Crane in the port. Port gantry cranes. Types of portal cranes

The portal crane has the appearance of a special crane, the rotating platform of which is installed on a high pedestal, and the moving mechanism itself moves on rails. These types of devices are often used in shipyards, as well as in ports and ship docks. The basic principle of operation of cranes is to grab and move large-scale loads. The portal crane itself consists of legs, as well as a head. The crane at the port is capable of lifting and moving large-scale cargo weighing from 5 to 300 tons.

Portal crane device

The portal crane has a base with a driving mechanism capable of rotating around its axis. Since this type of lift is capable of performing a variety of functions, namely moving various types loads, it can be equipped with various types of grips, such as a hook or a clamshell grip. Depending on their location and the functions they perform, cranes can be construction or installation. This type of equipment has a lot positive characteristics, and also easily moves from place to place.

Types of portal cranes

Portal cranes come in several types and varieties, each of them has its own purpose.

The dock crane, in comparison with similar crane models, has a rather low lifting capacity, which in many ways does not correspond to its intended purpose. This crane is protected from unexpected tip-overs and also has anti-angle grips.

The reloading crane is capable of lifting more weight than the previous one, namely about 30 tons. In some cases, such a lift may be equipped with a special magnet (for lifting metal parts), as well as a hook or grab (for moving bulk cargo). In most cases, such a crane has a winch or several to secure the cargo being moved.

An erection crane is used in ports, as well as at ship repair or shipbuilding enterprises. Externally, such a crane is almost identical to the previous one, only it is capable of lifting loads whose weight can reach 160 tons; several winches are also used for insurance.

Characteristics of cranes

A crane located in a port usually has several operating mechanisms. The traveling mechanism of the crane represents the installation function, and all the others are working mechanisms. Depending on the installation location, cranes are divided into various types according to their application, they can perform both the function of reloading and the function of supporting and grasping large-scale cargo. The mobile mechanism is a set of trolleys, which, in turn, can be of drive and non-drive types. The cranes used in the port are very light and economical, they are also able to withstand extremely low temperatures, namely down to -45 degrees. Regardless of their intended purpose and name, such cranes are often used in the oil and gas industry, as well as in the forestry and coal industries. The boom reach of a portal crane can reach 40 meters.

The characteristics of portal cranes are reflected in the direct name of the crane. For example, the Ganz 5/6-30-0.5 portal crane has the following characteristics:

• the lifting capacity of the hook, depending on the reach, varies smoothly from 5 to 6 tons;
• maximum reach - 30 m;
• portal track 0.5 m.

This lift would be advisable to use in construction and agriculture, since its carrying capacity is not so large.

Types of gantry cranes

Depending on the conditions of use, cranes are divided into two types - floating and shore. Floating cranes are used directly on the water and are the same vessel, only with a lifting mechanism. Portal cranes, specifications which involve the elimination of breakdowns and accidents that occurred on the water, as well as near land, are classified as floating.

Shore cranes include all those located on land, regardless of whether they are located in a port, dock or shipyard. Such cranes are used to lift all types of cargo, reaching a weight of 300 tons.

Since the post-war period, the fleet of gantry cranes of the USSR has been replenished in two ways: production at its own factories and receiving imported cranes. It’s sad to admit, but there were more gantry cranes imported to the USSR than those manufactured in-house. Not by times, but more. The main suppliers were factories in the GDR and Hungary. During the war, cranes made in the USA appeared. In the 50s, cranes came from Italy and France, and from the 60s, cranes from Finland began to appear. But cranes from these countries arrived in small quantities, not comparable to those from Hungary and Germany. The supply of imported cranes to Russia and the states of the former USSR practically stopped at the beginning of the 90s. In this article, imported cranes will not be considered.

In the USSR, there was a parent enterprise for the production of portal cranes - the S.M. Kirov Lifting and Transport Equipment Plant, which traces its history back to the mechanical workshops of the St. Petersburg - Warsaw Railway (the third most established in Russia). The plant was located on the Obvodny Canal in Leningrad and when associations were created in the early 70s of the twentieth century, it became part of the Podemtransmash association. With the start of the 1990s, production fell sharply, and by the early 2000s, only a few portals were assembled per year using parts from old stock. The last of the known portals was shipped from the factory in 2001. Then the fate of the plant was quite typical - the formation of several small companies on its basis, the sale of the territory, a business center was organized in one building, the rest were demolished and a hypermarket and parking lot were built in their place.

If ZPTO named after Kirov constantly produced portal cranes in the period 1948-2001, then there were a number of enterprises that produced portal cranes for a certain period of time. Unfortunately, the history of the production of portal cranes currently has more mysteries than answers, so we cannot describe them in detail. So far the following enterprises are known: Zhdanovmash, Zhdanov (now Mariupol, enterprise Azovmash); "Sibtyazhmash", Novosibirsk; "Kommunar" and Mining Equipment Plant, Perm; Bureya Mechanical (Crane) Plant. Perhaps there were a number of other enterprises that produced portal cranes before the 1990-2000s, but there is no information on them and it is unlikely that the number of cranes they produced was more than a few. In the 2000s, half a dozen enterprises in Russia and Ukraine began to produce portal cranes, but even together they are far from the volume of production of the Kirov ZVTO in Soviet times.

The current marking of portal cranes consists of 3 letters and numbers (according to the old system, 4 letters):
TO- Tap;
P- portal;
P / M / D- transshipment / installation / dock;
G / TO- grab/hook (old designation system).
Numerical indices usually indicate: 1- maximum lifting capacity of the main hook/at maximum reach; 2 - maximum reach; 3 - portal track. With variable load capacity values ​​at different reach, load capacity and reach can be indicated in two numbers separated by a fraction - at the maximum reach and at the reach of the maximum load capacity.

Now let’s take a closer look at the classification of portal cranes by purpose:
1) Reloading crane (the most common type of crane). Load capacity varies from 5 to 30 tons for different models. It can be equipped with a grab for bulk cargo, a magnetic washer for scrap metal, or a hook suspension for piece cargo. Grab cranes usually have two identical winches to operate the grab. When operating such hook cranes, only one winch is used.

2) Assembly crane. Widely used in ports, shipbuilding enterprises, ship repair yards. Structurally identical to the reloading crane and differs by the presence of a jib on the trunk and low speed of movement of the hook. There is either one winch or two different ones - for the main and auxiliary lifts. G/p in the range of 12.5 - 160 tons for various models.

3) Slipway crane. This type is one of the smallest. At its core, it is an assembly crane and is used exclusively in shipbuilding enterprises. Designed for mounting the ship's hull. Design features include a very high portal and trolley current supply. A feature of the operating mode should be noted is the fairly frequent retention of loads close to the maximum in weight for a long time (usually, installation of a section of the vessel takes several days). It has a large carrying capacity and low landing speeds. Typically the capacity is in the range of 30 - 160 tons.

4) Dock gantry crane. Due to the specific nature of the work performed, it has a relatively small carrying capacity. The design features are: a narrow portal (since the width of the dock tower is limited), the presence, in addition to anti-theft grips, also includes rollover protection. Has limitations on the ability to work during waves.

So, we have figured out the purpose and correct name, now you can familiarize yourself in more detail with the main structural elements of the type of crane in question.
Portal. The main purpose is to reduce the weight of the counterweights (and, accordingly, the weight of the crane itself) by increasing the area onto which the center of mass is projected to prevent the crane from tipping over. The second purpose is a passage between the legs of automobile or railway transport, passage over mechanisms or structures. It should be noted that not all portal cranes allow (there is no need) the passage of vehicles, and passage over mechanisms and structures is extremely rare, since it is impossible at the work site and is allowed only when moving from the work site to the repair one. The portal consists of legs and a head. The legs can be positioned symmetrically, but usually the portal in plan is not a square, but elongated along one coordinate. The most common cranes with a symmetrical portal are “Kirovtsy” (ZPTO cranes named after S.M. Kirov) with a passage distance of 10.5 m (two railway tracks). Typically, ties, ladders and other equipment are located between the legs located along the rail.

Leg- the portal element (usually 4, but in older designs there are portals with 3 legs) ends at the bottom with one or more trolleys. Carts are either motorized or single. An idle cart has no engine. Typically a gantry crane has four travel motors, i.e. one on each leg. In this case, the leg ends in a cart with two wheels, one of which is driven by a motor. There are cranes on which only two legs are wrapped, but these are very light cranes and this option is very rare.
There are also gantry cranes with 8 or 16 (very rarely) travel engines. These are heavy cranes, they have up to 4 (four) trolleys per leg, and sometimes the inner outer trolleys of adjacent legs have an additional connection in the form of a balancer. The combination of motorized and idle carts on one leg in this case can be the most bizarre.
The outer trolleys must end with buffers. Anti-theft grips are required on trolleys, the minimum number of them is one per leg, and a larger number is possible if the mass of the crane is such that one per leg may not be enough to hold the weight of the crane under the calculated wind load. On dock gantry cranes, in addition to anti-theft grips, roll hold devices are provided, which are also usually installed on the trolley. The inside of the leg is usually used for cable routing. Ladders for the driver are not placed inside the leg, only outside.

Portal head- the top of the “stool”. Serves to connect the legs, the main purpose is to receive loads from the rotating part onto the support bearing. The head contains electrical equipment that ensures the movement of the crane. It comes in different shapes. For example, on the old Kirovtsy it had a square shape in plan, on later ones it was round.

Travel size standardly considered in railway tracks - 1, 2 or 3. The most common are 2 tracks (10.5 meters). Portal cranes that do not work with transport inside the portal may have a different width. Thus, construction portal cranes usually have a reduced passage width.

Current supply There are two versions. The most common are cable drums and flexible cables that reel in or out as the crane moves. The cable drum is usually located on one of the legs, or together with anti-theft grips on the crossbar connecting the two legs. Requires minimal capital costs and is reliable. Mainly used in ports. A rather rare option is a trolley current supply, which is a long room below the level of the tracks, in which trolleys are stretched, and the crane has a special rod with current collectors. It is used in shipyards, where there is a risk of damage to the flexible cable, and it is necessary to be able to move the tracks in any place.

Upper rotary structure consists of a rotating part connected to the portal through rotary support devices of various designs, a boom and a counterweight.

Slewing ring In domestic cranes produced by ZPTO named after Kirov, the most widely used roller slewing device on the slewing ring. With this design, the turning part rests on rollers, which are in contact with two horizontal rails located on the portal and on the turning part.
A good example The slewing support device on the column can be a KPPG-5 crane. This design consists of two units: upper and lower. The upper unit is a system of horizontal rollers (depending on the load - single or double on the balancer) mounted on the column and transmitting the load to the portal in any direction of the vertical moment M. The lower unit receives vertical pressure from the weight of the rotating part with a load and horizontal pressure from the moment M.

Boom devices in portal cranes, the change in reach is a working movement, not an installation movement, i.e. performed with a load at high speeds of its horizontal movement. The operational nature of the change in reach determines two most important requirements for boom devices:
1) The boom device must be completely balanced relative to the boom swing axis, which is achieved using movable counterweights;
2) When changing the reach, the load must move along a trajectory that differs little from the horizontal.

The main types of arrows are:
- straight booms, both with and without devices allowing the load to move horizontally. Example of a dock crane and a KPPG-5 crane
- Articulated booms with a jib cable, used in the period 1930-1990s.
Articulated booms with a rigid jib guy have the advantage of being partially unloaded from torsion when the load swings transversely.

Mechanisms for changing the departure are:
- Rod type (the most common), they can use gear racks or screw rods;
- Hydraulic;
- Pulley, where the change in reach occurs by tightening the movable and stationary clips;
- Sector, used in early crane designs, where the counterweight was located at the lower end of the boom;
- Crank-rod, provide the reciprocating motion of the boom.

Portal jib cranes

Portal jib cranes are the most common type of concrete placing crane used in hydraulic engineering to supply buckets of concrete mixture from the overpass to the building blocks. Being installed in the main mechanization area, these cranes serve all preparatory work of the concrete complex, and are also used in open areas to service large-scale assembly and reloading work.

A portal jib crane is a supporting structure - a portal moving along rail tracks with a rotating crane part installed on it. The portal is the main difference between portal-jib cranes and jib cranes of other designs. The rotating crane part is unified for installation on various mobile support structures (Fig. 31). The crane portal can cover several railway tracks(one-, two-, three- and multi-track portals).

The lifting capacity of construction-type portal jib cranes reaches 20/30 g at an outreach of 50/20 m, which ensures the supply of concrete mixture in buckets with a capacity of 6 m3.

The depth of lowering the hook below the head of the crane rail depends on the height of the concrete trestle and reaches 70 m or more; the lifting height of the hook above the crane rail is 36 m.

Portal jib cranes of the construction type are made only of hook type. Their portals have a large height, since reinforcement trusses and other large-sized cargo for construction purposes can be transported under them along the overpass.

Construction cranes have the same high speeds- lifting, as well as loading cranes. However, their turning speeds and changes in reach are somewhat lower than those of reloading ones, which is necessary to reduce the swinging of the load, which usually hangs on long ropes.

The lifting capacity of special type portal jib cranes reaches 100 tons and reach up to 50 m.

A general view of the construction portal-jib crane is shown in Fig. 32. The main components of the crane are: boom, frame, slewing frame, slewing support, portal, mechanisms for rotating the slewing part, lifting the load and changing the reach, crane control cabin.

The movement of the crane is carried out by electric motors located on the portal's drive trolleys, from where rotation is transmitted to the wheels through a gearbox. An individual drive is easy to operate and repair and is not so sensitive to damage to the portal.

Rice. 31. Diagrams of portal jib cranes:
a - portal; b - semi-portal; c - on a triangular stand (sloping); g - moving along the portal; d - grab with hopper; 1 - loading hopper; 2 - conveyors; 3 - sleeves

Considering that these cranes in hydraulic engineering conditions are usually installed on high concrete trestles, and also keeping in mind the large windward area of ​​the crane and load, the number of drive wheels of the crane is normally taken to be 50%, and sometimes 100% of their total presence, which eliminates the risk of slipping.

In Fig. 33 shows typical running trolleys for portal jib cranes with a lifting capacity of 3-25 tons manufactured at the plant named after. Kirov. The gantry leg of the three-ton crane rests directly on the trolley; for five-ton cranes, the pressure of the portal leg is transferred to the same trolley and additionally to the third wheel; for 10- and 15-ton cranes, the gantry leg rests through a balancer on the drive and idle trolleys.

Rice. 32. Construction portal-jib crane: o - with a curved trunk and a flexible guy; b - with a straight trunk and a rigid guy

Rice. 33. Types of trolleys for portal jib cranes: a - two-wheeled; b and d - three-wheeled; c - four-wheeled; g - eight-wheeled

To ensure the correct movement of the portal along the paths, the following must be observed:
a) single-line installation of the stripes on each side of the portal and parallelism of the lines of the wheels of both sides of the portal;
b) equality of diameters of all driving wheels;
c) correct wheel profile. Failure to comply with these conditions leads to a violation of the geometry of the crane portal and to premature wear of its movement mechanism.

Portal jib cranes are distinguished mainly by the structure of the booms, which are the most characteristic elements that determine both the design of the cranes and their performance qualities.

Boom devices, as a rule, have horizontal movement of the load and are made with straight or articulated booms of various types.

Articulated booms with a balanced mechanism for changing the reach ensure a horizontal trajectory of movement of the load suspended on the hook, which simultaneously creates conditions for the balance of the load relative to the mechanism itself.

The most common are articulated booms with horizontal movement of the end blocks, made according to one of the following schemes: a) a boom with a flexible jib guy (see Fig. 32, a) and b) a boom with a rigid jib guy (see Fig. 32.6 ).

The supports of the booms are the lower hinges, which connect the booms to the rotating frame, and the boom rods, which connect the booms with the mechanisms for changing the reach and the counterweights that balance them.

For inspection and maintenance of the jib end blocks, the booms are equipped with a ladder with railings and a platform.

The crane booms are balanced by movable counterweights, which are selected so that the moment created by their weight relative to the axis of rotation of the lever, for all positions of the booms, is equal to the moment on the same axis created by the total weight of the booms (boom, jib and guy). With this arrangement, the arrows are always in a state of indifferent equilibrium, and little effort is required to change their reach.

Since when the angle of inclination (extension) of articulated booms changes, the load moves almost horizontally, when performing this operation, additional energy is not spent on lifting the load.

The use of articulated and balanced booms makes it possible to easily and safely change the reach of a crane with a load, using this movement as the main working movement, along with the lifting and turning movements.

Mechanisms for changing the reach usually have a rigid kinematic connection with the boom device in order to exclude spontaneous movements of the booms under the influence of horizontal forces (wind, inertia forces, deviation of cargo ropes from the vertical, etc.).

Rice. 34. Types of reach change mechanisms

In Fig. 34 shows the main types of mechanisms for changing reach: rack and pinion (a) with gear or pinion racks, screw (b) with a rotating nut or screw, hydraulic (c), sector (d), sector-crank (e) and crank-rod (e), in which the stepper is connected directly to the boom or to the rocker. The rack and pinion mechanism is the simplest of all types, easy to manufacture and is increasingly used.

The rotating part of the crane (Fig. 35) rests on a slewing device in the form of wheel, roller or ball bearings with a centering pin (column) fixed in the metal structure of the portal. The frame of the turning part is equipped with lifting winches, rotation and change mechanisms: take-off, electrical equipment and a cabin with a control panel.

The mechanisms for turning the portal-jib cranes consist of a slewing support device that supports and centers the slewing part of the crane, and a drive that rotates the slewing part.

Rice. 35. The rotating part of the portal-jib crane on the turntable:
1 - lever with a boom counterweight; 2 - rack and pinion mechanism for changing the reach; 3 - winch; 4 - rotation mechanism

Depending on the type of slewing support, a distinction is made between cranes with a device mounted on turntables (wheeled, roller and ball valves) and those installed on slewing columns. Turning mechanisms usually have torque limiting clutches and open controlled brakes. Recently, hydraulic drives have also been used.

The lifting mechanisms of jib cranes are very diverse. The main parts of the lifting mechanism are load-handling devices, rope pulleys, a drive winch, a control system and signaling and safety devices. The layout and design of lifting devices, winches and other components, as well as the rope reeving scheme depend on the lifting capacity, purpose of the crane and the type of its boom device.

All portal jib cranes are equipped with load limiters and boom outreach indicators.

Portal-jib full-rotating self-propelled cranes are most widely used when laying concrete mixtures from concrete trestles into the middle and high parts of structures. These cranes are especially important when combining construction and installation work during the construction of hydraulic structures, where, along with laying concrete, a large amount of work is carried out on the installation of metal structures of the switchboard compartment and embedded parts of hydraulic units. With the correct location of the cranes in relation to the switchboard compartment and suction pipes, it seems possible to service the entire area of ​​laying the concrete mixture and installation work on the hydroelectric power station building.

Installation of the crane must be carried out under the guidance of an experienced specialist according to a pre-drawn up project for organizing installation work. The installation method depends primarily on the available installation equipment, their load capacity and lifting height.

When operating portal jib cranes, the main attention should be paid to the condition of the rail tracks, compliance with established rules for lifting loads, ensuring the stability of the crane when not in operation and compliance with safety regulations. When operating cranes, a system of scheduled preventative and current repairs, regular inspection of cranes, adjustment and lubrication of individual components and parts in accordance with factory instructions, systematic monitoring of the condition of the supporting structure of the crane and its mechanisms.

The stability of a portal-jib crane lifting (or lowering) the maximum load is checked taking into account the influence of inertial forces and wind pressure directed towards the load with the calculated pressure for the operating state of the crane.

For a crane without a load, the stability check is carried out taking into account the effect of wind with the calculated pressure for the crane's non-operating state.

TO category: - Masts, chevres, portals and mast-jib cranes

Having visited any port city, paying attention directly to the port, you can always see the so-called port crane on the horizon. Without these lifting machines it is simply unrealistic to imagine not only sea or river “gates”, but also construction site hydraulic structures, shipbuilding enterprises. We will talk about these units in more detail in the article.

Marking

Let us immediately note that the expression “port crane” is not completely correct, since cranes of a wide variety of systems and types can be used in the port. The correct phrase would be “portal crane”, the name of which comes from its underlying structural element - the portal.

Port ports have the following designations:

• The letter "K" stands for "faucet".
• "P" - portal.
• D/M/P - dock, installation, transshipment.
• K/G - hook, grab (these letters refer to the old designation system).

The meaning of the numeric indices is:

• 1 - indicator of the maximum lifting capacity on the main hook or at maximum reach.
• 2 - maximum reach.
• 3 - portal track size.

In cases where the load capacity will differ depending on the reach, the designation of the reach itself and the load capacity indicator occurs in two numbers - separated by a fraction.

Job responsibilities

Now let's look at port cranes depending on their purpose:

• Reloading. This is the most mass appearance port reloaders. Its load capacity ranges from 5 to 30 tons. A grab (for bulk materials), a magnetic washer for reloading scrap metal, or a hook suspension for piece goods can be used as a load-handling device.

• Assembly is most often used in shipbuilding and ship repair plants, in ports. Its body is almost exactly the same as that of its overload “brother”, and the only difference is the presence of a jib on the trunk. It is also characterized by a low speed of movement of the hook. there may be two (for the main and auxiliary lift). Load capacity ranges from 12.5-60 tons.
• Slipway is perhaps the smallest type of portal units. In fact, it is an installation machine that has found its use only in enterprises involved in the construction of various ships. A characteristic feature of the crane is a high portal and trolley-type power supply. Capable of holding a load close in weight to the maximum carrying capacity for a very long period of time (installation of a ship’s hull takes more than one day). Load capacity is 30-160 tons.
• Dock's. Due to the specific nature of its work, this port crane has a very small lifting capacity. Among the design features, it is worth highlighting the narrow portal and the presence of anti-theft grips (in addition to rollover protection). Also, the operation of the mechanism is limited by the degree of excitement of the sea or river.

Main structural elements

Harbor cranes in most cases consist of the following main parts:

• Portal. Its main purpose is to reduce the mass of counterweights by increasing the platform. Due to this design of the center of gravity, the possibility of the crane overturning is eliminated. In addition, between the legs of the portal, a railway or road transport. It also allows the crane itself to pass over any structure.
• The leg is a part of the portal, the bottom of which ends with bogies (driven or idle).

• Portal head. With its help, the legs are connected. In addition, it absorbs loads from the rotating part. Electrical equipment for the crane movement mechanism is installed in the head.
• Rotary support device.
• Current supply.

Technical data

Harbor cranes, the characteristics of which may vary, are generally produced and operate taking into account the following indicators:

• Load capacity.
• Arrow reach and rate of change of its reach.
• Crane moving speed.
• Turning speed.
• Wheel load indicator.
• The speed of the cart (if any).

Also, when studying a port crane, special attention should be paid to the mechanism for changing the boom reach, which, in turn, can be hydraulic, rod, pulley or crank type.

This is lifting equipment with a rotating part installed on a mobile metal structure that rides on rails and is capable of passing railway cars and other vehicles under it. Portal cranes found wide application in the field of construction of power buildings, locks, dams, hydroelectric power stations and other important facilities. They are actively used in ship docks and at border warehouses, when working with bulk, critical piece, bulk cargo.

Portal crane device

In general, it consists of the following mechanisms:

A leg is an element with a trolley at the bottom (idle or motor) that provides movement along the crane track. The number of legs varies depending on the model and can be either 3 or 4 (classic version), or 8 or even 16. All carts are equipped with an anti-theft grip, each has an individual drive (if they are motorized), and the outer ones are necessarily buffered .

The head is a platform for connecting the legs, square or round. In addition to the final formation of the portal, with a travel distance of 10.5 m (standard for 2 tracks) or some other, it is also a connection point for electrical equipment - all bogie drives. Plus, the head is also a supporting element that receives loads from the rotating device.

Current lead is a cable, flexible or on a drum, which is attached to one of the legs or to the connecting crossbar, and is wound up/unwound when the crane moves. Also, current can be supplied using a trolley, but this is a rather expensive option, used only when it is inappropriate to lay a cable at a work site due to the high probability of its breakage or damage.

Rotating device - a column or circle on rollers in contact with the head. Supports and centers the drive that ensures the rotation of the gantry crane. Transfers loads and vertical pressure to the head.

Boom device - with a gripping mechanism that performs vertical and horizontal (if the reach can be changed) movement of cargo. Equipped with a system of movable counterweights, thanks to which balance is achieved in relation to the swing axis during operation.

Classification of portal cranes

By purpose they are distinguished:

According to the type (pattern) of the arrow there are:

• straight – the offset remains unchanged;
• articulated - with a flexible or rigid guy, a straight or profiled trunk, leveling blocks or pulleys - all this is aimed at changing the reach;

According to the design of the portal, cranes are classified into:

• lattice – each leg is a separate structure;
• frame - the legs are connected in pairs and thus attached to the crossbar through the head;
• frame-tower - similar to the previous ones, but only reach the top;
• frame-braced - each leg is hinged to the crossbar.

Based on the number of supports (legs) there are:

• three-
• four-
• multi-support.

According to the number of connections between the legs and the upper crossbar, portal cranes:

• two-
• four-
• multi-post.

In this case, the nature of the connection of the legs with the upper crossbar can be:

• rigid - legs do not move;
• articulated - the supports can change their position (after the head).

According to the running device, portal cranes are:

• on rails - they move exclusively along the paved path;
• pneumatic wheels are more mobile; they can even be turned on the spot.

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