Concrete Placing Boom Types, Components and Terminology
Boom configurations
Concrete placing booms fall into several families. Truck-mounted booms (boom pumps) carry the boom on a truck chassis with outriggers and a concrete pump. Trailer-mounted booms attach to a separate pump and rely on outriggers. Stationary or climbing booms are fixed to a base or building core and used on high-rise projects. Separate placing booms (SPBs) are mounted on a pedestal or crane-lifted base. Each type has different stability assumptions, so the operator must know which type they are running.
Core components
Know the terminology: the boom sections (typically three to five sections) fold and unfold via hydraulic rams; the slewing unit rotates the boom; the pedestal or turret is the mounting point; outriggers provide the support base; the pipeline runs along the boom to the end hose; the end hose (or placing hose) delivers concrete; the hopper and pump feed concrete into the pipeline; and the counterweight balances the boom. Safety devices include the boom limiting system, the outrigger interlock, the emergency stop, and the pipeline safety pins.
Traps in exam questions
Questions often test the difference between the boom's rated capacity and its structural limit - never exceed the load chart. Another trap is confusing the end hose with the pipeline; the hose is a flexible delivery point, and its weight and concrete load count toward the boom load. Also know that the boom must not be used as a crane or to lift loads, and that pipe blockages can cause sudden pressure release.
Rule of thumb
If you cannot name the component and its function, do not operate it. Pre-start familiarisation with the specific boom's manual is mandatory.