Extensible and multipurpose ladders
Equipment for height access allows the access of workers in work areas located in high places, both in indoor and outdoor areas. The main equipment used for this purpose are ladders, platforms and scaffolds.
Ladders are manufactured in various constructive versions:
-articulated, for low working heights.
Modular ladders consist of multiple mountable sections made of aluminium profiles which can be mounted in vertical position on the poles of electrical networks.
Extensible ladders consist of 2 - 4 sections, the ladder being extended by the translating movement of an upper section on top of a lower section. Extensible ladders are provided with self-locking mechanisms that prevent the slippage of sections during use and transportation, with guide elements on each section, which allow the extension of the ladder.
Multipurpose ladders are improved versions of extensible ladders, meaning that they allow both the extension of the ladder as extensible ladders and the use of ladders in other configurations, in the form of a double ladder (type A or λ).
Articulated ladders can be used for works at low heights (1 - 4 metres), some of them being transformable into platforms.
Considering the material of the rails and rungs, ladders can be divided in the following categories:
Extensible and multipurpose ladders presented below are manufactured by European manufacturers:
- Aluminium ladders, made completely of aluminium profiles (both the rails and the rungs).
- Ladders with GRP rails (glass reinforced polyester resin), made of “U” profiles, and their rungs and locking systems on the rails are made of aluminium.
- Hybrid ladders, where lower sections are made completely of aluminium profiles and the upper section provided with rails made of GRP (glass reinforced polyester resin) and aluminium rungs.
1. KRAUSE (Germany) ladders - extensible or multipurpose, made of aluminium.
KRAUSE extensible ladders are manufactured according to EN 131-1, made of aluminium profiles and provided with steel guide elements that allow the extension of the ladder. The ladder rungs are manufactured from ribbed profiles to provide enhanced safety during work.
KRAUSE ladders are provided with self-locking hooks which prevent the slide of one section from the other during work and transportation. In case of using the ladder as a double ladder (type A or λ), the use of straps is compulsory, avoiding the opening of the ladder by the accidental slippage of sections.
In order to be used for works on electrical network poles, KRAUSE ladders must be provided (on demand) with anchoring devices that allow the fixing of the ladder on the pole and protection of the worker against fall.
2. IRMUT (Italy) ladders - extensible or multipurpose, with GRP or hybrid rails.
IRMUT extensible ladders are manufactured according to SR EN 131-1 and SR EN 131-2 standards. The rails of the ladders are made of glass reinforced polyester resin (GRP) U-shaped profiles. Rungs and their fixing systems on rails are made of aluminium. The connection between the rungs and rails is made by riveted flanges that provide excellent tightening and optimal anti-roll rigidity of the rungs, and in case of damage they being easily replaced. At the upper end, each section is provided with a support and slide system on flat surfaces, consisting of one pair of rollers each, and at the lower ends the sections are provided with rubber plugs to prevent the ladder from slipping on flat surfaces.
Irmut Hybrid ladders have the lower sections manufactured completely from aluminium profiles and the upper section manufactured with rails made of glass reinforced polyester resin (GRP) and aluminium rungs. Thanks to the insulating properties of the top section, IRMUT ladders are recommended for works in electrical installations.