TECHNOLOGY ESCALATOR MODERNIZATION …

1 116 August 2000 Elevator WorldTECHNOLOGYB ackgroundTransit systems across the country have been usingescalators to move people between the street and trainplatforms for almost a century. In many ways, escalatorshave become a critical means of transportation withintransit systems. ESCALATOR codes have changed dramati-cally, as has the understanding of actual use and abuse towhich transit escalators are , the American Public Transit Association s(APTA) ESCALATOR Committee has developed a draft set ofguidelines for new ESCALATOR installations. While alreadyoutdated, important strides were made in differentiatingbetween department store commercial-type escalatorsand heavy-duty escalators . This article will contrast positiveand negative aspects of ESCALATOR replacement strategybased on using APTA guidelines for the new is the difference?It is critical to understand what a heavy-duty escalatoris.

2 Once that is understood, a better decision can be madewith regard to your own ESCALATOR strategy. APTA bor-rows its philosophy from the European ESCALATOR code,EN 115. The key here is that EN 115 recognizes that thereis a fundamental difference between commercial escala-tors and public-use Heavy Duty Feature Commercial>2,000 mmRadius1,000 mm standard674 poundsDesign load-brakes190 pounds674 poundsDesign load machines190 pounds674 poundsDesign load truss190 pounds674 poundsDesign load machinery/chain190 pounds<1:1000 between supportsTruss deflectionno standard100,000 hoursEngineered design lIfe25-30,000 hoursV-groove profileHandrail constructionU grooveGalvanizing to ASTM123 WeatherproofingGalvanized may warp lighter truss3 Flat steps23 mmTrack mmhigh deck solid balustradeBalustradeGlass or 3/8 inch steel sandwich panelwith 16 ga. stainless steelwaterproof, high insulationmotorsvariesrating available4 inches (100 mm)Roller diameter3 inches (75 mm) ESCALATOR MODERNIZATION VERSUS REPLACEMENTby Patrick J.

3 WelchPublic-use (heavy-duty for our discussion) escalatorscan be defined as any ESCALATOR in a public transporta-tion facility that operates 20 hours a day, with a crush-load situation in any three-hour period. A crush load isdefined as an ESCALATOR operating at full capacity for any30 minutes in any three hour are other key differences between heavy-dutyand commercial escalators that must be understood isshown in Table that many systems have modified the design loadrequirements as stated by APTA; 674 pounds can be con-sidered excessive and is actually considered an error thatshould no longer be in the guidelines. A common designload in use in transit facilities is 450 pounds per 40-in.(1,000-mm) step. This is the same structural design loadrequired by EN 115. Furthermore, it is becoming morecommon to use this design load for the motors andbrakes as is this important if you want to modernize?

4 It is critical to understand that APTA has developedexcellent guidelines in conjunction with active transitauthorities to develop these standards to improveContinuedSTable 1: Heavy Duty vs. Commercial Duty Based on escalators With a 40 inch (1,000 mm) Stepi. Skirt deflector device (skirt brushes);ii. Comb impact device;iii. Skirt switches; andiv. Handrail speed very important issue to understand is that a modernescalator has more safety devices than an ESCALATOR installedprior to 1987. What this means is that the oldescalator may shut down more often than it did prior tothe MODERNIZATION . What is critical to understand is thatunlike an elevator, or even a bus or a train, when an ESCALATOR shuts down, it is usually because somethingworked example of this is when a child gets a shoelacecaught between the step and skirt and it sets off eitherthe skirt switch or the comb impact devices (both post1987 code requirements).

5 The ESCALATOR will shut down,but it is not a malfunction. What has happened is that anincident involving a patron has been avoided or signifi-cantly reduced in a careful look at your ESCALATOR system to makesure your maintenance is as complete and thorough aspossible. If necessary, invest in increased maintenanceand repair before making a final decision to determine ifthe improved maintenance gets you the results you werelooking is important to understand that not all escalatorscan be upgraded to the same degree. Space limitationsor design may not permit certain upgrades you maydesire. Look before you leap is very good advice whenconsidering ESCALATOR MODERNIZATION !Table 2 illustrates some of the pluses and minuses ofescalator reliability and longevity. If you have escala-tors that are under-designed, you cannot turn them intoa heavy-duty ESCALATOR by modernizing what you are starting with and whatyou want to achieve are key objectives.

6 It should also beunderstood that there are many escalators in use installed prior to the APTA guidelines. Many of them canbe successfully modernized, but there are a significantnumber of them that may not be worth the to decide whether to modernize or replace my transit escalators ?First, determine why you want to modernize or replaceescalators in the first place. If the escalators are unreli-able, take a very close look at the maintenance programin place. Preventive maintenance in transit facilities istraditionally very difficult to systems permit unrestricted preventive mainte-nance during operating hours. Taking escalators out ofservice every week for preventive maintenance is oftenimpossible. Consider off-hours maintenance or escalators need major repairs, not is critical to conduct a thorough study and inspectionof any ESCALATOR you are considering to modernize.

7 Thebest time to conduct this review is during the annualcleaning and inspection. Once all the steps are out andthe unit is cleaned, you can perform a detailed inspectionto determine what devices can be added in a moderniza-tion is the difference between modernizing and repairing escalators ?Simply put, repairs include the following work:a. Replace step chains;b. Replace handrails;c. Replace track sections or turnarounds;d. Replace steps;e. Major cleaning and lubricating; floor plates, decking, balustradepanels;g. Drive repairs, including brake and drivechains; andh. Replace any existing safety of an ESCALATOR can bedone in certain increments and includesall of the above work, plus:a. Replace controller;b. Upgrade braking system;c. Upgrade motor;d. Change handrail drive system; ande. Addition of safety devices not includedin original installations, such as118 August 2000 Elevator WorldTECHNOLOGYC ontinuedTable 2: Decision Factors in MODERNIZATION of EscalatorsPositive + Negative -Minimal building work required Cannot increase number of flat stepsLess downtime once work startsCannot increase radiusMore bidders availableCannot replace rusted trussMore flexible scope of workBuilding supports may be badLess expensive than new Cannot increase design load heavy-duty escalatorson all devicesNo major rigging issues Cannot make a department storein delivery of partsescalator a true heavy-duty escalatorSignificant improvement in Structural integrity of ESCALATOR stepssafety and reliabilitymay be below standard for new 2000 Elevator WorldTECHNOLOGYC ontinuedspare parts that are currently available.

8 New escalatorswill require preventive maintenance of at least twice permonth, and in certain circumstances, weekly mainte-nance will be required. What will not be required forseveral years are large major repairs. This will permittransit facilities to spread their often thin preventivemaintenance resources toward equipment that has yetto be replaced or escalators has the singular advantage offlexibility. There are significant safety devices that can beadded into existing ESCALATOR systems without the timeand expense of a full MODERNIZATION . You can improve thesafety and reliability of your escalators in increments thatmay suit your budget, if you cannot yet afford a full replacement or particular note, the comb-impact device has beenadded to many escalators in transit systems without a fullmodernization being completed on the escalators .

9 Thisdevice shuts the ESCALATOR down if an object becomestrapped between the step and the combplate in the verticalor horizontal entire article could be written on the advantage ofthis single safety device. This article will simply recom-mend adding this device wherever possible on any esca-lator that does not have this device installed, regardless ofany other capital plans you may have for your escalators is not as straightforward asmodernizing elevators. Be wary of modernizations thatsolve all problems in your ESCALATOR system. It has manyadvantages as outlined here, but there will be instanceswhere MODERNIZATION is not worth the effort, or is sim-ply not your option; study your equipment, and you willunderstand the best choices for your ESCALATOR steps must be stringent engineeringtype tested, including a step fatigue certification step frames are subject to vibration, rain, salt,uneven wear and abuse (such as newspaper vendorsusing heavy handcarts on escalators ) that can lead toundetected fatigue in an ESCALATOR author has witnessed informal testing of newsteps versus steps over 25 years old.

10 The new steps hadan ultimate breaking strength of close to 1,700 pounds,a truly solid and excellent design. When an older stepin seemingly good condition was subjected to the sametest, it failed at only 700 pounds! While still within standards, this is certainly an alarming is currently no requirement by any code orstandard to re-test ESCALATOR steps at any interval. It isour recommendation to either sample test existing stepsin the system or supply new steps in any ESCALATOR mod-ernization in which step fatigue is a is also possible to submit sample steps to a new stepfatigue certification test. However, it is no longer valid asa type test, since each individual step will have been sub-ject to different stresses in the many years of service inthe transit 3 examines the pluses and minuses of a escalators look nice and, if properly specifiedfor your application, can last up to 20 years or morewith focused maintenance.