SQ16ZA4 Knuckle Boom Crane on a Tractor Unit in Qatar

A yellow knuckle boom crane with a high operator seat on its column, mounted behind the cab of a grey tractor unit and reaching out over a workshop yard: photos from our customer in Qatar show a BOB-LIFT SQ16ZA4 knuckle boom truck-mounted crane being fitted and tested.

At a glance: SQ16ZA4 16 t knuckle boom truck-mounted crane · Qatar · tractor unit with high seat · 5 customer photos.

What the photos show

• The fitting. In one photo, mechanics in overalls work on the crane base behind the cab, with the boom folded. The fifth wheel coupling is still on the tractor frame behind the crane.
• The crane. The yellow boom carries the BOB-LIFT name, the marking SQ16Z and a warning not to stand under the boom. A red hook hangs from the tip of the black extensions.
• The high seat. An operator sits in a seat with a curved guard rail high on the crane column, so the operator can see over the cab while the crane works.
• The test. With an outrigger leg set down on the left side, the boom is raised almost upright in one photo and reached out level in another.
• On the road. One photo shows the folded crane on a truck behind an orange trailer on a highway.

These are the customer's own photos. No load weights or comments came with them. A second yellow crane on another tractor unit stands behind in the yard.

About the SQ16ZA4

The SQ16ZA4 is an earlier 16 t knuckle boom truck-mounted crane. It is no longer in the current range, and the technical department has no current drawing for it, so this record does not quote load figures for it. For a new crane of this size, see the 16 t knuckle boom truck-mounted crane page, where each current model has its own dimension and load chart drawings.

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, a load the crane lifts easily close to the column can be too heavy once the extensions are pushed out. Outrigger span is the distance between the outrigger feet. A wider span keeps the truck steadier when the crane slews to the side. For general crane safety rules, see the OSHA cranes and derricks standard.

A high seat lets the operator see the load over the cab and the body, which helps on long reaches. A crane with a high seat also works in our delivery record from the Philippines, and a 12 t knuckle boom crane lifts machinery in our record from Argentina.

A large crane on a tractor unit

Fitting a crane behind the cab of a tractor unit lets one truck lift and tow a trailer. Four points to plan for:

1. Check the axle loads. A large crane behind the cab adds a lot of weight to the front axle. Weigh the finished truck and check each axle against its rating.
2. Keep the fifth wheel clear. The crane base and the folded boom must leave room for the trailer to couple and turn.
3. Set the outriggers on firm ground. A crane this size needs both outriggers down on firm ground or pads before the boom reaches out.
4. Test before work. Run every motion with no load, then test with a known weight before the first real job.

Other sizes are in the knuckle boom truck-mounted crane range, and the mounting and shipping page explains how mounting is handled.

Checking a truck for a 16 t crane

Before you order a current 16 t crane, check three things on your truck. They decide whether the crane fits it.

• Payload. The crane, its subframe and the outriggers all come off the truck's payload. Plan the body and the equipment you carry with what is left.
• Hydraulic power. The power take-off and pump on your truck must give the flow and pressure the crane needs.
• Space on the frame. Make sure the frame has room for the crane and its outriggers next to the equipment already on the truck.

If you run an SQ16ZA4 today, a photo of its nameplate helps us. Send 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.