patented lift frame has reduced by as much as 90% the time required to modify
rigging configurations over traditional assemblies. This innovative method of
rigging modules and other loads substantially reduces the HSE exposure hours
and increases the cost effectiveness of the overall heavy lift program.
of heavy industrial plant construction in the oil and gas and petrochemical
industries is a standard mode of operation, utilized to reduce costs, site
congestion, and schedule. Standard modules are 20 feet wide, from 80 to 120
feet long, up to 24 feet high, and range in weight from 50 to 160 metric tons.
Using a heavy crane, modules are lifted into place using tall columns that
extend from the top of the module. These “pick points” can vary in number and
configuration, depending on the size and composition of the module. Modules
also have differing centers of gravity, depending on their contents.
the rigging to accommodate the different pick point configurations and centers
of gravity has traditionally been a time-consuming and often dangerous process.
With PCL’s engineered module lift frame, however, rigging crews are able to
simply slide the connections into place using a patented slider assembly. What
used to take up to a day now takes a matter of minutes, setting a new bar for
productivity and safe work practices.
THE TRADITIONAL APPROACH TO MODULAR CONSTRUCTION
construction industry has for many years used a traditional rigging approach to
lifting and placing these modules onto their foundations or supporting
structures. Though the combination of spreader bars, slings, and rigging
hardware is well accepted and proven, the approach retains inherent risks and
can induce stresses within the lifted module,” said manager of construction
engineering Rick Hermann.
brought to the ground for reconfiguration between lifts in order to accommodate
changes in the dimensions and centre of gravity of the load to be lifted as
well as the number of points to which the rigging will be attached. This
process—affecting a crew of at least eight over five to ten hours—involves
handling heavy shackles, rigging components, and wooden timbers, while
increasing exposure to potential stored energy in the slings, and moving
rigging objects around the workers as they reconfigure the rigging
module does not rise evenly on lift, the rigging is disconnected and additional
shackles and rigging components are handled to make the adjustments that will
balance the load. During the assembly and hookup of the rigging to the module,
the rigging often hangs unevenly until it is hooked up to the module due to the
unsymmetrical configuration and the shackles added to balance the load during
lifting. During the assembly and hookup of the rigging to the module, the
slings and spreader bars can rotate and must be controlled by taglines,
especially when wind is present.
projects have a larger-than-average variety of module bay dimensions and number
of pick points. On a recent heavy industrial project, the rigging had to be
modified between lifts 58% of the time. Adjustments were made, over and above
that, to modify the center of gravity in both directions. The effect can easily
extend the heavy lift program by a few months, expose workers to pinch points
and other risk hazards, and add a huge cost to a project.
the variety of rigging configurations possible on a project using traditional
rigging methodology, a large inventory of slings, shackles, spreader bars, and
rigging hardware is required. It can take one full crew, onsite transporters,
and extra mobile cranes to manage the handling of these various components and
transport them to the lift sites on a project.
module is unequally loaded and relatively flexible, significant deflection can
occur, which has the potential to damage the module during lifting. If severe,
this can be very difficult to compensate for using traditional rigging methods.
Safety, schedule, and cost savings are the primary drivers for inventing a
better rigging methodology.
the issues that come with traditionally rigging and lifting these modules,”
said vice president Travis Chorney, “we took a hard look at where we could
improve the process that's been done the same way over and over again. We got
together with folks from the field who actually plan and execute the rigging
and looked at a process. We looked at different ideas: what can we make things
engineered, designed, and fabricated (in-house) an innovative method of rigging
modules to reduce site costs and improve safety. The PCL Engineered Module Lift
Frame is designed to meet AMSE BTH-1 design category B class 0, and also
Alberta OH&S, ASME B30-20, and CSA S16. It can easily handle a
160-metric-ton module for six to 16 point picks, 16- to 24-foot-wide modules,
and lengths up to 140 feet. To mitigate risk, the lift frame was load tested
three times and assembly tested once prior to placing it into service. The lift
frame has a provisional patent in place.
patented lift frame has reduced by as much as 90% the time required to modify
rigging configurations over traditional rigging assemblies. This substantially
reduces the HSE exposure hours and increases productivity of the heavy lift
PCL’s module lift frame was first to put to use for a client in August 2012 at the Conoco Phillips Surmont Phase 2 project near Anzac, Alberta, where it lifted 50 modules ranging from six to 16 points, and weighing up to 148 metric tons. Since then, PCL has fabricated two additional frames. To March 2017, PCL’s lift frames have been employed on five projects and lifted 643 modules.
The new lift frame uses two main running beams and a slider (a beam clamp-type mechanism) that allows for easy adjustment to the bay dimensions, while also allowing for center of gravity adjustments without the addition of shackles. These sliders are interconnected to enable easy adjustment of the rigging along the longitudinal axis, and can be locked in place at the end to prevent movement. The width of the module lift frame can be adjusted from 16 to 24 feet in six inch increments. These adjustments are performed more safely at ground level and take less than an hour to perform as compared to five to ten hours for traditional rigging.
“It takes an
average of half an hour to modify the rigging as compared to two to ten hours
for traditional rigging,” said operations manager Jamie Feuffel. “And due to
the symmetrical design, the module lift frame always picks level, making it
significantly easier to hook up to the module.”
Most of the
adjustments to the lift frame for bay dimensions, number of pick points, and
center of gravity do not require the use of assist cranes as do most
traditional rigging assemblies. The rigging height from the top of the module
to the crane hook block is 95 feet as compared to 130 to 165 feet for
traditional rigging. The rigging weight for 12- to 16-point pick modules
is quite similar to that of traditional rigging. The reduction in rigging
height has the potential to reduce the main boom length, which enables a higher
onsite, the lift frame is folded down with the top spreader bar and slings
removed, before being shipped on a transporter. This substantially reduces the
time required to dismantle and assemble the rigging. The stiffness of the lift
frame reduces the load redistribution forces within the module as compared to
traditional rigging. A dynamic finite element analysis was performed that
indicates an average reduction of 50%.
in less deflection of the module during lifting, and a reduction of potentially
damaging stresses within the module. Due to the efficiency of the rigging
changes of the lift frame as compared to traditional rigging assemblies, the
duration of the heavy lift program can be reduced by approximately 30%.
This is a significant gain in schedule that frees up areas for other trades to
perform their work.
other companies have attempted to form a rigid frame, truss, or other rigging
configuration to reduce the schedule and the cost of module installation,” said
vice president Chris Pullen, “PCL’s new system is much more flexible and more
quickly modified for the variety of modules that are installed on projects. The
inherent time savings it provides—as much as 90% over traditional rigging
configurations is huge. Every moment we can pull out of the schedule and to
reduce safety exposure, is great for us and our clients.”
are less exposure, lower risk to our workers doing the rigging, better
productivity, and better cost and schedule,” said Chorney. “In a nutshell we've
achieved all that with our lift frame.”
continuing to improve the design, to make the fold-down procedure easier, and
to extend the lift frame for longer and heavier modules.