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| | Spartanburg SC | GoUpstate.com | Spartanburg Herald-Journal |
 | | A tunnelling shield is a protective structure used in the excavation of tunnels through soil that is too soft or fluid to remain stable during the time it takes to line the tunnel with a support structure of concrete, cast iron or steel. |
 | | The shield was built by Maudslay, Sons & Field, of Lambeth, London, who also built the steam pumps for de-watering the tunnel. |
 | | Behind the shield, inside the finished part of the tunnel, several support mechanisms which are part of the TBM can be found: dirt removal, slurry pipelines if applicable, control rooms, rails for transport of the precast segments, etc. |
| www.goupstate.com /apps/pbcs.dll/section?category=NEWS&template=wiki&text=tunnelling_shield (612 words) |
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