Mitigating
Outage
Challenges
By Christopher Cox, PSC.
Christopher Cox
Christopher Cox has 20 years of
engineering experience. He has
developed solutions,
including several
patent-pending
designs, for clients
spanning the
nuclear, steel, heavy
lift and transport
industries. He is a
licensed professional
structural engineer in
multiple states.
Christopher joined
PSC in 1999 as a
structural engineer.
Leveraging his
expertise, business
acumen and passion
for his work,
Christopher ascended to the role of vice
president.
Under his leadership, PSC has grown
significantly. The company now provides
engineered solutions, fabrication, heavy
lift and rigging solutions for industrial
and commercial clients.
Christopher is active in several
professional associations including
the American Nuclear Society, the
Specialized Carriers & Rigging
Association (SC&RA) and the American
Institute of Steel Construction. He
earned a Bachelor of Science degree
in civil engineering from Southern
Illinois University. Prior to joining PSC,
Christopher served as design engineer
for David Mason & Associates and
Nooter Corporation.
Inclement weather can play havoc
on nuclear plant maintenance schedules.
Winds as low as 20 miles per hour can
shut down crane-based lifting operations.
Poor visibility from rain and fog can
increase the hazards from suspended
loads — potentially endangering
personnel and hindering rigging
operations critical to supplying materials
to elevated equipment hatches. Failure to
get critical path maintenance components
inside the plant means slipped schedules
and lost revenues.
To solve this problem, PSC reimag-
ined heavy lifting. The company’s new
patent-pending Pipe
Modular Lift System
(PMLS) eliminates
the hazards of sus-
pended loads, im-
pacts from wind, and
reliance on cranes
by employing a plat-
form that mechani-
cally raises and low-
ers
safety-related
components.
This
approach delivers a
safer, faster method
of lifting equipment
and materials up and
into elevated equip-
ment hatches.
Flexible Configuration
“We recognize that every nuclear
plant is different, so we designed the
PMLS with flexibility in mind,” said
Bogdan Gaita, director of projects with
PSC.
The PMLS’s capacity and footprint
can be custom configured for every
site. The system accommodates lifting
capacities of 400, 800 and 1,200 tons
at a vertical travel distance up to and
exceeding 50 feet depending on the
application, with exact height tailored to
match project requirements. Lift speed
is 20 inches per minute, twice as fast as
strand jack systems.
The standard column section can
be increased in 10-foot increments or
customized to meet plant needs. The
PMLS can be constructed in square,
rectangular and round layouts based on
site-specific conditions. It is designed for
five percent side loading with clear span
openings configurable to 50 feet or larger.
Safe, Reliable Operation
This
flexible,
platform-based
approach offers numerous advantages.
There are no cable drums or strands
that can fail or hydraulics that can
leak. The self-locking PMLS provides
synchronized lifting and positive
mechanical engagement of the cargo and
the platform — 100 percent of the time.
Computerized controls keep the
platform moving at a constant speed
and set the vertical travel distance
based on user input. Should the PMLS
lose power, the load remains in place
on the secured platform until power is
restored. Performance is not impacted by
unbalanced load.
The PMLS is also easy to transport
and quick to assemble. It ships in 12
standard ground transportation trailers,
versus 25 to 30 trailers needed for
cranes or gantries. It requires no wide
load or heavy load permits, and the
PMLS assembles in five shifts, or fewer,
compared to three to four weeks for
comparable systems.
Because the PMLS platform accepts
any mobile material handling equipment,
such as PSC’s self-propelled modular
transporter (SPMT), with the cargo
in place, load handling is minimized.
The original design concept and the
real-world result of the PMLS which
was utilized at a nuclear power plant
located in the Midwest to lift materials
and equipment 50 feet above the
ground to gain access to the building’s
only equipment hatch.
44
NuclearPlantJournal.com Nuclear Plant Journal, September-October 2015
