There are 16 main types of cranes. Let’s look at what they are and what they’re used for.
- Static Cranes & Mobile Cranes
- STATIC CRANES
- Tower Crane
- Other types of static cranes
- Jib Crane
- MOBILE CRANES
- Crawler Crane
- All-Terrain Crane
- Rough-Terrain Crane
- Compact Crane
- Glassboy Floor Crane
- Truck Mounted Crane
- Aerial Crane
- Floating Crane
- Bulk-Handling Crane
- Railroad Crane
- Mobile Harbour Crane
- Conclusion
Let’s tell you the two main categories of cranes, then decipher from there.
Static Cranes & Mobile Cranes
Cranes are divided into two main categories. Static cranes and mobile cranes.
Static cranes get mounted onto buildings, structures, or the ground (via a base). They stay there, unable to travel, while they carry out their operations, until they’re no longer needed. They’ll then get dismantled and transported to storage or another site, unless at a permanent business, where they’ll be needed until that business moves location or ceases to exist.
Mobile cranes are less restricted than static cranes, in that they’re able to travel. This is usually done on tracks or wheels.
Two things define them as being mobile. They can:
1) Move around the site or location that they are working, to carry out lifts in different areas.
2) Move themselves or get transported to other sites or locations, either whole or dismantled.
Some can even perform pick-and-carry duties. This is where they pick a load up and carry it to another area of the site to be placed down.
When lifting and landing loads, many of these cranes put legs out, called outriggers. These give the crane stability.
STATIC CRANES
Here, we’ll cover the different types of static cranes and their uses.
Tower Crane
Tower cranes are one of the most well-known types of cranes. They populate the city skyline that was mentioned in the intro. This is because their height makes them designed to build skyscrapers and high-rise buildings.
The main part of the crane – which is made up of a cab, a slew ring, a jib, ballast weights, and mechanical components – sits on a tower, otherwise known as a mast.
Tower cranes can continuously rotate 360° in a slew ring, which is driven by slew motors.
The cranes can be powered by mains electricity or by a diesel generator. When hiring the crane, hirers need to make sure the right size generator gets used. If a crane is too big for the generator, the generator can sometimes cut out, which will cut power to the crane. This can be dangerous if the crane is mid-lift.
Generally, tower crane lifting capacities range from around 2t for self-erecting cranes, up to 100t for luffing cranes.
However, some specialised cranes can lift much more, such as the XCMG XGT15000-600S, which is capable of lifting 600t. What a beast.
The amount a crane can lift depends on many things.
Here are just a few examples:
- the base
- mast thickness
- luffing rope thickness
- hoist rope thickness
- amount of falls of rope
- amount of ballast weight
- hook block size
- slew-ring size
- whether it is close to a train line
The ballast weight is located at the back of the crane. When no load is being lifted by the crane, the ballast weight usually makes the crane lean slightly backwards. Then, when a load is picked up (particularly a heavy one), the crane straightens up. The jib also bends forwards under this weight. This is called jib deflection.
There are three types of tower cranes:
- Saddle jib
- Luffing jib
- Self-erecting
Saddle Jib
A saddle jib is a crane where the whole jib, consisting of the front and back jib, lays horizontally on top of the slew ring and mast. This makes the crane look almost like a T. In effect, it saddles the mast, hence the name.
Saddle-jib cranes can also be known as hammerheads, topless or flat tops, and A-frames.
There are differences between A-frame and topless/flat top cranes. An A-frame is a triangular frame on top of the crane, consisting of wire ropes on either side that take the tension of the front and back of the jibs, like in the image above. Whereas, a topless/flat top does what it says on the tin, in that there’s nothing on top of the crane jib. It’s completely flat.
Saddle jib cranes are useful for covering large areas quickly. They’re also useful on jobs where more than one crane needs to cover the same airspace. The jibs can sail over the top of each other, providing the load of the higher crane does sail above the lower one. Only in special circumstance is this permitted.
A trolley, attached to the underside of the jib, travels backwards and forwards along the jib, without changing height, to take the load to its destination. The hook block (which the load attaches to) suspends from this trolley using wire ropes.
If needed, saddle jibs can be used on rails, rather than a fixed base. This is to enable two-way travel. It’s useful in yards, shipping bays, or areas where vast space needs to be reachable.
Luffing Jib
Luffing jib tower cranes are also known as luffing tower cranes, or simply luffers. Unlike saddle jibs, a luffer’s jib tilts up to around 83° using pivots. This motion is called luffing.
This is useful on multi-crane jobs or sites with small footprints, because the load can be jibbed up to small radii when slewing around, to keep away from other cranes and stay inside the site’s boundary. Large penalties can be charged if loads do sail over boundaries into public areas or other private land.
This means that luffing cranes reduce the need to obtain over-sailing rights. These licenses can be quite difficult to get in some cities.
However, zoning systems often get fitted to cranes, to help them to stay within site boundaries, and stop them from colliding with other cranes within the site.
Because there are more components, luffers are usually more expensive to hire than saddles.
You can learn more about saddle jib and luffing jib cranes here.
Self-Erecting Cranes
Self-Erecting cranes are also known as Pedestrian Operated Tower Cranes (POTC), or Ped-Op for short. This is because, unlike a luffer or saddle jib, there’s no cab at the top of the crane. The crane is operated on the ground by an operator with a control unit. The unit can be either connected to the crane by a long umbilical chord type cable or by remote control.
Also, unlike the other two categories, POTC operators don’t have a sole duty of operating the cranes. They often sling the loads that they’re lifting as well. This reduces the amount of personnel needed, which reduces cost.
Ped-Ops are the smallest of tower cranes. This makes them useful in mountainous areas, residential areas, and low-rise buildings, as well as warehouses and factory units. They can also be positioned on roofs, or slabs of buildings.
These cranes are quick to erect and are easy to operate. They usually get towed to site on a trailer, then unfolded and set up, ready for action.
The lifting capacity of self-erecting cranes can range from around 2t to 10t.
Level-Luffing Crane
This is a nice surprise for you. A bonus crane in the luffing family.
The jib on a level-luffing crane is different from that of a standard luffing jib. The jib is split in two parts, hinged almost in the middle. The bottom half of the jib (the mast end) tilts up and down in a luffing motion. As it does so, the end half moves outwards and inwards on a pivot point.
This is done using a sophisticated electrical and mechanical structure that anchors on the back jib and connects to both parts of the luffing jib using a levering and counterweight pulling system.
It enables the load to stay level with great accuracy while jibbing, sometimes within inches of the ground. This is important in areas where the crane works close to the ground a lot, such as shipping yards and city construction sites that don’t have much space.
Some even have technology where the driver’s cab cantilevers to follow the movement of the main jib. This enables the driver to see in difficult positions, which is especially useful when loading and unloading ships.
Level-luffing cranes are capable of lifting approximately 124t.
Other types of static cranes
Jib Crane
Jib cranes are designed to be used in confined work spaces, like factories and warehouses. Production environments like these can require lots of repetitive lifting. Some of which can be dangerous or even impossible to do manually.
This means that by doing all the lifting of small to mid/heavy tools, materials, and products, jib cranes can reduce injuries and increase productivity. They’re not expensive to run, and they’re easy to operate. They’re also quick to install.
Jib cranes operate using a trolley that travels the full length of the underside of the jib to transport loads, much like that of saddle jibs.
Similar to a tower crane’s zoning system, jib cranes can have systems in place to prevent them from colliding with nearby objects. These are called rotation stops. They’re crucial, as a lot of jib cranes are positioned on or close to walls or other objects.
There are two types of jib crane:
- Freestanding
- Wall mounted
Free Standing
Free-standing jib cranes fix to the ground. Usually on a concrete foundation. The jib arms can be braced either above or below the jib. The bracing connects to both the jib arm and the mast.
These jib cranes can slew up to 360°, but most commonly, 270°. The slew can be moved manually or by electrical or pneumatic power.
Free-standing jib cranes lift anything between 50kg-10,000kg (0.05t-10t).
Wall Mounted
The name might suggest that these cranes only get mounted to walls. But in fact, this name is given as an umbrella.
Just like their free-standing counterparts, wall-mounted jib cranes can be braced above or below the jib. But this time, the jibs get attached to mounting brackets that are bolted to suitable upright structures, such as columns or walls.
Because wall-mounted jib cranes get fixed to solid structures that don’t turn with it, the structures restrict the slew to a maximum of 180°-200° rotation.
Overhead Crane
Overhead cranes are very different to tower cranes. You’ll unlikely see an overhead crane on a construction site. They’re more suited to industrial sites, like workshops, railroads, freight yards, production lines, and shipping yards, etc.
An overhead crane is a machine structure with a beam across the top that travels on rails in a straight line. This beam has a trolley attached, which contains the hoist. This can travel along the full length of the beam. This hoist picks up and carries loads to be placed in different locations.
Because the beam and trolley can travel in two separate ways, a full rectangular area can be covered. This saves a lot of manual handling, so is safer, increases production, and prevents accidents and injuries.
There are a few types of overhead cranes:
- Gantry Cranes
- Bridge Cranes
- Monorail Cranes
Gantry Crane
A gantry crane’s beam is held up by freestanding legs. These legs travel back and forth either on tracks, wheels, or rails. They can be in the forms of A-frames or L shapes.
The beam can come in two categories: single or double girder. Double girders can lift heavier weights than single, which will mean the legs may need to be bigger and stronger, and more power will be used. This makes it more expensive to run.
Depending on the type or size of the crane, a gantry crane can be capable of lifting a few hundred ton. But this would be classed as a heavy-duty gantry crane, which would have a double girder beam.
Now it gets really interesting. There are even a few types of gantry cranes.
They are:
- Full-gantry crane
- Semi-gantry crane
- Adjustable gantry crane
- Truss gantry crane
- Portable gantry crane
- L-shape gantry crane
- U-shape gantry crane
- Workstation gantry crane
Full-gantry cranes are as mentioned above. They come as standard with a beam attached to a leg at either end. The legs travel back and forth on rails, wheels, or tracks. They can also be portable. But this depends on the size of the crane.
Semi-gantry cranes have a leg supporting one end of the beam instead of one at each end, like the full gantry. The other end of the beam travels along a raised rail. This rail is usually attached to either an independent gantry steel structure, a wall, or a column.
Semi-gantry cranes are useful if they’re not needed to cover the whole breadth of a workspace.
Sometimes, they’re used underneath a bigger overhead crane to increase work efficiency.
Adjustable gantry cranes are relatively small. They can have their height, width, and beam length adjusted to suit each task and lift. This provides great flexibility. Particularly when working in tight spaces. It can also reduce costs, because it saves using larger cranes that are more expensive to buy/hire, and have more running costs.
Truss gantry cranes have a top beam that mainly comprises lattice work steel. Sometimes, this is the case for the support legs at either end, but this is usually on the bigger cranes.
The trolley runs along the top of the beam. If the crane is large enough, the trolley is part of a cab, of which an operator sits in.
A truss gantry crane’s lifting capacity can range from 5 to 100t.
Portable gantry cranes are very useful if not much lifting needs to be done. Contractors can transport them to use at different sites that don’t need excessively heavy loads moved. They can usually lift 250kg to 5,000kg (0.25t – 5t).
L-shape gantry cranes do what they say on the tin. The legs are in the shape of an L. The upright parts of the legs are slightly angled or curved, which keeps them from being directly under the beam that they support.
This means that long loads can be lifted and moved, because any load that hangs down won’t hit the legs.
The beam that carries the load is a single girder. It can span from 18-35m.
The cranes are usually lower than A-frame type cranes, but can still be used to lift loads of up to 50t.
U-shape gantry cranes get their name from the frame looking like a U from a side profile. Unlike the single beam girder of the L-shape crane, U-shape cranes have double girders, with each girder attached to the tops of each rising part of the U-shape legs.
The space between each girder, and subsequently, each leg of the frame, allows this crane to lift large loads.
These cranes move on a fixed rail system that is usually embedded into the ground. It can have two hoists if need, and can lift up to 50t.
Workstation gantry cranes are some of the smallest and lightest of the family. This makes them ideal for working in small areas of workspace in production lines. They’re often light and mobile enough to move to different work benches, so that materials, tools, or products can get lifted onto the workbench.
The maximum lifting capacity of workstation gantry cranes, depending on the size of the crane, is approximately 2t.
Bridge Crane
Bridge cranes are similar to gantry cranes, in that one or more beams are supported above the head to lift and carry loads. Except, the difference is the beam isn’t attached to the tops of supporting legs. It’s suspended at the ends of the beam by parallel runways.
These runways are usually steel girders that are attached to the internal structure of a building or frame. The beam acts as a bridge between the runways. Hence, the name. It travels back and forth the full length of the track using end trucks. These are wheeled components at the ends of the beam. A trolley, comprising a hoist, travels along the beam.
As with gantry cranes, there are single and double girder beams. The one chosen depends on the lifting weight requirements and the span of the beam. Double girder beams are able to lift more weight. They can also be longer, due to the extra support.
The crane gets controlled using a control panel attached to a long lead, or by a remote-control unit that sends a signal to the crane.
Bridge cranes are often used inside warehouses, production lines, and factories, etc.
Under-running bridge cranes are where the bridge runs along the underside of the runways. The end trucks of the bridge usually have the wheels bear weight on the bottom flanges of the steel rails.
The runways are often attached to ceilings, which rids the need for extra support columns for the runways. This system allows for more floor space under the crane. It also allows the possibility of being fitted to sloped ceilings.
Under-running bridge cranes can have the capacity to lift up to 25t. But this isn’t common practice, as most cranes have a lift capacity vs safe working load (SWL) ratio, which means they give a little extra capacity than what you should actually lift.
By and large, the maximum load weight should be about 15t.
Top-running bridge cranes are where the bridge runs along the top of the runways. The runway beams get supported by either bespoke engineered columns or the building’s existing columns.
This is the most common, because:
1) It allows for heavier weight to be lifted, as the weight of each load gets transferred into the support columns.
2) It allows for more hoist height, as the bridge and hoist is above the runways rather than below.
Top-running bridge cranes can either lift small loads or in excess of 100t, depending on the configuration of the runways and column supports.
Monorail Crane
Some people class monorail cranes as a type of bridge crane. They are alike, in that the beam moves along runway tracks at either end of it. Except, with a monorail crane, the hoist that carries the load doesn’t travel along the beam via a trolley. It stays in one position and moves back and forth with the beam.
This doen’t give lateral movement like a bridge crane. The only motions it gives are the up and down of the hoist, and the back and forth of the beam, rather than the added side to side of the trolley.
The hoist sits on a single beam that runs along the bottom flanges of the tracks at either end. The tracks can run along a ceiling or top of a structure, either in a straight line, curved, or with separate branches. They can even change levels.
Although monorail cranes don’t have as much versatility as bridge cranes, this makes them a cheaper option.
Monorail cranes are capable of lifting up to 20t.
MOBILE CRANES
Here we’ll cover the different types of mobile cranes and their uses.
Crawler Crane
Crawler cranes are heavy-duty cranes that drive around on tracks that are like those of tanks.
Some crawler crane tracks can retract to make the base of the crane small or larger.
The cranes work on the same principle as luffing tower cranes, except they’re not on masts, and they can travel around.
The similarities they have are:
- a cab – where an operator sits to drive the crane.
- a jib – that moves in a luffing motion.
- a hoist drum – to accommodate and supply the crane with hoist rope. The rope moves the hook block up and down to pick up loads.
- a luffing drum – to accommodate and supply the jib with luffing rope. The rope moves the jib up and down, powered by a motor.
The jibs can either be lattice like on tower cranes, or telescopic like on the traditional mobile wheeled-cranes.
Crawler cranes are most commonly powered by diesel engines. But they’re sometimes run by mains power, using a long cable. However, the latter option isn’t always practical. Especially if the crane has to do a lot of travelling around the site. Some modern crawler cranes are even battery powered.
Constructions sites are where you’ll most likely see crawler cranes. But they’re not limited to construction site work. They can be sent anywhere that has sufficient ground to take the weight of the crane.
Because of the mobility and large lifting capacity, they’re often used to build things like wind turbines, bridges, low and sometimes high-level structures and buildings, pylons, stadiums, power stations, etc.
If the ground is too soft, special bases have to be laid down for the cranes to operate on. These are called crane mats.
If extra jib length is needed, a fly jib can be fitted to the end. The jib can also be fitted with other accessories that allow the crane to do tasks other than lifting, like winching, demolition, or excavation.
They can also perform pick-and-carry duties. This is where they pick a load up and carry it to another destination, then place it down. It’s done without the use of legs or outriggers to support it. The support comes by way of ballast weights at the back of the crane to counteract the weight of the load.
The ballast weight especially helps balance the crane out when lifting heavy loads. It’s an important feature to stop the crane from tipping over.
Crawler cranes are usually so big, they have to be dismantled before being transported elsewhere.
Crawler crane lifting capacities can be anything as small as 50t to gigantic amounts.
At the time of writing, the strongest crawler crane in the world is the SCC45000A.
Ring Crane
Ring cranes are similar to crawler cranes, in the shape and that they have derricking lattice booms. But ring cranes typically run on tracks. They could be classed as fixed or mobile, because some stay on a track that is located in one position, but others have tracks that allow the crane to travel to other areas of the site.
Unlike on a crawler crane, the ballast weights of a ring crane is not attached to the main body. They travel behind behind it, following the crane’s motion.
Ring cranes are suited to the offshore wind industry, nuclear industry, FPSO (Floating Production Storage and Offloading), and FLNG (Floating Liquefied Natural Gas) projects.
At present the largest ring crane in the world is Mammoet’s SK6000.
All-Terrain Crane
All-terrain cranes are more commonly known as the category they come under. Mobile cranes. Or even telescopic mobile cranes.
These wheeled cranes with two engines can drive to each location on the roads. They can also drive on bumpy terrains. Hence, the name, All-Terrain.
However, they don’t perform pick-and-carry duties like other mobile cranes. In order to lift, outriggers (supporting legs) have to be out on firm ground. Mats get placed under the feet of the outriggers to support the weight.
Also, ballast weights are at the back of the crane to counter the weight of each load lifted. These ballast weights are usually transported to site on a separate lorry. Then the crane installs them onto itself.
To be able to drive all-terrain cranes on the road, the driver needs to have a Cat-C license. The same cab is used for road driving as it is for operating the crane during lifting operations.
They can have between 4 and 18 wheels. On some cranes, all the wheels steer together to manoeuvre the crane in tight spaces.
All-terrain cranes are often used to erect other cranes. If they need extra jib length, they can have fly jibs fitted to the end, just like with crawler cranes.
Because of their versatility, they can be used for a whole range of other purposes. Like bridges, buildings, wind turbines. The list goes on. They often get used to finish the last of a building after a tower crane gets taken down when it’s no longer needed.
The maximum lifting capacity of all-terrain cranes is approximately 1,200t.
Rough-Terrain Crane
Rough-terrain cranes are smaller than all-terrain cranes. They have only one engine and four wheels. But the wheels are wider and taller to give the crane a wide base structure.
They’re usually four-wheel drive, with power steering, which gives grip and agility on uneven or rough terrains and in tight spaces. Especially with the deep treads in the tires. These factors, and the wide base, allow these cranes to move quicker than most others.
They’re great for construction sites. They can load and unload lorries, which can take some workload off the larger cranes on site, like tower cranes and crawlers. They can also work in busy storage yards, or for building low-level buildings and structures.
Outriggers are used when lifting heavier loads. But lighter loads can get picked up and travelled with (pick-and-carry).
The ballast weight stays attached to the back, which means there is no installation or set-up time to make the crane ready for action.
This is not a road vehicle, so there are some restricts to where the crane can be driven outside its working location.
Although this is an agile and compact crane, some larger ones have been known to be able to lift up to 165t.
Compact Crane
Compact cranes are small, so often get used in tight spaces and inside buildings. They can drive around on tracks or wheels.
Spider cranes are the larger of the compact cranes. They use four outrigger legs that stabilise them when doing lifts. The lowness and narrowness of the crane, and the shape of the legs, make them look like a spider. Hence the name.
These cranes get folded when in transport or not in use. In some cases, the main body can be as narrow as 590 to 750mm. This makes them very easy to move around. They even get lifted by other cranes or placed in lifts to be positioned where they’re going to work.
They’re often used in between floors or on roofs of buildings. They have a telescopic jib that stretches out past the external wall of the building to lift things on lower levels.
Spider cranes have the ability to slew 360°. They also have lots of sensors to prevent them from overloading or colliding the jib with obstructions.
A common use of spider cranes is for installing glass panels or cladding to the outside of a building. But they also get used for internal lifts, like steel erecting, for instance.
The crane shown in the picture can lift up to 3.2t, but larger ones can lift up to 10t.
Mini compact cranes are smaller than spider cranes. But there are other differences. They travel on wheels and can be pushed around with electrical assistance.
Mini compact cranes don’t have outriggers. There’s no need, because the cranes don’t lift excessive weights. The very most they’ll lift is 2t. They don’t slew either. The jib angle gets positioned by moving the whole crane. The jib extends to give the crane a little extra reach.
These cranes are great for working in very confined areas. They’re able to fit through doorways and under low obstructions. They’re useful for doing low-level lifts. They do those lifts that people might think they’d be able to do manually, but end up hurting themselves.
Glassboy Floor Crane
Now we’re at a really small crane. Using counterweights, the Glassboy is only capable of lifting up to 500kg (0.5t). Without counterweights, it will lift approximately 122kg.
Glassboys are used predominately to install glass panels or cladding, using a sucker attachment that sucks to the panel.
They’re very small and very light, which makes them easy to transport and position into place. They get pushed into position by hand.
The Glassboy has a small hydraulic lifting arm that can extend from around 900mm to 1760mm. An electric hoist gets lowered to pick up the loads. This gets controlled by control buttons that are on a long lead.
With a maximum width of 800mm, the Glassboy can easily fit through standard doors or gates.
Truck Mounted Crane
Truck-mounted cranes are hydraulic cranes that are attached to the backs of trucks or lorries. They’re usually positioned behind the vehicle cab.
They’re well known in the industry as HIABs. But HIAB is actually an abbreviation of a company that makes them. A Swedish manufacturer called Hydrauliska Industri AB.
These cranes are often used on delivery vehicles using a HIAB. Any builders’ merchant worth their weight will own at least one truck-mounted crane. The vehicle will take goods to a location (often a building site), then use the crane to unload the goods.
Truck-mounted cranes can also be used for a variety of other reasons. Scrap vehicles or vehicles that have been seriously damaged in an accident sometimes get loaded onto the truck. Vehicles and plant also get rescued from precarious positions, like a digger or dumber truck that has fallen down a trench.
The beauty of using truck-mounted cranes in these situations is that it saves a lot of time, money and logistical headache, compared to using an all-terrain-crane or crawler crane.
When lifting is in place, two outriggers go out either side of the vehicle, in line with the crane itself, as this is the source of all the pressure.
The lifting can be done with a hook on the end of a telescopic arm, but lots of other attachments get used, depending on the task at hand.
Here are some of the attachments that can be used:
Pallet Forks can slide under palletised goods to lift and manoeuvre them.
Grapples look like claws or clamps. They’re often used in forestry to pick up trunks or pull trees out at the roots.
Clamshell Buckets are like scooping cups that open and close via a hinge. These are most commonly used on grab lorries. They grab and scoop loose material, like mud or broken concrete, to be loading into the back of the wagon.
Brick grabs are square-looking clamps that hang down and grab the sides of products like packs of bricks, blocks, bulk bags full of loosed material, or packs of timber, etc.
Measuring the lifting capacity of truck-mounted cranes isn’t straightforward. The weight is measured in Tonne Metres ™. In other words, the tonnage of the load multiplied by the radius it’s being lifted at.
So, if the crane can lift 2.5t at a radius of 4 metres, the crane would be classed as a 10tm crane.
Some truck-mounted cranes are over 30tm.
Aerial Crane
We’ve recently covered some of the lowest cranes. Now we’ll cover the crane that goes highest.
An aerial crane can be an aeroplane or helicopter that lifts things that can’t be reached by ground. Or anywhere that is inaccessible, or even when no other method is feasible.
This can be from areas like the tops of buildings, remote areas, mountainous terrains, in seas or rivers, etc.
In fact, helicopter aerial cranes are often used in the logging industry. Sometimes in deep forests, there are no roads. Road building can be prohibited because of the environment. So the helicopters are the only option to get all the logging machinery in and transport the large trees out.
They also get used for tasks such as sea rescue, floods, putting out wild fires, etc.
They can lift using slings or long wire ropes. The amount of weight they can lift depends on the size and configuration of the aircraft.
When an aircraft is designed purely for lifting purposes, everything that isn’t essential gets stripped out to make it lighter. This way, they can get optimum lifting capacity for the least cost.
With heavy lifting, the pilot will often fill the aircraft with minimum fuel to keep the weight down.
Some heavy-lifting aircraft even design the whole machine solely around the lifting hook. The optimum place for this cargo hook is underneath the aircraft (the belly).
Once the aircraft is certified for lifting, it’s appointed a Maximum Gross Weight (MGW). This is the maximum weight the aircraft is allowed to be once it is in the air.
The weight includes internal and external load, passengers, pilots, fuel, and the weight of the aircraft itself.
The ruling is given to make sure stability and full control of the aircraft can be obtained during flight and in emergencies.
Helicopters are the most commonly used aircraft for lifting, because they’re versatile. They’re agile, lighter than aeroplanes, cost-effective, and have the ability to hover.
The smallest helicopters can lift no more than 180kg on the hook, whereas the most common lift between 900-1900kg.
However, there are much bigger lifters. Like the Russian Mi-26T2. This machine has broken many world records. It has lifted 25,000kg on the hook. That’s a staggering 25t. But the Maximum Gross Weight is roughly double that.
Bear in mind, these figures are given for sea level. When the aircraft goes higher, the air density reduces, which reduces the lifting capacity. To make sense of this, think about salty seas like the Black Sea. The water is so dense, it’s very difficult to sink in it. Floating becomes so much easier. It’s the same principle in the air.
Floating Crane
We’ve covered cranes in the sky. Now let’s talk about cranes on water. Yes, floating cranes literally float on water. They’re otherwise known as crane ships, crane vessels, and crane barges, among other names.
A floating crane is a sea-bearing vessel that has one or more lifting machines either fixed to it or resting on it. Some are used on open seas. Others can be used in harbours or shallow rivers.
They can be used for moving cargo to and from ships, offshore construction, oil-rigging, and even retrieving sunken ships or crashed aircraft.
The largest floating crane to date is the semi-submersible SSCV Sleipner. This vessel has four fixed cranes on it. The two largest have set a world record for lifting 20,000t in tandem. This means they both lift the load together.
Bulk-Handling Crane
A bulk-handling crane doesn’t have a hook like most others. It has a clamshell bucket, like what a grab lorry uses, or a claw-like attachment. Rather than picking up loads using slings or lifting points, this hinged device scoops and grabs loose material.
These materials can be of a wide range. Like coal, ballast, crushed concrete, or any other aggregates used for mining or construction. They can also dredge the bottoms of seas, rivers, lagoons, and such like.
They’re often used offshore on boats, in quarries, or at mines.
Unlike a grab lorry, where the bucket is at the end of a telescopic arm, the bucket on a bulk-handling crane hangs on the bottom of hoist ropes.
Some bulk-handling cranes can pick up a rock or loose material weighing 50t.
Railroad Crane
Railroad cranes – otherwise known as breakdown cranes, or simply rail cranes – work on railway lines for several reasons.
- They do maintenance work on the tracks, overhead cables, bridges, and anything else within the near vicinity of the track.
- They help to build new structures or buildings related to the line, like the bridges or substations.
- They help to recover trains that have broken down or crashed.
- They recover road vehicles that have somehow made their way onto the tracks, either through negligence or crashing.
- They undertake day-to-day freight management in depots or yards.
There are many types of configurations of railroad cranes, but most have a main body that slews. A jib is attached to this body. Sometimes the jib can be telescopic, to get some distance on the operations.
Depending on the size and configuration, rail cranes can have a decent lifting capacity. With a maximum of 160t.
Mobile Harbour Crane
Harbour cranes are also known as port cranes, quay cranes, or ship-to-shore cranes. They’re wheeled cranes that can drive around their working area to load and unload ships, using outriggers to stabilise the cranes when lifting. Or they can be on rails that allow them to travel along the port.
These cranes use a slew system and a variation of jibs to do the work. The key feature is where the cab is situated. Ships can be high or have a deep deck, so seeing into the working area could be difficult for the crane driver.
Because of this, as an additional option, the cab can be situated higher up than the main body of the crane. Almost like it’s on stilts. This can be done with a vertical pylon/mast, or an arm or frame that stretches the cab out directly over the top of the ship, so the driver can see easily.
There are two types of harbour cranes. Low-profile and high-profile.
- Low-profile harbour cranes use a luffing jib. They mainly load containers on and off ships.
- High-profile harbour cranes use a hinged jib that operates similarly to a digger arm. This can go up and over the side of the ship, then down into where the cargo is.
These days, a lot get powered by electricity, using a long cable that gets reeled up. This saves a lot of cost and is much kinder to the environment than fuel.
Harbour cranes usually lift 40-80t on average. But they are known to be able to lift up to 125t.
Conclusion
There’s a lot of information here. But that’s because there are a lot of cranes to talk about.
Hopefully, this article will help those of you who are trying to decide which types of cranes to learn how to operate. It will also help potential crane hirers figure out which ones are best for their needs.
You’ve been given the main categories of cranes, the different types, and the sub-categories within those types.
You’ve also been given what each crane is useful for, and what each maximum lifting capacity is.
We hope you’ve found this information useful. Feel free to contact us if you have any questions.
Construction courses and AP hire
Click on images for details
