location of the screw conveying for a TBM 1

[JTWATER]

Hi, I wanted to ask if anyone had information about the location of the screw conveying for a TBM. What is the difference, if any, between:

• locating the screw conveyor intake at the bottom of the cutterhead pressure chamber
• locating the screw conveyor intake at the center

are there disadvantages or advantages? Any information or documents you can share regarding this issue would be appreciated.

 

[BUGGAR]

Well it certainly is a challenge to come up with an answer for that one!

The TBM manufacturer has first choice on the answer. But, if everything else is equal (not likely), I like to run muck conveyers high to get them above the muck cars for discharge into the cars. Unless it is a large mole, the conveyor train will have to rise up to get over the cars; the less height, the shorter the screw conveyor. No magic qualifications here for this, just a note from an old tunnel stiff.

Also, I presume the conveyor train is on rails? More clearance below the conveyor makes it easier to get below the machinery to get it back on the rails when it inevitably goes off. Are you mucking with cars or pumping it in a slurry?

Do I get a beer for at least taking a shot at this question?