If you are shopping for an overhead crane and your loads regularly hit 10 tons or more — or your building span stretches past 25 meters — a double girder design is probably the right answer. Not the only answer, but usually the right one. I have seen too many buyers pick a single girder because it is cheaper upfront, then regret it three years later when operations scale up and they need to replace the whole system.
This guide walks through everything I think you should know before buying: capacities, dimensions, the single-vs-double tradeoff, what affects the price, and real numbers from cranes we ship to steel plants and shipyards around the world.
A double girder overhead crane has two parallel beams (girders) running across the width of your workshop. The trolley and hoist sit on rails mounted on top of the girders — not hanging below them. That is the critical difference. Because the trolley rides above, you get more usable hook height and you can move much heavier loads.
At SIEC we manufacture these for duty classes A5 through A8. That means they run continuously under heavy loads without overheating or wearing down fast. Our customers in the steel sector typically run them 16–20 hours a day, six days a week. The cranes hold up fine if maintenance is done on schedule.
The table below shows the standard parameters for a typical SIEC double girder overhead crane. If your requirement falls outside these numbers, we can usually custom-build. We recently shipped a 150-ton unit with a 32-meter span for a shipyard in Indonesia — that is outside the "standard" range but perfectly doable.
| Parameter | Range | Notes |
|---|---|---|
| Lifting Capacity | 5 – 100+ tons | Custom builds up to 250t available |
| Span | 5 – 35 m | Wider spans require deeper girders |
| Lifting Height | 6 – 30 m | Can extend with special hoist configurations |
| Working Duty | A5 – A8 | A5 = medium, A8 = continuous heavy-duty |
| Crane Travel Speed | 10 – 40 m/min | VFD allows stepless speed control |
| Trolley Travel Speed | 5 – 25 m/min | Slower speeds for precise positioning |
| Hoist Type | Wire rope / Trolley-mounted | Electric wire rope hoist is standard |
| Control | Remote / Cabin / Pendant | Radio remote most common for new orders |
| Power | 380V / 415V / 480V, 3-Phase | 50 or 60 Hz as required |
I get asked this every week. The honest answer: it depends on your loads, your building, and your budget. Here is a direct comparison based on what we actually ship.
| Factor | Single Girder | Double Girder |
|---|---|---|
| Max Capacity | 1 – 20 tons | 5 – 100+ tons |
| Max Span | ~25 m | ~35 m (custom up to 40 m) |
| Hook Height | Lower (hoist hangs below beam) | Higher (trolley rides on top) |
| Rough Cost (10t, 20m span) | USD 15,000 – 25,000 | USD 25,000 – 40,000 |
| Duty Cycle | A2 – A5 (light to medium) | A5 – A8 (medium to super heavy) |
| Installation | Lighter, easier, faster | Heavier, needs stronger runway beams |
| Best For | Warehouses, light assembly, maintenance shops | Steel mills, shipyards, heavy fab, foundries |
My take: if you are under 10 tons and your building height is tight, go single girder. If you plan to grow, or you are moving heavy stuff every day, pay the extra for double girder. The upgrade from 15 tons to 50 tons on a single girder frame is not really possible — you would need to rip out the runway beams and start over. That is expensive.
We ship double girder cranes to all kinds of industries. Here is the breakdown of what our customers actually do with them:
If you are in one of these industries, you probably already know what you need. If you are not sure, send us a message with your load weight, building dimensions, and how many lifts per day you plan to do. We will recommend the right configuration.
Here are the main factors that move the price up or down — based on what we quote every day:
This comes up all the time with our buyers in Europe, the Middle East, and Southeast Asia. European-standard cranes (designed to FEM or DIN) differ from Chinese standard cranes in a few important ways:
SIEC builds both standards. Most of our export orders are European-standard with CE certification, FEM design, and branded electrical components. That is what we recommend for anything that runs more than one shift per day.
Not all double girder cranes are built the same. Here is what I personally check when reviewing a design:
Variable frequency drive gives you smooth acceleration and deceleration. Reduces load swing by up to 60% compared to contactor step control. Also cuts power use by 15–25%.
Two independent brakes on each motion — one electro-mechanical, one disc. If one fails, the other holds the load. Mandatory for CE certification.
Electronic load cell cuts power if weight exceeds rated capacity by 10%. Prevents structural damage and safety incidents.
For bays with multiple cranes on the same runway. Radar or laser sensors maintain minimum distance. Prevents expensive collisions.
With proper maintenance, 20–30 years. The structural steel frame lasts decades. Components like wire ropes, brakes, and motors need periodic replacement — typically every 3–8 years depending on duty cycle.
Usually yes, but your existing columns and roof structure need to be strong enough to support the runway beams and the crane's wheel loads. A structural engineer should inspect the building before ordering. We can recommend a local engineering partner if needed.
Standard configurations: 45–60 days from order. Heavily customized cranes (100+ tons, special coatings, cabin control): 75–90 days. Shipping by sea from China to most ports takes another 20–35 days depending on destination.
Yes. We offer on-site supervision and commissioning for all export orders. An SIEC engineer can travel to your site for installation guidance. We also provide detailed installation manuals, drawings, and video support for customers who prefer to handle installation themselves.
We ship to over 40 countries. Recent destinations include Saudi Arabia, Vietnam, Indonesia, Philippines, Poland, Brazil, Nigeria, Kazakhstan, and the UK. We handle customs documentation and can recommend local freight forwarders. Just send your port of entry and we will quote shipping.
If you are planning a new crane installation or upgrading existing equipment, get in touch. We will ask for your load capacity, span, lift height, and operating environment — then send you a technical proposal with a price.
Read more about our Double Girder Crane product page or check out our guide on Single Girder Overhead Cranes if you are still comparing options.
SIEC Cranes — ZHE JIANG XIECHENG CRANE MACHINERY CO., LTD. | CE & ISO 9001 certified since 2010
Sources: SIEC Cranes engineering specs (2026), FEM 9.661 design standards, CMAA Specification 70. Pricing estimates are indicative FOB Shanghai and vary by configuration.