ESCALATOR REPLACEMENT

Industry estimates note that as many as 30,000 of existing escalators are 20 years old or more and are in need of updating. There are several reasons why: moving parts wear out over time, decreasing reliability and life span, changes to safety codes, replacing old parts with often-unavailable ?new' old parts becomes costly, etc. In addition, the efficiency, smoothness and reliability of new equipment set a higher standard so that older escalators appear painfully slow.

Perhaps the most important reason to update is that new technology has improved efficiency. New motors and drives require less electrical usage. Most of the starters on units over 15 years old employ a full voltage Wye Start/Delta Run connection that requires a higher starting and running amperage. New types of power control offered as options by manufacturers adjusts the motor power to the number of riders using the escalator while maintaining normal speed. Combined with a solid-state soft-start it can reduce electricity use by a significant amount. A study conducted by Nevada Power prepared by Paragon Consulting Services found electrical consumption was reduced by up to 40 percent.

There are two basic full replacement options for owners and design consultants seeking to update old escalators ? direct replacement or complete modernization. Again, each project must be evaluated on its own merits to determine which approach is appropriate. Different conditions require different solutions.

Replacement: Factors to consider
? Location. Does access for getting the old units out and the new units in even exist?
? Building occupancy. How will complete replacement impact traffic flow in the existing building? What will be the cost of doing business during replacement?
? Work by others. How much general contractor work is required in order to tear out and remove the existing units?
? Impact to finishes. How will removing existing units, construction and installing new units impact existing finishes within the building?
? Other factors to consider. How will additional security, housekeeping, and so forth, impact the budget and the building occupants?
? All factors must be looked at closely in order to come up with best overall value to the client.

Replacement: The Process
Since escalators become part of the foundation of a building structure, removing and replacing them can turn into a much larger project than first considered. Each stage from prep-work through wrap-up needs to be quantified.

Escalator Replacement Modules

Source: KONE Inc.

 

Prep-work required before the removal of the existing trusses includes installing OSHA-approved barricades around the entire escalator well way; protection of flooring; removal of all existing escalator cladding; demolition of adjacent finishes; demolition of adjacent features; installation of scaffolding.

Removal includes the removal of sprinklers and water lines, all electrical wiring, ventilation and ducts; and the concrete and tile surrounding the escalator access covers.

The major work is the demolition and removal of existing structural steel escalator truss, usually at overtime rates. The truss typically needs to be laid down flat and cut into pieces for removal from the building. In many cases, the existing pits need to be torn out and replaced since new escalators will require a different well-way size from the existing ones. Sprinklers and water lines may also need to be removed and re-installed.

Installation. New escalator trusses are brought into the building in pieces, married together on the floor and then hoisted into the newly constructed well ways.

Wrap-up. All finishes and features torn out in order to allow access for the new equipment must then be rebuilt or replaced before the new escalators can be put into service; the flooring repaired at the newly reconstructed pit; removal of scaffolding and barricades; ceramic or carpet replacement.

Builder risk insurance, city impact fees, architect/engineer design fees add to the cost, as does the additional work by the trades for replacing fire and sprinkler systems, lighting and HVAC. In many cases the work of the general contractor and by others can be more than the cost of the escalators.

Escalator modernization
Modernization, in essence, is removing all of the existing internal components of the escalator, while keeping the truss, and replacing them with brand new escalator technology. The end result is a new escalator without the time and expense of all the construction associated with a full replacement.

Modernization is often far less disruptive to the surrounding building operations and it is often possible to keep one escalator running while the other is being modernized.

The modernization process starts with stripping the existing escalator down to the structural steel truss. No adjoining finishes are removed or damaged and the need for most of the general contractor work associated with a full replacement is eliminated.

Modernization installation sequence
? Small barricades are installed around the upper and lower ends of the escalator. As one of the side by side pair of escalators is being modernized, a protective barricade is also installed between the two units.
? All internal components are removed from the old escalator. The torn out components are recycled when feasible. The truss and all other attached finishes are reused.
? Upper and lower end modules are set in place and aligned.
? Incline modules are then installed to the existing truss cross members. Step tracks are also installed throughout the entire length of the unit.
? Step chain and escalator steps are installed and the unit is put under a test run.
? Architectural features such as decking and balustrade panels are installed next.
? Finally, the handrails are installed and the units are cleaned and turned over for use.

In many cases, Escalator Modernization offers the best value solution for many customers when all final construction costs and the level of disruption associated with most replacement projects are avoided. That being said, a project specific analysis should always be performed to determine the best solution for each application.

 

CONCLUSION

Since their introduction a century ago, escalators have become an efficient means of routing and transporting large numbers of people in numerous market segments from hotels and airports to office buildings and public transit. New technology has made significant improvements in step and handrail drives efficiency and reduced electricity costs while changes in codes are requiring new safety features. A knowledge of basic design concepts and an understanding of various component systems is therefore critical.

Given the fact that a large portion of escalators now in service are 20 years old or more, designers are increasingly required to make the choice between replacement or modernization. Having the tools to evaluate and determine which option is most appropriate for a building will help in selecting the solution, which offers the best overall value for the client.

 

KONE's objective is to offer the best people flow experience by developing and delivering solutions that enable people to move smoothly, safely, comfortably and without waiting from one place to another. KONE, a global leader, provides its customers with industry-leading elevators, escalators and innovative solutions for modernization and maintenance. www.us.kone.com