Home > PB33A-4R-II — 32.4 m Four-Section Column-Climbing Placing Boom

PB33A-4R-II — 32.4 m Four-Section Column-Climbing Placing Boom

The PB33A-4R-II is the four-section member of the TRUEMAX column-climbing placing-boom line. Where the 3-section booms reach a wide radius with three long arms, this model uses four shorter, articulating sections to reach 32.4 m — and the point of the extra joint is manoeuvrability, not just reach. Four articulating sections let the boom bend down between columns, fold over rebar cages and snake the end hose into pour points that a three-section boom would struggle to thread. To drive that extra section under load, the hydraulics step up to an 18.5 kW motor and 30 MPa system pressure.

It is a self-climbing boom: it rides up the building on a floor frame or inside the core / elevator shaft, so it rises with the structure rather than being relifted by crane. A separate stationary or line concrete pump supplies it up a riser, and the boom distributes that concrete across the floor — it is the placing tool at the top of the line, not the pump. Running on a 380V/50Hz supply through its 18.5 kW motor, it is built and tested at the TRUEMAX factory in Haining, holds ISO 9001:2015 and CE certification, and is part of a placing-boom line exported to high-rise and infrastructure projects in more than 120 countries.

1. Four-section R-fold boom — Four articulating arms (the “4R” in the name) give a tighter, more adaptable fold than a three-section boom, so the boom can reach down, over and around obstructions to place concrete in congested layouts.

2. Reinforced hydraulics — An 18.5 kW motor and 30 MPa system pressure power the additional section and keep boom movements firm and controlled under load.

3. Self-climbing on the structure — Climbs on a floor or shaft frame and jacks itself up its own height as the building rises — no per-floor crane lift.

4. Full 360° gear slewing — Gear drive rotates the boom through a complete circle, with a slewing cushion valve damping start and stop for steady placing.

5. 32.4 m reach with a compact fold — The four sections deliver a 32.4 m radius yet stow tightly, which helps the boom move and climb in a confined core.

6. Balance-arm-free, integrated base — No counterweight arm for freer rotation; the hydraulic pump station and control cabinet share the lower support for quicker installation and fewer faults.

7. Flexible remote control — TRUEMAX electric-proportional remote plus switch-type radio and cable remotes, built around Omron / Schneider electrical components.

8. Quality, configurable hardware — Imported hydraulic hose and push-in couplers; columns available in 4 m, 5 m, 6 m and 10 m lengths with floor or shaft climbing frames.

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Technial Parameters

Item	Unit	PB33A-4R-II
Performance
Max. Radius of Placing Boom	m	32.4
Free-Standing Height (to boom root joint)	m	21.3
Slewing Range	/	360°
Mode of Slewing	/	Gear Slewing
Circumstance Temperature	℃	-20 ~ 55
Power Supply (customisable)	/	380V / 50Hz
Boom (4-Section R-Fold)
1st Section — Length	m	9.51
1st Section — Articulation	°	0 ~ 86
2nd Section — Length	m	7.56
2nd Section — Articulation	°	0 ~ 180
3rd Section — Length	m	7.65
3rd Section — Articulation	°	0 ~ 180
4th Section — Length	m	7.72
4th Section — Articulation	°	0 ~ 180
Delivery Line
Delivery Pipeline Diameter	mm	Φ125 × 4.5
Delivery Hose Diameter	in × mm	5" × 3000
Power & Hydraulics
Motor Power	kW	18.5
Hydraulic Pressure	MPa	30
Hydraulic Oil (5℃–55℃)	/	HM46 anti-wear
Hydraulic Oil (-20℃–5℃)	/	HM32 anti-wear
Installation & Weight
Application Scenario	/	Floor / Shaft Climbing
Balance Arm	/	None
Total Weight	kg	20100
Max. Lifting Unit	kg	4800

Dimensions & Working Range

The four-section boom gives a working envelope with more shape than a three-section one: as well as the 32.4 m radius swept through 360°, the extra joint lets the boom reach back under itself and into recesses. The working-range diagram shows that envelope, and the 21.3 m free-standing height is the height the boom holds above its support unbraced. Plan it against your core layout and the climbing-frame drawings.

Applications

The PB33A-4R-II is at its best on tall, busy structures where the boom has to place concrete in and around obstructions rather than simply sweep an open slab.

Congested high-rise floors

On floors crowded with columns, walls, rebar and embedded services, the four-section fold lets the boom drop the hose precisely between obstructions where a stiffer three-section arm cannot reach.

Core walls and elevator shafts

With a shaft frame the boom climbs inside the core or lift shaft, placing concrete to the surrounding deck and walls as the core leads the build.

Heavy and complex structural pours

The reinforced 30 MPa hydraulics suit demanding, continuous structural pours, holding the four-section boom steady while a pump feeds concrete up the riser.

Bridge pylons and tall piers

The self-climbing principle carries over to tall bridge pylons and piers, where the articulated boom places concrete around dense reinforcement as the element rises.

FAQs

What does the “4R” in PB33A-4R-II mean?

It denotes a four-section R-fold boom — four articulating arms rather than the three of the “3R” models. The extra section gives the boom a more flexible fold so it can reach over and around obstructions and place concrete in congested layouts, which is the main reason to choose a 4R boom.

How does it differ from the 3-section PB28A and PB32A?

The PB28A-3R-II (27.7 m) and PB32A-3R-II (31.7 m) use three sections and larger 11 kW / 28 MPa hydraulics; the PB33A-4R-II reaches a similar 32.4 m but with four sections and reinforced 18.5 kW / 30 MPa hydraulics. Pick a 3-section boom for open floors where reach is all you need, and the four-section PB33A-4R-II where the boom must manoeuvre around columns, walls and rebar.

How does the boom climb the building?

On a climbing frame — a floor frame for floor-by-floor climbing, or a shaft frame to climb inside an elevator shaft or core wall. It lifts itself up its standing height as the structure grows, so no crane is tied up moving it between levels.

Is the placing boom a concrete pump?

No — it places, it does not pump. Concrete is delivered by a separate stationary or line pump up a riser pipeline, and the PB33A-4R-II spreads it across the floor through its four-section boom. The two are used together.

Electric or diesel?

Electric: a 380V/50Hz supply driving an 18.5 kW motor (voltage and frequency customisable). There is no on-board engine, so it runs from mains power or a generator while the concrete comes from a separate pump.

What weight and crane capacity should we plan for?

Total installed weight is 20,100 kg, and the maximum single lifting unit during assembly is 4,800 kg — the figure to size your erection crane against, since the boom is built up from modular pieces.

What is supplied, and how is it shipped?

The package is the four-section boom, lower support, hydraulic pump station, control cabinet and remote. Columns, the floor or shaft climbing frame, delivery line, hose, spares, installation and commissioning are configured to your building and quoted separately. Send your floor and core details and we will propose a configuration.

Three-section vs four-section column-climbing booms

TRUEMAX offers the column-climbing placing boom in both three-section (3R) and four-section (4R) forms. A 3R boom — such as the 27.7 m PB28A-3R-II or 31.7 m PB32A-3R-II — reaches a wide radius simply and economically, ideal for open floors. A 4R boom — the 32.4 m PB33A-4R-II and the 32.55 m PB33D-4R — adds an arm for a more flexible fold, threading concrete into congested or obstructed layouts. If your floors are clear, the simpler 3R is enough; if they are dense with structure, the extra section earns its keep.

How the placing boom completes the pumping line

In a high-rise pour, concrete leaves the batching plant in a truck mixer and is driven up the building by a stationary or line pump through a riser. That riser ends at one point on the floor — and the placing boom turns that single outlet into reach across the whole slab. The PB33A-4R-II takes the concrete at the top and, thanks to its four sections, places it accurately even where columns and rebar crowd the deck, all under one operator's remote control.

Matching the boom to the structure

Choosing a column-climbing boom comes down to two questions: how far it must reach, and how cluttered the floor is. Reach sets the radius — 28, 32, 33 or 35 m across the TRUEMAX range. Clutter sets the section count — three sections for open work, four for obstructed work. The PB33A-4R-II answers a brief for solid reach with maximum manoeuvrability on busy structural floors; for the same radius in a lighter unit, the PB33D-4R is the alternative.