SQ3.2ZA3 Knuckle Crane Lifting a Trailer in the USA

A tandem-axle trailer swinging over a parking lot on four green round slings, under a blue BOB-LIFT SQ3.2ZA3 knuckle boom crane on a white flatbed truck: three photos from our customer in the United States show the crane at full stretch and then at work at dusk.

At a glance: SQ3.2ZA3 3.2 t knuckle boom crane · United States · behind-cab on a white cab-chassis flatbed · lifting a utility trailer · 3 customer photos.

At the yard

• The truck. A white cab-chassis truck with a blue flatbed and a tall blue headboard behind the cab. The crane is painted blue to match and carries the BOB-LIFT and SQ3.2Z markings.
• Full stretch. In daylight the crane is unfolded and fully extended over an empty lot, with the outrigger leg down beside the truck and a worker walking underneath. Behind the lot are a long service building with roll-up doors and dry, rocky hills.
• Lifting a trailer. Two photos taken at dusk show the boom raised with a blue tandem-axle utility trailer hanging from the hook on four green round slings, lifted clear of the ground beside the truck. A second blue trailer stands in the foreground, and a tanker truck is parked nearby.

These are the customer's own photos. No lift weights, dates or comments came with them.

SQ3.2ZA3 specifications

The SQ3.2ZA3 is a 3.2 t knuckle boom truck-mounted crane with a maximum lifting moment of 6.8 t·m and three boom sections. Reach and load figures are read from the technical department's load chart drawing; the hydraulic figures come from the BOB-LIFT brochure.

Lifting moment is the load times its distance from the slewing centre. That is why the rated load drops as the boom reaches out. For example, the SQ3.2ZA3 lifts 3,200 kg at 2.1 m but only 680 kg at 7.7 m. Outrigger span is the width between the outrigger feet when they are fully out. Set them on firm, level ground, such as concrete or compacted gravel, before each lift. For ground and outrigger rules, see the OSHA cranes and derricks standard.

The 3,200 kg rating applies at 2.1 m. At 4.35 m it is 1,350 kg, and at the full 7.7 m reach, the stretch seen in the daylight photo, it is 680 kg.

The SQ3.2ZA3 product page has the dimension drawing and the full specification.

A 3.2 t knuckle crane on a light flatbed

A crane in this class suits a cab-chassis truck like this one because it is light and folds into a short space behind the cab. Three numbers to check before building one:

1. Crane weight. At 1,330 kg plus the subframe, the crane takes a real share of a light chassis's payload. Check what is left for the deck load.
2. Installation space. The SQ3.2ZA3 needs about 850 mm behind the cab. The rest of the frame stays free for a long flatbed.
3. Hydraulics. The crane is specified for 25 L/min at 25 MPa, about 14 kW, a flow that a PTO and pump on a light truck can usually supply.

For a lift like the trailer in these photos, weigh the load first and keep it close: the rating at 4.35 m is less than half the rating at 2.1 m. Set the outriggers before unfolding the boom; they span up to about 3.5 m. How we fit cranes to customer chassis is on the mounting and shipping page, and other capacities are in the knuckle boom truck mounted crane range.

Checking a truck for the SQ3.2ZA3

Before you order, check three things on your truck. They decide whether the SQ3.2ZA3 fits it.

• Payload. The crane weighs 1,330 kg. Take this off the truck's payload, then plan the body and the loads you carry with what is left.
• Hydraulic power. The crane needs 25 L/min at 25 MPa, about 14 kW. The power take-off and pump on your truck must give at least this.
• Outrigger room. The outriggers span 2,250 to 3,513 mm. Make sure the frame has room for them, and that your job sites do too.

Send us the make, model and wheelbase of your truck through the contact page, and our team will check the fit.

Record compiled by Achord Chan, Product Operations Director at BOB-LIFT, from the customer's photos, the technical department's drawing and the BOB-LIFT brochure.