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 concrete. CAUTION 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 erection. If brace anchors must be set during erection, use a method that is fast and accurate. 3-41