SQ5ZA3T Marine Crane on a River Boat in Bangladesh

A yellow knuckle boom crane on the deck of a blue-hulled work boat, moored on a muddy river bank beside a shipyard: four photos from our customer in Bangladesh show a BOB-LIFT SQ5ZA3T knuckle boom marine crane on a river work boat.

At a glance: SQ5ZA3T 5 t knuckle boom marine crane · Bangladesh · river work boat · 4 customer photos.

What the photos show

• The crane up close. The folded boom is marked BOB-LIFT and SQ5Z. A winch drum with wire rope is mounted on the boom, and hydraulic hoses run along it. The column stands on a steel base welded to the deck, with a control stand beside it.
• The boat. The crane stands at the front of a flat green deck with red rails and bollards. A white wheelhouse sits at the other end.
• On the river bank. The boat lies at the water's edge, tied to the bank with a heavy rope. Water hyacinth floats beside it, and painted passenger boats lie behind.
• The shipyard. A wide photo shows the boat among ship hulls under construction, with steel scrap and bricks on the sandy bank.

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

SQ5ZA3T specifications

The SQ5ZA3T is a 5 t knuckle boom marine crane with a maximum lifting moment of 10.5 t·m. All figures are read from the technical department's 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, the SQ5ZA3T lifts 5,000 kg at 2.1 m but only 1,100 kg at 8.05 m. Working radius is the level distance from the slewing centre to the hook. On a vessel or a quay, the pedestal takes the place of outriggers. It must be strong enough for the crane's weight and its full lifting moment. For general crane safety rules, see the OSHA cranes and derricks standard.

At 6.2 m from the slewing centre the crane is rated for 1,600 kg; at full reach of 8.05 m it is 1,100 kg. With the boom raised to 75°, the tip reaches about 10.2 m high.

The SQ5ZA3T product page has the full drawings, and other models of this size are on the 5 t knuckle boom marine crane page. The same model is fitted on new work boats in our delivery record from Egypt, and a 5 t truck crane works in our record from India.

A marine crane on a river work boat

River boats are often flat and light, so a crane load over the side has a strong effect on them. Four points to plan for:

1. Moor the boat before lifting. Tie it at both ends, so it cannot swing away from the load or the bank during the lift.
2. Watch the heel. A load swung out over the side makes a light boat lean. Keep loads close in where you can, and check the boat builder's stability limits.
3. Use the winch for long drops. The winch lets the hook go down to the water or to a lower barge. Keep a few turns of rope on the drum at the lowest point.
4. Wash off mud and silt. River water and mud wear the slewing gear and cylinder rods. Rinse them with fresh water after work and grease the slewing ring as the manual says.

Sea water is hard on steel, so the marine cranes get an epoxy zinc primer with a polyurethane acrylic top coat. Other capacities are in the knuckle boom marine crane range, and the marine crane buying guide covers deck mounting in more detail.

What to send us for a marine crane

To check a crane like the SQ5ZA3T for your boat, we need a few details. Short answers are fine.

• The site. The vessel type and length, or the quay, and where the crane will stand.
• The lifts. The heaviest load, and how far from the crane it is picked up and set down.
• The power. The hydraulic power pack you have now, or whether you need a new one. The SQ5ZA3T needs 35 L/min at 28 MPa, about 22 kW.

Send these through the contact page, and our team will check reach and load against the chart.

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