Just returned home from a day of wandering around Chicago. As anyone who lives there or has been to Chicago knows, you can’t help but notice it’s impressive bridges. While I was there yesterday, Wednesday, I got to see them open up the bascule bridges over the Chicago river to let a queue of sailboats pass through. I was surprised to see that even the dual level bridges with the CTA lines on them open and close way faster than I imagined.
I’ve been out to look at the lift bridges that carry the St. Charles Air Line over the river. You can see these structures from I90/94 but, to see them up close is something else. They are massive pieces of construction. What I was wanting to know is, how do they install the counter-weights on lift bridges? Are they solid blocks of concrete that are fabricated and then installed or poured into forms on the bridge itself, or is there some other way?
I think stories about railroad infrastructure and the people who create it would make for an interesting Trains magazine article.
The two bridges you’re talking about, however, are also bascule bridges (just to clarify things). And only one of them (the lowered–permanently–one) is used for the St. Charles Air Line. The other one (permanently raised) was used by the B&O to bring its passenger trains (and those of other lines) into and out of Grand Central Station.
If the St. Charles Air Line is abandoned, there was some talk of leaving both bridges intact as architectural landmarks.
And that annual migration of the pleasure craft is quite an operation to watch, isn’t it?
I’m definitely out of my league on this question but the sheer size of the counterweights suggests that they would have to be fabricated in place. Keep in mind that they have to equal the weight of the movable part of the bridge. Chicago bascules (double-leaf) and vertical lift bridges have smaller counterweights since a vertical lift bridge has two counterweights and a Chicago bascule has two movable spans that have a locking pin in the middle when lowered.
In some cases the counterweights were poured in place as needed to keep things stable (at ground level, bridge lowered) as the bridge was being assembled.
Counterweights may be located above the bridge or below the deck of the bridge. There are two common designs of bascule bridge. One is the fixed-trunnion bascule design, which is where the bridge rotates around a large axle called a trunnion to raise. This bridge type is sometimes called the ‘Chicago bascule’ as this type was developed and perfected there and is used for many of that city’s river crossings. Joseph Strauss was a key person who worked on improving the trunnion bascule bridge. Another form of bascule bridge is the Scherzer rolling lift, also known as a Rolling Bascule Bridge. The city of Joliet, Illinois has a number of this structure type. The Scherzer rolling lift bridge essentially rolls or rocks like a simple rocking chair on a track to raise.
I’ve seen the bridge that you have in the photo. Not only is the lift section impressive, but so is the rest of the structure over the Ohio River.
There is a pedestrian trail that passes under this bridge. I was there one day watching the activities at the boat locks when they raised the bridge. It started out with a awful-sounding screech that made me a little nervous. Once under way, it moved rather quickly for something of that size.
Do you know if there is someone posted in the tower at all times? Also, how much rail traffic passes over the bridge?
Another big span in the Louisville area is the former Big Four bridge, which is now abandoned. I seem to recall that several workmen were killed in some sort of accident during construction of the spans.
Those bridges are indeed fascinating. And yes, they would make a great story idea.
One of my favorite stories in Trains detailed the railroad drawbridges of northern New Jersey. The story appeared in the July 1988 issue. (I was a subscriber back then, and crossing some of those bridges regularly.)
There are more than 20 movable bridges in a very compact area of North Jersey, and they’re used by some of the busiest freight and passenger lines in the East.
Watching the Chicago boat parade is a lot of fun. I witnessed it last fall from a city park in Chinatown, near Amtrak’s lift bridge over the Chicago River. A memorable day!
When we built the new bascule at LaCrosse, the main span was floated in and the counter weight boxes filled after it was in place.
As noted above, building these would be a matter of how the rest of the main span is being placed and what time frame you have to get it done. I would bet that every one would be just a little different.
Matt–Nice to see you and Mudchicken at Salt Lake City. There is an old 3 part article on the moveable railroads bridges of Chicago that I have burried in my foles somewhere. I’ll try to dig it out.
The three of us in SLC got to see a presentation (Tuesday - Structures Session)on how Amthrax removed one of these rascals at the Thames River, replaced it with a vertical lift and the effects on the foundation… Glad that wasn’t my headache.
Likewise Steve & Matt, looking forward to next time.
Yeah, the noise from that bridge lifting, would be good sound effects for a scary movie.
Yes, there is a ped/bike trail that runs underneath; really fun, if you like to bike or walk:
Depending on how far you want to walk/bike, you can see a lot of the river and shipping canal. Although, you won’t see too much railroad stuff that’s left from the earlier years.
I am not sure that someone is in the tower 24/7; the L&I seems to run one trip over and back each day to graineries, along with P & L, and CSX does use it sporatically.
The Big Four Bridge, while abandoned by the railroads in the late 60s, is now being transformed into a bike/ped walkway, due to open in 2009. The major holdups right now, are access ramps on both sides of the river (plus all the usual other holdups).
Without doing a search, I cannot say about any workman being killed during building of the Big Four in the
I recall reading in Trains of a wreck where a PC freight train ran into the counterweight that was lowered while the bridge was raised. It must have been in the 1970s. The entire momentum force of the train, being transmitted through the couplers and center beams of all the cars, was just below the bottom of the massive counterwieight. So the train force shoved the two locomotives under the counterweight, and the counterweight sheared off everything above the tops of the locomotive frames.
I do remember reading about the PC incident. It occurred in the early 1970’s and involved a bridge in Cleveland. The engineer was given a verbal clearance to proceed over the train radio and ignored restrictive wayside signals.
Another story about counter weights and vehicles, this time a hirail—
At the Truman lift bridge in N Kansas City, the roadmaster pulled up in his hirail, got out to get an order from the operator just as the bridge was being opened. You can guess what happened to the nose of his truck. This was in the Milwaukee Road days, before Soo Line took over.
I read or heard (probably from my older brother) that when a ship leaves Lake Michigan, heading toward the Mississippi or where ever, two bridge tenders start out, first at bridge 1 and bridge 2. When the first guy gets his bridge lowered, he heads for bridge 3, and the second guy will end up at bridge 4; they leap frog till they run out of bridges. Keeps the boat(s) moving and doesn’t tie up traffic too badly.
I think this is what they were doing when I was there last week. A truck would pull up to the bridge tower and one man went inside while the other stayed outside by the pedestrian crossings. After the boats passed through they lowered the bridge and sped off, probably to activate another bridge.
Until about 20 or so years ago, the movable non-rail bridges over the main branch and the North Branch of the Chicago River were manned full time because of cement boat traffic to a terminal on the North Branch. This may have been a Coast Guard requirement. South Branch non-rail bridges were manned by a “roving bridgetender” because of light traffic. The cement traffic has faded out and all Chicago River non-rail bridges are manned by a “roving bridgetender”. Since almost all masted traffic on the Chicago River consists of pleasure craft, there are designated times when these craft may pass to or from the Lake and their off-season marinas. The “roving bridgetender” consists of three crews from the city Transportation Department who move up or downriver in a leapfrog fashion to raise and lower the bridges for the masted pleasure craft. The bridges are usually unmanned. I’m not sure of the situation with the five non-rail movable bridges on the Calumet River.
A little of topic, Carl, but is that why the old bridge over the UP West line (between Damen and Askland is still in place, or was that because it was cheaper just to leave it? Also, I’m curious as to who that bridge belonged to and why it was abandoned. I visit a business down near there for work every now an then and have always found a surreal fascination with this “bridge to nowhere.” Thanks in advance to all for any info.
