UOMaryland

• July 2015

permanent-magnet hoist motors. This task required

innovation and expertise to incorporate the basement

tie-downs of the existing machines, while retaining the

overhead deflector sheaves. No overhead modifications

could be made to the design, due to overhead

restrictions.

The new hoist machine had to be designed to

support the upward thrust that would be exerted on to

the machine and, subsequently, onto the building

structure during normal operation cycle and

testing. The existing overhead sheave alignment had to

be calculated, and the new hoist machine had to be

engineered to create acceptable rope alignments.

Design concepts were created. These included

custom mounting plates to provide sufficient support to the upward thrust of the elevator system. Once the

machine’s upthrust was calculated, the mounting method was applied and sharpened as the load

calculations were anticipated. This detail was further complicated by the site’s reduced clearance. Since the

elevator machine room was placed at the second landing, elevator 1 was required to serve one floor below

the hoist machine and machine room. To retain elevator service to this portion of the building, the design

had to allow for the elevators to be removed and modernized one at a time. This made hoistway access and

maneuvering more difficult.

Quality Elevator Company completed this project on time and with no change orders. The

craftsmanship and engineering is second to none.

Jack Higgs

is president of Quality Elevator Co., Inc.

Clockwise from left:

• Completed hoistway

• Phase 1, Elevator 1

• Phase 2 Progress