Hellzapoppin

The hole is full of concrete, the metal tube you see above ground is a sleeve which only goes a short way into the hole.

In some areas the ballast is glued, Dawlish being one of them.

To answer your question about senior people remembering the layout as was in the 80s, yes there are and it's simply known as 4 tracking.

As has been mentioned earlier in this thread only a very small number of buried services have been hit, in fact I only know of 3 and only one of those has caused problems. It seems that these services or the lack of drawings has caused the project to fail. Utter hogwash and before you ask, yes I do know what I'm talking about.

Unexpected stuff isn't a true statement to be honest, trial holes were and still are excavated and these should highlight any issues. The problems with the project are many and each one has an impact on production and as yet I've seen no definitive answer to these and I don't think I will.

Pete, the ATF cable has to be kept at least a metre away from any other cables so in cuttings and on embankments the route is elevated as it's easier to install than conventional concrete troughs. In a flat section where there is more clearance the containment is laid on the ground. This is not always the case as it depends on the local situation but it's a good rule of thumb. The route kicks in around the piles to allow access also worth noting is that you can't put the route at the back as it would be difficult to install any new cable sections.

Conventional piling, which is augered holes filled with concrete, have a short sleeve fitted which looks like it's a chs pile filled with concrete but that isn't the case. The concrete is poured straight into the hole which allows it to form in and around the ground in the hole. Filling a chs pile wouldn't prove useful and in some ground conditions would allow the pile to sink. I also think the piles you see close by are for the stays at the portals. Hope this helps. LZ

The facade tiles are in fact ceramic and clip into the front of the EPs units, the coper units above are concrete. As you rightly say it would have been impossible to have done the upgrade using conventional methods plus the additional loading on the arches was too much. As a listed structure all the designs were scrutinized by everyone and their dog before work started, this was a massive undertaking trying to match engineering with consent.

Well as my first post on here I'd just like to say Hello and just add a bit of info regarding the comments made about the tubes. The tubes are actually CHS piles, circular hollow section, and is 1 of 3 ways in which the foundations are constructed, the others being conventional,which is an augered hole fitted with a cage and filled with concrete and a bespoke foundation known as a gravity slab which is a big lump of concrete sitting on the ground which the mast bolts on. Hope this helps. LZ