Contemporary technologies in forestry work

The execution of forestry work requires the use of a variety of specialised tools. An important role is played by a crane, which enables harvested timber to be loaded quickly. A loading crane is a crane mounted on a vehicle or trailer, usually located between the driver's cab and the load compartment or at the rear of the vehicle. Its main purpose is to facilitate the loading and unloading of goods. In some cases, the crane may also be mounted on a fixed foundation.

This group of equipment also includes forestry cranes, which are used for loading, unloading and logging. This category includes specialised machines such as harvesters and forwards designed for skidding and timber transport. These greatly increase the efficiency of forestry work, enabling precise and fast operations in difficult terrain. The next most popular machines are hydraulic cranes (HDS). Equipped with a powerful grab, they allow the easy handling of felled logs.

visible crane frame and timber bales

How do forest cranes work?

The most important component of the forestry crane is the aforementioned grapple, which consists of two wings. These jam around the tree trunk, allowing it to be gripped securely. The grapple is positioned on an arm made up of four segments, which move thanks to hydraulic cylinders.

The first segment, called the column, connects the crane to the tractor or trailer. Different models of cranes have different parameters, such as the angle of rotation of the column, the reach, the lifting capacity and the lifting moment. The trailers on which the cranes are mounted resemble traditional ladder wagons. They hold the load by means of elongated elements called stanchions, which are located on either side of the trailer. Like cranes, trailers vary in their parameters (length, width and load capacity) depending on the specific model.

Prevention of HDS failures

During the use of cranes, wear and tear occurs on their components as a result of normal operation and the ageing of individual parts such as rubber joints and bearings. In order for the equipment to operate efficiently for the intended period of time and maintain an adequate level of safety, it is important to carefully follow the instructions in the manufacturer's instructions. Ignoring these instructions can lead to damage to the equipment or dangerous situations associated with its use. It is therefore important to regularly check the condition of the equipment and replace worn parts, as well as to carry out maintenance inspections at the agreed times.

crane at work against a sky background

Technical inspection of cranes

Manufacturers of mobile cranes and forestry cranes usually recommend inspection and maintenance of the equipment every year, every six months, every three months, or after a certain number of operating hours. In addition to this, once a year or every two years, depending on the model, a test should be commissioned by an UDT inspector. Failure to comply with the maintenance intervals specified in the technical documentation may result in the loss of the unit's warranty. Maintenance records are required and controlled during periodic inspections. Equipment subject to technical supervision may only be used on the basis of a decision issued by the relevant technical supervision authority, which authorises its operation.

Repairs and modifications to mobile cranes

The maintenance person may replace crane components without consulting the relevant technical inspection authority, provided that the new parts have the same technical characteristics and properties as those previously used. This mainly applies to components related to electrical, hydraulic, pneumatic and mechanical equipment. In the case of repairs and modifications to cranes, it is necessary to:

  • replace worn parts with original parts or parts with the same specifications,
  • comply with the technical documentation of the equipment,
  • comply with the standards and regulations governing the modification of equipment,
  • contact an authorised service centre for major repairs,
  • carry out post-repair tests on the unit.

It is also necessary to comply with the provisions contained in the Regulation of the Minister of Economy of 29 October 2003 concerning the technical conditions of the Technical Supervision Authority for certain materials handling equipment. These documents list situations that require the equipment to be declared to the UDT for an ad hoc test. These include, among other things, the replacement of load-bearing tendons, gripping devices, the drive unit, lifting mechanism and safety devices, as well as any repairs to the load-bearing structure and its components. Repairs and upgrades may only be carried out by establishments with the appropriate authorisation issued by the technical inspection authority.

wood and crane arm

Accessories for cranes

When using cranes, there is sometimes a need to lift unusual loads, which requires the use of various accessories such as extensions, clamps or grabs. When selecting these items, it is crucial that they have the right parameters, such as lifting capacity and compliance with the manufacturer's instructions. The correct choice of accessories in terms of load capacity, where they are attached and how they are used is important to increase safety and stability when lifting loads. Manufacturers indicate in the instructions and on the equipment itself where accessories can be attached and specify the conditions for safe lifting.

Safety and efficiency in forestry work

Modern technology in forestry work relies on the use of specialised tools, among which transloading cranes play a significant role, as they are mounted on vehicles or trailers and greatly facilitate the loading and unloading of timber. This group also includes forestry cranes and machines such as harvesters and forwards, which are dedicated to harvesting and transporting timber in difficult terrain. To enable them to operate efficiently and safely, it is necessary to carry out regular technical inspections and maintenance in accordance with manufacturers' recommendations. When replacing parts and making repairs, it is important to use components with identical technical characteristics, and any modifications should be carried out by authorised workshops. The correct choice of crane accessories, such as extensions or grabs, is important for safety and stability during lifting operations of abnormal loads.

1. What are the uses of handling cranes in the forest?

Transshipment cranes in forestry are used for loading and unloading timber and for harvesting. They enable the efficient handling of tree trunks, which increases the productivity of forestry work.

2. How does the grapple work in forestry cranes?

The grapple consists of two wings that jam around the tree trunk, allowing it to be grasped securely. It is mounted on a crane arm that moves thanks to hydraulic cylinders.

3. What are the recommendations for crane inspections?

Manufacturers recommend that cranes are inspected and maintained annually, every six or three months or after a certain number of operating hours. It is also necessary to have the crane inspected by an OTU inspector once a year or every two years.

4. What are the rules for repairs and mobile cranes?

Replacement of crane components may be carried out without consulting the technical inspection authority, provided that the new parts have the same parameters as the original ones. Repairs must be carried out by workshops with the appropriate authorisations.