Drawbridge Style

It has been my privilege to be one of the few bridgetenders on the planet to have had the opportunity to operate all three of the most common styles of drawbridges. So here is an extremely basic primer.

 Ortega RiverBridge

This is a bascule bridge. These come in the form of a double span, like the Ortega River Bridge in Jacksonville, Florida…

 Draw bridge

Or a single span like this one in Mystic, Connecticut.

 IMG_7824

Here’s why all those movies where you see cars jumping over opened bascule bridges are pure fiction. When the span opens, a hole appears at the base. The only way a car can get on an opening span is if it drives on when the bridge has only just started to open…

 BridgeUniversal02.JPG

… or if the bridgetender isn’t paying attention and starts the lift when the vehicle is stopped on the span, as happened in Wisconsin.

 stupid drawbridge woman

Bascule bridges are responsible for the vast majority of drawbridge deaths and injuries. If you hear the warning signals and see the flashing lights and watch the gates lowering, you should have the sense to get out of the way, but you’d be amazed. It’s even more critical for pedestrians to be careful  nowadays because some of these bridges are operated remotely. If you want to read some very sad stories, just Google “Drawbridge” and “Dead” sometime.

 copy of Van Gogh picture and copy "Langlois Bridge" vangogh draw

This is probably the most famous bascule bridge, just outside of Arles, France, immortalized by Van Gogh.

 pride-of-baltimore-going-under-the-main-street-bridge_as

The next style is the lift bridge, like the Main Street Bridge in Jacksonville, Florida. These have counterweights in the towers that are attached to the span by cables. To open the bridge, brakes are released, allowing the counterweights to lower, which pulls up the span. Each one of the counterweights on Main Street weighs over a million pounds. Riding up on a lift bridge can be a heady experience, but it’s so big you don’t get that stomach lurching elevator feeling.

sunset bridge

You just get a spectacular view.

Scale Lane Bridge, England

Lastly, we have the swing bridge. These can pivot at the end, like the Scale Lane Bridge in Kingston upon Hull, England…

 swing bridge missouri, mississippi river

…or they can swivel on a central point like this bridge in Missouri which spans the Mississippi River. These bridges often have oval gears below deck level, which lift them up slightly above the fixed portion of the bridge before they turn.

 sullivansislandbridge

Incidentally, it’s always a good idea to have very good locking mechanisms on bridges. We learned that the hard way after Hurricane Hugo hit the Ben Sawyer Bridge in Mt. Pleasant, South Carolina.

There are a variety of creatively designed drawbridges out there, but these are the most common types. Of all three styles, the swing bridge is my favorite to operate. When on it, you don’t feel like you’re moving. It just looks like your surroundings are rotating around you. And since the world does revolve around me, that’s only fitting.

If you are as fascinated by drawbridges as I am, please join my Drawbridge Lovers Facebook page here.

33 thoughts on “Drawbridge Style

  1. Carole Lewis

    Thank You. I have always loved bridges, whether they
    moved or not. I can remember as a child, sitting and waiting as the bridge over the Intercostal waterway in FL went up and down. We would hang out the windows to see what size boat was coming through This was as exciting to us as the trip to the beach, and we got to experience it again on the way home. I don’t think my parents ever complained either.

      1. Carole Lewis

        Lol! A couple of years ago, My Sis, her Hubby and I took a train trip from Deland to Orlando, and had a great time. The BEST part was watching all the cars sitting and watching us go by. After 60 yrs of sitting and counting the cars on a train, we were finally on the moving side… Priceless.

  2. KerrickM

    …Famous last words. I can float like anything, but I am careful around water.
    I just discovered this blog. I too am a longtime fan of bridges that lift. We have several in my region, Pugetropolis, and that number is about to increase by one. Actually it is a replacement for an earlier one that was in such bad shape it had to be destroyed, but I am still looking forward to it. I have in 35 years seen 4 of them leave this world and only 2 arrive, and that is not an encouraging ratio.
    Google “South Park Bridge” if you want details. And thanks for your images and info.

    1. Omigod, I just applied for a job as a Bridge Operator with the City of Seattle. I want it so badly I can practically taste it. Don’t suppose you have any connections? Hope you’ll join my Drawbridge Lovers group on Facebook.

  3. KerrickM

    I am afacebookual and illtwitterate. And I fear I don’t have much in the way of connections. But if I can get the attention of one of the experts that I have been bombarding with questions, I will see if I can connect you with them.

  4. KerrickM

    There are a few things you should know about Seattle. First off, a handful of double bascules, a couple of onesider railroad ones, and an unusual double swing. Tacoma has 1 double bascule and 1 vertical lift, and Everett has 2 vertical lifts. We don’t have hurricanes, but there are occasional windstorms in the fall that knock out the power. Snow is uncommon but just 1 inch can bring the whole region to a standstill, despite we’ve supposedly seen it before. Winter days are most commonly “drismal”, even though the rain is less heavy overall than some other places, and people can suffer from seasonal depression if they come from regions far to the south. There will be more difference in day-length than you are used to. In summer, it’s warm, but temps over 100 are unusual and do not bring out the best in us. What we do have to consider is earthquakes–there was a 6.8-er in ’01, and we are right over a subduction zone that could do a lot worse, in 200 years or in the next minute.
    The traffic sucks. Rents are too damn high but I think that’s true a lot of places.
    What we do have is lots of pretty green trees and mountains under them, a mild climate, ferries, 2 huge wonderful bookstores, and 2 fine library systems, plus the library at the UW.
    There is also a floating bridge with a retractile span. It is being replaced by something that I have forgotten whether it will be the same kind or not.
    You might also consider Portland, which has much of the same advantages, in climate and books. I haven’t been there in a while, so can’t say a whole lot more but the bridges are an assortment of double bascules and vertical lifts, some of the latter being over 100 years old.
    I think there’s a “Newcomer’s Guide to Seattle” which you could look up on Amazon and have your library get for you.
    Good luck!

    1. Thank you so much. If it works out, I’ll be very excited for the change. Now that my boyfriend has passed away, there’s nothing holding me in Jacksonville, Florida except a lot of memories. Time for a do-over. But I’m told 166 people applied for the job, so we’ll see.

  5. Carole Lewis

    Well Kerrick, Welcome from all us fans of ” The View From A Drawbridge.” Some of us have grown very comfortable with this site and You have added to our pleasure. We would all love for Barb to find the job of her dreams.

  6. KerrickM

    Thanks, Carole. When I get a little more acclimated I am going to ask some technical questions, since the aforementioned local experts haven’t gotten back to me in quite some time. Due to some non-obvious disabilities I have never had the honor of operating a bridge, but I was lucky enough to get a tour one time.

  7. KerrickM

    Okay….1] Which kind is your favorite?
    2] Which kind has the most and least problems with pigeons getting caught in the works or under the live load thingies? What ideas have been come up with to prevent this?
    3] Why do some live load supports have the upper part curved so as to make a line contact, instead of 2 flat faces meeting?
    4] Are hydraulic bridges more or less reliable than the geared kind?
    5] It must be really interesting having one of those up during a lightning storm. Ever been hit?
    …I have read Hool’s and Hovey’s books from the early part of last century as well as Koglin’s recent one on movable spans, and I got to look thru many of the technical papers from the Heavy Movable Structures symposia before some party pooper decided to make them private. So I might know just a few things but there’s always more questions.
    BTW, some of our bridges are administered by the Wash State DOT and some by the Seattle DOT, I don’t recall the exact details. What are some related lines of work that you could do well in?

    1. 1) Swing bridges are by far my favorite, as I mentioned in the blog. They’re the most fun to drive. 2) Bascules are a pigeon nightmare. We usually just use a shovel to get them out after the fact, which is disgusting. Most lift bridges are so heavy that a pigeon would be pulverized and we wouldn’t realize it was there. 3)I have no idea. 4) I can’t do a reliability comparison, but hydraulic ones have to have reliable heaters or they’ll freeze up in cold weather. We usually have to do openings once every hour or so, whether needed or not, in the winter, to keep them fluid. That also goes for bridges that use slide locks that are lubricated with thick grease. 5) we get hit by lightning all the time. If people would stop stealing the copper wires from the lightning rod systems, thus putting our lives at risk, we’d barely notice.

      Sounds like you are more schooled in the technical aspects of bridges than I am! I never thought about delving deeper into that area. Hmmmm…

      As for other lines of work, I’m a fat 49 year old woman competing with skinny college graduates for jobs, so I haven’t been taken seriously in years. But I’m a heavy hitter in the bridge world. And I’d have to find a job I was madly in love with to move across the country.

  8. KerrickM

    My best friend, a machinist who made and installed parts for bridges, says that when he saw an offset at the centerbreak of a double bascule, one of the tenders would say “Looks like we have a bird shim.” In my town, SE of Seattle, there was a to-do over “smart meters” for utilities that seemed to be driving birds away, and one wonders if this could be used on a bridge.
    I hope you find ways to protect the lightning conductors better than what you have now. Recently, repair of a century-old vertical lift was complicated by some @#$holes who stole some copper wire out of it.
    As for certain other @#$holes, I don’t know what to say about age and weight discrimination. Some people urge us to do all manner of unhealthy things to conform, but I set limits on that and would still do so now. Google “fat activism” and “Health at Every Size”. That’s just a start…
    Thanks for filling me in on the details!

    1. Bird shim. That’s a good one. 🙂 Not for the bird, of course. One one recent bridge rehab here, they’ve encased the copper wire in PVC pipe to make it look like plumbing. I just wonder how it will look after the first lightning strike, though.

  9. KerrickM

    Well, if it really is continuous, the PVC shouldn’t be affected. Just better not talk about that detail any more though…Terry Koglin wrote a massive book called “Movable Bridge Engineering”, the first in many decades, which will help fill in many of the knowledge gaps you might have. It is real expensive, but you can probably get your library to fetch it for you. Google Scholar will also point you to some technical papers if you really do have time on your hands. Good luck!
    Has anyone tried using dry lube on those locks?

    1. And I strongly suspect that the type of people who steal copper off bridges, thus putting everyone’s lives at risk, just like the people who used to steal aluminum stop signs, are not the kind that actually read anything. Reading requires intelligence and an interest in something other than oneself.

  10. KerrickM

    I thought bridges had always had spanlocks… I understand that some have a bar that slides into a hole like the deadbolt on my door and others have a tab that some jaws grip onto. I am not sure what tail locks look like and now I can’t figure out what post locks look like either…do they have some sort of sliding thing?

    1. Post locks are the deadbolt kind. They are an alternative to span locks. Tail locks are an addition to span locks for added stability. They are placed at the part of the bascule that cantilevers. That way you have locks at the center and at the base.

  11. KerrickM

    …and by spanlocks [or span locks] I mean the ones in the center where it comes together [for bascules], is that what you mean?

  12. KerrickM

    So now you have the clamp kind that I haven’t been able to find a good picture of? Kind of like pincers grabbing something? I did find a picture of a tail lock.
    More questions. I think I read that there are a lot of Hopkins Frame mechanisms for bascules in your region. Do these work better or more reliably than when there’s just a couple of big racks on each side like here? Also, do you have any Scherzers? How do these compare with fixed trunnions? We had one Scherzer here–it is the one being replaced–and it wasn’t really the best design for an alluvial plain and a tidal river.
    Vertical lifts–tower drive or span drive? I hear the former is simpler but more skew-prone.
    And swings–rim bearing or center bearing? I know the least about those. We have a couple of old ones a county or two north of here. One has been inactive for decades. Even my dad said he had never seen it move and I said well maybe they only did it on the swing shift.
    But there is a nice specimen of a rare double swing in Seattle.

    1. 1) clamp kind- yes. 2) You’re getting close to going over my head. Send me a picture of a Hopkins and I’ll tell you. 3) I believe the FEC railroad bridge downtown is a Scherzer. 4) our lift is a span drive. It’s getting a little skewed, though. 5) No swings here. The one I drove was in South Carolina, and it was center bearing. I loved that bridge. Swing shift. Ha! 🙂

  13. KerrickM

    I didn’t find your e-address right off, and am reluctant to register for anything, but I will try to describe it–a Hopkins frame is where the motors and gearing are close together in the middle, between the trunnions, instead of behind them as with the regular Chicago style arrangement. That is, under the middle of the roadway instead of under the sidewalks where people stand and wait. I am not sure what the advantages and disadvantages are here.

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