Thursday, August 28, 2014

Putting Amtrak in the Hole

On my way back home from downtown Downers Grove August 27, I stopped in Starbucks to exploit  a gift card I had been given. When I came out, the gates on Main street went down. Since I had a view to the east and did not see a westbound commuter, there was a good chance this was not a false closing. So I found a place to put down the muffin and got the camera up. It was an Amtrak, and it was double headed so that meant either the Chief or the Zephyr. It was 5:43p. I believe the Amtraks are supposed to come through town before the dinky parade (commuter rush). Using the magic of the web, I see that the California Zephyr is supposed to arrive in Naperville at 1:43p and the Southwest Chief is supposed to arrive at 2:42p. But what really surprised me is how slow it was going. It was not making up any lost time. In fact, it was loosing more time. From the grab shots as the engines crossed Main you can see that a commuter had just arrived and that commuters were still working their way back to the buses, parking garage, condominiums, etc.

20140827 0030s, cropped

Because of the people and car clutter, I tried getting another shot of the engines.

This picture is disastrous even by my standards. (I checked the properties of the photo. The shutter was 1/200 sec. So I don't understand why it is so blurred.) But I include it because it shows that "smoke" is pouring out of both engines. My theory is that, since it was running late, BNSF held it west of Belmont in a regular holding spot rather than delay any of the commuters to clear a track for it. (The dinky parade uses all three tracks because they run the express commuters on the middle track.) And the Amtrak train was running slow across Main Street because it was having a hard time accelerating back to train speed.

I didn't bother to take pictures of the superliners since my viewpoint was so bad. But when I noticed the private cars on the end, I took several shots hoping something would come out. Note that the second car has an observation deck on the end.

When I took some pictures, the flash popped up on the camera. Why does the camera want to use the flash in daylight? Remember, last night I switched from Programmed to Auto. I checked the properties on that blurry picture above, and the camera chose ISO-100, f6.3, 1/200 sec, and flash. Stupid choices. I'm back to using ISO-400 and Programmed. Unlike my old Nikon FE, I don't have to worry about exceeding the shutter speed of 1/1000.

Wednesday, August 27, 2014

CB&Q 20140826 Main Street "Railfanning"

I put "railfanning" in quotes for a few reasons. One is that I no longer have been setting by the rail side waiting for trains. I've just been taking pictures of what I see when I do trips to downtown. But since I cross the CB&Q 3-track "racetrack" when I go downtown, I do see some trains. Two is that I'm learning that real railfanning seems to be taking publishable photos of the leading engine. I take photos for information. That means that I'll spend electrons on all of the engines and even some of the freight cars. Even if the sun is behind a cloud or I'm on the dark side of the train. I don't plan to publish, that is why my profile specifies a Copyleft. If a web picture is good enough for a student report, then go for it with proper acknowledgement. Three is particular to this post---I ran out of sun. So the photos are really bad even by my standards. So bad that I have to rely on my memory instead of the photos as to what I saw. Having to rely on my memory is why I have to quickly write a post for this set of pictures. (I'm still behind on three other days of train photos.)

19:20 On my way to downtown (Downers Grove), when I got to the crossing of Main and Warren, a westbound covered-hopper unit train came through. When I saw that it was CSX power I took some grab shots in hope that I could catch the engine numbers.  I also believe that the first unit has an older paint scheme and the second one has the current "boxcar" scheme.

The units were 688 and 4049. And we learn from The Diesel Shop that 668 is an AC6000CW (Powered by 16-cylinder 6000-hp GEVO engine) and 4049 is a SD40-3 (ex CSXT 8081). Since AC6000CW is a unit that was built during the horsepower race between EMD and GE, it is rather special so I'll include my other grab shot of it.

20140826 0025c

(Thank goodness that bike rider's hat was not in front of the number in the first picture.) I grabbed pictures of the SanteFe hoppers until I realized there were quite a few of them. I would estimate that about a third were SanteFe, a half were BNSF, and a sixth were "other."

19:49 Catching the engines of trains has been harder this Summer because there continue to be false gate closings for a few minutes. Before this Summer,  when I heard the bells start ringing, I would find the clearest shot I could find down the street and hold the camera to my face. Not this Summer. But on my way back home, it was not a false gate closing. It was a westbound mixed freight. I did grab the second unit, which indicated this was another CSX run through.

As usual, the dominate freight cars were covered hoppers and tank cars. There were a few empty lumber cards. But there was one full one. It is unusual to see lumber heading towards the west. I wonder where it was coming from. I took a picture of that car more as a test of the camera handling the lack of light because the sun was getting low than of the car itself. This train was taken with the camera ISO cranked up to 800. 400 has become my normal setting. Next time I see a train at dark, I'll try different freight cars with different ISO settings. The dark lighting experiment had results. It caused me the Read The Fine Manual again concerning ISO. I now understand the difference between Auto and Programmed mode----auto ISO setting. I switched the camera from Programmed to Auto unless I'm doing the above described freight car ISO experiment. I want to learn what the digital noise looks like. I already know what a grainy photo looks like.

Boxcars of all sizes are getting rare because of TOFC and container trains. So I took a picture when I saw that there were two extra-high boxcars in a row. The sun is getting lower, and I got an unintended "speed blur."

19:59 And then when I was about a block past the tracks, the gates went down again. Since I knew a westbound commuter was coming into the station and since they cause the false gate closings, I didn't pay much attention. But then I heard the sounds of a freight train. When I turned around and looked, two light-yellow engines rolled eastbound. I can't even guess what railroad uses light-yellow engines. I couldn't see the train very well, but I could see that it was another mixed freight. I took a picture, again as an experiment with the light because the sun was pretty much gone by now. If I zoom in, you can tell it is a boxcar and that confirms that it was a mixed freight.

And then I saw what looked like vehicle cars. But that did not make sense because they are always in unit trains or with container/tofc trains. And I've never seen them on this line. Just the old SanteFe line. So I took a picture. Sure enough, they are not vehicle cars. I guess it is a load on a flat car. What the load is will remain a mystery forever.

Just when I thought I had the camera figured out, I used Windows Photo Viewer to check the ISO values. Since I thought I was done for the night, I had set the camera back to ISO-400 so that the next day I was not inadvertently shooting with 800. Those for the second train's box cars is what I expected---ISO-800, f/3.5, 1/40 sec. But the above picture was a surprise---ISO-5000, f/5.6, 1/100 sec. I noticed at the time I took the picture that the shutter speed was a lot faster than I had expected. When I checked the camera again, I did notice that I had changed the ISO to Auto. So when the light is very low, even Programmed mode will do Auto ISO if you allow it. In previous weeks when I did not have ISO set to Auto and was using the default ISO-100, I can confirm that it will use a shutter speed that is so slow you can hear the click-click even with decent looking light.

So of the three freight trains I saw, none had engines painted with Omaha Orange. And two of them were mixed freights.

Tuesday, August 26, 2014

Reinforced and Prestressed Concrete

Concrete resists compresive (pushing/squeezing) forces well, but is weak with respect to tensive (pulling) forces. Steel is the opposite. Reinforced, pre-tensioned, and post-tensioned concrete combines these two materials to create a product that is much stronger than either material.

Reinforced Concrete

Concrete and steel in useful, economic quantities were developed in the 1800s. Joseph Monier obtained his second patent related to reinforced concrete in 1877. He used it in the making of flowerpots. Specifically, before concrete is poured into a form, rebar is added inside the form where the resulting structure would experience tensile forces. The rebar is a twisted spiral rod so that the concrete can "grip" it better after it sets. (Other types of reinforced concrete that use other tension resistant materials are being developed, but steel is still the most typical companion material.) Steel and concrete have similar coefficients of thermal expansion so internal stresses remain low as the temperature of the reinforced concrete changes. The concrete must be mixed correctly to make sure the steel does not rust. Rust expands, and it will crack the concrete. (Wikipedia)

When the Delaware, Lackawanna & Western Railroad built a 28.5-mile cutoff between 1908 and 1911, it used reinforced concrete for all of its structures. The Paulinskill Viaduct was 115 ft tall and, at the time it was built, the world's largest reinforced concrete structure. So why is it the DL&W Tunkannock Creek Viaduct that we see photos of instead?


safe_image [could not get link] for Difference Between Pretension and Post Tension

The percentage of steel can get rather high.
Building America USA posted
Unleash the Power of Reinforced Steel

Pre-Tensioned Prestressed Concrete

For concrete structures that can be constructed from many members of the same size such as the beams or girders in a bridge, precast plants are generally used. Rather than build a lot of complicated form work in the air at the bridge site, a few forms are built in the factory and used over and over again. After the beams have sufficiently cured at the factory, they are trucked to the site, and lifted in to place with cranes.

Having forms in a factory setting that are used to construct many beams made it feasible to prestress the steel members in the beam so that the concrete is always under compression. Specifically, the rebar is replaced by steel cables that are longer than the beam and that stick out of holes in the form's end. Before the concrete is poured into the form, hydraulic jacks are used to pull each rod to 5000-8000 psi of tensive force. After the beam is poured, it stays in the form until it has enough compressive strength to resist the tensive force in the cables. Then the tensive force is slowly released from the cables to compress the concrete. Now when a load is applied to the beam, instead of creating tensile forces below the centroid of the beam, the applied load just reduces the compressive forces. With only designed loads applied, the concrete never experiences tensile forces. Also the compressive forces added to the bottom of the beam causes the middle of the beam to camber (curve) up. (3:17 in video) This prevents the beam from sagging when a load is applied and makes it look safer.
I've seen references to "bulb" prestressed beams. The difference between I-beams and "bulb" beams is that the tension members are more spread out in the soffet (lower part) of the beam.

California I-Beam California Bulb Beam

Virginia Bulb Beam

Highway Engineering Discoveries posted
Construction of Box Girder, Reinforcement work

Post-Tensioned Prestressed Concrete

A limitation with pre-tensioned concrete beams and girders is that the length of a span (distance between piers in a bridge) is limited by the length of what can be trucked to the site. An advantage that steel plate beams had over concrete beams is that several beams can be joined together to create a longer span. For example, four field joints were used for the Seneca Illinois River Road Bridge to create the center span of 364 feet. Post-tensioning is an additional prestressing technique that allows multiple beams, or segments, to be used in a span. The dotted circles in the above California Bulb-Tee design are optional post-tensioning ducts. They are tubes placed in the form before the pour to create holes through the beams. During construction, falsework (temporary scaffolding) is used to hold the beam segments in place while they are being erected. After the segments are in place, tendons that are long enough to go through all of the segments are pulled through the ducts. A tendon consists of 7 high-strength steel wires wound together. Then a hydraulic or screw jack is used to pull the tendons about 4 inches for every 50 feet of length to apply 33,000 pound of load. (ConcreteWork) Bonded post-tensioned concrete means that grout is pumped into the ducts after the tendons have been stressed. And unbonded means that a protective lithium based grease was used instead of grout to protect the steel from corrosion. When pumping the grout, care must be exercised to avoid leaving any voids. Bridges have collapsed because of tendon corrosion. (Wikipedia)

Below is a pick during the construction of the I-355 Des Plaines River Valley Bridge. On the right side of the picture, under the beams that have already been placed, you can see the falsework. And on the far end of the picked beam you can see a segment brace that has been added to support this segment with the end of the segment that has been placed on the false work. And on the near end you can see the four ducts that have been cast in place.

Time 3:08 in video
I was surprised that the ducts were at the top of the beam instead of the bottom. Then I learned that for long beams the ducts are curved to follow the tensional forces of the span. The depth of the beam in the following diagram is exaggerated to illustrate the curved duct in red. So the above segment would be on the south side of a post-tensioned beam.

See jacks for some pictures of the big multi-strand stressing jacks needed for bridge spans. They have a table of jack sizes, and I notice that the largest can apply 150000 kN (or 21,756 psi) to 108 0.6"-strands and stretch them up to a half-meter. And it weighs almost 6 tons! And another manufacture illustrates equipment to cut, wind, and push the tendons as well as to stress them.

Another major application of post-tensioning is in the slabs (ceiling/floor) of buildings. It allows the slabs to be thinner and/or the columns spaced further apart than reinforced concrete would allow. Thinner slabs not only means less concrete needs to be pumped into the building, it means a lower overall building height for the same floor-to-floor height. In turn, this reduces the weight of the building, the pressure needed to pump concrete to the upper floors, and the costs of the mechanical systems and facade materials. The reduced weight also reduces the foundation costs. (DSI) The size of the hydraulic jacks used to tension slab tendons is much more manageable.

Copyleft, Shakespeare at English Wikipedia
I found pictures of rigs to place the bridge segments in the Facebook group "Railroad Maintenance of Way Photo's."
Photo posted by Wayne Helms

Photo by Jim Kissane of the Leroy Selmon Expressway in Tampa in a comment in the above Facebook link
Jim Jacobs -> Rail & Highway Heavy Loads
Jim's comment:
U-beam, 202' total length, 400,000+lbs. Axles spread to 16'. I was the rear steer driver for a dozen of these loads going to I-595/I-95 over passes a month ago. This was on the I-75 South on ramp from Hwy. 27.

Jim posted the following as a comment to his posting.
Jim Jacobs -> Rail & Highway Heavy Loads
Putting one in place.

This video implies a choice must be made. I would think they would want to pre-tension a beam so that it is strong enough that it can be lifted and hold the dead loads. And the post-tension so that it is strong enough to hanle the additional live loads.
4:38 video

The new Pensacola Bay Bridge uses concrete for the pilings as well as some superstructure components.

Most of a new hydro power plant is made with reinforced concrete.

Sunday, August 24, 2014

Steel: Tension vs. Compression

Steel can resist tension (pulling apart) forces much more easily than compression (pushing together) forces. Any big truss bridge will demonstrate this. Consider this swing bridge.

In particular, I zoom into the short span because it is less "busy" and has enough trusses to illustrate the topic.

You can easily tell which members are carrying tension forces, such as the top chords, because they are just a couple of steel bars. But the members that carry compression forces, such as the vertical member on the left, require more material and manufacturing expense because they are V-lattice beams fabricated from many individual pieces.

2007 I-355 Veterans Memorial Bridge

Update: overview shots from a bluff.

The Tollway's I-355 southern extension between I-55 and I-80 includes a bluff-to-bluff 1.3 mile long bridge across the Des Plaines River Valley. When the extension was opened on November 11, 2007, the entire I-355 tollway was renamed the Veterans Memorial Tollway and the bridge was named the Veterans Memorial Bridge.

On the way back home from a trip to Lockport, I stopped to take pictures from the south side. I've driven over the bridge many times since it was opened, but I had never noticed that it curves.

20140614 0366
I also tried to find somewhere along the road from which I could get more of an elevation shot. But there were just too many trees between public access and the bridge. This was the best clearing I found.

But I discovered in worldflicks that Mickey B. was able to find a nice view from the south. Note the red and green lights. The two red lights would be marking the edges of the shipping channel and helping to indicate bridge's clearance over the Chicago Sanitary and Ship Canal.

 Months later I discovered a trail under the north side of the bridge.

20140820 0027

I had noticed that the girders looked like concrete instead of steel. So I took a picture that had very little sky in it to get a good exposure of the girders.

 Did they curve the road to go around this mound?

 We see from a later picture from the south side of the trail that it is just that---a little mound.

My current theory is that it is a dolostone outcropping. This is why it resisted erosion by the historical Des Plaines river, which would have been much larger, and why the tollroad was willing to bend the bridge rather than chop dolostone. That is, it would not be cheap for the tollroad to remove a solid piece of rock so the cost of bending the bridge becomes a viable alternative. When I turn around from where I took the above picture, I get the rest of the bridge and some of the marine industry down by the Chicago Sanitary and Ship Canal

A video by the company that built the bridge, Walsh, saves me from a lot of typing. I describe the wetlands and endangered species in in my Towns and Nature blog. The video confirms that, instead of steel girders, they used concrete beams.

During the 10 years it took to do more traffic studies and to change the bridge's design to reduce the environmental impact, construction costs had skyrocketed due to the dramatic inflation in oil and raw material costs. The estimate for the original design had changed from $730 million to over 800. Rather than spend time doing another funding cycle, the engineers decided to get smarter. One change is that they repackaged the bids. Instead of seven large contracts, the work was broken down into 18 smaller contracts. This allowed many local contractors to get a piece of the action and saved $10 million. Since a lot of the large contractors would be out-of-state, the reduction of large contractors reduced the transportation costs needed to get heavy equipment moved to the site.  And it kept most of the money spent in the region, which helped bolster public support for the project.  The original plans for the bridge included two designs---"a segmental precast concrete box design and a steel delta frame design," and a contractor could choose which design they wanted to build. They added a performance specification package and gave the contractors the third option of using their own design. [Rethinking] Walsh formed a team that developed a concrete beam design that was $8 million cheaper than the concrete box girder design and $50 million less than the steel plate girder design. The concrete beams are simple span prestressed bulb tee girders up to 170 ft and post-tensioned, segmental concrete girders spanning up to 270 ft.  The beams were manufactured by Prestress Engineering Corporation in Blackstone, IL, [ConcreteProducts], and by DSI (WIDAG-Systems International) in Bollingbrook, IL. DSI also provided the strand tendon bundles. [DSI] A third bid change is that the Tollway Authority removed boilerplate specifications that had become obsolete. For example, they used to require a maximum strand diameter was 0.5". By allowing the designers to use 0.6" strands, they were able to save money. So the 10-year delay was a blessing in disguise---it forced the tollway to figure out a better way to contract the construction of roads and bridges.

1915 Amtrak/PRR South Branch Bridge (Canal Street)

(Update: pictures of the west side and video links.
"South Branch Bridge" is the correct name. [posting]
Some of the pictures of the bridge and interlock railroad towers include the bridge.
A USACE clearance table for the Illinois Waterway indicates this bridge has 11.1' of clearance. The next lowest clearance in the Chicagoland area is the 8-track Bridge at 17.6'.)

20150513 1385c, East Elevation
These pictures were taken from the Ping Tom Memorial Park. Unless specified otherwise, facts came from the Railway Age Gazette and Engineering Record provided by Historic Bridges.

The Canal Street RR Bridge was built in 1914 to replace a swing bridge. Its 185' tall towers can lift the 1600-ton, 273' long lift span to provide 130' feet of clearance.
Al Krasauskas posted
Photographic view of the former Railroad Swing Bridge over the South Branch of the Chicago River. Originally built by P. F. W. & C. R. R. (Pittsburgh, Fort Wayne and Chicago Rail Road). I believe the view is actually northeast, towards downtown Chicago. Photograph is dated 8-7-09.
Paul Webb shared

East Elevation North Tower
Each tower is a trapezoid rather than a rectangle because one set of sides are parallel to the tracks but the other set is parallel to the river. The 47.33-degree skew is easier to see in a satellite image. You can see three of the four 15', 31-ton sheaves at the top that each carry 16 2.25" plow-steel cables that connect the lift span with the counterweight. Note the six chains hanging below the counterweight. As the bridge is lifted, the counterweight goes down and the links at the bottom of the chain move their weight from the counterweight to the tower. This removes their weight from the counterweight to compensate for the additional weight of the longer cables on the counterweight side and the reduced weight of the shorter cables on the span side.

I see eight cables running between the lift span and the tower. They are attached halfway up the tower so that they are long enough to still reach the span when it is at the top of the tower.

The building on top of the span houses the machinery in a structure on top of the span. The control room was below the machinery room. The windows are boarded up because control of the bridge was transferred to a nearby interlocking tower a long time ago. I can't determine if control of the bridge has now been transferred to a CTC complex.
If so, they should remove the first option from the sign. The machinery turns the windlass drums on the sides of the building (detail picture below). The machinery room contains two 300-hp electric motors which can raise the span to its maximum height of 111 feet in 45 seconds. It also has a 50-hp gasoline engine for emergency service which can lift the span in about 10 minutes.

I zoomed into the top part of the north end of the span to show a deflection sheave. Two 1.125" down-haul cables go from the bottom of the tower up around the top side of the deflection sheave then over to the top of the drum. Two up-haul cables go from the top of the tower around the bottom side of the deflection sheave then over to the bottom of the drum. Note that as one pair of cables winds onto its drum, the other pair is played out. (Item 7 in MechanicalLift) All four drums on the sides of the machinery room are connected by gears to the motor so that the turning of the drums is synchronized and the length of the cables remains consistent for all four corners of the span. Note that this picture was taken before the walls of the control building were sheathed.


When I took the picture on the right, I thought I was taking a nature+technology photo. But I include it this post because it more clearly depicts the tower's trapezoidal shape than is revealed by a more traditional elevation photo.

Someone was doing some work on the south tower. Note that there are men walking on both the near and far first-level horizontal members. And I believe the boat under the tower is also part of the maintenance effort. Note in the above "East Elevation of North Tower" picture and in this closeup of the south tower that the piers on the east side are of excessive width. This was so that it could support the west side of another double-track bridge if train traffic grew to justify the construction of a second bridge.

I wasn't going to include this detail view until I spotted the bracket above the top guide roller. Since I could not figure out what the bracket was for, I zoomed in on it (below). Since the bridge is down, the bracket is in its "locked" position. Before the bridge is raised, it would have to swing out. These locks are interlocked with the train signalling system. That is, the bridge cannot be unlocked unless the signal is displaying "Stop." Furthermore, the signal cannot display "Go" unless the bridge is locked. And current cannot be supplied to the motors unless the bridge is unlocked. (MechanicalLift) Note the video camera that allows the operator can see how far the bridge still has to go down to allow the bracket to swing back in when the bridge is being lowered.
Note the video camera as well as the "locked fully down bracket"

The two maintenance workers allow you to correlate these two pictures of the south tower that I took as my "parting shots."

Photo from HAER ILL, 16-CHIG, 152--9 from il0706

They used a climbing derrick to build the towers. After the towers were built, they built the lift span in the raised position so that shipping would not be obstructed by the construction. The 1600-ton lift span was the heaviest in the world when the bridge was constructed. As the following photos illustrate, an A-derrick was used on each side to build the false work and the span until the derricks were close enough that they could cooperate to raise the center truss members. The photos also show the swing bridge that is being replaced by this 1914 lift bridge. It was important to not drop anything during construction because over 300 trains a day used this crossing. (Item 33 in MechanicalLift)

Railway Age Gazette
Railway Age Gazette

The Government required 120' of clearance, but to align the horizontal chords of the falsework with those of the tower, the span was built at 130' of clearance. (Item 29 in MechanicalLift)

It bridge had to do over 15,000 lifts a year, but many were for just a few feet to clear tugs. (Item 34 in MechanicalLift)
Later, when I circled back to the bridge because I heard train horns, I noticed that there was a boat parked at the dock. Looking at some other pictures I took that day, he appeared by 11:10. I asked if they were waiting for the bridge to go up. They were, but no one was answering their call on the marine radio. So I went up to 18th Street to kill time waiting for them to get a response. Unfortunately, my battery ran out at 12:03. I was kinda glad to have an excuse not to wait longer because if they had been ignored for almost an hour, who knows how much longer they would be ignored. (Update: The clearance of the bridge is 10.5 feet. Federal law prohibits opening the bridge if a train is approaching from either side and is scheduled to arrive in ten minutes or less. (The Chicago River An illustrated History and Guide to the River and Its Waterways, 2nd Edition, 2006, David M. Solzman, p.94) However, the were not enough trains crossing to justify having to wait hours.)

The towers were designed to accommodate plans to later raise the track elevation in this area by 20 to 25 feet. I'll bet these guys wished the plan to raise the tracks had been realized. They confirmed that this is the lowest bridge on the river and the only one that they can't clear.
One of the things I did on 18th street was get some portal shots of this bridge.

Others share my interest in this bridge. Mickey B. Photography has artistic and traditional portal photos. Joe Balynas also has a portal picture of note. I found a video of the bridge being raised and lowered for a sailboat migration between the harbor and the boatyards and then an Amtrak train. And I discovered that if you search Flickr with "chicago canal street bridge" you get a lot more pictures of this bridge including another video. Plus other images including an incredible wide-angle view of a sailboat migration to the boatyards on the main stem of the Chicago River.

I  end with the first picture I took when I got to the park because it captures the context of the bridge in the Springtime.

20150502 0665

.pdf copy from 1915 Smoke Abatement Report, p. 490
This picture was probably taken from a interlocking tower that is either gone or that I will never have access to. And trees would now block this view even if the tower was accessible. Since the view is irreplaceable, I include it even though this 1915 report does not have the resolution that we now expect for a picture.
Steven J. Brown shared his posting
I spent my 30th birthday aboard the Capitol Limited from Chicago to Washington DC shortly before the dome cars/heritage equipment were replaced with Superliners. I stayed awake in the dome the entire trip! This is a view of the train departing Chicago crossing the Chicago River at 21st Street - April 7, 1992.

Steven J Brown posted
The South Branch vertical-lift bridge (built 1914 by the Pennsylvania Railroad) over the Chicago River is in the lifted position. The bridge was designated as a Chicago Landmark in 2007. The photo looks north from Alton Junction. The 311 S Wacker Building (opened 1990) can be seen under construction in the distance. Chicago, Illinois - April 12, 1988.
Steven J Brown shared

Mark Hinsdale posted
"The Gray Brick..."
Minimally attired Iowa Pacific #4144 doesn't do much for the otherwise matched appearance of Chicago-Indianapolis Train #850, the "Hoosier State," but it's been getting the assigned task done for the past few weeks. Seen here this afternoon, clearing 21st Street, and about to diverge onto the old Chicago & Western Indiana Railroad, once the busy conduit for all of the six tenant roads' passenger trains that utilized Chicago's Dearborn Station.
[It is easy to get pictures of a portal view of the north tower. This is the first time I have a seen a portal view of the south tower.]
Howard Keil posted
[It is interesting how the black tresses were exposed as white in this view. I nice closeup of the V-lattice used to make compression truss members from rolled steel components.]
Patrick McNamara commented on the above posting
[The bridge is in the lower-left corner. The big building is the one you see on the left of Howard's photo. I believe it was a cold-storage building. It has been converted to condos. You can see the vacant land left by tearing down Grand Central Station in 1971 and all of the tracks that serviced that station and La Salle Station.]
Steven J. Brown posted
The Hoosier State is arriving Chicago for one of the last times with Iowa Pacific equipment. Crossing the Chicago River at Lumber Street - February 24, 2017.
Steven J. Brown posted
This is my favorite bridge. Over the years, I've had a close personal relationship with this bridge. I spent a lot of time here, day and night, and have photos of all kinds of trains passing through and around it. When attending UIC, I would drive over here and study. I've always known it as the 21st Street Bridge but officially its called the Canal Street Bridge or Pennsylvania Railroad Bridge #458. It became a designated Chicago Landmark in 2007. It is the only lift bridge on the Chicago River. I have a lot of images in the scanner now of it and was preparing some sort of then and now.
However, I did an internet search on the bridge just now to get some facts straight and a slew of great images from the 40's, 50's and 60's came up. It reinforced the sentiment a lot of foamers express: I was born to late, everything I have is crap, I'm just going to pack it up and go to bed.
Anyway: I suspect this is the Amtrak Southwest Chief on the bridge departing Chicago on February 8, 1991.
Bob Poortinga I worked at South Branch Bridge as an operator/bridge tender a few times in the early '70s and got to run the bridge a few times. I even got to ride the it once when I was 'posting' (learning) the job. Did you know that South Branch Bridge is the world's longest span vertical lift bridge?
Harold J. Krewer Bob Poortinga, it probably was the longest when built but the New Haven's vertical lift bridge at Buzzard's Bay on Cape Cod is the current record holder with a lift span over 550 feet long.
Gordon Leonard posted
February 1976, while prowling around 18th St., the bridge went up just enough to clear the tug.
[Now that they have remoted control of the bridge to Amtrak's dispatch center, I've noticed that they raise the bridge much higher than needed. The bride was still going up even though the boat had already passed well beyond the bridge. Evidently they don't have cameras to give them views of the boat going under the bridge. Of course, with the demise of heavy passenger traffic, mail, express packages (REA), and LCL (less than car-load) freight; the number of trains crossing this bridge is now lower than 1976.]
Gordon Leonard posted
Back in Feb. 1976, 18th St. was a magnet for railfans and photogs. The bridge, the trackplans, the yards and the sheer number of trains could coerce many of us to spend a Sunday camera shoot on the near southside. It never crossed our minds we were trespassing, since we were never hassled at all by anyone.
Steven Kakoczki I got thrown out of there in the mid 90s......
Mark Hinsdale posted
"Highly Unusual"
A one-off Union Pacific train moving 60 empty bottom drop hoppers from Global One Intermodal Terminal to Yard Center in South Hollland passed through "MH" this afternoon. In my nearly six years here, I've not seen a similar UP movement use this routing, and am not yet aware of exactly what circumstances precluded it.. Kind thanks to Marshall Beecher for the heads up.
Bill Molony posted
This is an Associated Press photograph and caption of a fatal accident that took place on January 7, 1957.
We have this original photograph in our archives, but we do not have any other information in regards to this derailment.
Paul Jevert Lumber Street Switchtenders Shanty ! Switchtender fatality.
David DaruszkaGroup Admin The train probably picked the switch into the Pennsy coach yard.
[It takes something exceptional to get a photo of the north side of the bridge.]
Todd Pendleton posted
Inbound Amtrak train, Sep. 19, 1996, Chicago, Ill.
Steven Holding A Bio-Fred on the rear??
Earl Sproule Jr. Been there done that,but I wouldn't recamend it!
Dennis DeBruler commented on Todd's posting
David Daruszka I was thinking he would have to use an end ladder. That is why I mentioned the clearance issue. It does not look like there is enough room between the car and bridge to safely ride on a side ladder. Although that bridge is big, maybe there is. It makes me appreciate why I sometimes see a "No Clearance" sign posted on the edge of a building next to an industrial siding.
David Daruszka I forgot that part. Clearance is an issue and the end ladder would have been a better alternative than riding in the center of the car.

MWRD posted
The Pennsylvania Railroad Bridge is pictured here on April 9, 1920 and in 2012. The vertical-lift bridge is a Chicago Landmark and was constructed in 1914. It is located on the South Branch of the Chicago River between 18th Street and Cermak Road near Ping Tom Memorial Park
[I see Amtrak is making commercial traffic wait before it raises the bridge. I one time saw them make a pleasure boat wait a long time without any train activity. I don't know how long they had to wait because after walking up to 18th Street and over to their yard, etc., I gave up waiting and went home.]

Fred Glasper posted three photos with the comment: "Spend the day on my boat moored next to the Penn Railroad Vertical Lift Bridge in Chicago. Works good, needs painting."
James Boudreaux What hangs below the equipment room is the original operators' shanty. Since it gives a clear view of both the South Branch River and trackage north and south,the operator made the lifts there electrically.That room also had a small coal stove for heat.


One of the photos posted by Coal & Steel Railroad Photography
[Looking West from an Amtrak train.]
Thomas Manz posted
[Taken from the top of one of the towers.

Chuck Belanger commented on a video of a (long) inbound Amtrak train crossing the bridge made from a boat while they were waiting for the bridge to go up. This was one of three photos of the bridge going down. The comments also discuss the procedure for a boat having the bridge raised.
Carsey Stamos posted
Figured you guys would like this views as well

MWRD posted

Mtnclimberjoe Rail Photography posted
Metra F40 122 leads an outbound commuter train from Union Station as it crosses the lift bridge over the Chicago River and heads down the South West District.

Mike McMahon posted
Military transport through Chinatown right now
Mac English That train came thru Galesburg, IL from the BNSF...
Wayne Koch posted
PRR 3760 5-1-1942.
Matthew Storino posted
It may not be an old photo, but I couldn't rightly call myself a Chicago Railroad Historian without making mention of the fact that the Pennsylvania Railroad Bridge (now called the Canal Street railroad bridge) was completed 104 years ago this past Monday, July 30th, 2018. I took this photo back in 2014.
Mark Jones In the hot — everyday over 100– month of August 1988, this bridge got “Stuck” in the up position for over a week. Amtrak had to detour around St Charles Airline— yet another reason to keep that SCAL trackage in place in case something like that happens again.Lawrence Smith sooner or later the urban planners will win - they want to open up the neighborhoods S of the SCAL to development but the SCAL track elevation is an issue - a natural wall. If/When the CREATE funds arrive for Grand Crossing improvements the wall will come down.Mark Jones That’s too bad— predictable, and sadly not preventable given how powerful these developer forces are. Infrastructure — roads and RR’s— seems to take a backseat to the all important task of building more houses and developments that people can not afford. Then, there’s not enough capacity to handle them as they shuttle to/from work.... Sadly, the way of the entire country now.
Steven J. Brown posted
Amtrak International departs Chicago for Toronto at 21st Street - September 12, 1988. The International used to alternate VIA/Amtrak equipment every other day. VIA Rail F40PH-2 6407 was built in 1986).
Dennis DeBruler It shows the one-story bridge tower by the bridge and the interlocking tower a little to the east.
Carl Venzke posted
Pennsylvania Railroad, South Branch Chicago River Bridge, Spanning South Branch of Chicago River Bridge east of Canal Street, Chicago, Cook County, IL - photo by Jet Lowe, undated
[While researching the ownership to comment on a duplicate Bridge Hunter web page, I came across this page to confirm it is owned by Amtrak. Amtrak has done other rehab work as well.]

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David Vondra posted
Steven J. Brown shared
Twenty-eight years in-between.
Amtrak on Pennsylvania Lift Bridge #458 (built 1914) over the Chicago River - May 13, 2019 and February 8, 1991.

Steven J. Brown posted
Amtrak on Pennsylvania Lift Bridge #458 (built 1914) over the Chicago River - May 13, 2019 and February 8, 1991.
Steven J. Brown shared

Patrick Finn commented on Steven's share
love that bridge... Grandad worked for the Pennsy...

MWRD posted

Steven J. Brown posted
Amtrak Texas Eagle #22 with P42 22 crossing the Chicago River on the way to Union Station in Chicago - May 13, 2019.

One of the photos posted by Dave Rogers
Dennis DeBruler Note the caboose on the IC route to Freeport.

David Vondra posted
Amtrak....South Branch, Chicago River

Dennis DeBruler commented on David's post
Given the trees on the left and the Orange Line overpass in the distance, this view is looking South. My view is from the 18th Street overpass.

Larry J. Perlman posted two photos with the comment: "Assume these sprinklers are on to reduce rail expansion at the bridge. I haven’t seen this before. Can anyone shed any light on this? (Lumber Street bridge)."
I would imagine that if the bridge gets too hot, it'll expand and lock up (if lowered) or won't seat (if being lowered).
That's exactly what happens....the metal expands in the heat and the bridge gets stuck. The spray is supposed to cool off the metal enough to prevent that.

2, cropped

Gill Welsch posted the comment:
Hi, Everyone. I had to go to Chicago for a business trip on Monday. My colleague and I got to ride Amtrak's Saluki from Carbondale. :-) The train took a slightly different route to Union Station. Rather than crossing the Chicago River on the Saint Charles Air Line Bridge, the train passed by some lovely parks and crossed the river on the Canal Street bridge (I hope that's what it's called). When we left on Wednesday's Illini, we crossed the river on the St. Charles Air Line, which is normal.
Does any one know why we would have detoured on Monday? Mind you, I'm NOT complaining. I really enjoyed the new scenery. Also, we still arrived EARLY. I'm just curious.
Mark Rickert No detour, they use both routes, the route I want to say is ex PRR for most part at the north end and operated by the NS.
Bob Friedlander There is no connection from the IC main to the NS main that goes by Sox Park. Guess the NKP had a connector from the Pennsy by Sox Park that connected to the IC main at Grand Crossing that has been long gone. Have no idea how the Salukis trains would come down the NS main line!
Dennis DeBruler They would be using the St. Charles Air Line to the beginning of the IC branch that goes to Freeport, IL.,-87.../data=!3m1!1e3
They go on that branch a little bit until they get to the connector that is under the Orange Line.,-87.../data=!3m1!1e3
The lovely park would be Ping Tom Memorial Park.

Sue Sacharski posted a photo taken from a tall building.
Steve Malachinski Spent many years crossing that bridge. Running from Global one to Canal St yard.
Karl M Andrews used to be a road switcher job that was a transfer from Eola to Glenn Yard on the ICG(Former G.M&O(C & A) used that bridge.
[I replied to Harold J. Krewer that the machinery is not on top of each tower.]
Mike Spencer commented on Sue's post

One of three photos of the bridge posted by Kevin Culver
[I picked this one because it shows the cables and chains real well.]

Steven J. Brown posted
PRR South Branch Lift Bridge (built 1913) and the Schoenhofen Brewery viewed from 16th Street and Normal Avenue in Chicago, Illinois - April 1, 1988.
Steven J. Brown shared
[The comments have a couple of photos of the bridge from the park.]

Mtnlimberjoe Rail Photography posted
A pair of Amtrak P42's pull down out of the yard at the 18th Street Shops, putting together a trainset for a night departure. The train is crossing the Chicago River on a lift bridge and diverges briefly on to the CN Joliet Sub at the 21st Street Junction where the train will pause before shoving back into the yard.
AMTK Chicago Sub
Chicago, IL
Unknown Symbol (Yard Job)
AMTK 11 P42DC Blt. 1996
AMTK 4 P42DC Blt. 1996
Joseph Cermak shared
[At first, I didn't recongize it because of the rust and because this is a rare view. He has to be doing some serious trespassing to get this shot.]
Marty Bernard
AMTK 66-67 Turboliner coming from the GM&O yards, Chicago, IL on June 16, 1977. Turbolines had two numbers, one at each end, so this was 66 and 67 and they were serviced at the GM&O Brighton Park Yard on the near southwest side, not the Amtrak facilities. That's the bridge over the South Branch of the Chicago River about 2 miles due south of Chicago Union Station.
Mitch Markovitz: Best riding set of the bunch.
Marty Bernard shared
Marty Bernard shared
Jon Roma: I didn't get to ride one of these when they were in service in Chicago connecting Milwaukee, Detroit, and St. Louis. But I lucked out in France in 1996 when one of these trainsets turned up as my ride for an early evening express journey from Caen to Paris-Saint-Lazare.
Patrick McNamara: Jon Roma =I had the distinct displeasure to ride one train to and from Detroit around this time period. The ride reminded me of the ride afforded by the silly AeroTrain I rode in CRI&P's suburban service - as if there was no suspension. "Rough ride" doesn't begin to describe the side-to-side rocking and noise from the undercarriage. The railbeds of America were not friendly to silly lightweight trainsets.
Tim JT White: Maybe, but it was fun to run. I worked that train to Chicago from Niles Mi. and back 110 mph a few times.
Marty Bernard posted
25 Pooches were built by GE (numbered 700 - 724) from July 1975 to Jan. 1976.  Wikipedia explaines: "The designation "P30CH" stood for the following: "P" for passenger service, "30" for the 3,000 horsepower V16 GE 7FDL diesel engine, "C" for C-C wheel arrangement, and "H" for head-end power."
6. AMTK P30CH 723 northbound at South Lumber St. (looking south at the South Branch of the Chicago River Bridge) Chicago, IL on August 20, 1976. my photo
Marty Bernard shared

Chris Ness posted
Pennsylvania Railroad Bridge, Chinatown, Chicago, IL. South of Union Station
Comments on Chris' post

Paul Musselman posted three photos:

2, cropped
..and lifting up...

3, cropped
..and up....
Very quiet, no clanks or screeches...

safe_image for Metra service on Southwest Service, Heritage Corridor lines delayed by drawbridge malfunction
"Metra said the drawbridge malfunction is related to the heat expanding metal, with temperatures again expected in the upper 90s Wednesday. The tracks are owned by Amtrak, which has crews working to resolve the issue. Crews could be seen spraying water on the tracks to cool them down."
David Dote: I remember extremely hot days in the past they had Chicago Fire Department boats spraying the bridge to cool it down so it would close.

safe_image for News photos: Aging lift bridge is Amtrak’s Achilles Heel in Chicago
Amtrak Lincoln Service train No. 300 crosses a former Pennsylvania Railroad bridge over the Chicago River, as water sprays to try to keep the bridge cool. (Bob Johnston)
[The article has a couple of more photos.]
[The problem isn't age, it is physics. Steel expands and Chicago broke some daily high records. And the records in June tend to be rather high.]
"If intense heat expands the steel and the bridge won’t close and lock properly, trains from the east, south, and southwest lose direct access to Chicago Union Station. When this happened in the past, a complicated alternative was possible utilizing the St. Charles Airline bridge over the Chicago River to get trains to and from Union Station via the BNSF’s western approach. But that bridge has been out of service for more than a year, so the only option would be a time-consuming, circuitous move west of downtown to get trains onto the BNSF."
[They had to raise the bridge for "two boats." It sounds like they were pleasure boats instead of a commercial barge tow.]

Barry Butler photos:
pictures of the bridge interlocking tower have additional views of the south end of the bridge from locations that I'm sure that I cannot legally access. The south side of this bridge also shows up in the background of many pictures of the 21 Street Crossing. A few bad railfans and 9/11 have made it much more difficult to capture views of railroad facilities.

Jozef Bernatak posted seven pictures to a public Facebook group including some with the lift span up.

Four photos by Sibio (source)

Patrick McBriarty's page   The clearance of this bridge is 10 feet, 6.5' below the standard.

2006 Flickr "before sunup"

Fred Van Dorpe posted 8 photos and a nice description including "after it was built, the bridge was crossed by about 300 trains per day on its 2 tracks, and raised for river traffic about 75 times."

James Aurand posted three videos.

A video that shows they need more cameras showing what the boats are doing. When it first stopped just a little ways up, I thought they could finally see what the boats were doing. But then the bridge goes up some more even though the boats have already passed under!

C Kent McKenzie: I’ve read someplace that it was designed to remain functional even if that line was elevated above street level, by simply working some of the cross-bracing. Fascinating!
Charlie Easton: That bridge is skewed up! The counterweights look like something off a bull! And the cables look pretty spindly for what they have to do. When they changed out the cables on the mouth of the Cuyahoga a few years ago I saw some stats on just the weight of the cables. Can't recall the number but heavy!
Dennis DeBruler: Charlie Easton Note the chains hanging from the counterweights. As the counterweights go down when the span is lifted, they lessen the weight hanging off the counterweights as the weight of the cables decrease because they become shorter.
Charlie Easton: Originally ocean going ship anchor chains.