Future Forward Interview: When In Doubt, Damp It Out
Douglas P. Taylor is president of Taylor Devices (www.taylordevices.com), which manufactures seismic dampers that protect structures during such events as earthquakes and high winds. He is inventor or co-inventor of 34 patents in the fields of energy management, hydraulics and shock isolation. In 2015, he was inducted into the Space Technology Hall of Fame by NASA and the Space Foundation.
V1: Please provide a brief background of your education and career before Taylor Devices.
Taylor: (laughs) My career has only been at Taylor Devices. I was 14 when I started. In 1971, I graduated from the State University in New York at Buffalo, School of Mechanical Engineering.
V1: How did you get into seismic dampers, and why did you then start Taylor Devices?
Taylor: Well I didn’t start it. My father started it back in the 1950s, and essentially we were a government contractor. He came out of the aircraft business, so he wanted to stay in aircraft-related items, and his company was probably 80 percent aerospace. During the 1970s, we developed a series of large shock isolators for the Department of Defense (DOD) that were used to protect ballistic missiles and their launch silos against attack by the old Soviet Bloc.
Years later, and I mean many years later, back in 1989 when the Cold War ended, those units became our seismic dampers simply because they had been fairly heavily classified during the Cold War. When the Cold War ended in 1989, we went to the DOD folks and asked, ‘Hey, can we sell these products commercially?’ And they kind of laughed. It didn’t strike them as something you could really sell commercially. Who wants to buy a ballistic missile blast isolator? We had ideas.
The technology itself was developed for DOD, but we also had some input from NASA, which, in the 1970s, had the Space Shuttle coming up, and we had done a lot of work with NASA on the old Apollo program, making some complex energy absorbers for use on the launch gantries. If you look at the Tom Hanks movie (The Right Stuff), you can see the big gantry swing arm swinging away from the missile when the rocket launch takes place. All of those big arms were caught by our damping devices. They were very complex. So combining the technology from the Air Force with NASA’s problem led us to develop some new means of flowing fluid within a damper that didn’t require the valves, which are always considered a big pain in the neck in making a shock absorber; internal valves would allow fluid to flow properly—safe, reliable and maintenance free.
So we came up with a design that had no moving parts, which is about as simple as you could get. Using supersonic oil flows inside the shock absorber cause it to alter its properties as you went through different speed ranges. That was the technology that became the seismic damper, starting roughly in 1990 when we did our first experiments at the State University of New York at Buffalo’s earthquake center.
V1: Could you describe how you decided to take that technology and use if for different applications?
Taylor: It all started at a roadhouse restaurant in San Bernardino, Calif. We’d just been told by the Air Force that the contracts we’d been running through multiple presidential administrations were all coming to a halt. Indeed, our base that we were dealing with was going to be closed. My West Coast rep and I, we sat in a restaurant trying to think about what we could do. We were doodling on napkins, and he drew a picture of a submarine, and he said, ‘Here, this kind of looks like a missile turned sideways with some fins and a propeller on it. We can sell them for submarines.’ And I said, ‘Okay, I’ll take the missile, I’ll lift it out of the ground, I’ll put a bunch of windows in it and square it off. It’s a building. Let’s do seismic dampers.’ In the long run, we did both.
He went out and looked around and talked to people in California, mostly when he was going to CalTech years before, and discovered that if earthquakes were assumed to be small, then you didn’t need seismic dampers. But if earthquakes were bigger, then you needed seismic dampers. At the same time, they had the World Series earthquake in California that kind of defied expectations. Everybody said, ‘Oh, my goodness. We didn’t really think we could have earthquakes that big.’ Of course, a few years later, you had Northridge, which shocked everyone again.
So, the interest in earthquake technology was up and coming, and we were lucky enough to have the U.S. National Earthquake Center located here in Buffalo in my old alma mater, the University of Buffalo.
So we had then set up a small, steel-framed building, and we put two tiny little dampers in it, and it tripled earthquake resistance, which kind of shocked everyone in the civil engineering community, because they didn’t really think technology like that existed. Not only did it work well, it was extremely compact and easy to install. Essentially, one thing led to another from then on.
A little bit before the Northridge quake, we had our first application for what’s now the Arrowhead Regional Medical Center in San Bernardino. At the same time, when the Northridge quake occurred, we had a lot of interest generated from various California-based companies and groups and owners. Today, we’ve done more than 700 buildings and bridges worldwide with our technology.
V1: What are some of the unique qualities of the dampers, and why are they the only dampers qualified by NASA and the U.S. military?
Taylor: The unique properties are the fact that the dampers are very compact. The trick to making dampers compact is to have an extremely reliable seal and an internal damping system that has no moving parts in its valves. No valves, just a solid-state machine we call a fluidic amplifier to provide the required damping output. Those are the two unique things.
The seals, of course, were developed back in the 1970s for the Air Force’s ballistic missile silos. You button it up, and it just sits there, and you have to wait for a war. So for a building, hopefully you won’t have an earthquake, but maybe you will some day. Because of that, seals were needed that wouldn’t rot away with age or stick themselves to the piston rod and kind of glue themselves in place over time.
We had developed a seal that has been proven to have the ability to operate whenever you need it. If you need it today, it will operate today. If you need it in 25 years, it will still operate just as well as it did when it was new. We were able to address the issue of high reliability and no maintenance simply by saying ‘Here’s the damper. We’ll give you a 35-year warranty on it.’ So far, we haven’t honored many of those warranties, because nobody has had any claims.
V1: What are your dampers typically used for?
Taylor: Typical customers range from the Army, Navy, Air Force and Marines to heavy industry, where we’ve got a branch, you might say, of the seismic damper technology that we use in steel mills for absorbing the energy of the large, overhead cranes, should the crane have a runaway. We also have products in place at the Orlando Airport. When you get off a plane in Orlando, they have these little rail trains that move you from your remote terminals to the main terminal. If you get out, you’ll see these big shock absorbers sitting at the end of the tracks to catch the car if it runs away. So there’s virtually any application where you’ve got a large amount of mass moving at least at a moderate speed that you have to catch and protect if it should run away and have an impact. In buildings, you can put them in to improve seismic resistance, and you can either build them in as a retrofit or design them in as new. On a bridge, the most obvious thing that moves on a highway bridge is the bridge deck, which will move relative to its expansion joints and the abutments at either end of the bridge. That’s a perfect place to put a seismic damper if you’ve got issues with the bridge subject to earthquakes or, in some cases, just truck-braking shock. When a truck comes on and slams on its breaks when it’s on the center section of the deck, that’s often enough breaking force from a large truck or from a traffic jam to cause the expansion joints to run out of travel and start to damage the bridge. And it’s a good place to put a damper.
V1: What can engineers and designers do differently in their designs and creations by using seismic dampers?
Taylor: Using seismic dampers in a building application, allows the building to remain elastic during the worst-case earthquake, so it essentially has no permanent yield or offset and no damage. Similarly with a bridge, you’ve got the same application. You don’t want to have to have an earthquake and replace the main deck or structural elements or all your expansion joints, so you put dampers in and eliminate the problem.
V1: How much research and development goes into your dampers. Can you describe your process?
Taylor: Most of our technology is spun off from military. That way, we don’t have to pass the cost of the research onto the conventional consumer—the typical user who’s not in the military. The nice thing about doing half your business with the government, the way we do, is that the government is always interested in funding new concepts for weapon systems and applications that they come up with. If we can find a way to spin that technology off for commercial use, the government is usually happy to give you the releases to do it. We probably have a half-dozen military programs in-house right now that are all new concepts—new airplanes, new ships, new rockets and new missiles. We learn things while going through the development cycle on these new products for the government that can be spun off someday and adapted to commercial use.
V1: So is there still room for improvement in seismic damper technology?
Taylor: I think the biggest issues we have now are keeping the cost down. The technology is perfectly viable. It’s been demonstrated for many years of service in applications all over the world. From our viewpoint, it’s an evolutionary design where you’re making small improvements.
One engineer may say, ‘I can make this particular building work with a little-bit-different damping function. Can you do this?’ In most cases, we say yes. Sometimes we say, ‘No, we can’t do that yet.’ So we’re working on pushing the envelope as to what we can do with the designs to make them more useful to the civil engineering community in general.
We’re doing some work now on bridge applications, where engineers want the damper to be available for earthquake shocks or other massive shock events that might occur on a bridge. However, at the same time, they don’t want the damper to be active when the bridge is vibrating back and forth under small motions. The advantage of having a damper that can handle both those things is the fact that it will last a lot longer. You get a lot of small vibration cycles on a damper. On a bridge application, you wear the seals out quicker than you’d like them to wear out. We’re coming up with concepts that allow the small vibrations to, let’s say, pass through the damper without moving it, and that seems to be promising for the bridge applications.
Back in 2002, we did the retrofit of the Millennium Bridge in the United Kingdom that was known as the ‘wobbly bridge.’ This was a bridge that was only open for 48 hours, and they had to close it because it had uncontrollable vibrations caused by pedestrian traffic. People walking on the bridge would excite the bridge. It was kind of like walking on a ship, and the occupants on the bridge were experiencing almost the equivalent of a continuous magnitude four or five earthquake as they tried to walk, so it was totally unacceptable.
No one knew how to fix the bridge without major changes to its structure, which would impact how it looked, and it was an architecturally important structure. So we borrowed some technology we usually used only on satellites in outer space—a damper that didn’t have seals of the conventional type. The damper was sealed with a flexible, welded metal bellows that could be designed with an infinite life because it was flexing metal as the damper stroke rather than sliding parts over one another. That bridge just celebrated its 15th anniversary, and everything’s still working perfectly.
We’ve taken that solution, and we’ve applied that to some tall buildings for wind motions; the dampers continuously cycling under small wind motions to keep the occupants of the building happy. We’ve applied it to other bridge applications, mostly for pedestrian bridges where the bridge is too flexible under pedestrian inputs. Dampers will clip off the motion from the footfalls to the point where people don’t notice anything’s moving.
V1: What are some of the key aspects of dampers that save lives?
Taylor: If a building falls over during an earthquake, you’re not in very good shape if you’re inside the building at the time. Dampers allow any building to be immediately reoccupied after a major quake, which saves downtime on the building. In many cases, it will greatly reduce the damage to the contents of the building during the earthquake, and, if you happen to have a hospital or something like that, you certainly don’t want to have the contents of the hospital damaged. Those are the two big advantages. There are hospitals in California that want to be able to do brain surgery during a magnitude 8 quake. If that’s what you want, that’s what we’ll give you.
There’s a video online of the Los Angeles City Hall, which we protected a number of years ago with seismic dampers, and there’s a city council meeting going on during an earthquake. I guess they hear the earthquake coming, and a city councilman gets up and goes ‘Hey, you don’t have to worry. This building is protected with large shock absorbers.’ As he’s talking, everyone in the city hall is just sitting there contentedly, not feeling much of anything because the damping system is soaking up all the earthquake motions and eliminating the earthquake energy. Outside city hall that day, TV studios were evacuating, because parts were falling off the ceilings and all that. There was a lot of localized damage. The folks in City Hall were perfectly happy because the building had a full damping system.
V1: Why aren’t damping systems required in all buildings in earthquake-prone areas?
Taylor: It’s the codes. If owners are aware that for a few dollars more, they can have a building that’s not going to require any fixing up after an earthquake, nor do any internal contents need to be replaced, they’ll often opt for it. Other building owners aren’t so anxious to spend a little bit of extra money. There are applications that we’ve done where, just due to the constraints of the structure, adding damping to the building actually reduced the cost of the building, because the building ended up needing less steel.
V1: You were recently inducted into the Space Technology Hall of Fame by NASA and The Space Foundation. What was that like, and what specifically were you inducted for?
Taylor: The Space Foundation honors companies that take NASA technology and find ways to spin it off commercially. The award was received for taking the technology from the Apollo and Space Shuttle programs, and incorporating it into the seismic dampers.
V1: How did that feel?
Taylor: Well, it was fun. (laughs)
One of my old friends in the engineering business who is in building design says, ‘When in doubt, damp it out.’ That’s kind of a good way to look at things if you’ve got something that vibrates, shakes or you’re worried about shocking it. An easy way to fix it is with dampers, and you can usually do it without changing anything in the building. One of the features of dampers is that you can increase earthquake resistance by a factor of two or three without having to change anything else. Dampers don’t change the maximum load capabilities of the building.
V1: How big are the dampers?
Taylor: Our smallest seismic damper is, maybe, three inches in diameter and 20 inches long. The biggest seismic damper is 30-some inches in diameter and 45-feet long. The small ones usually end up in school gymnasiums in California. That’s been a popular place for some of our smaller dampers. Typically these are steel frame buildings, and you put in maybe 12 dampers or so, and it increases the building’s earthquake resistance to the point where it meets school safety requirements. The big dampers are usually used on highway bridges. Our current record is Sutong Bridge in China, where the dampers weighed about 10 tons a piece and were in the 35-foot-length range.