Article 39 -Escalator Mechanical Hazards – The Escalator Accidents
One of the hazards threatening the life of passengers concerns escalator mechanical hazards as follows:
Escalator Accidents - Contacting the Machinery Moving Parts
Imperforate panels or walls are essential for enclosing all the moving mechanical parts of the escalator so that nobody can touch the interior moving parts from outside. These panels must resist under the applied force mentioned by standard without any permanent deformation. Of course, some apertures used for ventilation are authorized. The design of ventilation apertures must be according to the standard as well so that the openings of ventilation are not close to the moving parts and it reduces the possibility of touching which could further lead to injuries.
Only the authorized personnel can access the interior components including the main drive shaft, handrail drive system, etc. (for repair and maintenance purposes). However, there are some moving components, accessible to the passengers including steps, pallets, and handrails which could also cause serious accidents and injuries if safety requirements are not considered.
Escalator Accidents - Finger Crush or Shearing
Finger crush or shearing could happen between handrail and handrail frame guide located on the balustrade or in case the balustrade interior panels are installed with improper gaps more than the permitted clearance based on the standards. Such defects could cause someone to lose fingers or suffer from other serious injuries. This could especially happen to young kids who have smaller fingers.
The handrail frame guide and its joints to the balustrade must be designed and formed in a way that reduces the possibility of trapping fingers. In order to prevent such hazards, the permitted gap between the balustrade and handrail as well as the handrail and handrail frame must be according to the standard. In addition, no object must be closer to the handrail than the authorized lateral distance.
For example, if the anti-sliding, located between two parallel escalators, is too close to the handrail, it could cause serious finger entrapment hazards. In addition, if escalators are adjacent to each other, in parallel or criss-cross arrangements, the distance between the handrails must be based on the required standards to prevent any potential hazards.
Escalator Accidents - Cutting or Trapping of Clothing caused by adjacent panels
Such accidents could happen in case the interior balustrade panels or skirt panels are not smooth and flush enough. The permitted protrusion for the interior panels, in the direction of movement, must be based on the required standard.
This issue is highly important in solid balustrades. Therefore, by arranging the panel joints in a proper way so that they are not jutted out more than permitted standard, the risk of entrapment would be eliminated. Another important factor regarding the structure of panels is that the panel edges must also be rounded off or beveled to reduce the risk of cutting or trapping.
Escalator Accidents - Collision with Building Structures or other escalators
Colliding with building structures such as walls, roofs, or other escalators especially in a criss-cross arrangement, is another hazard when using an escalator for which proper measures must be taken to prevent injuries caused by building obstacles.
In order to prevent collision and crashing of passengers, which could cause serious injury, a proper free area around the escalator is recommended as well as applying some safety devices.
One of the hazards of colliding with building structure is the passengers crashing their heads with the roof when riding on an escalator. This hazard happens when the ceiling opening length is not long enough to provide appropriate headroom according to standard.
The hazard of passengers colliding usually happens in floor intersections or criss-cross escalators when they are bending on the handrail to look down or are exceeding their arm from the balustrade area.
In order to prevent such hazards, an appropriate width must be considered as well as installing an anti-colliding device. For this purpose, the rigid mounting of a vertical reflector with the standard height above the handrail level is necessary. This reflector must not present any sharp cutting edges.
Escalator Accidents - Fingers, Objects Being Grabbed at Handrail Entrance
Putting their hands at the entry point of the handrail, passengers, especially young kids, could have their fingers trapped and injured.
In addition, if an object such as clothing parts contacts the handrail, where the handrail is going inside the interior space, could be pulled and drawn inside the handrail entrance. To prevent such hazard, there is a part called “Inlet Guard” installed at the handrail entrance along with a safety contact and a brush.
In case any object is stuck at the handrail entrance, the inlet guard is pushed back and activates the safety contact to stop the machine.
Escalator Accidents - Trapping between skirt panels and steps, or comb and step/pallet
One of the most serious hazards of an escalator is when the gaps between the skirt panel and steps are more than the authorized distance which causes trapping of an object between moving steps and the skirt panels.
In case passengers are wearing shoes made of soft materials or in some countries where people wear long clothing, there is a higher possibility of such hazards. If such items are trapped in the escalator, they are pulled with an incredible force and may cause a very hazardous situation. To prevent these kinds of accidents a skirt brush would better be installed on the skirt panels as a deflector.
Another kind of trapping happens between the step and the comb. One of the reasons for installing combs in escalators is facilitating passenger transition through meshing with steps or pallets. The comb surface is rounded and shaped where it meshes with steps to minimize the risk of foot trapping between steps and comb.
This type of hazard would happen when a comb tooth is broken and it could cause serious foot finger injury or some other accidents.
Escalator Accidents - Entrapment between the floor and handrail
Where the handrail is going inside interior spaces, an object e.g. a ball could get stuck between the handrail and floor. To prevent such an incident, the distance between the lowest point of the handrail and the finished floor level must be based on the standard.
Escalator Accidents - trapping between step and step or pallet and pallet
The arrangement of steps must be properly adjusted based on the required standards; otherwise, it could make the steps collide with each other. In addition, the gap between two successive steps or pallets shall be based on the authorized standard.
In case the gaps between steps or pallets are too long, this defect could be seriously dangerous for the passengers. Shoes or sandals made of soft material increase the chance of entrapment between steps or pallets, which could further cause serious injuries such as crushing or shearing foot fingers.
Increasing the gap in the area of transition curves of moving walks and the rear edges of the pallets must be according to the authorized standard as well.