AN INVESTIGATION INTO FALLS OVER OR FROM THE SIDE OF ESCALATORS

By

David CooperBSc(Hons), MSc, CEng, FRSA, FIET, FCIBSE

• Between 2000 and 2005 I took an MSc at the University of Northampton, UK

• My dissertation subject was an investigation into accidents on escalators involving shopping trolleys and luggage carts

• During that research it became apparent that there was a problem with passengers falling over or from the side of escalators

• Data was collected into incidents where people had fallen from or over the sides of escalators.

• The data collection date was cut off on 7th November 2007 in order that analysis could be undertaken.

• Since that date I am aware of a number of further incidents.

4th April 2008 – Liverpool, UK

EIGHT KEY QUESTIONS

1. How many incidents are actually occurring?2. Is there a trend for the number of incidents

occurring?3. How many incidents involve fatal accidents?4. Is there a trend for the number of fatal

incidents occurring?5. How do the incidents occur?6. What is the age distribution of the victims7. What is the gender distribution?8. Where are the incidents occurring?

OBSTRUCTIONS TO RESEARCH

• There is no single authoritative body that collects accident data worldwide

• Escalator owners are reluctant to admit to incidents

• Escalator manufacturers are similarly reluctant

QUESTION (1)HOW MANY INCIDENTS ARE ACTUALLY OCCURRING?

• 330 Incidents of falls over the side or from the side of escalators have been located over a period of 20 years between 1987 and 2007.

• An additional 31 incidents have been located that occurred pre 1987 or are of an unknown vintage.

QUESTION (2)IS THERE A TREND FOR THE NUMBER OF INCIDENTS

OCCURRING?

• Plotting the number of accidents per annum shows an upward trend in the number of incidents occurring

QUESTION (2)POSSIBLE REASONS FOR THE INCREASING TREND OF

INCIDENTS OCCURRING

• Possibly accidents per unit are actually increasing?

• Possibly due to an increase in number of escalators installed worldwide

• Possibly due to an increase in the number of escalators suspended in atria or open sided environments

• Possibly due to improved access to information via internet

QUESTION (3)HOW MANY INCIDENTS INVOLVE FATALITIES?

• Looking at the period 1987 to 2007 inclusive:

• 96 of the 330 incidents located involved fatal accidents.

• This means that 29% of incidents identified result in a fatality.

• This is considered to be worryingly high.

QUESTION (4)IS THERE A TREND WITH THE NUMBER OF INCIDENTS

INVOLVING FATALITIES?

• Plotting the number of accidents per annum shows an upward trend in the number of fatal incidents occurring

QUESTION (5)HOW DO THE INCIDENTS OCCUR?

• 14 standard accident types of how these incidents occur have been identified

• Incidents of “falling over” occur

differently to “falling from”

• Incidents can differ between an up running and a down running escalator

QUESTION (5)HOW DO THE INCIDENTS OCCUR?

1. Falling over the side owing to sitting on or sliding down the handrail.

2. Falling from the side owing to walking up or down the outer deck using the handrail to secure oneself

3. Falling from the side owing to holding onto the handrail and being taken

4. Falling after being taken by the handrail as a result of friction by clothing.

5. Falling after jumping between escalators or over the side of escalators for entertainment purposes!

QUESTION (5)HOW DO THE INCIDENTS OCCUR?

6. Falling on the escalator with the subsequent ultimate event being a fall over the side of the escalator.

7. Falling over the side owing to leaning over the handrail

8. Falling over the side owing to being carried by an elder who has lost balance.

9. Falling owing to parents/guardians sitting child on handrail and then losing control of the child.

10. Suicide

QUESTION (5)HOW DO THE INCIDENTS OCCUR?

11. Child being carried on parents shoulders on an escalator!

12. Balustrade defect/collapse

13. Jumping over the side to avoid an obstruction

14. Unknown causation

TYPE (1) INCIDENTFALLING DUE TO SITTING ON THE HANDRAIL

TYPE (2) INCIDENTOUTER DECK ENCROACHMENT

TYPE (3) INCIDENTFALLING AFTER HOLDING ONTO THE HANDRAIL

TYPE (3) or (4) INCIDENTHOLDING ONTO THE HANDRAIL

POSSIBLY INITIALLY DUE TO CLOTHING FRICTION

• Being taken by the handrail as a

result of friction or holding on

TYPE (5) INCIDENTWHEN ENTERTAINMENT GOES WRONG

TYPE (6) INCIDENTFALLING ON THEN FALLING OVER

• Falling on the escalator with the subsequent ultimate event being a fall over the side

TYPE (13) INCIDENTFALLING ON THEN FALLING OVER

• Jumping over the handrail to avoid an obstruction

ANOTHER DISCOVERY!

• It has been discovered that some incidents involve more than one person falling over the balustrade during the same incident

• These tend to be situations where there has been a fight or the balustrade has collapsed

QUESTION (6)WHAT IS THE AGE DISTRIBUTION OF VICTIMS?

• Of the 330 incidents 146 involve children aged under 10

• This is the highest group in the analysis but accidents occur right across the age bands but they tail off with age

• This represents 44% of the incidents.

• This could be as high as 60% if some of the unknown age incidents are included.

• The previous slide demonstrates that most incidents involve children aged 10 and under

• These incidents tend to fall into two types; gaining access to the outer deck and being taken by the handrail

• The following slide demonstrates that the fatality age distribution pattern is generally spread in the younger age groups

• Based on the 20 year data, if we as an industry, deal with the incidents involving under 10’s the rate of incidence could reduce by about 44%

• I would suggest that the under 10’s are not aware of the consequences of their actions and therefore it is for us, as an industry, to resolve

• We could also reduce the number of fatalities by 25%

QUESTION (7)WHAT IS THE GENDER DISTRIBUTION OF VICTIMS?

• It has become apparent that a disproportionate number of

incidents involve male victims

• 234 of the 330 incidents involved male victims

• This equates to 71%

• There are only 21 incidents where the gender is not known

so at worse the percentage could be 77%

• Fatalities have been found to involve 77% male incidents

QUESTION (8)WHERE ARE THE INCIDENTS OCCURRING?

• The data suggest that incidents are occurring worldwide

• Incidents have been found in 35 countries

• This appears to eliminate cultural issues as being a

contributory factor to causation

• The majority of incidents occur in Europe and the USA

which is to be expected given these are the primary sales markets

CAUSATION

• THE RESEARCH HAS ESTABLISHED THAT THREE FACTORS HAVE TO BE PRESENT FOR AN INCIDENT OF THIS TYPE TO OCCUR:

• A VOID IN WHICH TO FALL HAS TO BE PRESENT• AN UNATTENDED CHILD HAS TO BE PRESENT• THE INCIDENT WILL ALWAYS START AT THE BOARDING END

ESCALATOR DESIGN CONSIDERATIONS

FRICTIONAL QUALITIES OF HANDRAILS

• THE EN115 STANDARD DOES NOT STATE ANY FRICTIONAL QUALITIES FOR HANDRAILS.

• WITNESS STATEMENTS HAVE BEEN LOCATED STATING THAT CHILDREN HAVE BEEN PICKED UP BY THE HANDRAIL AS A RESULT OF CLOTHING CONTACT

HANDRAIL HEIGHTS

• THE EN115 STANDARD ALLOWS HANDRAIL HEIGHTS OF 900 TO 1100 MM FROM THE STEP SURFACE.

• THIS CONFLICTS WITH THE BUILDING REGULATIONS REQUIREMENTS FOR GUARD RAILS WHEN AN ESCALATOR IS INSTALLED IN AN OPEN ATRIUM AS STATIC GUARDS NEED TO BE 1200 MM

• IN ADDITION ON A DOWN RUNNING 35° ESCALATOR THE HANDRAIL WILL FALL AWAY BY 266 MM OVER THE LENGTH OF A STEP DEPTH (380 MM)

• THIS WILL INCREASE THE LIKELIHOOD OF AN OVER THE SIDE INCIDENT AS THE TURNING MOMENT IS BELOW MOST HUMAN HIP HEIGHTS

• IT IS KNOWN THAT IN THE USA 35° ESCALATORS ARE NOT PERMITTED

HANDRAIL DIMENSIONS

• THE EN115 STANDARDS CALLS FOR HANDRAIL WIDTHS TO BE BETWEEN 70 MM AND 100 MM.

• THIS CONFLICTS WITH RESEARCH PUBLISHED BY THE BUILDING RESEARCH ESTABLISHMENT.

• THE ADDITIONAL WIDTH ALSO INCREASES THE SURFACE AREA WITH RESPECT TO FRICTIONAL INCIDENTS WITH CLOTHING

BALUSTRADE DESIGN

• EN115 STANDARD STATES THAT THE BALUSTRADE SHALL HAVE NO PARTS ON WHICH A PERSON WOULD NORMALLY STAND.

• MOST DESIGNS HAVE HORIZONTAL DECKS ASSISTING OUTER DECK ENCROACHMENT

OUTER DECK ENCROACHMENT DETECTION

• THERE IS NO OUTER DECK ENCROACHMENT DETECTION DEVICE

• SUCH A DEVICE COULD STOP AN ESCALATOR PRIOR TO A CHILD BEING FORCED INTO THE SOFFIT AND FALLING

OUTER DECK ENCROACHMENT GUARD DESIGN

• OUTER DECK ENCROACHMENT GUARDS ARE NOT DIMENSIONALLY SPECIFIED AND ARE INCONSISTENT FROM MANUFACTURER TO MANUFACTURER

• THE NEW EN115 STANDARD HAS MOVED TOWARDS DIMENSIONING ENCROACHMENT GUARDS WHICH IS A POSITIVE MOVE

• IT IS ALSO KNOWN THAT CHILDREN HAVE BEEN KNOWN TO HAVE BEEN PULLED OVER OR ROUND THE OLD STYLE GUARDS BY HANGING ONTO THE HANDRAIL

POLICY CONSIDERATIONS

• I AM NOT SUGGESTING THAT ESCALATOR DESIGN NEEDS TO CHANGE SIGNIFICANTLY.

• I AM SUGGESTING THAT POLICY DECISIONS AND CORRECT SPECIFICATION WILL REDUCE THE NUMBER OF ACCIDENTS OF THIS TYPE

• DO NOT USE 35 DEGREE MACHINES WITH VOIDS• ALWAYS USE 1100 MM HANDRAIL HEIGHTS WITH VOIDS• ENCOURAGE DESIGNERS NOT TO CREATE MULTI FLOOR

FALL POSSIBILITIES• USE 70 MM HANDRAILS WHERE VOIDS EXIST

THE RESEARCH CONTINUES………………….

• If you would like a copy of the final research report or the MSc research report into accidents involving trolleys and carts on escalators please contact me at david.cooper@lecs.co.uk