Escalators & moving walks
Just like lifts, escalators and moving walkways are also a consolidated part of the urban scenery: transportation means serving the mobility of people in the city, inside and outside the buildings.Elevatori has focused many times on this subject. One might wonder what there is still to say about this topic. But the theme still exists and it is an evergreen: safety. In fact, the number and types of accidents in Europe and in Italy remain unchanged. The accidents occurring more frequently are the following, as identified by Giovanni Varisco:
- a) Falls over the side by sitting or lying on the handrail;
- b) Falls using escalators moving in the opposite direction of travel;
- c) Falling of a child leaning on the handrail because his/her parents temporarily lose control;
- d) Impact against parts of the building of children kept on the shoulders of parents;
- e) accidents caused by loose clothing, unsuitable footwear, transporting and carrying objects not fit for transport on stairs/walkways (i.e. prams, cumbersome luggage, shopping carts, etc.).
Unfortunately these are well known situations which should be avoided by the users. So, what could prevent the accident? We share some assessments, building the discussion on some interrelated topics:
- 1. Accidents to users;
- 2. European and Italian standards;
- 3. Accidents to technicians working on escalators;
- 4. Assessments and considerations of some special uses;
- 5. Information and training for technicians.
ACCIDENTS TO USERS
Let us now try to understand why, in relative terms, escalator accidents are far more numerous than those related to the use of lifts. A ratio of almost 1 to 100, estimated on the basis of data provided by industry sector associations, as well as on the basis of the following statistics.In Italy there are almost one million lifts and 10,000 escalators and the number of accidents is about the same (these are estimates).The escalator attracts and invites us to use it. It is always ready and if it stops, you do not run the risk being trapped. Conversely, the idea of being trapped in a lift, causes fear of choking and discomfort. Almost everybody chooses the escalators, underestimating they are dangerous because of the several accessible moving parts. Unfortunately, European design standards can do very little to counter the improper conduct by users.Let us get back to the list of injuries and be more detailed. New recent accidents occurred in China, including one fatal accident, requires further consideration. The accident, in this case, is related to a non-conformity of the machine and/or poor maintenance. A mother and child fell into the escalator pit due to the failure of the step (maybe because of deformation and poorly secured).The mother saved her child but was eventually killed by the movement of the chain of steps and the steps themselves. This creepy episode suggests some considerations on the quality of the material and possible improper maintenance. Today, the European legislation, by referring to this potential accident, states the need for a protective casing in the pit to avoid contact with step motion and the locking for the platform opening.Other events can become a starting point for analysis. For example, long ago an expert pointed out that in shopping centres the cleaning is done quickly with heavy machines which inevitably weigh on the escalator step, causing a deformation.In order to avoid injury to the users, it is interesting what is defined by some transportation agencies of Canadian cities where walking on a moving escalator is explicitly forbidden and passing other passengers who are standing still and holding the handrail. In case of escalator shutdown, the user walking on the escalator is standing on a single foot and walking at a speed resulting from the sum of the escalator speed plus his/her walking speed (which is often close to that of the escalator).Finally, here below are some practical solutions. In an underground station in London, where numerous escalator accidents occurred, service operators (frustrated by the non-compliance to notice instructions) decided to switch to audio alerts listing the main rules). In Northern European countries, however, in some malls, it was decided to install safety nets under the escalators to cushion the effects of a disastrous fall.The www.ela-aisbl.org website offers the option to download free of charge the ELA (European Lift Association) document “Escalator and moving walk safety”, where some intuitive cartoons illustrate the main risks of escalators and suggest how to improve safety levels.
EUROPEAN AND ITALIAN STANDARDS
The escalator is ruled by the Machinery Directive; however, it remains the only machine controlled by a user unaware of risks related to moving parts and not by a trained professional. Technical standards relevant to EN 115 are increasing in number and focus on all aspects of safety (user and technician). These are (for the European context):
- EN 115-1 Design of new escalators;
- EN 115-2 Guidelines for safety upgrade of existing escalators;
- EN 115-3 Comparison of various releases of EN 115-1;
- EN 115-4 Queries on the above standards.
In this case the attention is never enough. In the draft of the next EN 115-1, a single escalator can operate in both directions according to the real-time user selection, upon activation of the step contact.My opinion is that we are going in the direction of a deterioration of the service, that is, the continuous availability of the service. For example, an elderly person who wants to go up, while the escalator is operating in the downwards direction, has to wait until the last user (perhaps a brave young man) and then reversing the motion.Finally, in the UNI Lift Committee the Working Group (GL13) was formed focusing specifically on escalators. The Group will draw up guidelines (similar to UNI 10411 for lifts) in order to define various intervention criteria on the occasion of interventions performed on escalators (i.e. even quick replacements of parts not related to safety upgrade). Work are progressing and the document could be ready in 2016.
ACCIDENTS TO ESCALATOR WORKERS
In the maintenance activity, the central elements for operator’s safety are the electrical energy control and the mechanical energy control (i.e. when working in the pit to replace the steps or components), in analogy with the recommendations for the lifts.For checking an escalator, today an inspection control panel is mandatory, to be plugged in the pit in order to achieve an exclusive control of the escalator while excluding any other interference. As with the lift inspection control panel, the various controls should be checked (i.e. the Stop or any other efficient exclusion of any external inputs, upwards and downwards movements.In this case, there must be the effective braking of the escalator as a result of the stop actuation. A too long braking would endanger the safety of the technician also in the case of the stop actuation).Finally, another case, which when underestimated leads to tragic accidents, refers to the dismantling of the steps. In fact, when removing a certain number of steps, the escalator behaves as an unbalanced chain, which if not retained (with belts or chains) can move in an unexpected manner with serious consequences for operators. Frequent accidents of those tempted to walk on the (slippery) axes connecting the two chains of steps should not be forgotten.
CONSIDERATIONS ON SOME SPECIAL USES
The escalator is not currently usable as an escape route in case of emergency (the step height is well above that of a standard stair and it is provided with sharp metal edges). For some locations (i.e. the underground) the possibility of using the escalator for this purpose is being discussed by ministers.This could cause risks greater than those aimed to be reduced. In this regard, during the VFA Forum (Interlift, October 2015), Eng. Giovanni Pappalardo (ANACAM – Italian Association of Elevator Companies) presented an interesting report (FEMS – Fire elevator, escalator, travelator and management system in an airport).The report was about the design of a fire protection system, with relevant management of lifts and escalators for Fiumicino airport in Rome, Italy. I asked some questions and also a manager of Amsterdam system took part to the discussion. The author of the report and the Dutch technician discussed about the following: if the escalator moves passengers to an area where a fire alarm is triggered, a proper procedure could be:
- Audible alert warning about the imminent stopping of the escalator because of a fire alarm at the destination;
- Invitation to hold the handrail;
- Smooth stop of the escalator;
- Reverse travel upon sound alarm warning that the escalator is changing direction at very slow speed, inviting users to turn towards the motion direction and hold the handrail.As regards the escalator as an advertising medium, it has been assessed that advertising messages on step risers are distracting. Conversely, there is a greater attention if the advertising message is written on the handrails: probably there is an unconscious urge to grab it.
TRAINING AND INFORMATION FOR TECHNICIANS
For “non-public use” escalators according to the legislation of the Ministry of Transportation, exclusively monitored by the Transportation and Fixed Systems Office (USTIF) the maintenance technician is required to be qualified neither there is the obligation for a scheduled maintenance or periodic visits. Considering that escalators operating in shopping malls fall into this category, we hope that the national legislation intervene given the growing number of escalators installed and to be installed. In this way the requirement of the EN 115-1 would be exceeded where it is suggested the maintenance by a skilled technician and the recording of maintenance interventions.As regards to users, rather than signs (no-one reads), a training at school would probably be more useful. In Japan, in primary schools there are volunteers from sector multinationals who through lessons and games offer important messages on safe use. There is an old-fashioned board game where one who reaches a cell of bad behaviour is downgraded. With regard to basic training, there is the important and occasional commitment by some schools with courses of four to eight hours and a four-day course at the Polytechnic of Milan (unfortunately the course is no longer offered). Moreover, in recent months, the College of Engineers of Milan has started two four-hour courses for its members. The lessons will be certainly repeated in 2016.Finally, for owners, operators or maintainers, besides the compulsory maintenance manual, there is the EN 13015 standard focusing mainly on lifts, but including also useful guidelines for escalator essential maintenance.
By Bruno Ciborra
According to ELA – European Lift Association report, presented by Ebru Gemici-Loukas (“Industrial statistics of lifts & escalators”, Asansör Istanbul Conference” March 2015), in 2013 lift accidents were 835 (data referred to 18 out of 29 countries represented by ELA). 17 fatal accidents (no fatal accidents in Italy), 144 serious accidents (11 in Italy) and 674 minor accidents (85 in Italy).According to ELA – European Lift Association report, presented by Ebru Gemici-Loukas (“Industrial statistics of lifts & escalators”, Asansör Istanbul Conference” March 2015), in 2013 lift accidents were 835 (data referred to 18 out of 29 countries represented by ELA). 17 fatal accidents (no fatal accidents in Italy), 144 serious accidents (11 in Italy) and 674 minor accidents (85 in Italy).For escalators (data from 17 out of 29 countries), in the same year, accidents were 375: 3 fatal accidents, 24 serious accidents and 330 minor accidents (the report does not list accidents by countries). The majority of accidents (70%) is relevant to risks described by the EN115-2 (Safety of escalators and moving walks – Part 2: Rules for the improvement of safety of existing escalators and moving walks) standard, also known as SNEE (Safety Norm for Existing Escalators):
- slipping on steps/pallets/belt and on landings 28% – (1 fatal)
- falling from a landing 19% – (1 fatal)
- entrapment between skirting and steps 10%
- entrapment between combs steps/ballets/belt 5%
- entrapment at handrail entry points 5%
- improper use of an escalator to move a shopping cart 5%
- entrapment between steps or pallets 2%
- climbing the balustrade 1% – (1 fatal)
- crushing fingers between handrail and balustrade 1%
- falling due to stopping distance being too short 2%
- others 12%.
In 2013, accidents relevant to escalators (data from 16 out of 29 countries – no data for each country) involving operators were 65: 2 fatal accidents, 10 serious accidents and 53 minor accidents. In this case, 36% is included in the cases covered by SNEE:
- insufficient space in working area 24% – (1 fatal)
- missing steps or pallets 5%
- no emergency stop switch in working area 2% – (1 fatal)
- electric shock due to contact with live parts 5%
- unsafe access to machine room 3%
- manual handling 17%
- unsafe working method 3%
- unsafe use of tools 2%
- others 32%.
By Fabio Liberali
Questo articolo è disponibile anche in: Italiano (Italian)