This is a publication of ITAtech committee of ITA (International Tunnelling and Underground Space Association).

The purpose of the document is described as:

"The purpose of this ITAtech Guideline is to establish definitions and minimum requirements for rebuilding pre-used tunnelling machinery, as defined in section 1.3, that can be used for contract or rebuild scope specifications, by the project owner or contractor."

It is basically a checklist for re-assembly of a pre-used Tunnel Boring Machine.

A very valuable reference document published in 2019.

ITAtech Guidelines on Rebuilds of Machinery for Mechanized Tunnel Excavation

Please check ITAtech site for many more valuable resources.