Life at a different level
Follow Us On:
Commercial Elevators Definitions
In Ground
 
This is the traditional design used for decades. It utilizes a single-stage hydraulic jack installed in the ground. The jack is located directly under the car, near the center of the platform. 
 

Advantages:

  • Usually the lowest material cost application.
  • Accommodates front and rear openings in any configuration.
  • No extensive pit or overhead is required.
  • Available for both low and high capacity cars.
  • Of all the application types, this equipment package is the easiest to install.

 

Disadvantages:
  • Oil contamination in the ground is possible. As a precaution, the jack can be enclosed in PVC pipe. Areas with frequent seismic activity will have the greatest risk of oil contamination.
  • The jack must go down into the ground roughly the same distance as the desired travel (multi-stage jacks can reduce this distance). Drilling a jack hole is expensive and may be nearly impossible in certain structural or geologic conditions.

In Ground, Rear/Slide Slung

This application is used when a side opening is required in addition to a front opening. The rails and brackets are located on one wall of the hoistway. Please note that the dimensions shown are only examples of applications possible. Please call MEI for job-specific dimensions.


Advantages:

  • Accommodates front and side openings.
  • No extensive pit or overhead is required.
  • Available for both low and high capacity cars.

 

Disadvantages:

  • Since the rail brackets are all mounted on one wall, additional rail force accommodations may be necessary.
  • Oil contamination in the ground is possible. As a precaution, the jack can be enclosed in PVC pipe. Areas with frequent seismic activity will have the greatest risk of oil contamination.
  • The jack must go down into the ground roughly the same distance as the desired travel (multi-stage jacks can reduce this distance). Drilling a jack hole is expensive and may be nearly impossible in certain structural or geologic conditions.

Twin Jack Holeless, Single Stage

 
This design utilizes two hydraulic jacks and provides maximum structural stability. The jacks, located on each side of the car, are either single-stage or telescopic. The appropriate jack type is determined by the amount of travel and the project conditions. The single-stage jacks are popular for two-stop arrangements, while telescopic jacks are generally used for three- and four-stop projects.
 
Advantages:
  • No jack hole is required. This eliminates the cost of drilling and the risk of oil contamination.
  • Accommodates front and rear openings in any configuration.
  • Available for both low and high capacity cars.

 

Disadvantages:
  • Usually requires more overhead than an In-Ground project. The greater the travel, the greater the overhead must be.
  • Requires a wider hoistway for the jacks.
  • The material cost is typically higher than that of an In-Ground package.

Cantilever Roped Hydraulic

 

This is a holeless design limited to low capacity applications. Wire ropes are utilized in conjunction with a hydraulic jack to lift the car at a 1:2 ratio. For every foot that the jack rises, the car rises two feet. The jack and rail equipment is mounted either to the side or to the rear of the car, depending upon the opening configuration.


Advantages:
  • No jack hole is required even though the travel can be as great as 100 feet. Without a jack in the ground, the risk of oil contamination is eliminated.
  • Front & side openings can be easily accommodated.
  • No extensive pit or overhead is required.

 

Disadvantages:

  •  Because the rail and jack equipment is located either at one side of the car or at the rear, additional space is required at that location.
  • Since the rail brackets are all mounted on one wall, considerable rail force accommodations are necessary.
  • The installation time is greater than that of an In-Ground application.
 

Twin Jack Roped Hydraulic

This design utilizes wire ropes in conjunction with two hydraulic jacks to lift the car at a 1:2 ratio. For every foot that the jacks rise, the car rises two feet. The use of two jacks, one on each side of the car, provides maximum structural stability.
 
Advantages
  • No jack holes are required even though the travel can be as great as 100 feet. Without any jacks in the ground, the risk of oil contamination is eliminated.
  • Accommodates front and rear openings in any configuration.
  • Available for both low and high capacity cars.
  • No extensive pit or overhead is required.
  • Large platform designs and high capacity projects can be accommodated.

 

Disadvantages:
  • Requires a wider hoistway for the jacks and roped equipment.
  • The installation time is greater than that of an In-Ground application.
 

Traction

 
This design utilizes a geared machine, ropes, and counterweights instead of hydraulic equipment. The main guide rails are mounted on each side of the car and an additional pair of counterweight rails is located on one side or at the rear. The geared machine, along with the related drive equipment, is generally located above the hoistway in a penthouse machine room. In some limited situations, it can be located next to the hoistway at a lower landing. This latter arrangement is referred to as a basement traction.
 
Advantages:
  • No risk of oil contamination to the ground.
  • Accommodates front and rear openings in any configuration.
  • Available for both low and high capacity cars.
  • Nearly unlimited floor travel is possible.
  • Has greater power efficiency than hydraulic applications.
  • Allows significantly higher car speeds than hydraulic designs.

 

Disadvantages:
  • The material cost is substantially higher than that of hydraulic applications.
  • There are structural building considerations because the elevator is supported by the top of the hoistway.
  • Elevator maintenance cost is generally greater than that of hydraulic elevators.
  • Cycle time for securing the material package and installing it is generally longer than that of hydraulic elevators.
 

Traction, MRL

 
This design utilizes a gearless machine, ropes, and counterweights instead of hydraulic equipment. The main guide rails are mounted on each side of the car and an additional pair of counterweight rails is located on one side or at the rear. The gearless machine, along with the related drive equipment is all installed inside the hoistway eliminating the need for a machine room saving you valuable floor space.

 

Advantages:

  • No risk of oil contamination to the ground
  • Accommodates front and rear openings in any configuration
  • Has no need for a machine room
  • Has greater power efficiency than hydraulic applications
  • Allows significantly higher car speeds than hydraulic designs
  • Generally cheaper then traditional traction applications

 

Disadvantages:

  • The material cost is substantially higher than that of hydraulic applications
  • There are structural building considerations because the equipment is all mounted inside the hoistway
  • Elevator maintenance cost is generally greater than that of hydraulic elevators
  • Cycle time for securing the material package and installing it is generally longer than that of hydraulic