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Knuckle Boom Marine Cranes

See all 8 Ton Cranes

8 Ton Knuckle Boom Marine Crane

Model SQ8ZA4TJSQ8Z-T Series

Choose your configuration

4 configurations in this series

Boom sections

1 main boomStandard

Winch

With or without a winch? Read our winch guide

Compared with SQ8ZA6TJ: Max reach ⁦−4.16 m⁩ · Lifting height ⁦−4 m⁩ · Self weight ⁦−180 kg⁩

Max lifting capacity
8,000kg
Max lifting moment
16.7t·m
Max reach
10.52m
Lifting height
≈ 13m
Self weight
2,550kg
8 Ton Knuckle Boom Marine Crane SQ8ZA4TJ

Engineering data

Technical Specifications

SQ8ZA4TJ

Model code explained

SQ
BOB-LIFT crane
8
8 t capacity class
Z
Knuckle boom
A4
1 main boom + 3 hydraulic booms
T
Marine version
J
With winch

Choose your configuration

Model Configuration Max reachLifting heightSelf weight
SQ8ZA4T A4 · No winch 10.52 m ≈ 13 m 2,470 kg
SQ8ZA4TJ A4 · With winch 10.52 m ≈ 13 m 2,550 kg
SQ8ZA5T A5 · No winch 12.63 m ≈ 15 m —
SQ8ZA5TJ A5 · With winch 12.63 m ≈ 15 m 2,650 kg
SQ8ZA6T A6 · No winch 14.68 m ≈ 17 m —
SQ8ZA6TJ A6 · With winch 14.68 m ≈ 17 m 2,730 kg

Knuckle boom marine cranes can be built with or without a winch.

— No-winch version: self weight confirmed with your quote

Lifting

Max Lifting Capacity
8,000kg
Max Lifting Moment
16.7t·m
Rotation Angle
360°
Winch
Included
Max Working Radius
10.52m
Max Lifting Height
≈ 13 m
Max Boom Angle
84°

Hydraulics and power

Recommended Power
25kW
Hydraulic System Flow
40L/min
Hydraulic System Pressure
28MPa
Oil Tank Capacity
160 L

Machine

Self Weight
2,550kg
Compare all Knuckle Boom Marine Cranes

Figures from the BOB-LIFT technical drawings. Confirm the final specification with our team before ordering.

Dimensions and load chart

SQ8ZA4TJ dimension drawing and technical parameters

SQ8ZA4TJ load chart

Select the drawing to view it full size.

How much it lifts at each reach The further the hook is from the crane, the less it can lift: 8,000 kg at 2 m, 1,420 kg at 10.52 m.
Lifts (kg) 8,000 3,700 2,470 1,820 1,420
Reach (m) 2 4.46 6.45 8.47 10.52

Reach is measured from the slewing centre to the hook. Figures from the drawing above.

Product details · SQ8ZA4TJ

8 Ton Knuckle Boom Marine Crane SQ8ZA4TJ

The SQ8ZA4TJ is an 8 ton knuckle boom marine crane. It lifts 8,000 kg at 2 m, 3,700 kg at 4.461 m and 1,420 kg at its full 10.515 m reach, with a maximum lifting moment of 16.7 t·m and 360° slewing. The crane itself weighs 2,550 kg.

Where the 8 ton SQ8ZA4TJ fits

The SQ8ZA4TJ has a winch on the boom, so the hook hangs from a rope: that helps when loads go down into a hold or onto a boat or quay below deck level. With a self weight of 2,550 kg and a Ø1,000 mm base plate, it is meant for barges, cargo vessels and quays with a strong, engineered pedestal.

Rated capacity always depends on radius. At 8.465 m the SQ8ZA4TJ lifts 1,820 kg and at 10.515 m it lifts 1,420 kg, so check the weight of your heaviest regular load at the distance you need before you choose a tonnage.

We size a marine crane by the load and the radius you need, not by vessel length. Send us the heaviest load, the furthest point it must reach and a deck drawing, and we check them against the SQ8ZA4TJ load chart.

Load at each radius

2 m 8,000 kg
4.461 m 3,700 kg
6.445 m 2,470 kg
8.465 m 1,820 kg
10.515 m 1,420 kg

Figures from the SQ8ZA4TJ load chart with the boom horizontal. Do not lift more than the chart shows at your working radius. Download the SQ8ZA4TJ load chart (PDF)

Deck mounting dimensions

These figures come from the SQ8ZA4TJ dimension drawing. Your shipyard or naval architect designs the pedestal and the deck reinforcement for the crane’s 2,550 kg self weight and its 16.7 t·m maximum lifting moment.

Base plate Ø1,000 mm
Mounting bolt holes 28 × Ø26 mm
Bolt circle diameter Ø930 mm
Centre hole in the base plate Ø500 mm
Folded size (L × W × H) 2,371 × 1,219 × 2,295 mm
Hydraulic supply 40 L/min at 28 MPa, about 25 kW
Oil tank 160 L

We can adapt the mounting to your vessel’s deck, for example by changing the pedestal height. Download the SQ8ZA4TJ dimension drawing (PDF)

Corrosion protection for sea duty

The T in SQ8ZA4TJ marks the marine version, which receives a multi-layer anti-rust treatment for salt air and spray. How long a crane lasts in a harbour still depends on routine care: rinse it with fresh water after salt-water work, grease the slewing bearing and pins on schedule, and check hoses and fittings for corrosion.

Warranty and service

BOB-LIFT covers the whole crane for 12 months. Common spare parts leave the factory within 48 hours, and our service team answers within 12 hours and can guide repairs by video. Cranes ship from Lianyungang, Qingdao or Shanghai.

All knuckle boom marine cranes · How to choose a marine crane

  • Capacity class

    8 t

    Max lifting moment 16.7 t·m

  • Knuckle boom sections

    4

    1 main boom + 3 hydraulic booms

  • Hydraulic flow

    40 L/min

    28 MPa · 25 kW recommended

Choosing the right model

Need more than 8 t? The next class up is the SQ10ZA6TJ at 10 t. For lighter loads, the SQ6.3ZA4TJ at 6.3 t is the class below.

Before ordering, check that the vessel's hydraulic supply can deliver 40 L/min at 28 MPa. We recommend 25 kW of hydraulic power.

Knuckle Boom Marine Crane

Product technical advantages

  • High-strength steel structure

    High-strength steel structure

    Compact, light and strong steel structure.

  • Custom installation

    Custom installation

    Pedestal mounting tailored to your deck.

  • Optional attachments

    Optional attachments

    Winch, drill pipe, basket or grapple.

  • Operation modes

    Operation modes

    Manual levers, overhead seat or wireless remote.

  • Dual four-bar linkage

    Dual four-bar linkage

    Reverse-angle reach for flexible work.

  • Dedicated torque limiter Load moment limiter, safety certified.
  • Marine anti-rust treatment Multi-layer anti-rust process for sea duty.

Manufacturing & delivery

From our workshop to your port

  1. Assembly 01

    Assembly

    Slewing base, column and booms are assembled by hand in our Xuzhou workshop.

  2. 02

    Marine test stand

    Mounted on a deck-style stand, the crane runs every boom and slewing motion before release.

  3. Final check 03

    Final check

    Finished cranes are inspected and lined up for dispatch.

  4. Packing 04

    Packing

    Wrapped in film and strapped to protect paint and hydraulics in transit.

  5. Container loading 05

    Container loading

    Loaded into containers at the factory and shipped to your port.

Shipping & warranty

Shipping, warranty and documents

Shipping

Lead time and container loading are confirmed with your quotation.

Warranty and parts

12 months

Send the model, serial number and a photo or video of the issue; our team guides the repair and ships the parts.

Order from 1 unit

Documents

FAQ

Questions about the SQ8ZA4TJ

About the SQ8ZA4TJ

Can the SQ8ZA4TJ lift 8 tons at full reach?

No. It lifts 8,000 kg at 2 m, and the capacity falls with radius to 1,420 kg at 10.515 m with the boom horizontal. Check the load chart on this page at your working radius.

What base plate and bolts does the SQ8ZA4TJ need on deck?

A Ø1,000 mm base plate with 28 × Ø26 mm holes on a Ø930 mm bolt circle. Your yard designs the pedestal and the deck reinforcement for the crane's 2,550 kg self weight and 16.7 t·m lifting moment.

What hydraulic power does the SQ8ZA4TJ need?

40 L/min at 28 MPa, about 25 kW, from the vessel's hydraulic power pack or an engine-driven pump. The crane carries a 160 L oil tank.

What warranty comes with the SQ8ZA4TJ?

12 months on the whole crane, with common spare parts dispatched within 48 hours.

How far can the SQ8ZA4TJ reach, and how far does it slew?

With every section unfolded it works out to 10.515 m and still holds 1,420 kg there, and the column turns through 360°. Place the crane on deck so that your heaviest regular load sits inside the radius the chart allows.

Not answered here?

Send us your question and our team replies with answers for your site.

+86 158 5249 9415

Ordering and service

Which configuration should we choose for this model?

Send the load, the outreach you need over the ship's side, the vessel type and where the crane will stand on deck. Our engineers confirm a practical model and mounting before quotation.

How is the crane mounted on the vessel?

The crane stands on its base plate, fixed to the deck or to a raised pedestal, and the base plate size is on the product drawing. Send us the deck structure at the crane position: we adapt the mounting to your vessel and confirm it with you.

Does this crane suit our sea conditions?

Tell us where the vessel works, whether you lift in port or at sea, and the conditions you expect during lifting. Our engineers check them against the load chart and confirm whether this model suits the job before quotation.

How is the crane protected against corrosion?

Tell us whether the vessel works in salt water or fresh water and where the crane sits on deck. We confirm the paint and surface protection for your conditions in writing with the quotation.

What is the delivery time, and which documents come with the order?

Lead time depends on the configuration, order quantity and destination, and we confirm it in writing with your quotation. Each order ships with a commercial invoice, packing list and bill of lading, plus the product documents required for the confirmed order.

Do you help with installation and after-sales service?

Your shipyard fits the crane with our installation guidance and remote technical support. Cranes carry a 12-month warranty, we reply to service requests within 12 hours, and common spare parts ship within 48 hours.

Guides and news

Read before you buy

All news

Need a crane matched to your vessel and lifting task?

Send the load, the outreach over the ship's side, the vessel type, the crane position on deck and the destination port. BOB-LIFT will help match a practical configuration.

Contact Engineer

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