A crane is defined by five essential specifications: rated lifting capacity, maximum working radius, hook lifting height, tail swing radius, and boom length. These five parameters determine how much a crane can lift, how far it can reach, how high it can raise a load, and whether it can operate safely within a given site.
No spec among a crane’s specs works in isolation. They affect each other.
- Long boom: More reach but less lift capacity
- Greater radius: Safe lift weight drastically lowers
- Add a jib: More height, less capacity
- Large tail swing: More space required on the job site
- Just because it’s high capacity on paper doesn’t mean it’s high capacity at a long radius.
1. Rated Lifting Capacity: “Can it lift the load?”
Rated lifting capacity is the maximum load a crane can safely lift under specific working conditions. It is usually measured in tons or kilograms. This specification is one of the most important because it shows whether the crane is strong enough for the job.
The max lifting capacity of the crane depends on various factors. For instance, when the load is not close to the crane, or the boom is extended beyond the maximum distance, then that “25-ton crane” may only have the capability to lift a few tons. This number is basically your go or no-go safety line. (read more： What is a Load Moment Limiter for Tower Crane and How Does It Work?）
2. Maximum Working Radius: “How far can it reach while lifting?”
The maximum working radius is the farthest horizontal distance between the crane’s center of rotation and the load. It affects how far the crane can reach. A larger working radius usually means lower lifting capacity, so this parameter must be checked carefully.
The working radius is how far the center of the crane is from the hook. The larger the radius, the weaker the crane.If your load is sitting behind a fence, pipe rack, or retaining wall, the radius expands—sometimes without people noticing—and the crane suddenly becomes under-rated for the lift.
3. Max Lifting Height: “How high do you need the hook to go?”
Hook lifting height refers to the maximum vertical height the hook can reach. It tells you how high the crane can lift a load. This is especially important when working on tall buildings, bridges, or elevated platforms.
The lift height will always be different from the length of the crane boom. Factors such as boom angle, extensions, and the lift block will all impact your height. When you’re on a high wall, lifting onto a rooftop, or reaching over structures, this spec is more important than anything else.
4. Tail-Swing Radius: “Can the crane physically fit in the job site?”
Tail swing radius is the space needed behind the crane when it rotates. It is an important safety factor because the rear of the crane may move outside the main body during operation. If the site is too narrow, the crane may not be able to turn safely.
Tail-swing radius informs people how much space the back end of the crane needs during rotation.In tight job sites — factories, power plants, construction sites on the road, and space between two buildings — this spec can literally decide if the crane can even get on the job site.
5. Boom Length: “What’s the real working range?”
Boom length is the length of the crane’s arm. It directly affects the crane’s reach and lifting height. In general, a longer boom allows greater reach, but it may also reduce lifting capacity.
- Boom length defines your height and radius potential.
- Longer boom length also reduces lifting capacity.
- Always think of it as the crane’s work envelope.
As your boom length increases, so does the height of your lift and the reach of your lift.
5 Specifications of 10 Commonly Used Cranes
| Crane Model | Rated Lifting Capacity | Max Working Radius | Max Lifting Height | Tail-Swing Radius | Boom Length |
| Tadano ATF 600G-8 | 600 t | ~104 m | ~147 m | – | 15.2–56 m |
| Tadano ATF 400G-6 | 400 t | 86 m | 125 m | – | 15–60 m |
| Tadano ATF 220G-5 | 220 t | 84 m | 107.5 m | – | 13.2–68 m |
| Grove GMK5130-1 | 130 t | ~56 m | ~61 m | 4.36 m | 6-section main boom |
| Liebherr LTM1095-5.1 | 95 t | 54 m | 58 m | 3.78 m | 6-section boom |
| Liebherr LTM1130-5.1 | 130 t | 56 m | 60 m | 4.20 m | 6-section boom |
| Liebherr LTM1100-5.2 | 100 t | 66 m | 84 m | 3.84 m | 11.5–52 m |
| Demag AC 100-4 | 109 t | 44 m | 77 m | – | 12–59 m |
| Grove GMK4090 | 90 t | – | – | 3.5 m | 51 m + jib |
| Liebherr LTM1060-3.1 | 60 t | 48 m | 63 m | – | 48 m boom |
