505 is remarkably hidden. The one shame is that you can't actually access the land bridge over the road, as it's private farmland, and fenced off!

From the south
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From the north
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Jim606
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Re: Green land-bridges

Post by Jim606 »

Great photos, thanks for posting. I always wondered why the tunnel couldn't have been a little longer especially to the south when looking at the depth of the cutting? I guess money was the answer. However, the extra greenery the tunnel provides is most welcome.
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Re: Green land-bridges

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Jim606 wrote: Sat May 27, 2023 12:50 Great photos, thanks for posting. I always wondered why the tunnel couldn't have been a little longer especially to the south when looking at the depth of the cutting? I guess money was the answer. However, the extra greenery the tunnel provides is most welcome.
IIRC the purpose of the tunnel was to preserve the line of the hilltop on the skyline, so the length of cutting wasn't an issue. It could have all been in cutting and the tunnel only had to be long enough to allow the top of the hill to be reinstated.
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Re: Green land-bridges

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Every time I go through the A505 tunnels, which is quite often, I ask myself “why do these tunnels have a circular cross-section which is suggestive of bored tunnels when they are cut and cover”?

Does anyone know? Or are circular/curved cross-section cut and covers more common than I suppose?
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Chris5156
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Re: Green land-bridges

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roadtester wrote: Sat May 27, 2023 17:34 Every time I go through the A505 tunnels, which is quite often, I ask myself “why do these tunnels have a circular cross-section which is suggestive of bored tunnels when they are cut and cover”?

Does anyone know? Or are circular/curved cross-section cut and covers more common than I suppose?
With apologies for pedantry, because I know what you mean… it’s not circular! A true bored tunnel has curved side walls, and a wider diameter since the roadway has to fit entirely within the circle. The A505 has a semi-circular roof, but straight vertical walls and a flat bottom. The arch design does look more tunnel-like, so there may have been aesthetic reasons, but in addition an arch is inherently a strong shape for supporting weight, so it’s also a good design for its purpose.

A flat roof would be possible but maybe only more desirable when you want to put something above it, as is the case for most urban cut and cover tunnels, or the ones on the M25 that are very close to the surface.
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Re: Green land-bridges

Post by Scratchwood »

Chris5156 wrote: Sat May 27, 2023 14:25
Jim606 wrote: Sat May 27, 2023 12:50 Great photos, thanks for posting. I always wondered why the tunnel couldn't have been a little longer especially to the south when looking at the depth of the cutting? I guess money was the answer. However, the extra greenery the tunnel provides is most welcome.
IIRC the purpose of the tunnel was to preserve the line of the hilltop on the skyline, so the length of cutting wasn't an issue. It could have all been in cutting and the tunnel only had to be long enough to allow the top of the hill to be reinstated.
I think the needs of wildlife played a part too, enabling wildlife to pass across the road "naturally" was also a major desire, especially as there's a nature reserve on the Baldock side.

From most angles the cutting isn't visible, and the 1970s/80s solution would have been to plant trees on top to block any visible gap...
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Re: Green land-bridges

Post by owen b »

I drive through those tunnels fairly often but hadn't noticed how much vegetation has taken over the previously starkly exposed chalk. I remember when the tunnels opened there was a stunning night time shot of the tunnels posted on SABRE which I think won photo of the month. It would be good to compare and contrast.
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Re: Green land-bridges

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Chris5156 wrote: Sat May 27, 2023 22:22 With apologies for pedantry, because I know what you mean… it’s not circular!
Ha ha - I did wonder whether I should pedant-proof my question by preempting that point in my original post! I should have known better than to expect get away with my original inexactitude on SABRE.
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Re: Green land-bridges

Post by trickstat »

Jim606 wrote: Sat May 27, 2023 12:50 Great photos, thanks for posting. I always wondered why the tunnel couldn't have been a little longer especially to the south when looking at the depth of the cutting? I guess money was the answer. However, the extra greenery the tunnel provides is most welcome.
There is a quite a steep incline just to the south of the tunnel which may have been a factor.
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Re: Green land-bridges

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roadtester wrote: Sun May 28, 2023 06:33
Chris5156 wrote: Sat May 27, 2023 22:22 With apologies for pedantry, because I know what you mean… it’s not circular!
Ha ha - I did wonder whether I should pedant-proof my question by preempting that point in my original post! I should have known better than to expect get away with my original inexactitude on SABRE.
Turns out I did not disappoint! Sorry :laugh:
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Re: Green land-bridges

Post by FosseWay »

There's one of these near me, over the E6.
20210109_122224.jpg
While it serves its function perfectly adequately - there were plenty of different paw- and hoofprints in the snow on the day I went there - it isn't exactly an exemplar of aesthetic wonder when seen from the E6:
20210109_121843.jpg
The A505 example above blends in much better with the surroundings.
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Re: Green land-bridges

Post by Burns »

FosseWay wrote: Sun May 28, 2023 10:29 There's one of these near me, over the E6.
The green bridges I've passed under whilst driving the E6 on the Norwegian side have all been a more aesthetically pleasing shape than that. Speaking of the E6, all being well, I'll be using it on Wednesday between Nordkjosbotn to Narvik. I sometimes find it difficult to comprehend the length of the road. Where I'll be compared to where you are is so completely different, yet they're linked by the same road.
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Re: Green land-bridges

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Burns wrote: Sun May 28, 2023 10:35
FosseWay wrote: Sun May 28, 2023 10:29 There's one of these near me, over the E6.
The green bridges I've passed under whilst driving the E6 on the Norwegian side have all been a more aesthetically pleasing shape than that. Speaking of the E6, all being well, I'll be using it on Wednesday between Nordkjosbotn to Narvik. I sometimes find it difficult to comprehend the length of the road. Where I'll be compared to where you are is so completely different, yet they're linked by the same road.
Enjoy! :D It's one of my ambitions to drive the whole way from here to Kirkenes on the E6. I also live very close to the E45, at around its mid-point.
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Re: Green land-bridges

Post by Burns »

FosseWay wrote: Sun May 28, 2023 10:46 Enjoy! :D It's one of my ambitions to drive the whole way from here to Kirkenes on the E6. I also live very close to the E45, at around its mid-point.
So far, I've driven it from Gardermoen to Dombås. I'm flying to Tromsø so as much fun as it'd be to drive all the way up, I've not quite got enough annual leave to justify the extra days it'd take to fill in all the gaps. One day, though.
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Re: Green land-bridges

Post by Vierwielen »

Chris5156 wrote: Sat May 27, 2023 22:22
roadtester wrote: Sat May 27, 2023 17:34 Every time I go through the A505 tunnels, which is quite often, I ask myself “why do these tunnels have a circular cross-section which is suggestive of bored tunnels when they are cut and cover”?

Does anyone know? Or are circular/curved cross-section cut and covers more common than I suppose?
With apologies for pedantry, because I know what you mean… it’s not circular! A true bored tunnel has curved side walls, and a wider diameter since the roadway has to fit entirely within the circle. The A505 has a semi-circular roof, but straight vertical walls and a flat bottom. The arch design does look more tunnel-like, so there may have been aesthetic reasons, but in addition an arch is inherently a strong shape for supporting weight, so it’s also a good design for its purpose.

A flat roof would be possible but maybe only more desirable when you want to put something above it, as is the case for most urban cut and cover tunnels, or the ones on the M25 that are very close to the surface.
I think that the inherently strong structure related to a arch is the real reason.
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Re: Green land-bridges

Post by wallmeerkat »

This bridge https://www.google.com/maps/@54.6410345 ... ?entry=ttu at the Clandeboye estate, Bangor

It would probably make sense to remove it as it is always getting striked by high vehicles

https://www.google.com/maps/@54.6409012 ... ?entry=ttu
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Jim606
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Re: Green land-bridges

Post by Jim606 »

I didn't realise that the proposed Norwich Western Link has some planned Green Bridges.
1. Morton (Green Bridge)
2. The Broadway (Green Bridge)
3. Foxburrow (Green Bridge)
4. Bat Crossing (Possible Green Bridge alternative)

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