A night that started out with fun, partying, and dancing, ended in tragedy. On July 17, 1981, 100 people were killed, and nearly 200 injured, when an elevated walkway collapsed at the Hyatt Regency in Kansas City. The 40-story Hyatt Regency had opened its doors only one year before this incident. The defining features of the structure were the elevated walkways that were suspended from the ceiling. Each walkway was about 40 yards long, and weighed 63,934 pounds. These walkways were configured in such a manner that the second and fourth level walkways were in line vertically.
The original design for these walkways was that they would be suspended from the ceiling with continuous threaded rods and secured with nuts. Contractors and the manufacturer had concerns regarding the installation and workload required to install and secure four-story long threaded rods, and then rotate nuts two stories into place. So, a decision was made to hang the fourth floor walkway from the ceiling, and suspend the second floor walkway from the fourth with a different set of rods. This design change was approved without a detailed review, or revised calculations. This configuration doubled the load on the main supporting beams (from which supported the fourth floor walkway). The added load caused the welded seam beams to fail and allowed the nuts to pull through. This caused the fourth floor walkway to “pancake” onto the second floor walkway beneath.
The full investigative report is available here, from NIST. Primary contributing factors identified in the cause of this collapse, include:
In the early 1900's the children's story character, Dr. Doolittle, introduced us to the pushmi-pullyu. This was a gazelle-unicorn like animal having two heads each pulling in its own direction. A more contemporary example might be that of Nickelodeon's CatDog, an animal with two heads on each end, one a cat, and the other a dog.
Now the fire service has it's two headed "animal". It is a tunnel rescue vehicle, being used in Croatia, called "Merkur".
The Merkur solves a unique set of problems found only in vehicle tunnel situations. These problems include:
poor visibility due to smoke in fire events
little room for vehicle maneuvering
lack of oxygen (needed to keep combustion engines running)
The Merkur has two cabs, allowing drive in both operations. It runs on electric, therefore, requiring no oxygen for operation. This vehicle is reported to be extremely simple to operate. There is no gearbox required, merely a lever indicating 'forward' and 'reverse'. Only one cab can be in operation at a time. The driver can simply walk through to the other side for operation. The Merkur is equipped with thermal imaging cameras allowing operation even under extremely low visibility conditions.
The driver gets oxygen through a personal breathing apparatus, however, the Merkur is equipped with a fresh air breathing unit, supplying oxygen to those in the vehicle. This vehicle can evacuate up to 12 people at one time, each spot has its own oxygen mask connected to the vehicles system. For firefighting, the Merkur puts out a fine water fog from the base of the vehicle and around all the tires, allowing access to the source of the fire.
This vehicle is an amazing testament to the power of creativity in the fire service. We must become more accustomed to utilizing our creative capacity in solving the problems that are unique to our departments and communities. As much as we must exercise creativity when it comes to fire ground strategy and rescue tactics, we also must utilized it in administration. We must exercise creativity in the marketing of our fire departments, and in the finances of our departments (to not just make cuts, but to create new revenues).
For more on the Merkur tunnel rescue vehicle check out Hemming Fire.
