DEPLOYABLE FIRE ESCAPES for TOWERING BUILDINGS Answered
The “9/11” World Trade Center disaster horrified Americans as they witnessed people leaping out of 100 story windows to their death. There was simply no available escape system to facilitate a safe yet quick evacuation to the ground floor. Elevators weren’t working and internal staircases were blocked by sporadic debris, black smoke and fires. The situation was virtually hopeless to the point where many chose to jump rather than be burned alive. So here we are, with technology capable of constructing 100+ story buildings but without the means for external fire-escapes. Unfortunately, the public isn’t aware that at our current level of technology we can finally address this problem with our architects.
We are talking about a means to rapidly deploy a flexible escape tube-chute from 100+ stories that hangs along a guy-wire which is pre-attached to our escape floor and anchored to the ground (Fig-1). This tube-chute escape system will deliver a person from 100-stories down to ground level and safely outside the building in under 10-minutes.
Prior to deployment, the entire system is housed inside a container that is either attached to the outside of the building or built into a structured wall, opening to the outside at various floor levels. When in deployment, the inlet of the flexible escape tube will be anchored to the outside wall of a designated escape window and contain an inner diameter sufficiently sized to accommodate an individual. The tube’s exit end is tethered to a rope-wire that runs down our permanently located guy-wire, through a series of guy-wire slip-rings, and quickly pulls the tube's exit end to ground. The rope-wire is permanently attached to a winch-motor located on the ground. During deployment, the winch pulls the tube’s rope-wire down to ground level by slipping along the guy-wire rings. As the tube-chute deploys downward, it automatically forms a spiral about the guy-wire, creating a very long escape slide that gets anchored to the ground.
A fully deployed tube-chute exhibits three basic attachments for stability: 1) a set of flexible slip-rings and tethers attached between the permanent guy-wire and tube to form its downward spiral, 2) a tube-chute inlet anchored to the outside of the building at various floor levels, and 3) a tube-chute exit anchored to the ground and providing a fully deployed and reliable escape system ready for use.
As each person enters the tube-chute, they are only aware of the outside winds which buffet the tube plus the internally hanging cloth fingers used to slow their descent as they slide down to safety. They are not aware of any height and feel relatively secure due to their complete envelopment by both the tube and its touching fingers. A 100-story descent would take about 6-to-10-minutes to reach the outside safety of ground while travelling at a speed of roughly 5-fps (3.5 MPH) as regulated by the spiral-ramp and internal cloth-fingers retarding gravity.
The tube-chute is reinforced by a sewn-in spiral wire that gives it strength and flexibility. Its tube is made of heavy duty nylon, much like the large yet light air-hoses used on many high stress applications today. The tube cork-screws its way down and around a permanently deployed guy-wire that stretches from the designated floor of the building to the ground. The tube is sized for a person to enter and slide down the spiraling pathway until he reaches ground level. Gravity will act to propel the sliding individual down the tube. To counter gravity, we rely on the tube’s spiraling design to produce a gradually declining ramp that slows and checks an individual’s descent speed. The number of spirals and ramp-angle necessary to reach the ground will be sized to limit the gravity-induced speed so as not to endanger an individual’s sliding descent. That and the internally hanging cloth fingers guard against excessive speeds and will prevent skin-burns from the sliding friction.
The tube’s nylon material is impregnated with anti-flammable chemistry and its exterior is aluminized to prevent radiative heatloads from causing a fire due to either direct flames or the radiant heat from indirect flames.
A final note on the overall weight for this flexible tube-chute structure. Clearly, since we are designing a deployable fire-escape system, its weight must be kept to a minimum for deployment safety and reliability. Items such as the cloth materials, tube-wire reinforcements, and spiraling tube tether attachments must be carefully chosen for weight, strength and durability. While issues of weathering may not be that important, as it will be housed and protected from the elements, the shelf life of the various materials chosen is of paramount importance.