Bramhope Tunnel

Si · Post by Si » Fri 16 Nov, 2007 4:08 pm

You are the font of all tunnel knowledge, Phill! I still can't figure out how those stones stay up. If they're wedged together every other stone (and therefore the whole thing) would fall. The same would be true if they were wedged at the back, and I can't imagine the bricks of the main vault doing the job, either. There's obviously a reason, or there would be no tunnel airshafts!!! I'd love to see some original drawings. That would solve it.

drapesy · Post by **drapesy** » Fri 16 Nov, 2007 4:27 pm

A simple arch works on the principle of a key-stone at the top of the arch - a principle discovered by the ancient Greeks I believe.[thats Greeks - not Geeks!]. I assume a brick arch works on a similar principle - with a row of key-stones(bricks) down the centre??

Phill_d · Post by **Phill_d** » Fri 16 Nov, 2007 4:28 pm

It's funny you bring this up Si.. take a trip to the National railway museum in York.. they have this section for the kids were you put this wooden arch template down & place material shaped blocks over it.. pull the arch away & you can walk on it... It's only flimsy stuff but the strength is there.. When i went to building college they taught you about arch physics & all that stuff were looking out of the window was more appealing... but all the weight above instead of pressing down is dispersed over the larger area pushing side ways meaning there is little weight pushing down on the tunnel.. it doesn't make sense i know but it works like that.

Phill_d · Post by **Phill_d** » Fri 16 Nov, 2007 4:41 pm

I agree they defy logic with all the weight above.. Amazing.. This is the open shaft in Gildersome.

Phill_d · Post by **Phill_d** » Fri 16 Nov, 2007 4:43 pm

looking up the shaft.

Phill_d · Post by **Phill_d** » Fri 16 Nov, 2007 4:45 pm

The only tell tale sign a tunnel is 120' below.

Si · Post by Si » Fri 16 Nov, 2007 5:37 pm

Hi Drapesy, Phill,I understand the principle of the arch, and how multiple courses of bricks add strength. It's the stones around the bottom of the shaft I don't get! How do they key into the surrounding brickwork? The key stones must be at the top of the arch at either side and the other stones angled accordingly, both against each other and the bricks...I know...I'm rambling!

Phill_d · Post by **Phill_d** » Fri 16 Nov, 2007 5:58 pm

There on a wedge shape.. thicker at the top you can't see to the bottom you can.. The courses of brick built around them trap them in.. It's all clever stuff how they key them in..

fell runner · Post by **fell runner** » Fri 22 Apr, 2011 9:38 am

We did a run the other night from Adel,over Cookridge golf course and then followed the trails over the fields around Bramhope.Passed 3 of the tunnel ventilation shafts, quite impressive structures when you see them close up.

Richard A Thackeray · Post by **Richard A Thackeray** » Mon 30 May, 2011 9:29 pm

fell runner wrote: Passed 3 of the tunnel ventilation shafts, quite impressive structures when you see them close up. As is the one by the road-side at Bramhope.I'll admit here, I used to tell my then G/f (now SWMBO) that it was the Scout-Hut, as it has a sign on it (or nearby) that's regarding the hut behind itShe believed me for a few months, until she told a friend of hers the same story.