THE STUDY OF ESCALATOR ACCIDENTS IN MALAYSIA: HOW INADEQUATE MAINTENANCE AND DESIGN ERROR CAUSED ESCALATOR ACCIDENT
PHANG CHUN MAN
May 2012
Abstract
Malaysia has thousands of escalators in public and private buildings. An escalator is a moving staircase, a conveyor transport device for carrying people between floors of a building. However, passenger accidents on escalators are one of the highest sources of minor injuries today. Escalators are said to be among the safest forms of transportation in the world but accidents can occur as a result of unsafe riding practices. Each year these machines are required to be inspected for safety, and several state regulations govern their design and maintenance. Despite these safeguards, each year hundreds of people are injured on defectively designed, inadequately inspected, or poorly maintained elevators and escalators. Some accidents result in wrongful deaths. The root cause of the escalator will be analysed in this report. The escalator accidents in Malaysia with regards to inadequate maintenance and design error will be analysed. Thirty-five maintenance technicians will be interviewed to obtain data. It is predicted that both the design error and inadequate maintenance are the highest contributes to the escalator accidents in Malaysia. An area of improvement to enhance maintenance process safety and surrounding environment of escalators will also be provided at the end of this report.
Table of Contents
Abstract i
List of Figures iii
List of Tables iv
1.0 Introduction 1
1.1Study Background 1
1.2Problem Statement 5
1.3Scope of Study 7
1.4Study Objectives 8
1.5Significance of Study 9
2.0Literature Review 10
2.1Design, Components and Operation 10
2.2Main Components of Escalator 13
2.3Escalator Safety Features 17
2.4Passenger Accident Escalator Model 19
2.5Escalator Accident by Accident Type 21
2.5.1Falling Accidents 21
2.5.2Entrapments 22
2.5.3Crushing Inside Escalator 23
3.0Proposed Methodology 23
4.0Expected Results 24
5.0References 25
List of Figures
Figure 1 ' Escalator in a Shopping Complex 3
Figure 2 ' Crisscross Layout of Escalator 11
Figure 3 ' Parallel Layout of Escalator 11
Figure 4 – Multiple Parallel Layout of Escalator 12
Figure 5 ' Main Components of an Escalator 13
Figure 6 ' Deck Board of an Escalator 14
Figure 7 ' Truss of an Escalator 15
Figure 8- Steps of an Escalator 16
Figure 9 ' Escalator Anti Climbing Device 17
Figure 10 ' Escalator Comb Plate Impact Switches 18
Figure 11 ' Escalator Deflector Brush 18
Figure 12 ' Escalator Emergency Stop Button 19
Figure 13 – Passenger Accident Model 20
List of Tables
Table 1 – Study Objectives of Research Proposal 7
Chapter 1
Introduction
Escalators are essentially 'moving stairs' that transport masses of people up or down between floors of a building. The purpose of an escalator is to transport people. It performs this task efficiently, allowing individuals to move between potentially many floors of a building in a relatively short amount of time, when compared to a staircase, for instance. Because escalators are generally quite long, they allow a large group of people to get on at once and reduce the need for waiting periods typical of elevators. They are installed indoors or outdoors and the constant speed can be adjusted to accommodate increases or decreases in volume of passengers. Escalator width depends upon the age of the mechanism as well as the volume of riders.
Malaysia has thousands of escalators in public and private buildings. Each year these machines are required to be inspected for safety, and several state regulations govern their design and maintenance. Despite these safeguards, each year hundreds of people are injured on defectively designed, inadequately inspected, or poorly maintained elevators and escalators. Some accidents result in wrongful deaths. The Department of Occupational Health and Safety (DOSH) Director-General Datuk Ir. Mohtar Musri in a statement said the department had received 31 reports regarding escalator accident in Malaysia from 2011 to May 2015 with 97% of the victims being young children. He added incidences involving escalators could be avoided if users adhere to the safety precautions, such as positioning themselves in the designated area and practising caution when wearing sandals and rubber shoes.
1.1 Study Background
An escalator is a moving staircase, a conveyor transport device for carrying people between floors of a building. The device consists of a motor-driven chain of individual, linked steps that move up or down on tracks, allowing the step treads to remain horizontal. The benefits of escalators are many. They have the capacity to move large numbers of people, and they can be placed in the same physical space as one might install a staircase.
They have no waiting interval (except during very heavy traffic), they can be used to guide people toward main exits or special exhibits, and they may be weather proofed for outdoor use. It has also been observed that a non-functioning escalator simply becomes a normal staircase.
Escalators are used around the world to move pedestrian traffic in places where elevators would be impractical. Principal areas of usage include department stores, shopping malls, airports, transit systems, convention centres, hotels, and public buildings.
An escalator transports people automatically when switched on, with individuals simply standing still. As such, traveling on an escalator requires little physical exertion. People who experience pain or difficulty when walking are thus able to traverse longer distances with ease and in relative comfort. Escalators offer plenty of space, too, especially when compared to an elevator or narrow staircase where people may be squashed together.
However, passenger accidents on escalators are one of the highest sources of minor injuries today. Escalators are said to be among the safest forms of transportation in the world but accidents can occur as a result of unsafe riding practices. Escalator safety is a big concern, especially for children. Each year, escalator accidents are responsible for numerous trips to the emergency room. Mangled hands and feet, lacerated tendons, broken or cut off fingers and toes, and head injuries are all documented escalator injuries, according to escalator safety experts. These accidents can occur due to loose scarves, shoe strings or other articles of clothing becoming stuck in the escalator. Little hands and feet have been caught in escalators as well.
There are two distinct groups of fall incidents, those that occur on the escalator and those that result in a passenger falling over the handrail of an escalator. Researchers have attributed the causes of falls on escalators to contact with another passenger, inappropriate footwear, balance and coordination issues in the elderly, among others. Falls over the handrails often have been tied to misuse, such as jumping from one level to another, or attempting to ride by sitting on the handrail, usually in a state of intoxication. But falls over handrails have also occurred as the result of entrapment; a passenger leaning over too far; inadvertently dropping a child who was being carried by an adult on the escalator; or a fall that begins on the escalator, but ends with the victim plunging over the side.
Figure 1 ' Escalator in a Shopping Complex
(Source: http://www.toshiba-elevator.co.jp/elv/infoeng/products/kindmover/index.html)
For every accident that happens on an elevator, there will be 18 accidents suffered on escalators. Escalator related injuries and deaths in the U.S. have been steadily rising every year in the U.S. In 1990 there were 4,900 reported escalator-related injuries and deaths. Each year sees about ten percent more injuries and deaths than the year before and, by 2000, there were over 10,100 injuries and deaths. During calendar year 2013, a total of 12,260 escalator-related injuries and deaths were reported. Sadly, children and senior citizens suffer a disproportionately high number of these injuries. Children 14 and under and those 65 and over, collectively, averaged 60% of the injuries reported between 1990 and 1994. There were an estimated 26,000 escalator-related injuries among children 0 to 19 years of age in the United States from 1990 to 2002. In 2011 there were 4,900 patients over 65 treated in emergency rooms for escalator injuries.
The Department of Occupational Health and Safety (DOSH) Director-General Datuk Ir. Mohtar Musri in a statement said the department had received 31 reports regarding escalator accident in Malaysia from 2011 to May 2015 with 97% of the victims being young children. He added incidences involving escalators could be avoided if users adhere to the safety precautions, such as positioning themselves in the designated area and practising caution when wearing sandals and rubber shoes.
The escalator industry has been very successful convincing accident investigators and the media reporting incidents to the public that most falls are caused by horseplay, intoxication, or some other seemingly gross misuse. Many times, because of this relatively successful media and lobbying campaign, the true cause of a fall is obscured or never discovered. Also, perhaps due to the relative lack of previous litigation in this area, the defect theories and available safer designs to prevent escalator falls have not been the subject of nearly as much discovery and are simply not as well-known as with many other products and injury modes subject to wider litigation. Despite this increase in accidents and the possible severity of the resulting injuries only few statistics on escalator-related injuries have been published worldwide, mostly studies on children and case reports.
Although many studies have examined ways to mitigate risks associated with escalators and moving sidewalk operations (Nicolson, 2008) and accidents due to human factors (Lufti, 2006), very few studies have examined the escalator accidents due to machinery failure. None of the studies included in the review examined the escalator accidents due to design error and inadequate maintenance of escalator. One question motivating this study was how design error and inadequate maintenance of escalator contributed to the high percentage of escalator accidents in Malaysia. This research project will provide an overview of analysing escalator accidents in Malaysia with regards of machinery failure and human error. In addition, it will propose area of improvement with regard to the escalator safety features.
1.2 Problem Statement
Today the escalator is everyday common means of transport. With a total length of 800 meters and a 24-hour transport capacity of 210,600 passengers, the longest outdoor escalator system in the world is used by more than 55,000 passengers in Hong Kong each day. The longest individual escalators can be found in St. Petersburg's underground stations, comprising a length of around 142 meters at a height of 71 meters each. Because escalators use is unavoidable, it is, however, not surprising that they have also attracted negative attention as an accident location.
On January 31, 2010 and approximately at 11:39 am a child aged around two to three years of his left leg was trapped between the escalator skirt and the side of escalator step while going down the escalator. This accident resulted in serious injuries to his leg where some parts of his legs were broken.
On February 8, 2016 a four-year-old boy lost half of his left foot when it got trapped in an escalator at KL Sentral earlier today. It was learnt that the toddler was travelling down the escalator from the first floor to the KTM station when the escalator 'swallowed' his foot. The toddler foot was trapped in between the metal panel and the stairs of the escalator. A similar accident happened at the same venue on June 17, 2015, when a toddler's hand was severed at the wrist after it got caught in an escalator. The 15-month-old infant was believed to have been playing near the escalator when the mishap occurred.
There are several causes of escalator accidents, but most are caused by some common defects such as:
' Improper installation, including missing parts and side panels
' Sudden stops
' Loose or missing parts, such as the metal teeth known as "comb plates"
' Inadequate maintenance
' Side entrapment involving soft shoes such as Crocs
Unfortunately, many escalator accidents involve young children, who are attracted to the moving parts on the escalator, but are too young to appreciate the dangers of the machine. Children are also more frequently victims in side entrapment cases, since they stand closer to the side panels when trying to hold onto the railing. Their shoes or body parts can get caught in the moving parts.
There is limited information on examined the escalator accidents due to design error and inadequate maintenance of escalator. Although, there is little research on examined ways to mitigate risks associated with escalators and moving sidewalk operations, there is also insufficient research on escalator accidents due to human factors and machinery failure. This research project will provide an overview of analysing escalator accidents in Malaysia with regards of machinery failure and human error. In addition, this research will also propose area of improvement with regard to the escalator safety features.
More specifically, the following research questions need to be addressed:
i. What are the percentage of escalator accidents in Malaysia that are due to machinery failure and human error?
ii. What is the root cause of escalator accidents that are due to machinery failure and human error?
iii. Is the root cause of escalator accidents due to design failure of railing or inadequate maintenance of escalator?
iv. What can be done to reduce escalator accidents in Malaysia based on the date collected from the studies conducted?
1.3 Scope of Study
The aim of the research project is to analyse escalator accident in Malaysia and propose area of improvement to reduce the accidents. Four specific project objectives were presented:
Objective 1 To determine the number of escalator accidents in Malaysia that is due to machinery failure and human error.
Objective 2 To determine the root cause of escalator accidents that is due to machinery failure and human error.
Objective 3 To determine root cause of escalator accidents with regards to design failure or inadequate maintenance of escalator.
Objective 4 To propose area of improvement with regards of design of escalator surroundings and maintenance of escalator to reduce escalator accidents.
Table 1 – Study Objectives of Research Proposal
A range of research methodologies was used to investigate current escalator accident causes and to capture data about the scope and relative escalator machinery and design failure. The literature review and accident reports covering the issues associated with injuries due to escalator accidents nationally and internationally and a series of interviews and questionnaires are also part of research methodologies used in this research paper.
Although this research was carefully prepared, there are still limitations and shortcomings that should be taken into considerations. First of all, the research was conducted in the period of 1 semester. Four months is not enough for the researcher to study and analyse all of the escalators accident in Malaysia. It would be better if it was done in a longer time.
Second, the population of the questionnaire group is small, only thirty-five escalator maintenance technicians for a single competent firm to maintain escalator and might not able to cover all escalators accidents in Malaysia. This is because there are many other competent firms which are able to perform maintenance of escalators in Malaysia and due to limited resources; we are not able to cover all of the firms.
Third, since the questionnaire designed to determine the escalators accidents in Malaysia due to inadequate maintenance and design failure; it seems not to provide enough evidence of the technicians to determine the root causes due to the certain degree of subjectivity can be found. The technicians are prone to conclude that the root causes was due to human error and not related to inadequate maintenance or machinery failure.
1.4 Study Objectives
The long term goal of the research is to develop an area of improvement to reduce escalators accidents in Malaysia with regards of design of escalator surroundings and proper maintenance of escalator. Passenger accidents on escalators are one of the highest sources of minor injuries today. Preventing the passenger accidents involves understanding their causes and eliminating or mitigating such causes. This paper identifies the causes of passenger accidents and suggests way of eliminating their contribution. Particularly, the study has the following sub-objectives:
i. To determine the number of escalator accidents in Malaysia that is due to machinery failure and human error.
ii. To determine the root cause of escalator accidents that is due to machinery failure and human error.
iii. To determine root cause of escalator accidents with regards to design failure or inadequate maintenance of escalator.
iv. To propose area of improvement with regards of design of escalator surroundings and maintenance of escalator to reduce escalator accidents.
1.5 Significance of Study
For every accident that happens on an elevator, there will be 18 accidents suffered on escalators. Escalator-related injuries and deaths worldwide have been steadily rising every year. Each year sees about ten percent more injuries and deaths than the year before and, by 2000, there were over 10,100 injuries and deaths. During calendar year 2013, a total of 12,260 escalator-related injuries and deaths were reported worldwide.
Sadly, children and senior citizens suffer a disproportionately high number of these injuries. Children 14 and under and those 65 and over, collectively, averaged 60% of the injuries reported between 1990 and 1994. There were an estimated 26,000 escalator-related injuries among children 0 to 19 years of age from 1990 to 2002. In 2011 there were 4,900 patients over 65 treated in emergency rooms for escalator injuries.
Despite this increase in accidents and the possible severity of the resulting injuries only few statistics on escalator-related injuries have been published worldwide, mostly studies on children and case reports. In contrast, this study is a comprehensive analysis with regards to determine the root cause of escalator accidents that is due to machinery failure and human error. Next, the study to determine root cause of escalator accidents with regards to design failure or inadequate maintenance of escalator will also be part of this paper. Our aim is to understand the character of escalator-related accidents and to identify root causes, in order to contribute to the development of effective preventive measurements.
Chapter 2
Literature review
There are many causes of escalator accidents happened. (Chi et al, 2005) examined that the major causes of accidents generate two hazard patterns: falls, and entrapment and cutting. Their study indicated that falls happened more than 86% among all accidents while entrapment was only 5.7% of all the accidents. They also revealed that there are significant association between age and gender which indicated that male passengers age below 5 and 5-14 years or 65 years and above and female passengers aged 15 -64 years were more likely to be involved in escalator riding accidents than their gender counterparts. Passenger accidents on escalators are one of the highest sources of minor injuries today. Preventing the passenger accidents involves understanding their causes and eliminating or mitigating such causes.
2.1 Design, Components and Operation
Escalators, like moving walkways, are powered by constant-speed alternating current motors and move at approximately 1'2 feet (0.30'0.61 m) per second. The maximum angle of inclination of an escalator to the horizontal floor level is 30 degrees with a standard rise up to about 60 feet
(18 m). Modern escalators have single piece aluminium or steel steps that move on a system of tracks in a continuous loop.
Escalators have three typical configuration options: parallel (up and down escalators "side by side or separated by a distance", seen often in metro stations and multilevel motion picture theatres), crisscross (minimizes structural space requirements by "stacking" escalators that go in one direction, frequently used in department stores or shopping centres), and multiple parallel (two or more escalators together that travel in one direction next to one or two escalators in the same bank that travel in the other direction). Figure below shows 3 typical configuration options of escalators.
Figure 2 ' Crisscross Layout of Escalator
(Source: http://www.electrical-knowhow.com/2012/04/escalators-basic-components.html)
Figure 3 ' Parallel Layout of Escalator
(Source: http://www.electrical-knowhow.com/2012/04/escalators-basic-components.html)