SQ6.3ZA4 Knuckle Boom Crane Mounting in El Salvador

One crane truck lifting another crane: a photo from our customer in El Salvador shows a yellow BOB-LIFT SQ6.3ZA4 knuckle boom crane hanging from an older orange crane truck, held over the bare frame of a black truck chassis.

At a glance: SQ6.3ZA4 6.3 t knuckle boom crane · El Salvador · lifting the crane onto a truck chassis · 1 customer photo.

What the photo shows

• The crane. The yellow crane, folded and marked BOB-LIFT and SQ6.3Z, hangs from a hook on a chain sling. It comes up as one unit, with its column and base below the folded boom.
• The chassis. Below it stands a black truck chassis with yellow wheels. Behind the cab the frame is still bare, with timber blocks laid across it.
• The lifting truck. An older orange crane truck with a straight boom does the lift. Its outrigger legs are down on the paved yard, and one man sits at the controls on the crane seat.
• The tag line. A second man stands back from the load and steadies it with a rope.
• The yard. The work is done in a paved yard beside a street, under overhead power lines.

This is the customer's own photo. No weights, dates or comments came with it.

SQ6.3ZA4 specifications

The SQ6.3ZA4 is a 6.3 t knuckle boom truck-mounted crane with a maximum lifting moment of 13.2 t·m. 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 SQ6.3ZA4 lifts 6,300 kg at 2.1 m but only 1,190 kg at 10.2 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.

At 6.3 m from the slewing centre the crane is rated for 2,020 kg; at the full 10.2 m reach it is 1,190 kg.

The SQ6.3ZA4 is now a previous model. In the same 6.3 t class we currently build the SQ6.3ZA5 and the BLZ129K4. The SQ6.3ZA4 page compares all three and shows the full drawings. The same model sets concrete poles in our delivery record from Honduras and handles steel coils in our record from Mexico.

Lifting a knuckle boom crane onto a chassis

Before a crane can work on a truck, it has to be lifted onto the frame. That is a lift in its own right, and the crane being fitted is the load. Before the lift:

1. Know the weight. The SQ6.3ZA4 weighs 2,180 kg on its own. The crane doing the lift must be rated for that weight, plus the slings and hook, at the radius where it will set the crane down.
2. Sling it to hang level. Rig the folded crane so it hangs level with the column upright. It can then be lowered straight down onto the frame without tipping.
3. Get the frame ready first. Have the mounting area behind the cab clear and prepared before the crane goes up, so it hangs in the air for as short a time as possible.
4. Steady it from a distance. As in the photo, one person guides the load with a tag line. Nobody stands under the hanging crane or between it and the truck.
5. Watch the power lines. The yard in the photo has lines overhead. Keep the boom, the load line and the hanging crane clear of them, as the OSHA standard linked above requires.

How we fit cranes to customer chassis is on the mounting and shipping page. Other capacities are in the knuckle boom truck mounted crane range.

Checking a truck for the SQ6.3ZA4

Before you order, check three things on your truck. They decide whether the SQ6.3ZA4 fits it.

• Payload. The crane weighs 2,180 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 40 L/min at 28 MPa, about 22 kW. The power take-off and pump on your truck must give at least this.
• Outrigger room. The outriggers need room to extend fully. 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 photo, the technical department's drawing and the BOB-LIFT brochure.