TTK. Slinging cargo for various purposes. Schemes for slinging rails, sleepers, crosspieces and other materials! Basic rules for slinging and moving pipes

When performing loading and unloading operations, it is important to adhere to a number of rules. One of these requirements is that standard slinging diagrams must be issued to employees of the enterprise (or posted in a place accessible to specialists). It is prohibited to work with loads without diagrams. Their strict adherence can significantly reduce the likelihood of an unforeseen situation during the production process. In our article we will discuss the basic schemes for slinging loads with the most typical loads.

Rules for slinging schemes

When developing slinging schemes, material handling managers must adhere to a number of rules. The main ones are:

• the load is depicted as voluminous;
• with irregularly shaped loads, the center of gravity must be indicated;
• the wiring diagram must contain visible and invisible branches of the node;
• in the case of multi-leg slings, there must be an angle between the branches.

Slinging diagrams with pictures

Below are the slinging diagrams for the most common loads, which are widely used in enterprises in various fields: from construction companies to manufacturing firms. Knowledge and adherence to such schemes is the key to safe and efficient loading and unloading operations.

Pipe slinging diagram

When slinging pipes, as a rule, all the requirements associated with long objects apply. Pipes up to two meters long can be transported using single-leg slings.

The diagram shows pipe slinging:

a) using end grips;

b) using double-loop slings with a sleeve;

c) scheme of slinging with traverses;

d) using a pincer grip;

e) towel slings;

g) transportation of a package of pipes using double-loop slings.

The number 1 marks the spacer.

It is worth noting: when unloading pipes from gondola cars, as well as during their loading onto pipe carriers, the vehicle should be installed parallel to the rails.

Beam slinging diagram

In the case of beams, everything happens almost the same as when slinging pipes. The only thing here is that it is important to take into account parameter A – the length of the beam’s girth with slings. It is necessary that the distance from the crane hook to the beam itself is no less than 75% of parameter A, and the distance between the points of attachment of different branches to the beam is equal to parameter A.

In the diagram you can see the slinging of beams:

a) metal (in girth);

b) reinforced concrete (in girth);

c) metal (traverse, using pincer grips).

Equipment slinging diagrams

Such schemes for slinging parts and equipment are of particular interest for industrial enterprises. First of all, here it is worth starting from a number of parameters, including the type of such unit, its size and shape. As a rule, multi-branch slings are used (namely 4SK, or 2 slings 2SK). This allows you to achieve maximum stability of heavy loads during loading and unloading operations with equipment.

The diagram shows the sling:

a) vessels using two double-loop slings;

b) valves with a two-loop sling;

c) the unit, using two double-loop slings;

d) a cylindrical tank (two double-loop slings);

e) boxes using two double-loop slings;

f) schemes for slinging machine parts (two double-loop slings);

g) equipment that is in a wooden container (two double-loop slings).

Slinging scheme for metal structures

Another relevant scheme is the metal slinging scheme. Due to the popularity of such structures, it is important to know exactly how they are transported using slings.

In the diagram you can see the sling:

a) single load;

b) a package of sheet steel;

c) wire coil;

d) package with I-beams;

e) a package of sheet steel (in the case where the grips are located symmetrically with respect to the center of gravity, the distance is 1/3 of the length from the extreme point of the metal structure);

f) eccentric clamping devices.

Number 1 marks the clamp, 2 – mounting brackets, 3 – spacers.

Column slinging diagram

The process of transporting columns can take place both vertically and horizontally. In this case, as a rule, two-legged slings or traverses are used.

Slinging diagram for metal supports

In the case when the load is moved onto special metal supports, the following slinging scheme is used.

Trusses that have a length of less than 18 m are slung at two points. In the case where structures exceed a length of 18 m, four fastening points are used, or traverses are used, which can provide stable tension at all stages of lifting.

It is worth noting: The branches of the gear must not deviate from the vertical position, otherwise strong compression will be created in the upper chord of the truss.

When moving such objects, be sure to use four-legged slings, or a pair of two-legged slings. It is unacceptable to use only two-legged slings, making attachment points in opposite corners.

The panel strapping scheme is almost identical.

The container slinging scheme is quite similar to the previous version. The only thing here is that you can fasten the slings to the eyes. In the case of not too long containers, the use of two-legged slings is acceptable.

Pallet strapping diagram

When transporting pallets, it is important to consider the size and shape of the structure, as well as the presence of additional cargo on the pallet. In the latter case, it is necessary to take measures to prevent spontaneous movement of goods on the pallet, as well as their falling from it.

Regardless of what the slinging scheme and other similar devices look like, it is important to adhere to a number of rules:

• When tying loads, twisting of the slings and the presence of knots on them are not allowed. If the cargo has sharp components, it is necessary to use special spacers that prevent damage to the gear;
• if there are unused branches of multi-branch slings, they must be strengthened so that there is no possibility of free branches touching third-party objects;
• when using chain slings, there should be no bends in the links on the edges of the load;
• it is possible to move loosely stowed loads on loop slings only if there are elements on the load that prevent its unauthorized displacement;
• when slinging a load using a loop tightening method, it is necessary to reduce the load-carrying capacity of the gear by 20 percent;
• during regular use of rope slings for the purpose of tying loads with curves, the radius of which is less than 10 rope diameters, the permissible load on the branches of the gear should be reduced.

If you adhere to these rules, as well as cargo slinging schemes in accordance with GOST and STO, you can avoid most unforeseen situations during loading and unloading operations. In addition, you should buy only high-quality gear from trusted manufacturers that have all the necessary certificates for such activities. You can view the permitting documentation of the Freight Mechanics company, which is confirmation of the high quality, durability and reliability of our lifting gear, directly on the website.

TYPICAL TECHNOLOGICAL CARD

SLINGING OF CARGOES FOR VARIOUS PURPOSE

I. SCOPE OF APPLICATION

I. SCOPE OF APPLICATION

1.1. A standard technological map (hereinafter referred to as TTK) is a comprehensive regulatory document that establishes, according to a specific technology, the organization of work processes for the construction of a structure using the most modern means of mechanization, progressive designs and methods of performing work. They are designed for some average operating conditions. The TTK is intended for use in the development of Work Performance Projects (WPP), other organizational and technological documentation, as well as for the purpose of familiarizing (training) workers and engineers with the rules for carrying out work on slinging cargo for various purposes.

1.2. This map provides instructions on the organization and technology of work on slinging cargo for various purposes, rational means of mechanization, data on quality control and acceptance of work, industrial safety and labor protection requirements during the production of work.

1.3. The regulatory framework for the development of technological maps is: SNiP, SN, SP, GESN-2001 ENiR, production standards for material consumption, local progressive standards and prices, labor cost standards, material and technical resource consumption standards.

1.4. The purpose of creating the TC is to describe solutions for the organization and technology of work on slinging cargo for various purposes in order to ensure their high quality, as well as:

- reducing the cost of work;

- reduction of construction duration;

- ensuring the safety of work performed;

- organization of rhythmic work;

- rational use of labor resources and machines;

- unification of technological solutions.

1.5. On the basis of the TTK, as part of the PPR (as mandatory components of the Work Project), Working Technological Maps (RTC) are developed for the implementation of certain types of slinging cargo for various purposes. Working technological maps are developed on the basis of standard maps for the specific conditions of a given construction organization, taking into account its design materials, natural conditions, the available fleet of machines and building materials tied to local conditions. Working technological maps regulate the means of technological support and the rules for performing technological processes during the production of work. Design features for slinging cargo for various purposes are decided on a working design basis in each specific case. The composition and degree of detail of materials developed in the RTK are established by the relevant contracting construction organization, based on the specifics and volume of work performed.

Working flow charts are reviewed and approved as part of the PPR by the head of the General Contracting Construction Organization, in agreement with the Customer's organization, the Customer's Technical Supervision.

1.6. The technological map is intended for work producers, foremen and foremen who perform work on slinging cargo for various purposes, as well as the Customer’s technical supervision workers and is designed for specific conditions of work in the third temperature zone.

II. GENERAL PROVISIONS

2.1. The technological map has been developed for a set of works on slinging cargo for various purposes.

2.2. Work on slinging cargo for various purposes is carried out in one shift, the duration of working hours during a shift is:

Where 0.06 is the coefficient of reduction in efficiency due to an increase in the duration of the work shift from 8 hours to 10 hours.

2.3. The work performed sequentially when slinging cargo for various purposes includes:



- selection of load-handling devices;



- slinging loads and securing guy ropes.

2.4. The technological map provides for the work to be carried out by an integrated mechanized unit with automobile jib crane KS-45717 "Ivanovets"(maximum load capacity 25.0 t, boom length 21.7 m), as a driving mechanism.

Fig.1. Automotive jib crane KS-45717

Fig.2. Chart of crane lifting capacity depending on availability and boom radius

2.5. Work on slinging cargo for various purposes should be carried out in accordance with the requirements of the following regulatory documents:

- SP 48.13330.2011. Organization of construction;

- SNiP 12-03-2001. Occupational safety in construction. Part 1. General requirements;

- SNiP 12-04-2002. Occupational safety in construction. Part 2. Construction production;

- RD 11-05-2007. The procedure for maintaining a general and (or) special log of work performed during construction, reconstruction, major repairs of capital construction projects;

- PB 10-14-92*. Rules for the design and safe operation of load-lifting cranes;
________________
* PB 10-14-92 lost force with the introduction of the “Rules for the design and safe operation of load-lifting cranes” (PB 10-382-00).


- RD 10-33-93. General purpose cargo slings. Requirements for the device and safe operation;

- GOST 25573-82. Cargo rope slings for construction.

III. ORGANIZATION AND TECHNOLOGY OF WORK EXECUTION

3.1. In accordance with SP 48.13330.2001 “Construction Organization”, before the start of unloading and loading work at the site, the Contractor is obliged to obtain design documentation and permission to carry out construction and installation work from the Customer in the prescribed manner. Carrying out work without permission is prohibited.

3.2. Before loading and unloading operations begin, it is necessary to carry out a set of organizational and technical measures, including:

- appoint persons responsible for the quality and safety of work;

- conduct safety training for team members;

- install temporary inventory household premises for storing building materials, tools, equipment, heating workers, eating, drying and storing work clothes, bathrooms, etc.;

- arrange temporary driveways and entrances to the loading area;

- prepare the base of the site for installing the crane;

- provide workers with tools and personal protective equipment;

- prepare places for storing materials, inventory and other necessary equipment;

- protect the loading area with warning signs illuminated at night;

- provide the loading area with fire-fighting equipment and alarm systems;

- draw up an act of readiness of the facility for work;

- obtain permission to carry out work from the Customer’s technical supervision.

3.3. Before loading and unloading operations begin, you must:

- conduct a technical examination of load-handling devices;

- carry out culling of load-handling devices;

- check the completeness of the load-handling devices.

3.3.1. During technical inspection, slings must be subjected to external inspection and testing with a load 1.25 times greater than their rated load capacity.

Slings that have passed acceptance tests at the manufacturer after manufacture are not subject to initial technical examination.

Damaged slings identified during inspection or technical examination are removed from work until repairs are carried out.

The results of the inspection of slings are recorded in the registration and inspection log. (For the journal form, see Appendix 5, RD 10-33-93).

3.3.2. Rejection of ropes and chains of slings must be carried out in accordance with the requirements of Article 7.3.28 “Rules for the design and safe operation of load-lifting cranes”.

Rejection of rings, loops and hooks is carried out:

- in the presence of cracks;

- when the surface of elements is worn out or local dents lead to a decrease in cross-sectional area by 10%;

- in the presence of residual deformations leading to a change in the original size of the element by more than 5%.

The following slings are not allowed for use:

- having the defects stated above;

- if the marking tag is missing or damaged;

- with deformed thimbles or when the latter are worn out with a decrease in the original cross-sectional dimensions by more than 15%;

- with cracks on the crimp bushings or when the size of the latter changes by more than 10% of the original;

- with signs of displacement of the rope in the braid or bushings;

- with damaged or missing braids or other protective elements in the presence of protruding ends of the wire at the braiding point;

- with hooks that do not have safety locks.

The manufacturer must guarantee compliance of slings with the requirements of RD 10-33-93, subject to the consumer's compliance with storage and operating conditions.

3.3.3. The sling delivery package should include:

- lanyard with marking tag;

- passport.

The label must indicate:



- serial number of the sling according to the manufacturer’s numbering system;

- lifting capacity of the sling;

- test date (month, year).

The method of attaching the marking tag must ensure its safety until the end of the sling’s operation.

The following must be applied to each element and sling grip at the place designated for marking, by stamping or impact:

- name of the manufacturer or its trademark;

- symbol of the element or grip according to the manufacturer’s system;

- serial number according to the manufacturer’s numbering system or batch number.

3.3.4. The warranty period for rope slings during single-shift operation is 3 months from the date of commissioning, for chain slings - 18 months.

3.3.5. The completion of preparatory work is recorded in the General Work Log (The recommended form is given in RD 11-05-2007).

3.4. Equipment for loading and unloading steel pipes

3.4.1. It is used for loading and unloading steel pipes using a truck-mounted jib crane. traverses (see Fig. 3) and end grips (see Fig. 4) with different load capacities and for different pipe diameters. To prevent damage to the ends of the pipes, the lifting hooks of the traverses and grips are equipped with caprolon pads. The devices must be checked for burrs and distortions on the end grips in contact with the pipe.

Fig.3. Diagram of the TRV-162 traverse with a lifting capacity of 16.0 t

1 - detachable part of the beam; 2 - traverse beam; 3 - earring; 4 - hooks for hanging slings when working with different lengths of pipes; 5 - sling with hook

Fig.4. Scheme of the end gripper ZT-1422 with a lifting capacity of 9.0 t

1 - earring; 2 - sling; 3 - hook; 4 - cheeks; 5 - bracket; 6 - lower caprolon pad; 7 - upper caprolon lining; 8 - cotter pin; 9 - heel

3.4.2. For unloading insulated pipes and double-pipe sections from pipe-carriers and further moving them over short distances, for laying out along a trench or storing in a stack, pipe-laying cranes equipped with assembly towels (see Fig. 5) or pincer grips (see Fig. 6).

Fig.5. Diagram of soft towel PM-1428R with a load capacity of 63.0 tons

1 - towel; 2 - rocker axles; 3 - rocker arm; 4 - axis for hanging on a crane hook

Fig.6. Scheme of pincer gripper ZTA-102 with a lifting capacity of 28.0 tons

1 - earring; 2 - link; 3 - fixation mechanism; 4 - lever; 5 - body; 6 - axis; 7 - foot; 8 - foot axis

3.4.3. The lifting devices used must be branded and labeled indicating the load capacity and test date. In this case, it is necessary to use only such devices that are designed to work with pipes of a given diameter, and monitor their condition during the work.

3.4.4. Persons who must monitor the operation of machines and mechanisms must periodically inspect lifting devices during operation:

- every 10 days - slings;

- every 6 months - traverses.

3.4.5. Load-handling devices for lifting pipes must prevent unintentional release and ensure stability of the load during lifting.

Slingers must be assigned to hook and strap (sling) the load onto the hook of the lifting machine. Other workers (riggers, assemblers, etc.) trained in the profession of slinger in the manner established by the State Mining and Technical Supervision Authority of Russia may be allowed as slingers.

3.4.6. The lifting devices used must be designed only for working with pipes of a given diameter. Slinging of pipes during unloading is carried out by certified slingers.

3.5. To lift building structures, various lifting devices are used in the form of flexible steel ropes, various traverse systems, mechanical and vacuum grips. Load-handling devices must provide simple and convenient slinging and unslinging of elements, reliable engagement or gripping, excluding the possibility of free uncoupling and falling of the load. Load-handling devices must be tested with a test static or dynamic load exceeding their rated load-carrying capacity.

3.5.1. Flexible slings made from steel ropes. They are used when lifting light columns, beams, slabs, wall panels, containers, etc. The slings are made universal and lightweight depending on the technological purpose - one-, two-, four- and six-legged (Fig. 4). Universal slings are made in the form of closed loops 6...15 m long, made from cables with a diameter of 18...30 mm, lightweight slings - from cables with a diameter of 12...20 mm. Loops on thimbles, hooks or carabiners are installed at the ends. Select the lifting capacity of the sling depending on the weight of the mounting unit.

Fig.7. Flexible slings made from steel ropes

A - flexible slings; b - two-branch rope; c - four-branch rope; 1 - universal sling; 2, 3 - lightweight with hook and loop; 4 - carbines

3.5.2. Traverses made in the form of metal beams or triangular welded trusses. At the ends of the lower belt, blocks are installed through which the slings pass. This sling suspension system ensures uniform transmission of forces to all gripping points. Long structures are lifted using traverses. Slinging can be done at two or four points. To lift large-sized structures, spatial traverses are used, and for lifting heavy elements with a displaced center of gravity, traverses with a balancing system are used. Lightweight slings and grips can be installed on the traverse.

Fig.8. Traverse designs:

A - beam; b - console; c - spatial; 1 - suspension; 2 - flexible rods; 3 - beam; 4 - bracket for suspension to the cargo hook; 5 - block

3.5.3. Grips designed for loopless lifting of mounted elements. Structurally, the grippers are mechanical, electromagnetic and vacuum.

With mechanical grippers, the structure is held by frictionally engaging, clamping or picking up protruding parts.

Electromagnetic grippers are based on holding conductive structures using a magnetic field. Such grips are used primarily for installation and loading and unloading of sheet metal structures.

Vacuum grippers are used to lift thin-walled flat structures. The structure is held in place by forces caused by rarefaction of air.

Fig.9. Designs of grippers for loopless installation of elements:

A- friction grip for slinging columns; b- mechanical grip for lifting beams; V- device for slinging slabs; G- fork for mounting ribbed slabs; d- device for slinging structures; e- collet grip; and- pincer grip; h- traverse with vacuum grippers;
1 - mounted structural element; 2 - friction grip beam; 3 - traverse; 4 - mechanical grip; 5 - threaded bracket; 6 - clamp; 7 - fork element; 8, 9 - system of rods for fixation; 10 - wedge liner; 11 - friction sleeve; 12 - pincer grip; 13 - pressure gauge; 14 - vacuum pump; 15 - vacuum cross-beam; 16 - vacuum chamber

3.6. Cargo slinging work includes the following operations:

- moving the crane and installing it into working position on all available outriggers;

- preparing cargo for slinging;

- selection of removable load-handling devices;

- hanging load-handling devices on a hook;

- inspection and slinging of cargo, and, if necessary, securing guy ropes (for long cargo);

- giving signals to the crane operator;

- loading and unloading cargo with lifting or lowering it and turning the crane boom;

- laying linings and gaskets under structures or parts;

- unslinging the load, uncoupling the guy ropes.

3.6.1. In a certain place, on a prepared site, the person responsible for the safe performance of work with cranes checks the correct installation of the crane in the specified place and then makes an entry in the crane operator’s logbook about permission to carry out the work, putting his signature. Also checks the correct installation of safety signs on the border of the dangerous zone from crane operation and the coordinate protection system.

3.6.2. Hanging lifting devices on the crane hook and removing them from the hook (see Fig. 10) is performed by a worker performing rigging work in the following sequence:

- checks the serviceability of the sling 1 , inspecting it from the load-carrying organs to the ring-bracket;

- takes the ring-clip with both hands 4 , lifts it, dragging the branches of the sling behind it, and puts it on the hook 2 tap;

- checks the correctness of the technique by comparing it with the diagram;

- with both hands, slightly lifts the sling by the ring-bracket and removes it from the hook;

- places the sling on the table.

Fig. 10. Scheme of hanging load-handling devices on a crane hook

1 - ropes (staples); 2 - hook; 3 - latch; 4 - ring-bracket

3.6.3. Preparing loads for slinging and selecting load-handling equipment is carried out in the following sequence:

- the slinger approaches the prefabricated structure and checks whether its quality meets the standards of the tolerance table (surface cleanliness, number of concrete edges and cracks, serviceability of mounting loops and their readiness for slinging, presence of bent reinforcement outlets, concrete sagging on embedded metal parts in grooves and in sockets for mounting loops). If the number of defects exceeds the norm, then the element is rejected;

- if necessary, performs the following: straightens bent reinforcement outlets with an overhead reinforcing wrench, removes concrete deposits using a scarpel and a hammer, additionally cleans embedded parts with a wire brush, removes dirt and ice with a brush, scrapes off with a scraper, sweeps away with a broom;

- checks the markings;

- using tables, determines the mass of the structure;

- depending on the weight of the structure and the slinging scheme, selects a load-handling device;

- goes to the table with lifting equipment and, using the tables, selects slings;

- using the tag, checks the compliance of the selected means with the weight of the load being lifted;

- using the table of permissible defects, checks the suitability of the product for work.

3.6.4. Slinging and lifting of prefabricated structures is carried out in the following sequence:

- the slinger climbs onto the platform where the purlin, beam, etc. lie. cargo;

- gives a signal to the crane operator to bring the slings to the slinging point;

- alternately inserts both hooks of the sling into the opening of the mounting loops from the outside of the part towards its center of gravity, in order to prevent the safety lock from lowering inside the hook;

- moves away from the structure, checks the correctness of the sling and gives the crane operator a signal to tighten the slings;

- checks the quality of the sling and descends from the platform;

- gives a signal to the crane operator to raise the structure by 20...30 cm;

- climbs onto the platform and once again checks the slings and the tension of the slings;

- gives a command to the crane operator to lift the load to a height of 1.0 m;

- after a short pause (20...30 seconds), signals the crane operator about the need to lower the load;

- at a height of 20...30 cm from the surface of the platform, at the command of the worker performing rigging work, the crane operator stops the structure;

- climbs onto the platform, orients and places the structure in place;

- gives a signal to the crane operator to loosen the slings;

- removes the sling hooks from the mounting loops;

- gives the command to the crane operator to lift the slings and move them to the side (raise them to a height of 1.0 m). During lifting, make sure that the hooks do not cling to the loops and protruding parts of the prefabricated element, and keeps the slings from swinging;

- slingers accept the load at a height of up to 1.0 m from the level of the site (ground), orient it in accordance with the storage diagram, and the senior slinger gives a signal to the crane operator to lower the load so that the lower part of the load is at a height from the level of the storage site up to 0.4-0.5 m;

- having made sure that the load is correctly oriented above the storage area (stack), the slinger gives a signal to the crane operator to lower the load onto the platform. The slings remain taut. When the load is lowered and the slinger is convinced that the load is in a stable position, the slinger signals the crane operator to loosen the slings;

- then the slinger unslings the load.

STRAPING DIAGRAMS FOR VARIOUS LOADS

Fig. 11. Slinging structures with flexible slings:

G- slinging with a four-legged sling; d- the same, three-traverse; e- the same, three-block

Fig. 12. Slinging diagrams for pipe assemblies and products

Fig. 13. Slinging diagrams for ball valve units

Fig. 14. Slinging diagrams for crane units with pneumatic-hydraulic drive

1. Classification of cargo

Depending on the type, method of storage and slinging, cargo is classified into the following groups:

1. Piece non-stackable loads() – metal structures, engines, machine tools, machines, mechanisms, large reinforced concrete products, etc. The group of piece non-stackable cargo is the most numerous and diverse in shape, therefore there are no uniform standard methods for slinging them, suitable for all cargo in this group.
   
2. Piece stackable loads() - rolled steel, pipes, timber and sawn timber, brick, cinder blocks, standard reinforced concrete products, slabs, panels, blocks, beams, flights of stairs, boxes, barrels and other products of geometrically correct shape.
   
3. Bulk cargo() are transported in containers, grabs, conveyors, etc. They are stored in stacks determined by the angle of repose of the material and bounding surfaces (coal, peat, slag, sand, crushed stone, cement, lime, small metal shavings, etc.).
   

   Figure 1.3 – Bulk cargo

4. Semi-liquid plastic loads– loads that have the ability to retain their given shape for some time or harden over time. Such cargoes include concrete masses, mortars, lime paste, bitumen, lubricants, etc. The viscosity of semi-liquid cargo and their hanging on the walls of containers of transport vehicles, the ability to quickly set and harden (concrete, mortar, etc. cargo) make their transportation difficult. Such goods must be transported in special containers.
5. Liquid cargo– goods that do not have a specific shape are transported in barrels, cans, bottles, tanks, ladles, etc. (water, liquid flammable and lubricants, acids, alkalis, mastics, etc.).
6. Gaseous cargo They are usually transported under pressure in cylinders (), other vessels and pipeline transport.

   

   Figure 1.4 – Container for cylinders

Depending on the weight, cargo is divided into four categories:

1. Lightweight cargo– loads weighing no more than 250 kg. These include materials such as felt, leather, tow, plywood, dry plaster, lightweight machine parts, etc.
2. Heavy cargo– cargo whose weight ranges from 250 kg to 50 tons. Heavy cargo includes all stackable, bulk, semi-liquid, liquid and non-stackable cargo, the weight of which does not exceed 50 tons.
3. Very heavy loads– loads whose weight exceeds 50 tons. These include piece non-stackable loads. Slinging of these loads is permitted only to highly qualified slingers.
4. Dead weights– a special category of cargo of unknown mass. Loads that are secured to the foundation with anchor bolts, buried in the ground, frozen to the ground, pressed by another load, or lifted with an oblique beam are considered dead. Lifting dead weights with a crane is prohibited.

Depending on the shape and size, cargo is divided into:

1. Dimensional cargo- cargo, the dimensions of which do not exceed the dimensions of the rolling stock of railways, and for automobile and other types of ground-based trackless transport - the norms established by the Road Traffic Rules of the Russian Federation.
2. Oversized cargo– cargo whose dimensions exceed the dimensions of the rolling stock of railways or ground trackless transport. Oversized cargo can be large boilers, machines, transformers, etc. The size of the clearance violations should not exceed certain values ​​at which cargo transportation is still possible by reducing the gap between the approach dimensions of buildings and rolling stock.

Depending on the size of the oversize violation, cargo is divided into five degrees of oversize, each of which has its own limiting outlines. When transporting oversized cargo by rail, the corresponding degree of oversized cargo is indicated.

Long cargo constitute a special group of goods (parts and assemblies of large machines, equipment, metal structures, etc.), which are transported on special railway platforms or trailers. Oversized, oversized and long cargo are permitted for transportation in wagons or on platforms only after approval of the loading scheme by the railway department or management.

2. What does the slinger need to know about the load?

To lift a load, its mass, center of gravity and slinging pattern must be known.

The mass of the load can be determined using the formulas:

• for simple loads –Q = m · V ;
• for complex loads –Q = m · ∑ V i,

WhereQ – mass of cargo,m – specific gravity (numerically equal to density) of the material,V – cargo volume,∑V i – the sum of all parts of the cargo volume.

The specific gravity of commonly encountered materials is given in.

Specific gravity of materials

How should a slinger act if the mass of the load is unknown?

The slinger is prohibited from slinging loads whose mass is unknown. In this case, the slinger must notify the person responsible for the safe performance of work with cranes and obtain from him information about the weight of the load.

What is the center of gravity of a load? Where it is located?

Load center of gravity- this is the point relative to which the load is balanced in all directions.

The center of gravity of simple-shaped loads (cube, parallelepiped, cylinder, ball) is located in their geometric center. The position of the center of gravity of the load must be indicated by a handling sign if it is shifted relative to the geometric center of the load. In this case, the location for slinging the load can also be indicated with a handling sign ().

Figure 2.1 – Using a manipulation sign

How to perform slinging taking into account the location of the load’s center of gravity?

A load that is strapped without taking into account the location of the center of gravity may end up in an unstable position.

The load will be stable if its center of gravity is located between the slinging points. It is permissible to tie the load with one sling at the location of the center of gravity if the length of the load is no more than 2 m.

What kind of slinging parts can loads have?

Hooking loads with branch slings is a simpler and safer method than tying. For hooking, loads can have loops, eye bolts (), holes, axles (a axle is the bearing or supporting part of an axle or shaft).

Figure 2.2 – Eye bolt

What do manipulation and danger signs indicate?

Handling signs indicate the method of handling the cargo. They are applied to packaging, containers or directly to cargo. Some of the manipulation signs that the slinger needs to know are shown.

Figure 2.3 – Manipulation signs

Danger signs are applied to goods that, during transportation and loading and unloading operations, can cause harm to people and the environment. The danger sign is a square mounted on an edge, in which a symbol is depicted indicating the type of danger (explosion hazard, fire hazard, toxicity, radioactivity, etc.).

Before performing loading and unloading operations with dangerous goods, the slinger must be instructed.

Figure 2.6 – Transportation of cargo with loose stowage on loop slings

10. When tying loads with chain slings, do not allow the links to bend on the edges of the load ().

Figure 2.7 – Slinging loads with chain slings

11. Moving cargo using hook slings is shown in.

Figure 2.8 – Installation of the sling hook in the eye

12. Slinging loads from stacks (rolled metal, pipes, timber, etc.) should be carried out in the following sequence:

• on the most protruding end of the structure, located in the top row, a loop of a ring sling is put on, hanging on the hook of a two- or four-branch sling;
• the slinger moves to a safe distance and gives the command to raise the end of the load to a height of 0.4-0.5 m;
• the slinger approaches the raised load from the side and places wooden pads with a cross-section of 100×100 mm under it at a distance of ¼ from its ends (when lifting pipes and logs, there should be stops on the pad to prevent the load from rolling out);
• the slinger moves to a safe distance and gives the command to lower the load onto the pads and loosen the sling (safe distance means the distance to places that are outside the danger zone at the appropriate lifting height; these places should not be in the danger zone);
• The slinger approaches the load and, using a metal hook (made of wire with a diameter of 6 mm), places the ring slings under the load at a distance of ¼ of the length of the load from its end, then removes the first sling, and tightens the supplied ring slings onto a “noose” and puts two hooks on them. or four-legged sling;
• The slinger gives the command to lift the load to a height of 20-30 cm, makes sure that the sling is secure and gives the command to further move the load.

13. Slinging a load into a girth (on a “noose”) with a load length of less than 2 m is allowed to be done in one place (except for rolled metal).

14. Unslinging of structures installed in the design position should be done only after they have been permanently or reliably temporarily secured.

15. The movement of small-piece cargo must be carried out in containers specially designed for this purpose. In this case, the possibility of individual loads falling out should be excluded. To avoid spontaneous loss of cargo, containers must be loaded 100 mm below its sides.

16. To install structures at height, it is necessary to use load-handling devices with remote slinging.

4. Selection of lifting devices

When moving a load, load-handling device or container horizontally, it should first be lifted 500 mm above equipment, building structures and other objects encountered along the way.

Slinging diagrams, graphic representations of methods for slinging and hooking loads should be handed out to slingers and crane operators or posted at work sites. The crane owner or operating organization must also develop methods for tying parts and assemblies of machines moved by cranes during their installation, dismantling and repair, indicating the devices used, as well as methods for safely tilting loads when such an operation is performed using a crane.

Schemes for slinging and tilting loads and a list of used load-handling devices must be given in the technological regulations. The movement of cargo for which slinging schemes have not been developed must be carried out in the presence and under the guidance of a person responsible for the safe performance of work with cranes. The management of sea and river ports is obliged to ensure that loading and unloading operations are carried out using cranes in accordance with the technological maps approved by them.

Example of safety posters for lifting operations

Moving cargo is one of the most complex and critical activities in the production process. In production of all types of industry, the heaviest loads are moved using cranes, but many loads do not have special fastenings for transportation, so intermediate lifting elements are used. Rope and tape slings most often act as such intermediate elements. At our enterprise we produce most types of slings, which you can find in the catalog of our website.

To sling a load intended for lifting, cargo slings must be used that correspond to the weight and nature of the load being lifted, taking into account the number of branches and their angle of inclination. General purpose slings should be selected so that the angle between their branches does not exceed 90°. Depending on the type of sling, the lifting capacity of the slings is recalculated.

Sheet structures and small steel elements are lifted and transported to the workplace using grippers and brackets. Steel and reinforced concrete elements (purlins, connections, floor slabs, lintels) are lifted using special cross beams that allow multi-tiered arrangement of mounted parts. Crossbars are necessary for uniform load distribution and can be either linear or spatial, depending on the type of load being lifted. During the operation of our enterprise, the design department has developed a large number of ready-made traverses, which you can order from us.

To lift and move a package of pipes, round bars or logs, the “noose” slinging method is used. To do this, one end of the sling is threaded through the loop, and the other end of the loop is put on the crane hook so that when lifting, the loop tightens and firmly holds the load suspended. Slinging of a bundle of sheet metal is also done with a universal two-loop sling for a “noose”. The hooks of a two-legged sling are inserted into the free loops, and when they are lifted with the hooks, the universal slings tighten the bundle of metal.

Methods of slinging various materials

In order to prevent loads from falling during lifting and moving them by cranes, the following slinging rules should be observed:

• When tying the load, the slings must be applied without knots or twists. When moving loads with sharp edges using rope slings, spacers should be placed between the ribs and ropes to protect the latter from damage.
• The ends of a multi-leg sling that are not used for hooking must be strengthened so that when moving the load by crane, the possibility of these ends touching objects encountered on the way is excluded.
• When tying loads with chain slings, do not allow the links to bend on the edges of the load.
• When regularly using rope slings for tying loads with curves, the radii of which are less than 10 rope diameters, it is recommended to reduce the permissible load on the sling branches. When slinging a load and tightening it with a loop of a rope sling, it is recommended to reduce its carrying capacity by 20%.
• movement of loads with their free placement on loop slings is allowed only if there are elements on the load that reliably prevent it from shifting in the longitudinal direction.