• Feb 21, 2025
• News

Technical specifications for STS Cranes

The main technical specifications for ship to shore cranes usually include rated load，lifting height，outreach and so on.

In the previous article introduces what ship to shore crane selection factors, which involves a lot of parameter specifications are not introduced. This article focuses on some common specification parameters in the ship to shore crane. Whether you are engaged in related industries or just to satisfy curiosity, I hope this article can help you.

Weight Capacity and Spreader Considerations

As we touched on earlier, capacity is king. When you're looking at specs, remember that the rated lifting capacity usually doesn't include the spreader weight. So, if you see a crane listed as "40.5 tons capacity," that's for the cargo plus the spreader. Spreaders themselves can weigh around 8-10 tons, sometimes a bit less with newer designs.

• Rated Load: Make sure the rated load is sufficient for your heaviest anticipated containers, including the spreader.
• Twin Lift Capability: If you want to boost efficiency by handling two 20-foot containers at once, you'll need to specifically look for cranes designed for twin-lifting and check their twin-lift capacity.

Dimensional Parameters

Crane dimensions are crucial for fitting the crane to your quayside and handling the ships you expect. Key dimensions include:

• Lifting Height (above and below rail): This dictates how high the crane can lift containers above the quayside rail and how low it can reach below the rail into the ship's hold. Aim for around 25 meters above the rail and 12 meters below as a starting point, but adjust based on your ship types and tidal range. Total lifting height around 37 meters is common.
• Outreach (Seaward Reach): This is how far the crane's boom extends out over the water, determining how wide of a ship it can service. Consider the beam of the largest ships you'll handle and aim for enough outreach to reach containers stacked on the far side of the deck, even with the ship listing slightly.
• Back Reach (Landward Reach): This is how far the crane reaches back inland from the quayside rail. A good back reach gives you space to handle hatch covers, provides a buffer zone, and can be important depending on how power is supplied to the crane from the land side. Aim for around 7-11 meters of back reach.
• Rail Gauge (Track Gauge): This is the width between the crane's rails on the quayside. The rail gauge affects the crane's stability and also how you can organize your container yard behind the crane. A wider gauge (like 26 meters for wide-gauge cranes) offers greater stability but also takes up more quayside space. A standard gauge is around 16 meters. Choose based on your stability needs and yard layout.
• Portal Clearance Height: This is the height under the crane's portal (the legs) that allows vehicles to pass underneath. You need enough clearance for your straddle carriers or other container handling equipment to move freely under the crane. Around 10 meters of clearance is typical to accommodate straddle carriers stacking containers a few tiers high.

Working Speeds

We've talked about hoisting and trolley speeds, but here are the typical ranges and some context:

• Hoisting Speed (Laden and Unladen): As mentioned, aim for laden hoisting speeds of 35-50 meters per minute and unladen speeds significantly faster (70-120+ meters per minute) for good productivity.
• Trolley Speed: Look for trolley speeds in the range of 120-150 meters per minute or even higher, but again, consider sway control implications at very high speeds. Speeds above 140 m/min usually necessitate anti-sway tech.
• Gantry Speed (Travel Speed): This is how fast the crane moves along the quayside rails. It's less critical than hoisting and trolley speed because it's mainly for repositioning the crane, not cycle time. Speeds of 25-45 meters per minute are usually sufficient.
• Boom Hoisting Time (Boom Lift/Lower Time): This is how long it takes to raise and lower the crane's boom. Boom hoisting isn't part of the regular container handling cycle, but it's needed when ships are arriving or departing to clear the ship's superstructure. A boom lift/lower cycle time of 8-10 minutes is typical.

Conclusion

The specification parameters of a ship to shore crane encompass a number of aspects that make choosing the right ship to shore crane a complex process for anyone. Understanding these specification parameters can determine your needs faster. If you have any questions about the shoreline crane, you can always consult us.