Article 41 -Escalators Risks & Hazards – Slipping, Tripping, or Falling
Escalators Risks & Hazards Due to Slipping, Tripping, and Falling
Slipping, tripping, and falling are the most common accidents of escalators and moving walks and are considered in the category of escalators risks & hazards. Elderly and very young children are at a higher risk of tripping and falling. Some careless passengers who may run or walk fast on the escalators could also slip and fall. They could either hurt themselves or cause the other passengers to fall and get hurt.
The major reasons for slipping and falling of passengers are as follows:
Escalators Slipping Hazards on Steps/Pallets or on the Comb Plate/Floor Plate:
Accidents due to falls are estimated as the major cause of escalator injuries. Two factors of design and material play important roles in manufacturing steps, pallets, and floor plates so that they reduce the risk of slipping and falling to the least percent. If the steps and pallets are not designed properly and made of proper materials, they could simply cause slipping of a passenger and since the steps are moving, it could cause the other passengers to fall on each other. In addition, a wet or slippery spot on the escalator could cause the passengers to trip or fall. This issue also is the same about the floor plate and comb plate. If they are not made of proper materials, which does not make adequate friction, and in case there is not sufficient foothold on them according to standard, it could cause the hazard of falling and slipping. They happen especially when the escalator or moving walk is installed outdoors and in exposure rain, snow, and other climate conditions, which could make the steps and floor plate wet and slippery.
Moreover, when designing the escalator it must be considered that the horizontal tolerance in the step treat surface must neither exceed nor be lower than the standard requirements. Also, the parameters of the foothold in each landing must comply with the standard to prevent such possible hazards.
Escalators Falling Hazard Caused by Handrail Speed Deviation:
Since the speed of the main drive is slower than the handrail, therefore, the deviation must not be in a way that the passenger has to release their hands at intervals and hold it again. Some passengers, especially kids and the elderly, hold the handrail the moment from the moment they step on the escalator and do not release it until to the moment they get off to keep their balance. If the deviation between the speed of the handrail and the device exceeds the standard deviation, the handrail would pull the passenger’s arm and cause them to fall. Moreover, such a hazard could happen when the handrail stops completely and, as mentioned above, it could cause a falling hazard.
To prevent such an issue, there must be a safety device called “Handrail Speed Monitor”, which must be installed on the machine to control the deviation.
Escalator Falling Hazard Caused by the Change of the Direction of Movement:
Any reason, which causes a change in direction of movement in an escalator or moving walks, could lead to passengers falling. Such a hazard happens when the direction of movement occurs for any reason such as when the machine suddenly stops and starts moving reversely. The reversal could happen due to a defect in the braking system while there is a heavy load of passengers on the steps and it could also happen due to step chain breakage.
To prevent the reversal, a device must be installed on the machine to detect the excessive speed before the speed exceeds the nominal value. If the escalator is designed the way that prevents excessive speed, this requirement is permitted to be neglected. A monitoring device must also be provided for escalators and inclined moving walks (a = 6°) to detect the reversal as soon as it happens.
Escalator Falling Hazard Caused by Increased Acceleration/Deceleration:
Such hazards could happen when the escalator is off or it is on the standby mode and starts moving with high acceleration, which causes the passenger to lose their balance and fall. It could also occur when the machine stops with a high deceleration.
According to the standards, the maximum downward deceleration in escalators and moving walks must not exceed 1 m/s2, and considering this regulation, the shortest stopping distance is required.
Escalators Falling Hazard Caused by Unexpected Start/Stopping or Excessive Speed of the Machine:
In case the moving machine stops or starts due to any unexpected reasons, the conversion of motive force to inertia and vice versa could cause the passengers to lose their control and fall on the steps or on other passengers.
Stopping occurs when the protective, safety, or control devices and functions cause a breakage sequence. Two main reasons could cause automatic stopping in escalators or moving walks:
- If the voltage supply is lost
- If the voltage supply to the control circuits is lost
The excessive speed of the machine could also cause another falling hazard for the passengers. The speed deviation of an unloaded escalator must not be more than ± 5 % from the standard nominal speeds at nominal frequency and nominal voltage. The permitted nominal speed must not exceed the standard requirements as it could cause the hazard of falling.
Escalator Falling Hazard Caused by Inadequate Lighting at the Landings:
There must be a number of horizontal steps in both landings, which provides an appropriate foothold for the passenger to step on. There must be an illumination mounted under these horizontal steps so that the clearance between the steps is conspectus and the passengers could step on the safe area. This prevents the passengers from stepping on the gap between the steps, which causes them to fall by the steps rising.
There must always be a proper illumination provided for the surrounding of the escalator or moving walk, especially the area surrounding the combs. Such illumination starts from the horizontal steps and helps the passengers have better lighting in the landing area to step on or exit the escalator. Obviously, lack of proper lighting could cause tripping and falling, which could potentially cause serious injuries. The standard quantity of illumination at the landings including the combs depends on the intensity of illumination of the general lighting in the area. However, the least intensity of illumination must not be less than 50 lx at the comb intersection line measured at the floor level.