Tomlinson Group was involved in
excavating extra space for mechanical
systems which featured tunnels,
blasting rock near a building of historical
significance with strict vibration criteria,
interior bedrock excavation to a
40-foot depth and removal of rock from
a central courtyard via tower crane.
40,000 cubic metres of bedrock
Workers blasted through about 40,000
cubic metres of bedrock to create
three new underground levels that
extend below the House chamber.
Two of these floors would eventually
contain committee rooms and offices,
and connect to other parliamentary
buildings through a tunnel system,
while the other floor was constructed
for mechanical and electrical systems.
“They wanted to expand the
mechanical space within the Centre
Courtyard and the North Wing to
create more access,” said Hammel.
“Most of Parliament Hill is supplied
with heating and cooling from Cliff
Street Plant so we had to bring in
additional tunnels and access shafts.
We were the prime contractor on
some of this work and then we had
a subcontractor that did some of the
work on the tunnels.”
Tomlinson Group began work
on the project in August 2013 and
completed their tasks by July 2018.
Hammel said that it was probably the
largest project he has been involved
with. One of the biggest challenges
was to coordinate the equipment in
and out of a busy worksite.
“We had a lot of equipment that was
landlocked by the Centre Courtyard.
We were breaking up the bedrock and
then had to use tower cranes to load
it up and bring the material out on
tri axles. These trucks had very little
access due to security measures and
had to make their way through Public
Services and Procurement Canada.
They had a checkpoint on the way in
to make sure things went well, but
obviously there was heightened
security at Parliament Hill, and some
of our trucks were having to go around
Centre Block while Parliament was in
session,” said Hammel.
Before the project began, the
Tomlinson Group developed an
action plan that was revised as the
project unfolded. With so many trades
working on-site, it was important to
remain flexible and accommodating
to other contractors. There were also
opportunities to streamline operations
as some work was complementary.
For example, Tomlinson Group as a
PCL subcontractor worked with PCL
to get approval on shaft construction
at the same time as the courtyard
renovations to help accelerate the
renovation schedule. This approach
allowed Public Works to have access
to several quasi-permanent shafts that
could be used to excavate materials to
the surface and provide better access
to bring materials if required.
“It was definitely difficult to plan in
advance,” said Hammel. “I remember
when we were excavating the Centre
Courtyard, we brought in some brand
new CAT 324s on lease to minimize
any maintenance if we required them.
We actually had to bring in a 300 tonne
crane that we had just purchased and
we actually used that to lift the shovels
into the Centre Courtyard so we could
do the excavation.”
Special equipment used
In terms of special equipment,
Hammel said the company brought
in a Brokk machine, which has “more
of a punch” for the size and space
requirements that they were working
under. The subcontractors who worked
on the tunnelling also had to make
special arrangements.
Tomlinson Group used two
main subcontractors: Marathon
Underground (formerly Marathon
Drilling) for the tunnelling portion
and M-Roc for the blasting. Since
Parliament was often meeting in
Centre Block, noise and vibrations
had to be kept to a minimum. In order
to meet these requirements, M-Roc
placed the spacing of the holes closer
together to minimize vibrations.
PROJECT SPOTLIGHT
Workers blasted through about 40,000 m3
of bedrock to create new underground levels
that extended below the House chamber
Tower crane moving equipment into the Centre Courtyard
56 Q3 2019 www.pilingcanada.ca
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