Hyatt Regency Walkway Demonstration Models

Description

We have created these models to showcase how critical it is to consider fundamental engineering principles in design. The failure of the Hyatt Regency Walkways is an important case study to teach engineers with the hope that such a disaster will never occur again. We have created two models that demonstrate the primary cause of the walkway failure. The first one shows the originally proposed design, in which the blue bars represent the two suspended walkways. The original design called for a single pair of hanger rods, which would pass through the fourth floor walkway to the second floor below. In this setup, the load of the two walkways is independently transferred to the hanger rods. We are able to lift one floor without affecting the other. The second design models a design change that was implemented for budgetary reasons. In this configuration, the entire weight of the second floor walkway is being supported not directly by the hanger rod, but by the fourth floor walkway above. When we lift the upper walkway, the lower walkway moves too. The hanger rods are still carrying the same load at the top, but the two nuts on the upper floor are now supporting the weight of both walkways. This seemingly small design change effectively doubled the load on the bolted connections.

Engineering Topic Covered

The implementation of the second design effectively doubled the load on the bolted connections.

Learning Objective

1. Students will be able to recognize what caused the Hyatt Regency walkway failure

2. Students can analyze statics principles for when failures may occur

3. Students will be able to explain in their own words the difference between the two designs

How to use

1. Lift the upper “walkway”, or the top blue bar, up and down in both models

2. Point out that in the original design, lifting the upper walkway does not affect the lower walkway, and vice versa for the second design

3. Ask students to speculate why this difference might be important

Annotated Model Components