Orville Douglas Denison, 72, has been modeling his inventions since he was a child, even receiving recognition for his aeronautics concepts that were published in the Academy of Model Aeronautics when he was just 15 years old. However, it was the events of 9/11 that led to one of his most common-sense inventions: a new type of ladder that can be used on fire trucks in order to quickly evacuate victims and first responders.

Denison said that on 9/11, occupants of the World Trade Center were unable to exit via the interior staircases, and many firefighters who perished did so trying to assist with the evacuation. He began studying fire-rescue technology, including ways to develop a more efficient rescue approach.

After years of research, Denison developed a prototype hydraulic- or electric-powered ladder system. The system consists of a power source and two cables running at each end of the ladder rungs. The cables rotate and grab the rungs and pull them forward or backward. Firefighters step on to the ladder, which can be controlled, stopped, forward or reversed either by an operator below or via a handheld remote control. The model ladder system moves at 200 feet per minute, he said.

“Powering the ladder rungs meant firefighters could ride up and the people could ride down, especially those unconscious or unable to walk or move,” Denison said.

Victims are place in a rescue bag that is then zipped up securely. The bag has straps on top and bottom that hook on the ladder rungs or snap on. In fact, firefighter can load the victim inside the building and use the straps and pulley system to pull them from the floor to the top of the ladder system, Denison said.

“Then you hook two straps onto the ladder, and he will travel down the face of the ladder system without any further assistance from the firefighters,” Denison said.

Denison says it can now take up to 15 minutes to carry one victim down a ladder from 10 stories. He estimates that his ladder could lower four people to the ground in less than four minutes.

While the invention hasn’t officially been picked up by a manufacturer, Denison believes the adoption of the new ladder could change the way fire departments fight fires and approach rescues.

“It’s gonna be built by someone today or tomorrow,” he said. “I only hope I see it in my lifetime.”