About Cranes

Cranes are lifting machines that use levers and pulleys to lift very big weights. These machines are very old in its history, it's not an invention from the modern industry but in fact they have been used over the last 2000 years. It was invented by the ancient Greeks



At that time there was no hydraulic power or steam engines to power these cranes, so it was powered by men and powerful animals in some times. The Greeks used cranes made of wood to build their monuments so they are the original inventors of this great machine. Also the ancient Egyptians used simple cranes to build the pyramids. After that by a short time a larger cranes were invented and widely used in lifting weights 


The widespread use of cranes and derricks had to wait the development in the steam engine to provide power. steam cranes became common in the 19 th century.  Cranes were also used in harbors to load and unload ships and were used in train stations too for the same reason. By the coming of the industrial revolution, the material of building cranes was changed from wood to steel. modern cranes are now constructed of steel and use wire ropes for both lifting and bracing


Not only the material has changed, but also the powering system changed from men or animals and steam engines to electric motor and hydraulic systems. Cranes are used in a lot of aspects, such as in construction for lifting materials and to speed the construction process. In industry, they used in assembling and lifting heavy things. In harbors and train stations, for loading/unloading ships and trains and many heavy work


with the modernizing of almost everything, many work activities came up and many changes in our living style too, and as a result, many types from cranes ere invented to suit different purposes

Mobile		Fixed
Truck mounted crane	1	Tower crane	1
Railroad crane	2	Telescopic crane	2
Floating crane	3	Gantry crane	3
Crawler crane	4	Deck crane	4
Aerial crane	5	Loader crane	5

there is also a type of tower crane called self erecting crane
and a type of gantry crane called overhead crane

Truck Mounted Crane

The truck mounted crane is one of the mobile cranes, as it is mounted on truck. These cranes can travel at high speed on highways, which makes them a good choice for quick need for such equipment. For its own stability, the truck-mounted crane use counterweights. 

And also for stability in job sites, there are triggers  hold the crane to the ground. This crane's construction is similar to many other cranes, it consists of the rotating body mounted on the truck. This body supports the boom. The boom may be telescopic or jointed sections. As for the powering system, may be hydraulic or electric. 

For avoiding the over turning of the crane, these cranes are tested at the factory first. They are fixed by the outriggers and loaded with different loads until it reaches its maximum value. Their capacity ranges between (14.5 and 1300 short ton) and between ( 12.9 and 1161 long ton). The advantage of this crane is the mobility and high speed. But it can't serve ragged places and un flatted areas.

Railroad Crane

Rail road crane is one of the mobile cranes type. The name tells us that this crane runs on rail tracks. It is mobile but in limited way as it can't serve areas out of its operating area. We can see this type at train station, as it used in maintenance work. Also it is uses in accidents recovery operations and freight loading in goods yards

A railroad crane is specifically designed with flanged wheels so it can travel along railroad tracks. Although the design differs according to the type of work, the basic configuration is the same  in all cases which is a rotating crane body is mounted on a sturdy chassis fitted with flanged wheels

The body supports the boom of the crane and contain all mechanism of lifting and operating.The first appearing of these cranes was at 1910, the year of cranes development. In  1990s a new generation of railway cranes was developed. The new generation had a professional high speed railway chassis for up to 75 mph. The superstructure is also diesel hydraulic with telescopic boom and counterweight and designed to the railway's specific needs

Floating Crane

Floating crane is one mobile crane, they are sea vessels have cranes mounted on them or ships equipped with cranes but not like deck cranes. They are mainly used in building bridges and port construction. 

They are capable of carrying whole sections of bridge through the water and installing it in position due to their loads capacity which exceeds 10,000 ton their capacity of loading is great. These types of missions are often made increasingly difficult by rough sea conditions. It requires an experienced operator and crew to complete successfully a lift in these conditions. 

These cranes are also used in salvaging sunken ships and other offshore operations. These cranes speed the work at the oil rigs construction. The floating cranes type was known in 1920, since this date, they are widely used in all offshore construction. The massive weight of these cranes gives them the stability in water. 

The floating cranes work with the electric system for powering wire ropes that lift the loads. The earliest floating crane designs were no more than old ships converted to include a large crane mounted on the deck.   

Aerial Crane

Aerial cranes are helicopters used for lifting weights. they are one of the mobile cranes type.Also they are called sky cranes. These helicopters lift the loads by its long cables. They are used in remote and accessible places where
it is very hard to get any crane type. 

These places like buildings tops, hill or mountain top and other places that cost a lot of money and time to get any other crane like telescopic or tower crane. This type of crane was first used in 1950 by a  plane "Bell 47" but this type of lifting was not popular until 1960. after that the planes companies started to design special helicopters for lifting and moving loads which are called sky cranes. Then they were used in construction for loading many utilities on building roofs such as conditioning systems and water reservoirs and any other materials needed. 

Sky cranes also can be used in fire fighting in far forests, the helicopter has a bucket attached to a rope connected to the plane. The helicopter fills the bucket from near lake or river and then empties the water on the fire from the above. They are very effective in this field as they also used in rescuing operations. 

The aerial cranes are economical and quick in their work, but nothing is all good, they also have some disadvantages, like the load limit they can lift and the skills needed near this crane. The pilot has to be very clever to avoid terrible accidents. in the next video,aerial crane is used for rugged area.

Crawler Crane

Crawler crane is a mobile crane; it consists of
track based vehicle and attached crane apparatus over it. The set of tracks gives the crane high stability in its position. These cranes are able to work on soft ground due to the weight dispersal properties of the tracks

The crane with crawlers can lift bigger weights than the one with rubber wheels. The crawler crane has a main advantage that it can move around the site freely without fixing problem. It also can move with the weight lifted by its ropes.  But the disadvantage of the crawler crane is the enormous weight and the great size. Some of them are very large, so they must be taken apart and moved from site to another by truck or train. 

The massive size gives the crane the ability of lifting massive loads can reach 3500 ton to big heights. For lifting these cranes generally use wire ropes connected to electric motor and may be a combination with  hydraulic power. They can work at any type of land and any type of weather. Their high stability on the ground is because the big contact area between the crawlers and the ground.

Tower Crane

Tower crane is the most common crane in construction sites It is one of the fixed cranes' type. It consists of two main parts, the mast of the crane is fixed through the base to the ground on a concrete slab or on the building sides. The upper part which is the horizontal jib is the part used for lifting. The upper jib is divided in two parts, one long and the other is short. 

The long part is responsible for lifting and moving weights. The short jib is used for keeping balance of the crane. This short part is loaded with concrete blocks or steel weights to keep the stability on both sides of the jib. The crane uses wire ropes for both lifting and bracing weights. These ropes are connected to electric engine. There is operator chamber for operating the whole crane. This chamber can be at the top of the mast under the horizontal jib or attached to the turntable. 

Some cranes do not have the operator cab installed on it because it's operated through a radio remote control from the ground. For holding the lifted weights, the crane use hook which is hooked to the weights with the workers help. The operator in the cab must communicate with the men on the ground to know when and how to lift the weights. 

This crane reaches the construction site  in pieces then it is assembled by the aid of telescopic crane . when the height needed is bigger than the telescopic crane lifting range , a specific type of tower crane is used . this specific type is called self erecting crane. The tower crane must be fixed to the building walls when the height exceeds 80 meters. 

After the construction is complete, a small crane is lifted to the built tower to disassemble the tower crane. There are reasons for this crane to be number one in construction projects such as 1-stability   2- carry massive loads for great heights  3- it speeds the work very well. But nothing is all good, it has some disadvantages too like the high cost and the many precautions should be taken near this crane

Telescopic crane

Telescopic crane is one of the fixed types of cranes that need stability by fixing to the ground while working. Some of us can get confused between telescopic and loader crane, but no, there is an obvious difference between these two 

The loader crane's arm consists of jointed sections that unfold to increase the arm length, some of these sections may be telescopic. But in telescopic crane, the arm which consists of number of tubes fitted one inside the other is one piece often powered by hydraulic system that extracts the tubes to change its length

This type of cranes can also be truck mounted crane if it is put on crane. This modification gives it the ability of being mobile crane. Telescopic cranes are used in construction for short term usage, rescue operation, lifting damaged cars off the road and also in putting heavy items like transmission towers and steel columns in place

Gantry Crane

gantry crane ( twin girder

Gantry crane is a type of overhead crane and one of the fixed cranes' type. But this crane can't move either working or not, it is fixed in its position the supports holding the crane up are fixed in location. Then how it serves weights if it can't move? Well, the weights must come to the crane's operating area. It has a hoist in a fixed machinery house that runs horizontally along rails

The hoist is fitted on one beam for mono girder and two beams for twin girder. On the gantry rail, the crane frame which is supported on gantry system runs forward and backward to lift the weights. Gantry cranes are very common in factories as it moves along certain product assembling line. We can see gantry crane at shipping ports

They are used in loading containers on and off the ships. Because it is fixed at the edge, the trolley or machinery house travels on cantilevered rail at the top of the crane. In the previous case gantry crane can be called container crane.the difference between container and gantry is that container crane can move horizontally while gantry one can't.

Deck Crane

Deck crane a fixed crane, this type of cranes is fixed to the ships or boats deck. This gives the ship advantage as it can load it self without the help of gantry crane or container crane. The ship with deck crane can be used for cargo operation and loading/unloading from shores without loading facilities.

Also it can be used for shipping other ships in water. This type is powered by many systems such as hydraulic system and electric system. Deck crane consists of two main parts, the first is the one fixed to the ship deck and the other is the crane's arm that moves in horizontally and vertically to control the load as desired. 

These cranes were first used on offshore oil platforms In loading equipment from ships to the platform and oil barrels to the ships. The only disadvantage is that it is fixed, that force loads to come to its operating area to lift them besides the weight of the crane which is not an issue for huge ships. The length for loading arm is very important, it gives bigger operating radius. The arm's range is from five m to 18 m in hydraulic cranes

Loader Crane

Loader crane is one of the fixed cranes type. It consists of two main parts, the articulated arm which is fitted to a truck or trailer. The fitted arm consists of jointed section that can be folded when crane is not in use

Some of these sections may be telescopic to add more length to the crane's arm and also durability .The loader crane is powered by hydraulic system that makes it strong enough to deal with big weights. This type of cranes is used for loading and unloading goods from the vehicles' trailer , so it is the optimum crane for goods  transfer companies and any other similar circumstances

The loader crane often has a degree of self control, as it can stow itself and unload goods without the operator instructions. The range of loading for the loader crane varies among light capacity (< 10 ton/m), medium capacity (10—23ton/m) and high capacity (> 23 ton/m). It is also known with the name of boom crane.

Overhead Crane

overhead crane

Overhead crane is fixed crane and similar in its work to gantry crane. From its name, this type of cranes is fixed over the head of the purpose needed to be lifted. The mechanism of lifting and moving weights relies on the upper part of the crane called trolley 

This trolley carries the operating mechanism and runs on single or double beam. The beams are supported by the sides of the crane. These cranes are capable of lifting very heavy weights and huge volumes

So we can easily see them in ports all over the world for loading and unloading ships, the ships get in position and the cranes do their jobs. Also they are used in heavy industries factories like steel mills. The overhead crane can be built inside the construction. Being fixed gives the crane great stability, but some cranes builders add wheels to them for more flexibility. There are small size of these cranes that they can be used in a house workshop and small business. Also they are called the suspended cranes

Self Erecting Crane

   Self Erecting Crane is a type from tower crane which is a fixed cranes type. The " self erecting crane" also called self assembling because it assembles itself using hydraulic power system . A self-erecting tower crane contains a hydraulic base, which force sections of the tower up to a specified height

A secondary crane is used to attach the jib before the hydraulic mechanism is activated. this crane is used for very high buildings and also the complex building sites that is hard for cranes to reach and install the tower crane section by section. Unlike the tower crane, this crane here doesn’t reach its high limit at one time before the construction, But it grows itself up as the building do 

Self erecting crane take the shape of T letter after being finished. For the success of installing process, it should be controlled by professional workers. This type of cranes is the modern version of tower crane and also has a high cost and certain safety precautions. These precautions like making sure that the crane base is away from electric cables, water leaking, unstable soil, excavation areas and to be near enough from the building to be attached to it later. And other safety precautions