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.


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

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

Photo posted by Wayne Helms
Update: I found pictures of rigs to place the bridge segments in the Facebook group "Railroad Maintenance of Way Photo's."

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
Update: 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.

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.

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 curved.

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 the large number of contractors needed 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.

Canal Street (Pennsylvania) RR Lift Bridge

Update: pictures of the west side and video links.

20150513 1385c, East Elevation
(Bridge Hunter, Historic Bridges)
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.
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 the first floor and the control room was in the second floor. 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."

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 clearence 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
Steven's comment:
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.
Update: 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.
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......
Gordon Leonard posted
It's still Feb. 1976. We're still at The Bridge. Check out the damage at the lower right front. It hit something....!
Bjarne Henderson They ran fast and were a pleasure to work on from a service attendant's perspective. They had access doors near the food service area so you didn't need to schlep all your stuff from one end of the car or the other as you still have to do with Amfleet. Clearly, whoever designed the Turbocafe considered the needs of employees as well as the passengers. Too bad that they wore out too quickly compared to their peers.
[Note the signal heads are missing many positions because only slow speeds are indicated for crossing the bridge.]
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.

Barry Butler photo