In March 2006, field construction
of the utility connector began with the
installation of 800 trench ft of direct-buried piping that extended out and away
from the new terminal building. By mid-June, the tunnel-boring machine arrived
on site and was placed in the jacking pit.
Boring commenced June 27. The machine
was fully buried, and the first ring of
liner plate was set in place July 6. As
the tunnel-boring machine moved beneath
the runway and taxiways toward the south
side of the airfield, the receiving pit was
constructed; direct-buried piping, electric
and telecommunications duct banks were
installed; and the piping for the temporary
opening was preassembled above ground.
On Nov. 6, 2006, the tunnel-boring machine
broke through – 2,016 ft from the jacking pit.
Work on the central plant modifications began in December 2006. The targeted deadline for their completion was
September 2007 – timed to coordinate
with the anticipated completion of the
utility connector. Fiber optic cabling was
installed between the Central Energy
Plant and new terminal as part of Phase 1,
the utility connector project; however,
connection of the fiber to instrumentation and controls at either end of the
connector was covered by Phase 2, the
Central Energy Plant modifications project.
To date, two contractors have
received national awards for
their respective efforts on the
airport system project.
As plant modifications continued
through winter 2006, the long lengths of
preassembled piping were pulled into
place. By late spring 2007, piping through
the temporary liner-plate opening was
fully tested and in position, and placement
of cellular concrete within the remaining
void of the temporary opening was complete. Into summer 2007, expansion vaults
were constructed at each end of the
bore, remaining direct-buried and arbor
piping was installed and connected to
the Central Energy Plant, and an additional 1,300-ft electric duct bank was
constructed. At the same time, mechanical, electrical, instrumentation and con-
Courtesy Bowen Engineering.
To reduce construction time and cost, eight 1,000-ft lengths of thermal piping were assembled above-ground and pulled length by length into place beneath the runway.
trols work was being finalized as part of
the Central Energy Plant modifications.
Circulation of chilled water to the new
Midfield Terminal began Sept. 24.
Circulation of high-temperature hot water
at 180 F began Oct. 31, with supply temperature increased to 200 F in December;
and the system was placed fully in service at 325 F on Jan. 22, 2008.
Through the assembly and use of a
project team concept, BHMM/CTE was
able to coordinate numerous technical
specialties in a short period of time to
offer, develop and implement an alternate
contract delivery method. The approach
also yielded innovative ideas – using
direct-buried piping, constructing it above
ground and pulling it into place within a
temporary opening – that shortened construction time and reduced cost.
Plans for the utility connector were
taken from revised concept to final design
in 24 weeks, and construction took just
20 months (March 2006-November 2007).
The majority of Central Energy Plant
modifications occurred between December
2006 and September 2007. Controls and
instrumentation work was finalized as
the plant and various systems within
the new terminal became available for
The actual cost of construction for
the utility connector was $24.4 million.
Against a final adjusted target of $28.2
million, the owner was able to realize
savings of more than $3.8 million. The
Central Energy Plant modifications, initially estimated at $2.2 million, were
completed for $2.6 million. In total, the
cost of providing district heating and
cooling to the new terminal was just
short of $27 million.
To date, two contractors have received
national awards for their respective efforts
on the airport system project: Midwest
Mole received Trenchless Technology
magazine’s 2007 Project of the Year
Award for the utility connector construction, while Bowen Engineering was honored with a 2008 Aon Build America
Award from the Associated General
Contractors of America, in the category
Municipal & Utilities New.
Thanks to the entire project team
and their innovative work, tenants and
travelers at Indianapolis’s new Midfield
Terminal will be able to experience the
benefits and comfort of district heating
and cooling – when the terminal opens
later this fall, and for many years to come.
For nearly eight years, Mark
Vogler has managed the thermal
engineering group for Citizens
Thermal Energy, a division of
Citizens Gas & Coke Utility,
Indianapolis. During that time, he
has had responsibility for budget, design and
construction of engineering projects related to
the operation, maintenance and support of
Citizens’ steam and chilled-water plants and
associated distribution systems. Prior to joining
Citizens, Vogler worked for 10 years as a
steam distribution and plant engineer for
Indianapolis Power & Light Co. A member of
IDEA and the American Society of Mechanical
Engineers, he currently is co-chair of IDEA’s
Distribution Forum. He can be reached at