Tiller Fire Lookout Tower

This  page contains the complete design, created by Rogers Engineering, for the fire lookout  tower built in 2010 outside Tiller, Oregon. You may use or adapt this open-source design without further permission to build  a similar lookout tower as long as you understand each lookout tower site has its own characteristics, so you should not rely on the Rogers Engineering analysis if you build elsewhere.

An interview with Tom Rogers

In August 2022, Dave Sullivan drove to Roseburg, Oregon to interview Tom Rogers about his design for the Tiller Fire Lookout Tower. Here is an edited version of that interview.

Tom Rogers: After high school, I worked at construction, and after a few years of that, I had an on-the-job injury: broken back. I couldn't walk, spent time in the hospital, and I couldn't go back to my earlier jobs. So, I went to community college and ended up in a four-year college earning a degree in engineering. So essentially, I got into engineering by accident. Literally.

Then I went to work for Eugene in a public works and building department, and I eventually became their overall building official. When I left the city to teach engineering at a local community college, my salary went down dramatically, and that's where the part-time engineering came in. I started doing a few consulting projects here and there. Soon, I was doing two jobs, and it just got too busy. It kind of grew into my own business of just doing design.

Dave Sullivan: When was that?

Tom Rogers: 1992 to 2000.

Dave Sullivan: Okay, you switched out to be full-time consulting engineer. So, today in this office, this a sole proprietor thing that you do? When you retire in a year or two, then it just disappears?

Tom Rogers: Right. At one point, I had three or four people working me, draftsman, engineer, secretary, all of that. And we were just really busy. But as they retired or moved away, I didn't keep doing that. So now it’s just me.

It was a matter of doing engineering things, but it seemed like I ended up with just all the odd stuff. It was the roof cover for the restaurant or something else, or a lookout tower. It seemed if it was easy, it didn't show up here.

Dave Sullivan: Well, if it's a standard prescriptive thing like a home, then you normally don't need to mess with it.

Tom Rogers: Right. But the engineering things I do always seem to be the ones that were unique and different with a real issue to try to solve. That's what I ended up with.

Dave Sullivan: So that's how you got started with the lookout tower portion of your business?

Tom Rogers: Right.

Dave Sullivan: So, what portion of your overall engineering business is dealing with lookout towers?

Tom Rogers: Just that one [the Tiller lookout tower].

Dave Sullivan: Just that one? I got the impression when we were talking the phone that you had been asked by the forest service to update, like, a 1950 design.

Tom Rogers: It was the Douglas Forest Protective Association [see https://www.dfpa.net/], the local fire protection guys, and they had some plans. They came in with drawings and said, “Our towers are getting old, and we're thinking about rebuilding them.” So, it was a matter of going through those plans to see if they still met standards. I went through them, and a few things had changed, but generally, they looked good. The whole concept was okay, just parts and pieces and bolts and miscellaneous things needed to be changed. That was about the time they were looking at all the camera systems. [Editorial note: The Douglas Forest Protective Association was a pioneer in Oregon about switching to camera detection of forest fires.]

Dave Sullivan: So roughly when would this have been?

Tom Rogers: We did the [Tiller lookout] tower in 2008, so it was probably 2006.

Dave Sullivan: Was the Douglas Fire Protection Association interested in renovating their towers or building new?

Tom Rogers: That depended on the tower. Some they would renovate; some they would just build a new tower if it was that bad. Okay, so it was kind of, “What would it cost to do that?” And just about then, the camera systems were coming in that could monitor everything, and they started looking at cost-benefit. If you build a tower, then you’ve got to maintain it, and you’ve got to pay somebody and everything. The cameras won out, so they didn't do anything with the towers.

Dave Sullivan: To your knowledge, how many new lookouts have been built in Oregon in the last 20 years, as far as you know? The Tiller one that you designed is the only one that I know about. 

Tom Rogers: That’s the only one I know of either.

I get calls [about the Tiller Lookout Tower], not many in Oregon. I've only had one or two in Oregon, it seems like the inquiries I get, they see the Tiller Lookout website and get a hold of the owners who refer them to me. Most of these inquiries are out of state. I mean, Florida, West Virginia, all over the United States.

 Dave Sullivan: You said you've been getting inquiries internationally.

Tom Rogers: Canada, France, Bulgaria. I haven’t kept track. I should have written them down.

Dave Sullivan: That’s just fun. This is, I would assume, outside of your normal experience. Has any other project in your career had this kind of a follow-on?

Tom Rogers: No. Some of the projects you'll do and several years later they'll remodel it and you do it again.

Some [people I talk to about the Tiller Lookout] are going to build a one- or two-level tower, or not a tall one, or maybe just all sorts of things like that. For the ones that are out-of-state or are out of the country, I'm not licensed there, and my insurance wouldn't cover it. So, I really don't want to get involved in the ones where I'm not covered. But I've sent them the PDF plans saying: “Here's the plan, here's what we did. And it may not meet your conditions, but here's a starting place.” That's generally what I've done so far. Since 2008, I've probably had 30 inquiries, maybe.

Dave Sullivan: Roughly how much time did it take you to create the [Tiller Lookout Tower] design?

Tom Rogers: I had the model from the Forest Service, and we pretty much went with that. The base was more or less done … they were in like ten-foot modules, I think. So, I ended up doing a computer model, structural model of that. You can't sit down for 8 hours a day and do it, right? But I'm just thinking a week … two weeks … of just trying to figure out how to make it work. Once the model is done, then all you've got is forces and you've got to figure out how to bolt this piece to that piece, right? So, once you’ve got a couple of those connections done, then it worked throughout the building. And I had a draftsman: he did all the drawing on it. I bet he's got a few weeks of time of drawing and detailing.

Dave Sullivan: Can you make a ballpark guess as to what the total cost for the design would have been?

Tom Rogers: I don't remember, but that would have been 15 years ago, so it wouldn't be the same number. The dollars are no longer quite the same. $10,000 in the amount of time he had, about the time I had.

Dave Sullivan: The corner posts in the Tiller Lookout are quite small, only 6” by 7” or so.

 Tom Rogers: I think the posts were probably bigger than the original [forest service] plan. The original ones were solid lumber, where the glulams [in the Tiller Lookout] were stronger.

Dave Sullivan: Well, you’ve got specs for glulams that you can trust more because they're standardized things.

Tom Rogers: And even when I did the one that was out of timbers, that's where some of the weak links were, was bolting those pieces together. But the reason that it works with the small pieces, it's just a big three-dimensional truss: a vertical one as opposed to horizontal, but every direction you go, it's braced.

Originally, I think I tried it without the guy wires on it. But as soon as I hooked the guy wires on it, the amount of movement changed for the better. And the foundation was smaller.

Dave Sullivan: Because you don't have any possibility uplift, right?

Tom Rogers: The amount of concrete you need to keep it from tipping over when you anchor it out there with guy wire: that dramatically helps it. So, it was running the model and changing things.

Dave Sullivan: You were using a software model? Do you know the name of the program?

Tom Rogers: RISA. [Available at https://risa.com/].

Dave Sullivan: Is it like an add-on for AutoCAD?

Tom Rogers: No, it's its own little entity, and there's several of them out there.

Dave Sullivan: Were the drawings themselves in AutoCAD?

Tom Rogers: Yeah. They were essentially done in 2D in parts and pieces, as opposed to Revit or any of the new modeling things. But back then it was almost like drawing by hand on the computer.

The original lookout towers have the stairs, almost a ladder, but when it got to the top, there was a weighted platform or door that flipped up. They could close and lock it so nobody could get up there. My clients wanted a bigger deck. So now we've got a glulam beam hanging out there to give them a bigger deck. We changed that three, four or five times to put a large deck on it, which then affected the rest of the structure. So that's where it was unique to their condition because of the deck’s size. Most lookout towers don't have that big of a deck.