have a swivel pad that can allow the outrigger to slide off of un-level cribbing. After the outrigger pads
are in place, put the full weight of the unit on each outrigger as you jack it down. If the pad begins to
sink, retract the outrigger and use cribbing to increase the size of the pad. Repeat this procedure until
the cribbing doesn‘t sink. Keep away from any open-cut ditches, box culverts, curbs and unsupported
sidewalks. Once the boom is unfolded, carefully rotate and extend the boom over each outrigger. If
the outrigger pad sinks or is unstable, place the boom over the other side of the truck or refold the
boom, lift up the outrigger and increase the size of the cribbing. Repeat this procedure until all
outriggers are stabilized. If you are unable to stabilize the unit, you must relocate or not do the pour.
Continue to check the outriggers for sinking throughout the pour. When setting the outrigger on an
existing slab or footing, keep the center of the outrigger back three feet from the edge. The pump can
"rock" or "surge" forward and slip off the edge of the slab. Also, the slab can break easier near the
edge and can allow the outrigger to sink or tip.
When the operator is requested to operate the boom from a position away from the closest point of
the outrigger structure, it is imperative to have a competent person to monitor the concrete pumping
operations as well as the outrigger structure. This person must be trained in the operation of the
emergency stop, be able to safely and correctly guide the concrete delivery trucks to the concrete
hopper, to not let the hopper run low or empty, to watch for mechanical problems, and very
importantly, to watch the stability of the outrigger structure. This person should be instructed that it is
not acceptable to leave the concrete pumping operation unattended. It is recommended that this
person have two-way verbal communications with the concrete pump operator.
When priming the boom, proper grouting techniques are critical. Grouting techniques may vary by
company, by the geographic area that you are working in and/or by the concrete mix design that you
are to pump. In most cases, a yard of pre-mixed primer grout is considered the most dependable
method and therefore recommended. Although plugging up during the priming process of any size
boom is not desirable, with a 50-meter or larger boom it is even more important to prime up
successfully for each pour. Be aware the boom can sag up to 10 feet when being loaded with
concrete. Sagging can also occur when restarting the flow of concrete into the boom during the pour.
Use caution when restarting because if the end of the boom comes down and kinks the tip hose while
pumping, a serious accident could occur. If extra hoses or pipe are added to the end of the boom
beyond the tip hose, the weight must not impose an additional load on the end of the boom as it may
cause tipping or damage to the boom.
During the pour, frequently check the stability of the outrigger pads. If they are sinking or tipping,
fold up the boom and reset the cribbing. As you retract the boom, watch the area behind you because
the boom can extend far behind the pump.
Some booms have restricted areas in which the boom cannot be operated because too much
weight is exerted behind the turret. You must be aware of these limitations. While pumping, you may
experience some boom bounce, which can be minimized by adjusting the pumping speed.
If you end up with a completely full boom, you will end up sucking back nearly one
yard of concrete. It is important to end up with an empty hopper and have somewhere to discharge