ITAtech Guidelines on Rebuilds of Machinery for Mechanized Tunnel Excavation Featured

The use of previously used and rebuilt
equipment is quite a common practice
in underground construction. For
environmental (reduction of carbon
footprint) as well as economic or schedule
reasons the multiple use of equipment can
be considered a reliable and safe solution.
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.
1.2 BACKGROund
To date, there is no specific guidance
available for the tunnelling industry to
establish minimum quality requirements for
rebuilding pre-used tunnelling machinery.
To achieve an adapted level of quality and
scope for the requirements of the intended
future use of tunnelling machinery rebuilds,
two rebuild levels and their minimum
requirements are established:
• Remanufacturing as defined in section 2.2
• Refurbishment as defined in section 2.3
Note : The selection of the appropriate
excavation and support system or TBM
type for a tunnel project is primarily
influenced by the anticipated ground and
groundwater conditions. The intended
use of the tunnelling machinery is agreed
between the rebuilder and the user taking
into account information on predicted
ground conditions provided by the user
(e.g. Geotechnical Baseline Report).
The guideline covers shielded and
unshielded Tunnel Boring Machines (TBMs)
and their backup structures along with
non-man-accessible Micro Tunnelling
Machines (MTBMs), including associated
equipment (e.g. towed California switches,
booster pump stations, above ground
power packs, control containers or jacking
were the country of the intended future
use of rebuilt tunnelling machinery is
different to the country of previous use
care has to be taken for compliance with
national standards and regulations of the
location of intended future use.
Note : In the absence of relevant
standards applicable in the county of
intended future use EN 12110 and EN
16191 may be used for guidance.
The requirements set out in this guideline
may be applied to complete machines,
individual subassemblies or components
of machines.
Note : In many cases only individual parts
or subassemblies (e.g. main drive) of
contractor-owned tunnelling machinery are
shipped to the rebuilder for refurbishment
or remanufacturing based on a specified
and agreed scope of work.
General requirements are given for
hydraulic -, electric -, pneumatic face
pressure regulation - and soil conditioning
Decompression chambers, pressure
vessels, refuge chambers and crane
systems are not within the scope of this
guideline. For clarity, the requalification of
such components has to comply with the
national standards and regulations of the
country of intended future use.
Note : General guidance on refuge
chambers can be found in ITA Report No
14, “Guidelines for the provision of refuge
chambers in tunnels under construction”.