A barge crane is chosen by two numbers: the load it lifts at the reach you need, and the heel that lift puts on your barge. Maximum tonnage comes third. A 20 t telescopic crane lifts 20,000 kg only 2.5 m from its column; at its full 22 m reach it lifts 1,500 kg. On a small pontoon, even a lift of about 1 t at 15.5 m can tilt the deck by around 5° (worked example below).
This guide is for owners and builders who want to fit a hydraulic crane to a work barge, flat-top barge or pontoon. It explains what “barge crane” means and how far the crane must reach. It shows how to estimate heel, how to choose between knuckle and telescopic booms, and how to mount and power the crane. Every crane figure comes from the technical drawings for our 17 marine models, 4 t to 25 t. Achord Chan, Product Operations Director at BOB-LIFT, compiled the guide from those drawings.
Key takeaways
- Size a barge crane by the load at your working reach. Our 25 t knuckle boom marine crane lifts 2,000 kg at its full 18.0 m reach.
- Telescopic boom marine cranes reach further: our 20 t model reaches 22.0 m and still lifts 1,500 kg there.
- Heel matters more on a small barge. In our worked example, the same 16.3 t·m lift heels a 30 × 10 m barge about 0.5° and a 15 × 6 m pontoon about 5°.
- The crane’s own weight goes high on the deck: from 1,256 kg (4 t) to 6,950 kg (20 t telescopic). A naval architect should check stability and deck strength.
- A barge without an engine needs its own hydraulic power unit. Our barge-size cranes need 25 to 80 L/min at 20 to 35 MPa and 15 to 55 kW; the 20 t telescopic runs two circuits, 80 + 63 L/min.
What is a barge crane?
A barge crane is a crane that works from a barge, and the term covers two main things. A crane barge, also called a floating crane, is a barge built to carry one large crane for heavy lifts. A barge-mounted crane is a hydraulic crane fitted to a working barge to load and unload it; on a pontoon, the same unit is often called a pontoon crane. With a crane barge, used for heavy lifts in ports and on construction sites, the barge exists to carry the crane. A barge-mounted crane is the opposite: a crane added to a barge that already has a job, such as carrying cargo, supporting a dredger or serving a marine works site.
| Type | What it is | Typical lift |
|---|---|---|
| Crane barge / floating crane | A barge or pontoon built to carry one large crane, often a crawler or lattice-boom crane | Tens to hundreds of tonnes |
| Barge-mounted or pontoon hydraulic crane | A pedestal-mounted knuckle boom or telescopic boom crane on the deck of a working barge | A few hundred kilograms to a few tonnes at working reach |
| Deck crane on a self-propelled vessel | The same kind of hydraulic crane on a cargo vessel, landing craft or workboat | As above |
The table adds a close relative, the deck crane on a self-propelled vessel, because it is built the same way. We build the second and third kinds: hydraulic marine cranes for barges, pontoons and small cargo vessels, from 4 t to 25 t rated capacity in this guide. We do not build floating cranes. In the United States, cranes on barges and pontoons are covered by the voluntary consensus standard ASME B30.8, Floating Cranes and Floating Derricks, and, on construction work, by OSHA rule 29 CFR 1926.1437. Both are worth reading before you plan any barge lift.
How far does the crane need to reach?
Start with a deck plan. Mark where the crane’s slewing centre will stand, then measure to the furthest point you need to lift from or land on. On a barge that is usually one of three places: the far side of the cargo deck, the quay edge when the barge lies alongside, or a second vessel moored outboard. Add the distance from the barge’s side to the load’s centre, not just to the quay edge.
A crane standing on the centreline of a 10 m wide barge already needs about 5 m to reach the side. Landing a pallet 3 m inland on the quay takes the reach to 8 m or more. A crane placed at one side, as many barge cranes are, reaches the quay easily but must work across the full beam to serve the far side of the deck.
The chart shows why rated capacity is a poor guide on a barge. Our 8 t telescopic crane reaches 18.5 m but lifts 400 kg there. Our 10 t knuckle boom crane reaches 14.68 m and lifts 1,150 kg at that point. Which one suits you depends on whether your loads are light and far away, or heavier and closer in.
Barge crane sizes: load at full reach for 4 t to 25 t
The table lists our marine cranes in the size range most barges use. Each row comes from the model’s technical drawing (figures checked in October 2026), and each model links to its product page with the full load chart. The maximum lifting moment is the figure your naval architect will ask for.
| Model | Boom | Max lifting moment | Max load (at reach) | Load at full reach | Crane weight | Hydraulic supply |
|---|---|---|---|---|---|---|
| SQ4ZA3TJ (4 t) | Knuckle | 8.4 t·m | 4,000 kg at 2.1 m | 850 kg at 7.7 m | 1,256 kg | 25 L/min, 26 MPa |
| BLZ90K5TJ (4.6 t) | Knuckle | 9.2 t·m (90 kN·m) | 4,600 kg at 1.9 m | 590 kg at 11.7 m | 1,520 kg | 25 L/min, 28 MPa |
| SQ5ZA3TJ (5 t) | Knuckle | 10.5 t·m | 5,000 kg at 2.1 m | 1,100 kg at 8.05 m | 2,120 kg | 35 L/min, 28 MPa |
| SQ6.3ZA4TJ (6.3 t) | Knuckle | 13.2 t·m | 6,300 kg at 2.1 m | 1,190 kg at 10.2 m | 1,740 kg | 40 L/min, 28 MPa |
| SQ8ZA6TJ (8 t) | Knuckle | 16.7 t·m | 8,000 kg at 2.0 m | 850 kg at 14.68 m | 2,730 kg | 40 L/min, 28 MPa |
| SQ10ZA6TJ (10 t) | Knuckle | 21 t·m | 10,000 kg at 2.0 m | 1,150 kg at 14.68 m | 2,920 kg | 40 L/min, 30 MPa |
| SQ12ZA6T (12 t) | Knuckle | 27 t·m | 12,000 kg at 2.25 m | 1,000 kg at 14.5 m | 4,350 kg | 55 L/min, 28 MPa |
| SQZ330T (16 t) | Knuckle | 34.8 t·m | 16,000 kg at 2.0 m | 1,450 kg at 15.9 m | 4,500 kg | 63 L/min, 33 MPa |
| SQZ430T (20 t) | Knuckle | 42.3 t·m | 20,000 kg at 2.0 m | 1,910 kg at 16.6 m | 4,900 kg | 63 L/min, 33 MPa |
| SQZ500T (25 t) | Knuckle | 53 t·m | 25,000 kg at 2.0 m | 2,000 kg at 18.0 m | 6,474 kg | 80 L/min, 35 MPa |
| SQ5SA4T (5 t) | Telescopic | 12.5 t·m | 5,000 kg at 2.5 m | 600 kg at 11.79 m | 2,100 kg | 32 L/min, 21 MPa |
| SQ6.3SA4T (6.3 t) | Telescopic | 15.75 t·m | 6,300 kg at 2.5 m | 600 kg at 12.6 m | 2,200 kg | 40 L/min, 20 MPa |
| SQ8SA5T (8 t) | Telescopic | 20 t·m | 8,000 kg at 2.5 m | 400 kg at 18.5 m | 3,250 kg | 55 L/min, 26 MPa |
| SQ10SA4T (10 t) | Telescopic | 25 t·m | 10,000 kg at 2.5 m | 1,050 kg at 15.5 m | 3,250 kg | 63 L/min, 26 MPa |
| SQ12SA4T (12 t) | Telescopic | 33 t·m | 12,000 kg at 2.5 m | 1,200 kg at 16.19 m | 4,050 kg | 75 L/min, 26 MPa |
| SQ16SA5T (16 t) | Telescopic | 40 t·m | 16,000 kg at 2.5 m | 1,050 kg at 22.3 m | 5,800 kg | 80 L/min, 30 MPa |
| SQ20SA5T (20 t) | Telescopic | 50 t·m | 20,000 kg at 2.5 m | 1,500 kg at 22.0 m | 6,950 kg | 80 + 63 L/min, 25 MPa |
All of these slew 360°. Between the two ends of each row, the load chart on the product page gives the rated load at every reach. Plan your lifts from that chart, not from the headline tonnage. The max lifting moment is the rated moment printed on each drawing. It is set by the boom position that limits the crane, so it is not always the max load multiplied by its reach. Crane weights are also taken from the drawings; confirm the exact weight on your quotation drawing before the stability check.
How much will the barge heel when the crane lifts?
Heel is the sideways tilt of the barge. When a crane on a barge swings a load over the side, the load’s weight acts at the hook, far from the barge’s centreline. That creates a heeling moment roughly equal to the load multiplied by its distance outboard. The barge tilts until its own buoyancy balances that moment. A big, heavy barge barely moves; a small, light pontoon can heel enough to put the deck edge near the water.
For a first estimate at small angles, naval architects use tan(heel) ≈ heeling moment ÷ (displacement × GM), where GM is the barge’s metacentric height, a measure of how strongly it resists tilting. For a box-shaped barge, GM = KB + BM − KG, with KB = draught ÷ 2 and BM = beam² ÷ (12 × draught). We ran that estimate for one lift on two box-shaped barges: our 10 t telescopic crane lifting 1,050 kg at 15.5 m, a moment of about 16.3 t·m. The estimate assumes the crane stands on the barge’s centreline and leaves out the crane’s own weight. If the crane stands at one side of the pontoon and slews outboard, the load is about 18.5 m from the centreline and the heel rises to about 6°.
The 30 × 10 m barge at 1.5 m draught displaces about 461 t in seawater. With an assumed KG (height of the centre of gravity) of 2.0 m, its GM is about 4.3 m and it heels about 0.5°. The 15 × 6 m pontoon at 1.0 m draught displaces about 92 t. With an assumed KG of 1.5 m, its GM is about 2.0 m and it heels about 5°. At 5°, the deck edge of a 6 m wide pontoon drops about 0.26 m, and a load swinging on the hook adds a dynamic swing on top. That is why the same crane can be comfortable on one barge and marginal on another.
Treat these numbers as a reason to ask questions, not as a design. Give your naval architect or the barge’s builder these figures from the crane’s drawings: crane weight, the height of its centre of gravity, the foundation loads, the largest load moment you plan to lift, and the slewing range. They can then check heel, freeboard and whether ballast or a crane counterweight is needed. Ask your supplier as well what list and trim the crane’s load chart allows.
Knuckle boom or telescopic boom on a barge?
Both work on barges. The choice depends on your loads and your deck.
- Telescopic boom marine crane: a straight boom that reaches far for its size, and a long boom laid flat along the deck when stowed. It suits light to medium loads lifted across a wide deck or from a quay several metres away, such as bagged cargo, pallets and pipes.
- Knuckle boom marine crane: a folding boom that stows in a compact package beside the column, leaving the cargo deck clear. At the same rated capacity it usually lifts more at the end of its shorter reach, and it can reach down into a hold or over an obstacle. Our models with J in the name are drawn with a winch drum for lifting below deck level.
Our customers use both types on open-deck vessels that work much like barges. In the Maldives, telescopic marine cranes work on open-deck cargo vessels and on a quay, lifting bagged cargo between boat and shore. In Egypt, SQ5ZA3T knuckle boom marine cranes were fitted to harbour workboats, where a folded crane leaves the small aft deck free. For a fuller comparison of the two boom types, see our marine crane buying guide.
Where to put the crane, and how to mount it
Most barge cranes stand near one end or at one side of the cargo deck, so the crane can serve the whole deck and still reach over the side to the quay. Wherever it goes, the slewing circle must clear wheelhouses, masts and rails, and the operator needs a clear view of the hook.
A deck crane for a barge is only as good as its foundation. The deck under the crane carries its weight and its overturning moment. That moment is the load moment, rated at up to 53 t·m for our 25 t knuckle boom crane, plus the moment of the boom’s own weight and dynamic allowances. Design the pedestal from the foundation loads on the crane’s base drawing, not from the rated moment alone. A plain deck plate will not take that load by itself. The usual solution is a steel pedestal welded to deck structure that has been reinforced below, with the crane bolted to a flange on top. Photos in the Egypt case study above show this set-up on a small workboat: each crane on a raised pedestal, with a seated control station, an access ladder and a hydraulic power unit housed on deck beside it. The pedestal height also lifts the boom clear of rails and deck cargo.
Base flange sizes, bolt patterns and foundation loads for each model are in our pedestal crane guide.
We supply the crane’s base dimensions, bolt pattern and loads with the drawing. The pedestal and the deck reinforcement are designed by the barge’s builder or naval architect, who knows the structure underneath.
Hydraulic power on a barge
A self-propelled barge or cargo vessel can often drive the crane pump from a power take-off on the main engine or a generator engine. Many barges have no engine at all; they are pushed or towed. Those need a separate hydraulic power unit on deck, usually diesel or, where shore or ship power is available, electric.
Whichever you use, it must deliver the flow and pressure on the crane’s drawing. Across the cranes in this guide, the drawings give a range from 25 L/min at 26 MPa (15 kW) for the 4 t knuckle boom to 80 L/min at 35 MPa (55 kW) for the 25 t knuckle boom. Our 20 t telescopic crane uses two circuits, 80 and 63 L/min. The kW figures are the pump power stated on each drawing. An undersized pump makes the crane slow; too little pressure means it cannot lift its rated load.
Corrosion protection, maintenance and lifting regulations
A barge crane lives in spray and is often left outside between jobs. Ask your supplier about the paint system, how cylinder rods and pins are protected, and how electrical parts are sealed. Rinse the crane with fresh water after work in salt spray, grease slewing and pivot points on the schedule in the manual, and stow the boom with the hook secured before the barge moves.
Rules depend on where the barge works and how it is registered. In the UK, for example, lifting equipment on ships falls under the Merchant Shipping LOLER regulations described in MGN 332, including periodic thorough examination. Our marine cranes are not certified by a classification society. If your barge is classed, or your project specifies class approval for the crane, confirm the requirement with us before you order.
A six-step barge crane checklist
- Loads. List your heaviest load and your most frequent one, including slings, nets or a lifting frame.
- Reach. On the deck plan, measure from the slewing centre to the furthest pick-up and landing points.
- Load at that reach. Choose a crane whose load chart covers the load at that distance, with margin.
- Heel and deck strength. Give the crane weight and your largest load moment to the naval architect or builder.
- Power. Confirm a PTO or a hydraulic power unit that meets the crane’s flow and pressure.
- Boom type and winch. Telescopic for long reach across a wide deck; knuckle boom for compact stowage, heavier loads at reach and lifts below deck.
Frequently asked questions
What size crane do I need for a barge?
Work it out from your heaviest load and the furthest point you lift it from, then check the heel with your naval architect. As a rough guide from the table above, leaving some margin:
- About 1 t at 8 m: our 5 t knuckle boom (1,100 kg at 8.05 m).
- About 1 t at 10 m: the 6.3 t knuckle boom (1,190 kg at 10.2 m).
- About 1 t at 14.5 m: the 10 t knuckle boom (1,150 kg at 14.68 m). The 12 t knuckle boom is at its limit there, with 1,000 kg at 14.5 m.
- About 1 t at 15.5 to 16 m: the 10 t telescopic (1,050 kg at 15.5 m) or the 12 t telescopic (1,200 kg at 16.19 m).
- About 1.4 t at up to 15.9 m: the 16 t knuckle boom (1,450 kg at 15.9 m).
- About 1.9 t at up to 16.6 m: the 20 t knuckle boom (1,910 kg at 16.6 m). Up to 18 m: the 25 t knuckle boom (2,000 kg at 18.0 m).
- About 1.5 t beyond 18 m: the 20 t telescopic (1,500 kg at 22 m).
Between these points, read the load chart on each product page.
What size barge do I need for a 10 t crane?
There is no fixed minimum. The answer depends on the heel you can accept and on the barge’s stability, which your naval architect sets. Our heel example gives a sense of scale. Take our 10 t telescopic crane lifting 1,050 kg at 15.5 m. A 30 × 10 m barge at 1.5 m draught heels about 0.5°; a 15 × 6 m pontoon at 1.0 m draught heels about 5°. Send us the barge’s length, beam and draught, and we will give you the crane weight and load moments to work with.
Do I need a winch on a barge crane?
You need one when loads must go below the crane’s base, for example into a hold, down to a low quay or into the water, because the winch pays out rope instead of relying on the boom alone. On our drawings, the knuckle boom models with J in the code, such as the SQ10ZA6TJ, are drawn with a winch drum. Winch line pull and rope length are not on the drawings, so we confirm them with the quotation.
Can a barge crane lift while the barge is moving or in swell?
Load charts assume the barge is close to level and still. Swell, wash from passing vessels and the barge’s own heel swing the load and add force to the crane. Lift in sheltered water, moor the barge before lifting, and ask your supplier what list and trim the ratings allow.
Can I fit a truck-mounted crane to a barge?
We do not recommend it. A truck crane is protected for road use, not salt spray, and its base is designed for a truck chassis rather than a pedestal on a deck. A marine version has the same lifting geometry with protection for work at sea.
Do I need class approval for a crane on a barge?
It depends on the barge’s flag, its class and the project. Many harbour and inland barges are not classed, but some contracts and authorities require it. Our marine cranes are not class certified, so check with your flag administration or class society first, and tell us the requirement when you ask for a quote.
What is the difference between a barge crane and a deck crane?
Deck crane is the general name for any crane on a vessel’s deck. A barge crane is a deck crane on a barge or pontoon. The selection questions are the same, but barges are often wider, flatter and without their own engine, so heel, reach across the beam and hydraulic power need more attention.
For self-propelled cargo vessels, landing craft and workboats, our deck crane guide covers outreach over the side, stowage at sea and deck strength.
Send us your deck plan
The fastest way to a crane that fits is to start from your barge, not from a catalogue. Send us the barge’s length, beam and draught, a deck plan with the crane position you have in mind, your heaviest loads and where you lift them, and the power available on board. We will suggest models from our knuckle boom marine cranes and telescopic boom marine cranes, with the load chart and base drawing for each. For smaller fishing boats and workboats, our boat crane guide covers 0.8 t to 5 t. Contact us to start.
