What Is That Tall Concrete Placing Boom? Separate vs Truck-Mounted Booms
By PumpX Team ·
If you spotted a tall metal arm that looks like a crane but pours concrete, there's a good chance it's a concrete placing boom. I'm working from the title only and can't see the photo, so this is a general explainer of what these machines usually are, not an identification of that one.
Placing boom, in plain terms
A placing boom is a hinged boom with a pipe running along it, used to deliver concrete to where it's needed. The key point is that it doesn't have its own engine and pump on a truck chassis. Instead, a separate stationary pump (or truck pump) pushes concrete up a pipeline to the base of the boom, which then positions the end hose precisely.
Because it's fixed to a structure or a mast, a placing boom can stay in place for weeks or months on one project. That suits big pours repeated over many floors.
Common types
- Column or mast-mounted placing booms. The boom sits on a vertical column or tower, often at the centre of a building. The mast may climb with the building as it rises, working floor by floor. This is the style most people mean by tall and metal.
- Free-standing or ballasted booms. A base with weight or supports allows the boom to stand alone on a flat deck or site.
- Crane-mounted or tower-attached systems. The boom clips onto a tower crane or other structure. I won't claim details beyond that, as arrangements differ.
- Rail- or track-mounted booms. Used in some large civil jobs, though less common.
Manufacturers such as Putzmeister and Schwing make placing booms among other products. Ask a maker or hirer for specs on any specific unit.
How it differs from a truck-mounted boom pump
| Feature | Placing boom | Truck-mounted boom pump |
|---|---|---|
| Pump | Separate stationary or line pump | Built into the truck |
| Mobility | Fixed or climbing; takes time to set up | Drives in, sets up in minutes |
| Best for | High-rise, long programmes, big repeated pours | One-off pours, mixed sites |
| Footprint | Small on the structure | Needs room for outriggers on the ground |
| Cost profile | Hire or install cost spread over long job | Hourly hire per pour |
A truck pump is the answer for a house slab or a single commercial pour. For a 40-storey core, hauling a truck pump up is impossible, so a pump at the base pumps concrete up a rising pipe to a placing boom on the structure. See how concrete reaches the top of a high-rise.
Why "precision"?
The boom lets an operator control the end hose position through a remote, often with the pipe hanging straight down to the pour. This reduces the need to drag a hose around by hand across rebar, and puts concrete where the formwork crew needs it. It's less about being more accurate than a truck boom, and more about giving continuous coverage from a fixed point.
Where you'd see them
- High-rise cores and floor slabs
- Large industrial or infrastructure sites
- Bridge piers or tall walls, depending on the setup
- Sites where a truck pump can't get close enough
Safety
Placing booms bring particular hazards:
- Falling concrete or hoses from height. Exclusion zones apply below.
- Wind loading on a tall boom. Follow the manufacturer's wind limits.
- Powerlines and cranes. Coordinate with crane operations and keep clear of overhead lines.
- Anchoring and ballast. The base must be designed and installed by competent people.
- Blockages in vertical lines can hold large pressure. Don't open couplings under load. See unsafe concrete pump operation hazards.
Cost
Placing boom systems are usually part of a larger contract, with pricing depending on duration, height and setup. Figures vary widely by region, so ask suppliers for a quote. For a standard truck pump comparison, try the rate calculator.
If you're not sure what you saw
Other tall metal machines near construction include tower cranes with concrete buckets, mast climbers, and telehandler booms. A boom with a pipe along it and a flexible hose at the tip is the giveaway for concrete. If you can see the tip hose, you've likely found it. For other identifications see what is this concrete pump machine.
Hiring or buying one
Most builders hire placing boom systems as part of a package with a specialist pumping contractor, rather than buying. The contractor supplies the boom, the base or mast, the pipeline and the operators. If you are a builder, ask how the boom is anchored to your structure and what loads it puts on it, because your engineer needs to check that. If you are an owner of an older boom, it may still be listed for sale or hire, so it is worth a look through the browse section.
Key takeaways
- A placing boom delivers concrete from a fixed position, fed by a separate pump.
- They suit tall buildings and long programmes where a truck pump can't reach.
- Truck-mounted boom pumps are mobile and self-contained; placing booms are not.
- Wind, falling objects and overhead hazards are the main safety concerns.
- Without the photo, treat any ID as general rather than certain.
Need pumping for tall or complex sites? Browse pumping services on PumpX.
Original question on Reddit: r/whatisthisthing: This big precision cement pourer crane thing? It's tall, metal