Lifting Equipment and Attachments
Tilt-up panels can be set up in many different ways
and with various kinds of power equipment. The
choice depends upon the size of the job. Besides the
equipment, a number of attachments are used.
EQUIPMENT. The most popular power
equipment is a crane. But other equipment used
includes a winch and an A-frame, used either on the
ground or mounted on a truck. When a considerable
number of panels are ready for tilting at one time,
power equipment speeds up the job.
ATTACHMENTS. Many types of lifting
attachments are used to lift tilt-up panels. Some of
these attachments are locally made and are called
hairpins; other types are available commercially.
Hairpin types are made on the jobsite from rebar.
These are made by making 180-degree bends in the
ends of two vertical reinforcing bars. The hairpins are
then placed in the end of the panel before the concrete
is poured. These lifting attachments must protrude
from the top of the form for attaching the lifting chains
or cables, but go deep enough in the panel form so they
will not pull out.
Among the commercial types of lifting
attachments, you will find many styles with greater
lifting capacities that are more dependable than
hairpins if properly installed. These are used with
lifting plates. For proper placement of lifting inserts,
refer to the plans or specs.
SPREADER BARS. Spreader bars may be
permanent or adjustable but must be designed and
made according to the heaviest load they will carry
plus a safety factor. They are used to distribute the
lifting stresses evenly, reduce the lateral force applied
by slings, and reduce the tendency of panels to bow.
Point Pickup Methods
Once the concrete has reached the desired
strength, the panels are ready to be lifted. The strength
of the inserts is governed by the strength of the
An early lift may result in cracking the
panel, pulling out the insert, or total concrete
failure. The time taken to wait until the concrete
has reached its full strength prevents problems
and minimizes the risk of injury.
Several different pickup methods are used. The
following are just some of the basics. Before using
these methods on a job, make sure that you check the
plans and the specs to see if these are stated there.
Figure 3-22 shows four different pickup methods: 2,
2-2, 4-4, and 2-2-2.
The 2-point pickup is the simplest method
particularly for smaller panels. The pickup cables, or
chains, are fastened directly from the crane hook or
spreader bar to two pickup points on or near the top of
the precast panel.
The 2-2 point pickup is a better method and is more
commonly used. Variations of the 2-2 are 4-4 and
2-2-2 or combinations of pickup points as designated
in the jobsite specifications. These methods use a
combination of spreader bars, sheaves, and
equal-length cables. The main purpose is to distribute
the lifting stresses throughout the panel during
erection. Remember, the cables must be long enough
to allow ample clearance between the top of the panel
and the sheaves or spreader bar.
Erecting, Bracing, and Jointing Panels
Erecting is an important step in the construction
phase of the project. Before you start the erecting
phase and for increased safety, you should make sure
that all your tools, equipment, and braces are in proper
working order. All personnel must be well-informed
and the signalman and crane operator understand and
agree on the signals to be used. During the erection of
the panels, make sure that the signalman and line
handler are not under the panel and that all
unnecessary personnel and equipment are away from
the lifting area. After the erection is done, make sure
that all panels are properly braced and secured before
unhooking the lifting cables.
Bracing is an especially important step. After all
the work of casting and placing the panels, you want
them to stay in place. The following are some steps to
take before lifting the panels:
Install the brace inserts into the panels during
casting if possible.
Install the brace inserts into the floor slab either
during pouring or the day before erection.
Install solid brace anchors before the day of
If brace anchors must be set during erection, use
a method that is fast and accurate.