Scratchbuilding Towers for a Vertical Lift Bridge

[richhotrain]

Track fiddler

The bridge is really coming along and looking excellent Rich.  I can hardly wait to see it finished and a picture of it on your layout,  hopefully. 

Now get back to work on that thing, I need to see some more progress,  you can't just park this thread on page 4 

TF 

TF, not to worry. I had to put the towers aside last weekend while out of town to attend two of our grandchildren's graduations.

However, I am about to install handrails around the sheave platforms up at the top of the towers. And, I need to fine some suitable chain to hang from the towers to the underside of the counterweights. These chains are used on the prototype to balance the added weight of the pulley cables.

I still face a big task in terms of installing the bridge and towers on the layout. At the moment, I have a 30" wide open space on the layout that the bridge must span. Trains run over a temporary plywood sheet that spans the open space. That 30" wide open space needs to be further opened to accomodate the towers.

So, I have some sawing and trimming facing me before I can complete the installation of the bridge and towers on the layout.

Stay tuned.

Rich

[Track fiddler]

The bridge is really coming along and looking excellent Rich.  I can hardly wait to see it finished and a picture of it on your layout,  hopefully. 

Now get back to work on that thing, I need to see some more progress,  you can't just park this thread on page 4 

TF

[toptrain]

My son Steve has been working on one to be apart of a rolling section that when the layout is being run would be put in place. 

[richhotrain]

mbinsewi

Looking good Rich .

I didn't realize that the actual lifting was done at the control house, and the big sheaves on top were just part of the counter weight set-up.  

Have you found something decent to use as the cable?

Mike

Thanks, Mike. I have not yet settled on cable. I have been checking various alternatives, but I need to physically view the possibilities. If you noticed on that diagram that I posted, there are two different types of cable which I depicted in red and blue.

The cable (red) that is strung over the sheaves up on top of the tower platform connects the bridge to the counterweights. On the prototype, there are 16 cables running over each pair of sheaves, for a total of 64 sheave cables.

The cable (blue) that is strung over the pulleys on the bridge is a single cable. It connects near the top and the bottom of the tower.

Currently, the bridge is raised and lowered from a remote location 3 miles north of the bridge. But, for many years, the bridge was raised and lowered by the bridge tender in the shack on top of the bridge. The system is powered by two 220-volt, 300 HP motors inside the bridge tender's shack. The motors rotate the four pulleys located just outside the bridge tender's shack, which is turn rotate the other eight pullleys via the cable.

As the pulleys rotate, the bridge responds by raising or lowering as the counterweights provide balance in the form of equalizing the loads. So, in effect, the bridge itself and the counterweights do the heavy lifting with the sheaves acting as a sort of fixed fulcrum.

Rich

 

[mbinsewi]

Looking good Rich .

I didn't realize that the actual lifting was done at the control house, and the big sheaves on top were just part of the counter weight set-up.  

With all the pictures in the link that Ed posted, I had to look through them until I found the cable and sheaves along the top of the bridge, and then I seen the picture with the two huge pulleys on each side of the control house.

Have you found something decent to use as the cable?

Mike.

[richhotrain]

Yesterday, I added supports to the tower platform walkways and, more importantly, I added the 12 pulleys on the bridge. There are 6 pulleys on each side of the bridge. Four pulleys are located around the bridge tender's shack, four more pulleys are located mid-way on the top of the bridge, and four pulleys are located on the ends of the bridge.

I want to thank mobilman44 for generously providing the 12 pulleys which are actually wheels from a Sherman tank kit that he built. The 12 wheels were surplus parts from the kit. The wheels are perfect as pulleys with their 5-spoke configuration and size. I still need to cut grooves in them when I add the cable.

My plan is to add the cables at a later date after I install the bridge and towers on the layout. But, first, I need to cut out some plywood and framing to properly position the bridge and towers. Once the bridge and towers are in their final position, I can string the cables. I also need to add handrails up on the tower sheave platforms.

This project has now consumed 6 weeks of my time, so I am going to take a break before actually installing it on the layout. Besides, my golf clubs are calling for me now that Spring has finally arrived in the Chicago area.

Here are some near-final photos of the whole setup, absent the cables. I am also including a diagram that illustrates how the cables are connected to the pulleys sheaves and counterweights.

Thank you all for your interest, advice, and critique on this project.

Rich

[richhotrain]

mbinsewi

 

richhotrain

. Scratchbuilding is not for the timid because there are no plans, 

I'll tell ya Rich, I'm follow a plan, from the MILW. Engineering Dept., for my little terminal caboose scratch build, and to me, it seems harder, trying to keep all the dimensions right. 

Mike. 

So true, Mike. There is something to be said for kits and RTR stuff.

Rich

[mbinsewi]

richhotrain

. Scratchbuilding is not for the timid because there are no plans,

I'll tell ya Rich, I'm follow a plan, from the MILW. Engineering Dept., for my little terminal caboose scratch build, and to me, it seems harder, trying to keep all the dimensions right. 

Mike.

[richhotrain]

toptrain

I like the work being done on this lift bridge. It is high quality work.  

Thanks, toptrain, I very much appreciate your kind words.

It is not museum quality by any means, but I am doing my darndest to make this bridge and towers look good. Scratchbuilding is not for the timid because there are no plans, no instructions, no tight fits, no interlocking parts.

Thanks again.

Rich

[toptrain]

I like the work being done on this lift bridge. It is high quality work. 

[zstripe]

Rich,

You do not have to add any grooves to them. As long as they have covers to protect the cables. Use the covers in the appropriate thickness of the cable you will use and notch out on the inside of the covers where they go over 1/2 of the sheeve to hold the cables in place. On the sheeves of the CMR bridge, they do exactly that. The cables don't go around the sheeve, only have way up, with built in notches on the center spacer sheeve, which is a little smaller in diameter, along with the notches, than the two outside ones. Use the covers you will make for a similar arrangement. This photo should show you what I mean:

They are a little blurred, I didn't use My tripod, but You should get the idea.

Take Care! 

Frank

[richhotrain]

I have been back and forth in my own mind about how to "string" the cables over the sheaves. Since the bridge will not be operational, there is no risk of lateral cable movement in the absence of grooves on the sheave rims.

And, as Ed has pointed out and illustrated with photos, you cannot see the grooves since the cables are banded together at the top of the tower, and the sheaves are covered with metal "roofs". In fact, if you use Google Maps to view the bridge from above, the sheaves are not even visible.

So, while I would like to reflect the prototype as much and as accurately as possible, I am not sure that adding grooves is necessary.

At the moment, I am also uncertain as to how many cables will be strung over each sheave. On the prototype, there are 16 cables on each sheave, a total of 64 cables on the two towers. No way can I string that many cables on a 1/2" wide sheave unless I use human hair. LOL. I am thinking, 3 or 4 cables maximum per sheave.

Rich

[gmpullman]

As Rich mentioned, the sheave/flywheel originally had grooves but he was unable to capture the thin section in the mold so he already wrapped it with styrene.

Sheave-width by Edmund, on Flickr

 

Actually, the Canal Street tower sheaves have a sheet metal guard over them so you wouldn't see any grooves:

Canal_sheave by Edmund, on Flickr

Here's another example of a similar guard. Note the bracing and rivets:

NJ_bridge_sheave-guard by Edmund, on Flickr

It would be a trade-off, modeling-wise. Leave the guards off and show the groovy grooves or stick with accuracy had have the sheaves hidden under guards?

richhotrain

I have problems too. When I posted it initially, I did not do anything different, but it does seem to be corrupted. Rich

Not only the MR site, the whole Interweb seems to be wonky today?!?

Cheers, Ed

 

[richhotrain]

mbinsewi

Notice what, Rich....?? 

I have been trying to respond to your last post, but when I try, the page is all messed up.  Everything you see on the right side, shows up under your post????

I couldn't quote you, or respond.  I could respond to any other post in your thread, except for your last one???

I am able to respond, in normal fashion to Dr Wayne's post. ?? This is really strange,  I wonder if it has to do with the mysterious page 5, and the goofy page number system in here, when threads get to page 5.

ANYWAY!  Maybe you could chuck them in a drill and cut grooves?  

Mike.

 

Mike, not sure what the problem is or what is causing it, but when I hit the Reply button to that particular post of mine, I have problems too. When I posted it initially, I did not do anything different, but it does seem to be corrupted.

Rich

[Track fiddler]

That's a great idea Mike.  Maybe one could put a variable speed drill in a vise, taping the trigger on a slower speed and use a very small round or V notch jewelers file..... Maybe

TF

 

A very small machine thread screw, micro washers and nut to hold the sheave stable in the drill

[mbinsewi]

Notice what, Rich....?? 

I have been trying to respond to your last post, but when I try, the page is all messed up.  Everything you see on the right side, shows up under your post????

I couldn't quote you, or respond.  I could respond to any other post in your thread, except for your last one???

I am able to respond, in normal fashion to Dr Wayne's post. ?? This is really strange,  I wonder if it has to do with the mysterious page 5, and the goofy page number system in here, when threads get to page 5.

ANYWAY!  Maybe you could chuck them in a drill and cut grooves?  

Mike.

[doctorwayne]

You're making great progress, Rich.

If you want to give your flywheels grooves to make them more pulley-like, you could use strips of styrene (Evergreen HO scale 1"x2" or 2"x2") or small diameter soft brass wire to replicate the raised portions, using ca to affix either material in place.
If you opt for wire, I'd suggest drilling starter holes in a place on the pulley where they won't be seen, ca-ing the end of the wire in place, then wrapping it around the circumference and also ca-ing that end into a suitably-hidden hole, too.

Perhaps a little tedious, but the sheaves will be one of the most readily visible details on the project.

Wayne

[richhotrain]

zstripe

Rich,

I was also wondering why You only have two I-beam girders on the top platform under the wide section. Should the wide section where the pulleys rest have four? Two perpendicular to the wide section, then they can extend out some.

Then it would look more like the proto and function.

Take Care! 

Frank

EDIT: For Your info......Sheeves/Pulleys & Flywheels:

The main difference between them is their function. The function of a flywheel is to provide a rotating mechanism more inercia, so it won't be so affected by other forces (Such as friction or gravity). The function of a pulley is to transmit the rotating motion from one shaft to another through a belt.

Frank, I do intend to add support to the girders that support the tower platforms. I have a bad habit of not finishing various aspects of the project, choosing instead to move forward, then eventually double back to finish. That is the case here with the walkway supports. 

[zstripe]

Rich,

I was also wondering why You only have two I-beam girders on the top platform under the wide section. Should the wide section where the pulleys rest have four? Two perpendicular to the wide section, then they can extend out some.

Then it would look more like the proto and function.

Take Care! 

Frank

EDIT: For Your info......Sheeves/Pulleys & Flywheels:

The main difference between them is their function. The function of a flywheel is to provide a rotating mechanism more inercia, so it won't be so affected by other forces (Such as friction or gravity). The function of a pulley is to transmit the rotating motion from one shaft to another through a belt.

 

[richhotrain]

zstripe

Rich,

I commend You on Your efforts......they look good, But, I have to ask. Those are flat belt pulleys, not cable pulleys. There is no provision for keeping a cable in place so they don't spin off. Are You going to add anything to them? Also it looks like You may have them in too far on the hoist plarform and the cables will rub on the side frame of the tower.

Associate Design Engineer...........

Frank 

Ahh, good points from my Associate Design Engineer.

Like all of my construction methods on this scratch build, a lot of the components reman a work in progress. For that reason, I have not yet permanently attached much of anything to the bridge or the towers. 

The bridge and the towers superstructure are essentially complete, but the add-ons such as the sheaves and pulleys, the cables and chains, the counterweights, the bridge tender's shack all need further refinements to make the entire structure as prototypical as possible.

Regarding the sheaves, the Chooch master that I used is actually a flywheel, not a sheave. But, I was going for form over function. That Chooch flywheel was the closest thing that I could find to remind me of the actual sheaves atop the PRR vertical lift bridge. Big, bulky, massive, yet small enough to look right in proportion to the tower superstrucures. On the prototype, the cable sheave has grooves to route the cables over the sheave. But, on the PRR bridge, the cables are banded together to run over the sheave.

 

The banding was done to take uneven pressures of the individual sheaves into account. So, in practice, the grooves are not visible. That said, what is to prevent the banded cables from slipping off the rim. Answer: the rim has raised sides to contain the banded cables. So, I have to work that out in terms of finalizing construction.

Regarding the unimpeded vertical drop of the cables without rubbing against the sides of the towers, Frank is right. On the prototype, the sheaves usually extend slightly over the edge of the towers for this purpose. In finalizing the location of the sheave mounts on the tower platforms, I will need to take this into account. What I may do is either trim the bottom mounting plates or drill holes through those bottom mounting plates. I still need to think that through. The following photos show the cable drop from the sheave on the PRR bridge. It appears that the sheave does not extend over the edge of the tower and that the cables drop through an opening in the bottom of the mounting plate.

Frank, keep up your excellent critique. You are earning your pay!

Rich

[zstripe]

Rich,

I commend You on Your efforts......they look good, But, I have to ask. Those are flat belt pulleys, not cable pulleys. There is no provision for keeping a cable in place so they don't spin off. Are You going to add anything to them? Also it looks like You may have them in too far on the hoist plarform and the cables will rub on the side frame of the tower.

Associate Design Engineer...........

Take Care! 

Frank

Notice the overhang.....

This photo is a little blurred, but you can see the cables are well away from rubbing on the towers:

[richhotrain]

I hope that Mel chimes in here because he is the resident forum expert on resin casting.

Alumilite is the source for my resin casting. The company makes a variety of products, one of which is Amazing Mold Rubber.

https://www.alumilite.com/products/mold-making/amazing-mold-rubber

I use this product to make the rubber mold master in which the sheaves are then cast in resin. The rubber mold is made from a liquid rubber mixed with a catalyst to produce a flexible rubber mold. It takes about 8 hours to get a truly usable mold as a result of curing.

The casting resin is made by mixing equal parts of a resin casting material which is poured into the rubber mold and hardens in about 20 minutes. This is the resin mix that I used which is one of several different resin mixes available from Alumilite.

https://www.alumilite.com/store/p/665-AlumiRes-RC-3-Tan.aspx

So, in theory, I should be able to make the 8 sheaves in 160 minutes, that is, 2 hours and 40 minutes. In practice, however, it takes a bit longer. The idea of resin casting seems simple, but it can be quite complex depending upon the size and shape of the item to be cast. I literally had to make 19 castings to get 8 good and usable sheaves.

The 8 sheaves at the bottom of the photo are the finished product that I used. The reason for so many failures is attributable to a couple of factors.

For one thing, the Chooch flywheel which I used to make the master is not a well finished product. Rather, it is finished on only the face side, not the back side, and the rim of the flywheel is imperfect. So, this affects the quality of the casting.

For another thing, the rim is thin and that results in a master rubber mold in which the liquid resin does not always fill the entire space. The result is a resin casting with gaps that would need to be filled before painting. So, I needed to thicken the rim by wrapping a 0.020" styrene strip around the rim. That worked to provide a larger space for the resin to penetrate. But, I wound up making three rubber molds before I got the one that I used as the master.

Rich

[Track fiddler]

Thanks Ed.  I will definitely check this out.

[gmpullman]

Track fiddler

I could very much appreciate a lesson like that.

https://www.smooth-on.com/howto/basics-mold-making/

Alumilite is another popular brand of mold-making products:

https://www.alumilite.com/store/pg/21-How-To-Videos-Alumilite-Mold-Making-Casting-Materials.aspx

Cheers, Ed

[Track fiddler]

Bringing in the sheaves, bringing in the sheaves, we shall come rejoicing, bringing in the sheaves

No really.  That is really something Rich,  Hats off to you.  The only thing I ever casted was a silver ring in jewelry class in high school.  I remember that and understand that Well.

To cast eight replicas out of a single plastic piece,  molded in a rubber casting with resin........... I could very much appreciate a lesson like that.

Track Fiddler

[hon30critter]

gmpullman

Excellent Progress  Rich! Those "top-off" the towers beautifully —  Thanks for the updates, Ed

Ditto!!

Dave

[gmpullman]

Excellent Progress  Rich!

Those "top-off" the towers beautifully — 

Thanks for the updates, Ed

[richhotrain]

mbinsewi

Those sheaves look great Rich!  I've never tried casting anything.

So, you used the Chooch sheave to make the mold?

Looking great!

Mike. 

Thanks, Mike.

Ed was kind enough to send a spare Chooch sheave to me, and I used it cast the 8 sheaves that I needed.

Mel first got me into resin casting a while back when I needed an alternative to the discontinued Walthers Modulars. But I always struggled with finding an adhesive to join resin cast parts together. With the sheaves, no adhesive is required.

Rich

[mbinsewi]

Those sheaves look great Rich!  I've never tried casting anything.

So, you used the Chooch sheave to make the mold?

Looking great!

Mike.

[richhotrain]

I finally decided on the tower sheaves. I went with the Chooch sheave. Since that sheave is being discontinued and unavailable in the quantity that I need, I made a rubber mold and then cast 8 sheaves in resin.

I then built 8 sheave mounts out of styrene sheet.

I used 1/8" brass rod as the sheave pins and mounted the sheaves in the mounts.

Here are a couple of photos of the sheaves mounted on the tower platforms. Now I need to make mounts for the pulleys. Getting close to completing this project.

[richhotrain]

I have now added the tower sheave platforms.

At one time, the PRR vertical lift bridge in downtown Chicago had a floor on each platform on which was housed a gear complex to synchronize the cable sheaves that lifted and lowered the bridge. However, the gear complex was later removed when two powerful motors were housed inside the bridge tender's shack for the purpose of synchronizing the lifting and lowering movements of the bridge.

Now, the platform is nothing more than a metal plate mounted on a girder for each sheave. The metal plates are wide enough to provide access for maintenance. Now, I need to install appropriately sized and shaped sheaves.

The front and back sheave girder plates are connected by walkways. So, I still need to add handrails to the walkways and install the sheaves on the metal plates. I also need to add lacing support for the walkways.

Rich

[richhotrain]

Marc_Magnus

 

These pulleys are made of brass and offered by a french company Cap maquettes

You can find a lot of pulleys with many size in the ship modeling hardware.

these brass pulleys are for my N scale High lift coal dumper, they come in size  from 6mm to a huge 18mm diameter. 

Thanks for that info, very interesting.

Rich

[Marc_Magnus]

 

These pulleys are made of brass and offered by a french company Cap maquettes

You can find a lot of pulleys with many size in the ship modeling hardware.

these brass pulleys are for my N scale High lift coal dumper, they come in size  from 6mm to a huge 18mm diameter.

 

[hon30critter]

Nice work Frank!

Dave

[richhotrain]

zstripe

A couple of pic's with three sheaves together. I have a bolt & nut holding them together. I will be making the center hole smaller. I have a light coat of primer on them to aid in sanding any imperfections, before final painting, which is air-brushed. I'm thinking black but can be any color You want......

Frank, those sheaves are gorgeous.  You do great work, and you certainly have the right tools.

I will send you a PM.

Rich

[richhotrain]

zstripe

Rich,

Maybe it was the hoist platform shacks that You were not going to do!

Ahh, yes, that was it. The platform shacks.

I have been studying photos and drawings of the sheave platforms. On the PRR bridge at 18th Street in Chicago, my prototype, there are no platform shacks, just the bridge tender's shack on top of the bridge itself.

There is also no "platform" between the two sheaves on the front of each tower and the two sheaves on the back of each tower. The sheaves rest on girders and the girders are connected by narrow walkways with handrails.

Rich

[zstripe]

Rich,

Maybe it was the hoist platform shacks that You were not going to do!

A couple of pic's with three sheaves together. I have a bolt & nut holding them together. I will be making the center hole smaller. I have a light coat of primer on them to aid in sanding any imperfections, before final painting, which is air-brushed. I'm thinking black but can be any color You want......

Take Care! 

Frank

 

 

[richhotrain]

Frank, those pulleys (sheaves) look fantastic. I will definitely get back to you on your most generous offer. 

Remind me what you mean by me changing my mind about the shack. I had always intended to build it as part of the bridge/towers project.

Rich

[zstripe]

Rich,

I see You changed Your mind about the shack......I kinda' figured You would. Looks great so far!

I did not get the pully's until today, but I did manage to make a test one. They are 11 3/4ft. HO scale tall, by 1 3/4ft wide. Three of them together are a scale 5 1/4ft. wide. Here are three pic's of the one I drilled out and next to the CMR ones which are 7 1/2ft tall. The brass rod is 1/16'', the holes are 5/16'' drilled with My shop drill press. I can drill six at a time but I will just do three at a time:

I will make all of them for You if You like......there is a learning curve with getting the holes cut that I learned from cutting the first one. The plastic appears to be a composite, which will flake if not cut properly.......not for a first timer. Let Me know and I would recommend three (3) cables, which means you need 24. Two more packs of ten, plus what I have, FREE.

Take Care! 

Frank

 

[mobilman44]

Good Morning!

Well, I only got one word for this project............

"OUTSTANDING"  !!!!!

[richhotrain]

The bridge tender's shack was a somewhat easy build. I used Evergreen Scale Models Metal Corrugated Siding for the walls and roofs, which closely simulated the prototype shack. The grooves made it easy to keep things square and plumb. I used Walthers Modulars for the windows and doors. 

I will be installing pulleys on each corner of the bridge tender's shack, as shown in the prototype photo.

Rich

 

[richhotrain]

Thanks, guys. Weathering is not my strong suit, but I will give it a try.

Rich

[gmpullman]

I agree, nice job on the counterweights, massive and imposing but not overwhelming. 

Carry on, Rich 

Ed

[mbinsewi]

Counter weights look good Rich, just need some "weathering/aging", which I'm sure will come, as you progress with the complete bridge.   , I'm buying, have one!

Mike.

[richhotrain]

Here are the counterweights. I strung one up on the tower temporarily just to see how they look. I like them.

Rich

[richhotrain]

Still working on the towers but, meanwhile, I spent the last few days working on the bridge tender's shack which sits on top of the bridge. The shack is still a little rough, so I need to do some finishing work on it.

Rich

[richhotrain]

gmpullman

 

richhotrain

I have contacted Chooch to inquire about purchasing 8 of them separately, as opposed to the entire kit. 

I hope they can come through for you, Rich  You're welcome to this one as a master if you decide to make your own. It really is a neat looking piece of "heavy" machinery. 

Regards, Ed 

I contacted Chooch about the possibility of purchasing 8 sheaves (flywheels). I was informed that the item is being retired, and there are none available for purchase outside of available kits that contain that sheave (flywheel).

So, the search continues.

Rich

[gmpullman]

richhotrain

I have contacted Chooch to inquire about purchasing 8 of them separately, as opposed to the entire kit.

I hope they can come through for you, Rich  You're welcome to this one as a master if you decide to make your own. It really is a neat looking piece of "heavy" machinery. 

Regards, Ed

[richhotrain]

gmpullman

While rummaging through my "stuff" I found that Chooch flywheel!

Sheave-chooch_dia by Edmund, on Flickr

1.5 inch diameter, 5/16 width. The back side is sanded smooth (with extra material that should be removed).

The downside is that the flywheel is part of the 120 ton steam boiler flat car load. I wonder if Chooch would be willing to sell some separately?

Ed, that "flywheel" would be excellent for my sheave. I have contacted Chooch to inquire about purchasing 8 of them separately, as opposed to the entire kit.

Rich

[richhotrain]

mbinsewi

 

richhotrain

Keep it up, Mike. Expose me for who I really am - - - an indecisive bridge engineer! 

Please Mr. Pratt, not indecisive, but constantly searching for the correct solution.

I've worked with plenty of structural engineers.  I have lots of erasers. 

Mike. 

Well, in that case, all is forgiven, Mr. Waddell.   

Rich

[mbinsewi]

richhotrain

Keep it up, Mike. Expose me for who I really am - - - an indecisive bridge engineer!

Please Mr. Pratt, not indecisive, but constantly searching for the correct solution.

I've worked with plenty of structural engineers.  I have lots of erasers. 

Mike.

[gmpullman]

Here's a better photo of those "steampunk" gears, Rich.

Sheave-group-A by Edmund, on Flickr

Sheave-group by Edmund, on Flickr

And yet another choice. While rummaging through my "stuff" I found that Chooch flywheel!

Sheave-chooch_dia by Edmund, on Flickr

1.5 inch diameter, 5/16 width. The back side is sanded smooth (with extra material that should be removed)

Sheave-chooch_dia-B by Edmund, on Flickr

The downside is that the flywheel is part of the 120 ton steam boiler flat car load. I wonder if Chooch would be willing to sell some separately?

https://tinyurl.com/y3nj7ag3

I'll reply to your PM with a suggestion.

Sheave-chooch by Edmund, on Flickr

Chooch has several similar flywheels BUT some are cast with the pallet and would have to be cut off.

So many choices, none perfect but we're getting close 

Good Luck, Ed

 

[richhotrain]

zstripe

  

Rich,

I just ordered 10 of these, will be here Thurs. and I figured with the appropiate size holes in the neighborhood of 1/4'' or larger in size for the holes, which would be drilled in a five point star pattern, (like wheel lug spacing for auto wheels) would make a pretty good looking sheave for that bridge. They are 38mm in diameter or 1 1/2'' and that is an equivalent of 11 scale ft. in HO scale. The prototypes are 15ft. so that shoud be pretty good. It does have a 4mm center hole, but that can be filled in with a Evergreen plastic tube for a smaller hole. When I get them, I'll do what I said above and You can make up Your mind.........I'll even send You the master or more.

https://www.amazon.com/Ajax-Scientific-Plastic-Pulley-Diameter/dp/B00EPQMOH2?ref_=fsclp_pl_dp_4

Take Care! 

Frank 

11 scale feet in HO scale would work quite nicely for me because I have further scaled down the entire bridge/towers structure to 80% of the prototype in HO scale. So, the sheaves need only be 12' in diamter (80%x15'). That works out to 1.65".  Even, 1.5" would be appropriate.

Rich

[zstripe]

richhotrain

 

 

zstripe

Rich,

I think I may have found a viable answer..........take a look at all these. They may just have the size You could use and it would not be too hard to drill holes into them, they are plastic. I have used similar ones before. It also looks like you get 10 pc's for the price...........I for one would surely try them and get them to work...........

https://www.amazon.com/slp/plastic-pulley/upeuzpqdpeyt67b

Take Care! 

Frank 

 

 

 

Frank, those are excellent and the price is right. I need to give serious consideration to that alternative. Thanks for the link.

 

Rich

 

Rich,

I just ordered 10 of these, will be here Thurs. and I figured with the appropriate size holes in the neighborhood of 1/4'' or larger in size for the holes, which would be drilled in a five point star pattern, (like wheel lug spacing for auto wheels) would make a pretty good looking sheave for that bridge. They are 38mm in diameter or 1 1/2'' and that is an equivalent of 11 scale ft. in HO scale. The prototypes are 15ft. so that shoud be pretty good. It does have a 4mm center hole, but that can be filled in with a Evergreen plastic tube for a smaller hole. When I get them, I'll do what I said above and You can make up Your mind.........I'll even send You the master or more.

https://www.amazon.com/Ajax-Scientific-Plastic-Pulley-Diameter/dp/B00EPQMOH2?ref_=fsclp_pl_dp_4

Take Care! 

Frank

[richhotrain]

mbinsewi

I thought you wanted the spokes 

Keep it up, Mike. Expose me for who I really am - - - an indecisive bridge engineer! 

Rich

[mbinsewi]

Those do look good.  Shapeways has lots of "solid" sheaves, at about $7 a piece.  I thought you wanted the spokes 

You could do the rivet decals, like what Dr. Wayne uses,  to make them more prototypical, probably only have to do the outside sheaves, that show.

Mike.

 

[richhotrain]

gmpullman

 

One of the gears I showed in this photo from March 30 looks like it would make a good starting place (the one that looks like a telephone dial?)

Ed, when I first read your reply, I inadvertently overlooked this part. That sure does look cool, and it would sure be a practical solution.

I PM'd you on this issue.

Rich

[richhotrain]

zstripe

Rich,

I think I may have found a viable answer..........take a look at all these. They may just have the size You could use and it would not be too hard to drill holes into them, they are plastic. I have used similar ones before. It also looks like you get 10 pc's for the price...........I for one would surely try them and get them to work...........

https://www.amazon.com/slp/plastic-pulley/upeuzpqdpeyt67b

Take Care! 

Frank 

Frank, those are excellent and the price is right. I need to give serious consideration to that alternative. Thanks for the link.

Rich

[richhotrain]

Frank, Ed, Mike, Dave, et. al.,

Thanks to everyone for their suggestions to date on possible sheaves. I cannot thank you all enough for your interest in this project.

I am seriously considering a contest to select the best sheave for the towers. All of your suggestions are good ones, and I am having trouble deciding on the best alternative, even disregarding cost as a consideration.

Stayed tuned and keep searching.

Rich

[hon30critter]

Hi Rich,

Interesting challenge with the pulleys.

I'm wondering if you could draw up a side view of the original pulley (you might have to use your imagination because you can't see much of it), and then make photocopies to glue to either side of the plastic pulleys that Rich suggested.

Just speculating.

Dave

[zstripe]

Rich,

I think I may have found a viable answer..........take a look at all these. They may just have the size You could use and it would not be too hard to drill holes into them, they are plastic. I have used similar ones before. It also looks like you get 10 pc's for the price...........I for one would surely try them and get them to work...........

https://www.amazon.com/slp/plastic-pulley/upeuzpqdpeyt67b

Take Care! 

Frank

 

[richhotrain]

Ed, I am going to have to paid you a finder's fee for all of the good work that you are doing on my behalf.

I do have resin casting materials, thanks to Mel who was instrumental in helping me with an alternative to Walthers Modulars when they were no longer available. My problem with resin castings, though, is that I have been totally unsuccessful with finding an adhesive for resin castings.

I have thought about using Tinker Toys. In fact, Shapeways has a sheave that looks a lot like a Tinker Toy. LOL.

Those wood spools look excellent. I am going to make a trip over to Hobby Lobby to check them out.

Thanks for all of your help, Ed. And don't stop looking. Remember that finder's fee. 

Rich

[gmpullman]

richhotrain

Yep, I do like those a lot. The problem for me is price.

I feel your pain, there, Rich. I figured the casting route wouldn't be cheap, either, after all the silicone and resin, so these might balance out.

Come to think of it, old Tinker-Toy hubs... oh, wait, those are rare, vintage collectables, now. Maybe some of the craft stores would have wood wheels or craft doo-dads that you could drill and carve?

Still trying out ideas.

[edit] Hey, look at this, first try out!

https://tinyurl.com/y5gbb5lc

I Googled "wood craft wheels"

Buck a piece at Hobby Lobby (the 2" are 50¢ each):

https://www.hobbylobby.com/Crafts-Hobbies/Painting-Surfaces/Wood/Birch-Wood-Tread-Wheels-with-3-8%22-Hole---2-1-2%22/p/23024

You could cut out a styrene disk cap for the sides.

Cheers, Ed

[richhotrain]

gmpullman

Don't forget about these "Scene Master" gears. For all that trouble, these things would sure make a good starting place.

Cog-Life-Like by Edmund, on Flickr

They measure 1.3795 OD. If you wrap them with grooved material you can get to your 1.900 (1-½" pipe OD).

Ed

Yep, I do like those a lot. The problem for me is price. I need 8 sheaves, so that would be four 2-packs at $7.00 a pack. But, to make this look right, I might neded eight 2-packs at $7.00 a pack, so I can bulk up the appearance of hefty sheaves.

This little project is already costing me more than if I had just purchased the CMR double track lift bridge like Frank did. Frank warned me that the sheaves for going to be an expensive add-on, and he was right. 

Rich

 

[gmpullman]

Don't forget about these "Scene Master" gears. For all that trouble, these things would sure make a good starting place.

Cog-Life-Like by Edmund, on Flickr

They measure 1.3795 OD. If you wrap them with grooved material you can get to your 1.900 (1-½" pipe OD).

Ed

[richhotrain]

gmpullman

 

richhotrain

Here is a partially concealed view of the actual sheave. I would really like to find something that is solid, as opposed to open spoke, but that is proving difficult. 

Have you considered making a styrene master then a silicone mold and resin castings? You could add Archer rivets. Maybe even cast any other parts while you are making the mold?

I had hours into making parts for a Hulett ore unloader right about the time Walthers came along with theirs 

Cheers, Ed 

Good question, Ed. Yes, I am considering a master from which I can do 8 resin castings.

I am also considering the use of 1 1/2" Schedule 40 PVC, thin wall water pipe, to cut eight 3/4" wide sections of 1 1/2" diameter pipe sections. I would then cover the ends of each section with styrene sheet cut to fit over the opening and add "ribs" of rivet plate to simulate the embedded spokes.

Rich

[gmpullman]

richhotrain

Here is a partially concealed view of the actual sheave. I would really like to find something that is solid, as opposed to open spoke, but that is proving difficult.

Have you considered making a styrene master then a silicone mold and resin castings? You could add Archer rivets. Maybe even cast any other parts while you are making the mold?

One of the gears I showed in this photo from March 30 looks like it would make a good starting place (the one that looks like a telephone dial?)

cog_3 by Edmund, on Flickr

Slice some styrene tubing or wrap the circumference with strip styrene and you have the beginnings of your master.

I had hours into making parts for a Hulett ore unloader right about the time Walthers came along with theirs 

Cheers, Ed

[richhotrain]

mbinsewi

Rich, I was on Shapeways earlier this am, read your last post, so I thought I'd look around.

I found these, they are 1.77", with 6 spokes.  

//www.shapeways.com/product/R4ZY5JNEW/45mm-sheaves?optionId=61536622&li=marketplace

Just thought I'd pass it back to you.

Mike 

Thanks for that link, Mike. That could work.  I am getting close to focusing on the exact sheave that I need to select.

Here is a partially concealed view of the actual sheave. I would really like to find something that is solid, as opposed to open spoke, but that is proving difficult.

Rich

[gmpullman]

Perhaps take a second look at the Tichy offerings? 

https://www.tichytraingroup.com/Shop/tabid/91/p/8310-4-diameter-sheaves/Default.aspx

If they are ganged together the spokes won't look so "spindly". Actually the 1/2" diameter sheave is a little beefier than the larger ones but on the small side for your HO needs. Dave Tichy might be able to put together a quantity package for you. 

 

Good Luck, Ed

[mbinsewi]

Rich, I was on Shapeways earlier this am, read your last post, so I thought I'd look around.

I found these, they are 1.77", with 6 spokes.  

//www.shapeways.com/product/R4ZY5JNEW/45mm-sheaves?optionId=61536622&li=marketplace

Just thought I'd pass it back to you.

Mike.

[richhotrain]

zstripe

 

richhotrain

Frank, tell me more about those sheaves. Are they from the CMR bridge kit? Shapeways?  

Rich,

They are from the CMR kit. For some reason, they had a complete sheet of parts to make two more hoist platforms which are extra, once kit is finished. They are 7/8ths'' in dia. To make one sheave, it takes three piece's, two outer, one inner. 

Thanks for that info, Frank.

I continue to search for the most appropriately shaped and sized sheaves for the towers. There are 8 sheaves up there, 4 per tower.

On the actual PRR lift bridge, the sheaves were 15 feet in diameter, which converts to 2.07 inches in HO scale.  However, since my bridge and towers are scaled further down to 80% of the prototype in HO scale, the sheaves would be 1.65 inches in diameter. Right now, I am considering sheaves from Shapeways that are either 1.2 inches or 1.4 inches in diameter.

The actual sheaves on the PRR bridge have 8-spokes, just like those in your CMR kit. The Shapeways sheaves that I am considering only have 4 spokes.

Rich

[zstripe]

richhotrain

Frank, tell me more about those sheaves. Are they from the CMR bridge kit? Shapeways? 

Rich,

They are from the CMR kit. For some reason, they had a complete sheet of parts to make two more hoist platforms which are extra, once kit is finished. They are 7/8ths'' in dia. To make one sheave, it takes three piece's, two outer, one inner. I also still have two 50ft. complete decks with piers, that I did not use.

Take Care! 

Frank

[richhotrain]

Track fiddler

I fell out of the progress here with vacation and then back to work and all.  

The progression quality looks just as good as where I had left off.   Still looking Great Rich, keep up the good work.

TF, as always, I appreciate your kind words of support.

Rich

 

 

[richhotrain]

zstripe

Rich,

I would just like to also say, that you can use hardened brass rod from K&S in the appropiate diameter for the cables. It will be much easier to bend/cut than music wire, You may find that is better to use for You. It will also keep it shape and remain tawnt for the cables. It comes in various diameters in 12'' lengths and 36''. I made a mock-up using 3/64'' brass rod and used the sheave to make the bend on both sides to go over/in the sheave for the main span and over to the counterweight to the other sheave to give you an idea of how you can do it on the hoist platform. Do some measuring for the lengths/bends and use that for a master to make the others you will need so they are all the same:

Be Happy, in Your Work! 

Frank 

Frank, tell me more about those sheaves. Are they from the CMR bridge kit? Shapeways? 

I appreciate your work with the K&S brass rod to illustrate the point. Something for me to think seriously about.

Rich

[Track fiddler]

I fell out of the progress here with vacation and then back to work and all.  

The progression quality looks just as good as where I had left off.   Still looking Great Rich, keep up the good work.

TF

 

Frank I got to say your Bridge looks pretty sweet too.  Some good ideas shared.  I like the pulley idea.

[zstripe]

Rich,

I would just like to also say, that you can use hardened brass rod from K&S in the appropiate diameter for the cables. It will be much easier to bend/cut than music wire, You may find that is better to use for You. It will also keep it shape and remain tawnt for the cables. It comes in various diameters in 12'' lengths and 36''. I made a mock-up using 3/64'' brass rod and used the sheave to make the bend on both sides to go over/in the sheave for the main span and over to the counterweight to the other sheave to give you an idea of how you can do it on the hoist platform. Do some measuring for the lengths/bends and use that for a master to make the others you will need so they are all the same:

Be Happy, in Your Work! 

Frank

 

 

[richhotrain]

BroadwayLion

You is a model builder, where as I, on the other hand, am a fat furry LION with big furry paws, If it looks like a bridge, then it might be a bridge. 

ROARING! 

Maybe so, but to tell you the truth, him posts interesting photos of bridges and me ain't LION.

Rich

[BroadwayLion]

You is a model builder, where as I, on the other hand, am a fat furry LION with big furry paws, If it looks like a bridge, then it might be a bridge.

 

ROARING!

[richhotrain]

zstripe

Without any doubt...use K&S music wire for the cable. 

Hmmm, I have given some thought to the cable, but I had not considered music wire.

I plan to follow the prototype somewhat closely, so I will need a system of 12 pulleys and 8 sheaves.

The sheaves will be placed on the top of the towers, one on each corner of each tower. The sheaves will control the movement of the cables between the bridge and the counterweights. I haven't decided yet on the number of cables.

The pulleys will be mounted on the bridge, four outside the bridge tender's shack in the center of the bridge, four on the top of the bridge near the ends of rhe bridge, and four on the ends of the bridge. The cables will be routed around this system of pulley and connect to the towers near the top and bottom. This pulley system, activated by the bridge tender inside the shack will activate the cables that initiate the lifting and lowering of the bridge.

Rich

[zstripe]

Rich,

Without any doubt...use K&S music wire for the cable. Not a problem to keep tawnt and having all of them the same. Mine are close to 1/16th and they hold the counterweight in the air...nothing else holds the counterweight in place. Mine are plastic acrylic boxes. Yours as a suggestion.....a white pine block of wood, sanded to a texture of concrete. The music wire is more than enough to hold the wood. I would also invest some money into the  Xuron cutters #2193 they DO NOT distort the cylindrical shape like a side cutter will and cut like butter. Well worth the investment for Me, I use a lot of music wire for projects. A small size pair and large for cutting over a 1/8''. I air brushed My cable steel color from MM after lightly sanding the music wire and used Medium CA for bonding.

This pic was not touched up yet!

Take Care! 

Frank

[mbinsewi]

Have to go back and check out the pictures Ed posted again, and take another look at the tower foundations.

Mike.

[richhotrain]

I have added the tower decks, a system of welded girders that match the bridge girder deck. One advantage of having purchased three bridge kits is that I had plenty of extra parts after lengthening the bridge. I was able to use the extra bridge girders to build the two tower decks.

I am uncertain as to whether I should add the girder lacings and X-braces to the tower decks to match the girder lacings and X-braces on the bridge. Any thoughts on whether tower deck lacings and X-braces exist on the prototype? Or, are those lacings and X-braces only required on the bridge span over open water?

Rich

 

[BroadwayLion]

The next crossing of the Gowanus Canal is at Carroll Street.

 

It is a slide bridge.

 

Isn't that ROARING

[richhotrain]

Thanks, Ed. 

Hey, go ahead and build a vertical lift bridge. Frank and I could use the company.

I have been considering both cable and sheaves. I haven't decided on anything yet, so I am open to suggestions.

Rich

[richhotrain]

LION, thanks for posting that photo. That is one heckuva lift bridge.

Rich

[BroadwayLion]

LION's EASY Lift Bridge...

 

The lift bridge in question is directly below the Subway bridge above it.

As you can see, the towers are enclosed. You can see the roadway that lifts just above the water.

 

Makes for easy construction.

 

ROAR

 

Add:

It is a four track subway running above 9th Street in Brooklyn, the station is on the bridge structure and is 600' long. The only exit is on the west end of the station. The bridge thakes the subway right over several four story buildings that were there first, so the structure only touches ground on the cross streets and bridges across the buildings.

It was a concrete and steel structure, and the concrete was spalling badly, dropping chuncks on the traffic below. They wrapped the entire structure in that black wrapper, sort of looks like heavy duty tar paper. Concrete can rot, but at least it will not fall to the street below.

 

Now as for the lift bridge, 9th Street is only two lanes wide (plus sideqwalkks) and the towers of said bridge are completely encloxed. They fit entirely under the subway. Only barges and small tow boats will raise the bridge. One cannot imagine a recreational boater putting their craft in the Gowanus Cannal!

 

ROAR

[gmpullman]

Excellent progress, Rich 

If I didn't already have a Bascule bridge I could easily get the itch bo build a massive vertical lift. 

Hummm 

Have you given thought to cable? One frustration I have with using thread or fishing line is trying to keep each strand taught when threading multiple lines. The Berkshire Jct. Easy Line is great in this respect but, upon close inspection, you can see that it has a flat cross section. 

Thanks for the photos and updates!

Regards, Ed

[mbinsewi]

Looking good Rich.

You have a different tower base situation than Frank's, his are right out there, and on a totally seperate piling/foundation,  while yours are bit more obscure, on the shore line with much of it sort of hidden.

Mike.

[richhotrain]

I have completed the two decks that will be installed at the base of the towers. The fitting, cutting and painting is done. So now, I just have to glue the front and back sections of the towers to the decks.

Many thanks to Frank, Ed and Mike for their support and advice on this critical step.

Rich

[richhotrain]

hon30critter

Hi Rich,

Looks good!

Thanks for reminding me about using clamps when doing the initial assembly. I have a bunch of Micro Engineering bridges and bents to build for the club.

Dave 

Thanks, Dave. Yep, you gotta have those clamps as a 2nd set of hands and many times even more.

Rich

[richhotrain]

mbinsewi

Coming right along Rich!   

 When I built my over head crane, I did the same, I used clamps and painters tap to temporarily put things together until I had most of the main parts made.

Mike. 

Thanks, Mike. Yes, those spring clamps are invaluable for temporarily holding parts together or for holding parts together while the glue dries.

Rich

[hon30critter]

Nice straight lines. Nice joints too.

Dave

[richhotrain]

A few more pics.

 

[hon30critter]

Hi Rich,

Looks good!

Thanks for reminding me about using clamps when doing the initial assembly. I have a bunch of Micro Engineering bridges and bents to build for the club.

Dave

[mbinsewi]

Coming right along Rich!   

 When I built my over head crane, I did the same, I used clamps and painters tap to temporarily put things together until I had most of the main parts made.

Mike.

[richhotrain]

I finally got the second tower superstructure done. I still have lots of fitting and trimming and painting to do, but I consider the most difficult part now to be behind me. This has taken three weeks to build the two tower superstructures. It is painstaking to say the least.

For the moment, I still have the four sides of each tower held together with spring clamps. Until I can get the decks installed at the base of each tower, I will hold off on final gluing.

Rich

[richhotrain]

 

richhotrain

The towers are massive and do seem to dwarf the prototype. 

The prototype towers being at a skew angle are the reason for that.

Keep up the Good Work.

Cheers, the Bear. 

Thanks, Bear. Yeah, I'm sure that the skewed construction has a lot to do with it.

Rich

["JaBear"]

richhotrain

The towers are massive and do seem to dwarf the prototype.

The prototype towers being at a skew angle are the reason for that.

Keep up the Good Work.

Cheers, the Bear.

[richhotrain]

Here is a side-by-side comparison of my model and the prototype. The towers are massive and do seem to dwarf the prototype.

Rich

[richhotrain]

mbinsewi

Lookin great Rich!  Massive.  It's going to be great!

Nothing gets in the way of my PM naps, because after nap time, it's  time, before diner. 

Mike. 

Thanks very much, Mike. It is, indeed, massive, and I have to continually compare it to photos of the prototype to make sure that I maintain the proper proportionality.

Rich. 

[mbinsewi]

Lookin great Rich!  Massive.  It's going to be great!

Nothing gets in the way of my PM naps, because after nap time, it's  time, before diner. 

Mike.

[richhotrain]

Track fiddler

Fascinating Rich.  She is a thing of beauty.  Your efforts are all worthwhile.

One of my bridges I built took me an excess of 90 hours.  That bridge was not as complex as the one you are building.  Keep up the great work

TF 

Thank you very much, TF. The amount of time consumed on this project is enormous. I have no time for afternoon naps. 

Rich

[richhotrain]

gmpullman

 

richhotrain

I have to say, I knew that this would be a difficult project, but this is proving even more difficult than I could have imagined. 

But the results are fantastic and you have a piece of artwork that is unique to your layout.

You have captured the massiveness which is a hallmark of this type of structure. Excellent work, indeed!

Regards, Ed 

Thank you very much, Ed. I am sticking with the same proportions between the towers and the bridge as the prototype so that it will look like the prototype.

Rich

[Track fiddler]

Fascinating Rich.  She is a thing of beauty.  Your efforts are all worthwhile.

One of my bridges I built took me an excess of 90 hours.  That bridge was not as complex as the one you are building.  Keep up the great work

TF

[gmpullman]

richhotrain

I have to say, I knew that this would be a difficult project, but this is proving even more difficult than I could have imagined.

But the results are fantastic and you have a piece of artwork that is unique to your layout.

You have captured the massiveness which is a hallmark of this type of structure. Excellent work, indeed!

Regards, Ed

[richhotrain]

I have to say, I knew that this would be a difficult project, but this is proving even more difficult than I could have imagined. The parts are small and require a lot of gluing and fitting. There are a lot of angles and squaring is critical. I am finding out that I lack the proper tools in some instances. 

I just finished the superstructure of the first tower, and it took 128 pieces of Central Valley Model Works Heavy Laced Beams, plus a whole bunch of Tichy Train Group Rivet Plates.

These photos are preliminary, and probably premature, but here is the first tower superstructure before adding the deck at the base and the sheave platform on top. I haven't glued the four sides together yet because I want to use these sections as templates for the second tower.

So, forgive me for using spring clamps in these photos. I also have a lot of finishing work to do including some putty for gaps and some final painting of missed spots.

Rich 

[richhotrain]

zstripe

Rich,

I answered You and also showed a photo of the abutment arrangement I was talking about in my first PM.....should help You understand better........

Take Care! 

Frank 

Thanks Frank, that helped a lot.

Rich

[zstripe]

Rich,

I answered You and also showed a photo of the abutment arrangement I was talking about in my first PM.....should help You understand better........

Take Care! 

Frank

[richhotrain]

Frank, check your PM's.

Rich

[richhotrain]

Thanks, guys, I appreciate the kind words.

Yeah, I was very pleased with the Coors Family Mansion. It was a true scratchbuild, and it was my first real effort at scratchbuilding.

I finished the second section of the first tower yesterday. It is a mirror image of the first section, and it will become the rear section of the tower from a viewer's perspective when it is on the layout. I plan to start the first of the two side sections next, and I will post some pics when I have something to show.

Rich

[mbinsewi]

Yep, I like following his build.  That Coors house was cool too!

And besides, from this current bridge stuff, I learned what the Alton Junction thing is all about.  

Mike.

[mobilman44]

As a native Chicagoan (Lane Tech - '62), I've followed this project with interest since the beginning.  Rich has done an outstanding job on this very unusual, complicated, difficult and time consuming project.  This is what serious modeling is about, and I applaud him for his efforts!

[richhotrain]

zstripe

Rich,

What I am trying to say........If You do not add any footings to the towers and have the tower track deck set inside and the towers setting directly on the ground, the bridge main span will not go high enough to give clearance to river traffic and in effect the mainspan will be too low to the river.

OK, I see what you are driving at. 

The bridge that I built is designed so that the bridge track rests on a system of girders, floor beams and stringers. I am thinking that I will build this same system at the base of the towers. The four legs of each tower will sit on bridge shoes, or something similar.

Rich

[richhotrain]

gmpullman

By keeping the span shorter considerable weight can be saved. 

Yes, that is the key reason for the engineers selecting skewed towers as the preferred design.

Rich

[gmpullman]

Here's a good example of the reasoning behind the skew:

Calumet-skew by Edmund, on Flickr

By keeping the span shorter considerable weight can be saved. Thus counterweights, lifting machinery and steel members are kept to a minimum when a waterway must be crossed at an angle.

For anyone interested, here is a very interesting history of the details on these Calumet River spans:

https://cdn.loc.gov/master/pnp/habshaer/il/il0800/il0836/data/il0836data.pdf

Cheers, Ed

[zstripe]

Rich,

What I am trying to say........If You do not add any footings to the towers and have the tower track deck set inside and the towers setting directly on the ground, the bridge main span will not go high enough to give clearance to river traffic and in effect the mainspan will be too low to the river.

Look at this pic' and think of the Homasote the bridge is on as the water and where the towers and approach track deck is as the ground. The principal is the same with the square or boxed towers. On the photos that Ed posted show an abutment built into the ground side and concrete extensions a little further from the abutments so the closest tower footings rest on them. The CMR bridge was based on a wider river, where there was no need to go bank to bank with a Canal type river bridge like the  Chgo bridge is used for. They set up the CMR mainspan at the deepest center of the river.

There is also a lot more weight having to be supported on both tower ends so the deck beams and everything else would be larger in size than the mainspan deck. Like the size of the deck girders under the tower that ED is referring to.

Pic' can be clicked on for a larger view........

Think of the towers in the pic' as being vertical/square where the sloped one is and move the end/deck footings where the speaker is on the right, directly under the tower end.

Take Care! 

Frank

[richhotrain]

gmpullman

 

richhotrain

Ed, which "beefy gusset plates" are you referring to? 

Looking at the "freeze frame" of the Youtube video above, I was refering to the eight gussets that support the roller guides. 

richhotrain

which beams are you referring to that "support the track above the concrete"?

The approach to the movable span looks like it is supported on girders that are similar to those you would find on a deck-type box-beam bridge. 

OK, I see what you are saying. Thanks, Ed. It's been a long day. 

Rich

[gmpullman]

richhotrain

Ed, which "beefy gusset plates" are you referring to?

Looking at the "freeze frame" of the Youtube video above, I was refering to the eight gussets that support the roller guides.

 

PRR Guide Roller by Edmund, on Flickr ^{Nathan Holth Photo}

It looks like there is a part on that Walthers sprue that would probably work for these.

 

richhotrain

which beams are you referring to that "support the track above the concrete"?

Calumet_lift-crop-beam by Edmund, on Flickr

The approach to the movable span looks like it is supported on girders that are similar to those you would find on a deck-type box-beam bridge. 

Micro Engineering and Central Valley both have bridge beams that could be used here.

Cheers, Ed

[richhotrain]

gmpullman

Here's a typical, shaky, Youtube video of 21st. Street but there are a few "glimpses" between the chain-link fence of the landing feet and the beefy gusset plates located at the bottom of the movable span and the tower.

Note that there are beams similar to a deck girder bridge that supports the track above the concrete. Probably a good detail to try to incorporate into your design.

OK, I must be slow today. I am not understanding something here.

Ed, which "beefy gusset plates" are you referring to? And, which beams are you referring to that "support the track above the concrete"? Sorry if I am confused, but I need a little more help here.

Rich

[richhotrain]

zstripe

You will still need a deck in the towers so You could make the footings part of the deck. 

I'm losing you, Frank. When you say that I need a deck in the towers, I am not sure what you mean. I also am not clear what you mean when you sat that I could make the footings part of the deck. Do you mean a deck at the base of each tower?

zstripe

 

It looks to Me that the towers You have made already, may be a little short, height wise. You can make up for that with the deck. I made sure that the inside height clearance for mine would allow Intermodal double stacks......top of rail to bottom inside girders/bracing on mainspan and towers with a little extra at 24' and 1/2'' scale ft.

I am confused here as well. A little short height wise?  Do you mean the overall height of the tower, or the height of the lowest X-braced section?

Rich

[gmpullman]

Here's a typical, shaky, Youtube video of 21st. Street but there are a few "glimpses" between the chain-link fence of the landing feet and the beefy gusset plates located at the bottom of the movable span and the tower.

At least is gives some idea of the arrangement. Note that there are beams similar to a deck girder bridge that supports the track above the concrete. Probably a good detail to try to incorporate into your design.

Also note: a good look at the "guide plates" that hold the movable span in alignment with the towers.

Here are some detail photos from one of those Calumet lift bridges that may give you some ideas:

Calumet_lift by Edmund, on Flickr

And a crop. Note the spare sheave in the weeds. What is that cut-off lattice column from? Lots of interesting details here. The Central Valley stair and railing kits would be handy, too.

Calumet_lift-crop by Edmund, on Flickr

The blurry figure on the walkway looks like it is the operator or maintenance worker looking over the passing Amtrak train?

Calumet_lift-crop-sheave by Edmund, on Flickr

—and here is a look at the landing of the middle bridge:

Calumet_lift-crop-R by Edmund, on Flickr

Perhaps the Walther's 933-4559 bridge shoe set could have some useful parts for the anchor plates?

 

https://www.walthers.com/bridge-shoes-adapters-assortment-kit

 

Thanks again for keeping us informed on your great project.

Regards, Ed

[mbinsewi]

Looking the pictures from Ed's link, it looks like the North foundation is surrounded by sheet pile, and small trees and shrubs.

The South end, looks like the two front legs of the tower are on on a piling/coffer dam type pier, then there is a short section of bridge, and then the rear legs.

No close up of the South end rear legs, but probably the concrete is wrapped in sheet piling like North end.

Frank's foundation is different than your prototype.

I just notice the last picture in Ed's post with the 5 bridges side by side !  Wow.  Those iron workers had a steady job!

Tower section is looking good!

Mike.

[zstripe]

Rich,

On the last pic' above where the pier bumper pilings are above the light, You could put two on each end of the towers that You just made, but not quite as tall as the ones are above. Sort of like putting legs on a table. Those footings are bolted to the concrete pilings that are sunk into the ground. They are there to keep the girders of the towers off the direct groundand impead rain run-off. You will still need a deck in the towers so You could make the footings part of the deck. Keeping in mind.....to give ample room for clearance, height most important and width. It looks to Me that the towers You have made already, may be a little short, height wise. You can make up for that with the deck. I made sure that the inside height clearance for mine would allow Intermodal double stacks......top of rail to bottom inside girders/bracing on mainspan and towers with a little extra at 24' and 1/2'' scale ft.

Just like how this double stack fits under the end of this overpass, with a few scale inches to spare......there are I-beams under the overpass that also had to be set the same clearance.

Take Care! 

Frank

[richhotrain]

zstripe

 

richhotrain

I finished the front side of one tower, so 1 side down and 7 to go. 

Rich,

Looks good so far!......

Hopefully, You mean You only have 3 more to go......remember the inside 4 are different than the outside 4 and are as wide as the mainspan, with height clearance for the equipment. You also don't show any footings on the bottom of the side structure. Are You going to add those?

You asked Me to stay with You.....so just asking......

Frank 

Good points, good questions. And, yes, Frank, I am counting on your continuing comments and advice.

Yeah, it all depends on how you count the "sides". Two towers, so each tower has a front and back section and two side sections. And, as you point out, the side sections are different than the front and back sections.

I need to consider some type of footings for the towers. I have thought about it, but I have not reached any conclusions. Give me your thoughts. On the prototype, the towers for this bridge sit on concrete piers sunk deep into the ground.

Rich

[zstripe]

richhotrain

I finished the front side of one tower, so 1 side down and 7 to go.

Rich,

Looks good so far!......

Hopefully, You mean You only have 3 more to go......remember the inside 4 are different than the outside 4 and are as wide as the mainspan, with height clearance for the equipment. You also don't show any footings on the bottom of the side structure. Are You going to add those?

You asked Me to stay with You.....so just asking......

Take Care! 

Frank

[richhotrain]

Track fiddler

Great looking start on the side tower Rich  Good to see your project moving into phase 2.

I wouldn't model the right side tower in a parallelogram configuration either  That would definitely complicate things, quite a bit.

I think you made a good choice in your choice of materials as well.

TF 

Thanks, TF.  At one time, I had considered trying to model a more exact replica of the area south of downtown Chicago up to and including the so-called "Alton Junction, just a few yards south of the PRR lift bridge. That fantasy included a skewed PRR bridge over an angled South Branch of the Chicago River. But, reality set it in terms of time and space, and the acknowledgment that a master craftsman I ain't. I know my limits, so I settled for a rectangular set of towers.

Rich

[Track fiddler]

Great looking start on the side tower Rich  Good to see your project moving into phase 2.

I wouldn't model the right side tower in a parallelogram configuration either  That would definitely complicate things, quite a bit.

I think you made a good choice in your choice of materials as well.

TF

[richhotrain]

mrrdad

Rich,

That looks fantastic!

Being a former Chicago area resident, I know the area you are modeling. I love what you're doing. Thank you so much for sharing.

Ed 

Thanks, Ed, glad to read that you are enjoying this project. As a lifelong Chicagoan, born and raised in the city, and later married and transplanted into the southwest suburbs, big city railroading is all I know.

Before retiring, I rode the Metra Rock Island downtown to work each day for years, crossing bridges in Blue Island and passing by the PRR lift bridge and the SCAL/BOCT bascule bridges. Pulling into downtown LaSalle Street Station, Grand Central Station was on the left and Dearborn Station was on the right. A lot is gone now, but the bridges all remain.

Rich

[mrrdad]

Rich,

That looks fantastic!

Being a former Chicago area resident, I know the area you are modeling. I love what you're doing. Thank you so much for sharing.

Ed

[richhotrain]

I finished the front side of one tower, so 1 side down and 7 to go. I do like the overall look of it, and I am satisfied with the types of beams that I have selected to capture the look of the prototype.

I am reasonably happy with the fit of the inidividual parts, though not entirely pleased. So, I am going to fall back on one of my favorite moel railroading expresssions, "it is good enough", at least for a first attempt.

I still have to make three more "face" sides, so I will choose the best two face sides to use on my layout, and the other two can be the back sides, away from the camera and layout visitors.

Go easy on me.

Rich

[richhotrain]

mbinsewi

Ed's second link shows just about every detail there is for modeling the bridge, wow, what a collection!

Great stuff!

Mike. 

Yep, I agree. I found that link several years ago, and it has been invaluable to me as I contemplated scratchbuilding the bridge and towers. The close up photos of that structure are extremely informative about the actual construction methods.

One thing that I find interesting about the towers is that there seems to have been no set pattern when it came to designing beams or gussets. If you look at a tower as a system of boxes stack atop one another, the types of beams used seem to vary from one box to another. And, even the gussets vary in shape from one box to another. That left me initially bewildered over how to design towers with a more repetitive pattern to simplify construction.

Rich

[mbinsewi]

Ed's second link shows just about every detail there is for modeling the bridge, wow, what a collection!

Great stuff!

Mike.

[mlehman]

Rich,

That does make things much simpler. The prototype's limited, if any (??), movement at this point certainly suggests that is a convincing option.

As for the skew, IIRC it was much more obvious why things were that way back in the mid-70s when I first went through them. There were the rail lines that Ed helpfully provided the sketches for, but the water traffic had clearly also been a factor in earlier days. Bringing all those connections together was Chicago's big strength, packing things in densely with things like that skew was how this was achieved.

[gmpullman]

This was a pretty tight area, railroad-wise. Engineers probably looked at the additional work to skew the bridge and towers and decided it was worthwhile. As far as material it really wouldn't be too much more of a modification.

Here's everything you'd want to know about 21^st. Street Crossing or Alton Junction.

LOTS of great photos!

http://industrialscenery.blogspot.com/2015/02/21st-street-crossing-or-alton-junction.html

...and a gallery of detail photos here:

https://historicbridges.org/bridges/browser/photosviewer.php?bridgebrowser=illinois/sblift/&gallerynum=1&gallerysize=1

 

PRR_S-Branch-Alton-Jct by Edmund, on Flickr

 There are three skewed lift bridges over the Calumet River, side-by-side. Talk about a modeling challenge!

Thanks for the effort you are making to document your work on this project, Rich 

Cheers, Ed

[richhotrain]

ROBERT PETRICK

Side note to OP Rich: glad you decided to ignore the skewed aspect of the prototype. No sense driving yourself nuts; plenty of other things to worry about. My goal is to try to capture the essence of the scene, and modifying reality to suit is not really a big deal. 

Agreed. As I am modeling the river, it runs at a 90 degree angle to the bridge, so no need to skew the towers.

Rich

[richhotrain]

mlehman

Rich is wise to make the piers non-skewed. The twin lift towers will still be tricky, as they must be both vertical and parallel. Is there a nice solid base to build on here yet to hold all in alignment, mount the drive mechanism on, etc? Then have the whole shebang drop into the location to then attach to the approaches? 

Two comments.

One, I do not intend to make the lift operable. That bridge will just sit motionless on my layout.

Two, I have never fully understood why the engineers designed the towers to be skewed. True, the bridge crosses the river where it runs on an angle, but the towers still could have been built in non-skewed fashion. I believe that a skewed design was selected to avoid having to make the bridge longer (and heavier) if the towers were set further back on solid ground.

Rich

[richhotrain]

zstripe

Rich,

I forgot they don't have any tips on the ones You have. The ones I used do, 1902-5. I wound up getting all the ones they made for different projects. Used all kinds of sizes in the Rolling Lift Bridge bash

I will say this, the total absence of instructions and tips lends itself to maximum creativity.

Rich

[zstripe]

Rich,

I forgot they don't have any tips on the ones You have. The ones I used do, 1902-5. I wound up getting all the ones they made for different projects. Used all kinds of sizes in the Rolling Lift Bridge bash:

Pic' may be clicked on for larger view.

Take Care! 

Frank

[mlehman]

Lift bridge by Bear, on Flickr

 

Well, there is a submarine that's been sitting dead at the curb in the basement of the Museum of Science and Industry. Could patch the extra holes they cut in it, hotwire it - common enough in Chicago - but getting it out of that hole would be a neat trick.

Rich is wise to make the piers non-skewed. The twin lift towers will still be tricky, as they must be both vertical and parallel. Is there a nice solid base to build on here yet to hold all in alignment, mount the drive mechanism on, etc? Then have the whole shebang drop into the location to then attach to the approaches?

[ROBERT PETRICK]

I want to add one more vote in favor of posting progress photos, mainly for inspiration to others, but also out of curiosity and general interest. Ours is a visually intensive hobby.

Side note to OP Rich: glad you decided to ignore the skewed aspect of the prototype. No sense driving yourself nuts; plenty of other things to worry about. My goal is to try to capture the essence of the scene, and modifying reality to suit is not really a big deal.

Photos!

Robert 

[richhotrain]

I have made a template to faciltate building the towers.

What I simply did was to draw the contemplated dimensions and trace the parts needed to complete the face and rear portions of each tower on a Masonite board.

Then, I clamped wood strips to hold the parts in position. The trickiest part is forming the X-brace across each "box". Gussets will hide imperfections in the fitting process.

Rich

[richhotrain]

zstripe

make sure You Read the instructions thoroughly, because they will give You tips on what to use to keep the lattice work even......drill bit sizes.

 

Instructions? Ha, you're looking at 'em.  Not much there, so easy to read thoroughly.

[zstripe]

You are a card Bear!.........LOL

Rich,

You will find it much easier to build those CV girders if You build a right angle jig, to hold them square and in place while glueing, I know I did. Also make sure You Read the instructions thoroughly, because they will give You tips on what to use to keep the lattice work even......drill bit sizes. I made my jig out of 1x2 pine and a 5/16ths square piece of pine screwed to the 1x2. Then just brushed a bead of adhesive down the seam, capillary action did the rest. I used Plastruct orange bottle.

After making the jig, I found many more uses for it.

Take Care! 

Frank

["JaBear"]

Lift bridge by Bear, on Flickr

[hon30critter]

richhotrain

Dave, just be sure to post on your progress. I, for one, love to see all kinds of structure building, especially kitbashing and scratch building.

Will do!

Dave

[richhotrain]

hon30critter

 

richhotrain

I have to say, building an 83" long bridge with an easement in the curve is going to be some kind of challenge. I hope you will post your progress on that project. That 83" long bridge will dwarf my 30" effort. 

Actually Rich I think your project is much more challenging. The length of my bridge doesn't really make it more complex. You are scratchbuilding. I am simply making some standard modifications to ME components. I think my project will be more tedious than difficult. I have to figure out the instructions for building the bents but once I have those down pat it will just be a process of repetition. I have to shorten the bents by about 1 1/4" so that will require some contemplating. The curve will be easy to duplicate because the  plywood roadbed is already in place where the bridge will be. We are going to imprint the track position on a sheet of 1/2" rigid foam so it should be easy to mitre the deck girder bridges to match the curve.

Maybe I am being naive. It wouldn't be the first time.

Dave 

Dave, just be sure to post on your progress. I, for one, love to see all kinds of structure building, especially kitbashing and scratch building.

Rich

[richhotrain]

mbinsewi

 

caldreamer

That is an easy scratch building project using Pastruct and/or Evergreen sturctural pieces.  

OK then....  nothing like some positive encouragement.

Can't wait to see as you progress with the tower build, Rich.

And actually, I'm waiting to see some of the Hulett. 

Mike. 

LOL

Mike, I just hope that Cal is right. I prefer easy to challenging.

Rich

[hon30critter]

richhotrain

I have to say, building an 83" long bridge with an easement in the curve is going to be some kind of challenge. I hope you will post your progress on that project. That 83" long bridge will dwarf my 30" effort.

Actually Rich I think your project is much more challenging. The length of my bridge doesn't really make it more complex. You are scratchbuilding. I am simply making some standard modifications to ME components. I think my project will be more tedious than difficult. I have to figure out the instructions for building the bents but once I have those down pat it will just be a process of repetition. I have to shorten the bents by about 1 1/4" so that will require some contemplating. The curve will be easy to duplicate because the  plywood roadbed is already in place where the bridge will be. We are going to imprint the track position on a sheet of 1/2" rigid foam so it should be easy to mitre the deck girder bridges to match the curve.

Maybe I am being naive. It wouldn't be the first time.

Dave

[mbinsewi]

caldreamer

That is an easy scratch building project using Pastruct and/or Evergreen sturctural pieces. 

OK then....  nothing like some positive encouragement.

Can't wait to see as you progress with the tower build, Rich.

And actually, I'm waiting to see some of the Hulett. 

Mike.

[richhotrain]

hon30critter

Hey Rich,

You have already proven your bridge building skills so I'm looking forward to following your building of the towers. Great project!!

I am about to start building a bridge for the club which will be 83" long with an easement in the curve. The bridge starts with a Central Valley 200' truss bridge and then uses an ME 85' plate girder followed by a series of 30' plate girder sections on the bents with 50' plate girder bridges between the bents. I have never attempted anything like this before but having seen what modellers like you have done, I'm not worried that I can pull it off.

Dave 

Thanks, Dave.

I have to say, building an 83" long bridge with an easement in the curve is going to be some kind of challenge. I hope you will post your progress on that project. That 83" long bridge will dwarf my 30" effort.

Rich

[richhotrain]

caldreamer

That is an easy scratch building project using Pastruct and/or Evergreen sturctural pieces.  Try building an ore hullett.  I did and it took me three months to build. I used the article in the October 1997 RMC.  It is really a complicated beast.

 

An easy scratch build project?? Ooh, that hurts. 

I'll tell ya what. Post some photos of your ore hulett for my needed inspiration. I would have no objection to you posting some photos on this thread. It would be fun and instructive to see them.

Rich

[hon30critter]

Hey Rich,

You have already proven your bridge building skills so I'm looking forward to following your building of the towers. Great project!!

I am about to start building a bridge for the club which will be 83" long with an easement in the curve. The bridge starts with a Central Valley 200' truss bridge and then uses an ME 85' plate girder followed by a series of 30' plate girder sections on the bents with 50' plate girder bridges between the bents. I have never attempted anything like this before but having seen what modellers like you have done, I'm not worried that I can pull it off.

Dave

[caldreamer]

That is an easy scratch building project using Pastruct and/or Evergreen sturctural pieces.  Try building an ore hullett.  I did and it took me three months to build. I used the article in the October 1997 RMC.  It is really a complicated beast.

[richhotrain]

I will be using Central Valley Model Works Heavy Duty Laced Bridge Girders (#1900-5) to build the tower superstructures. 

One of these kits contains 5 sprues, and each sprue contains 2 solid beams, 6 large X-braced beams and 3 small V-braced beams. Actually, these are half beams that need to be joined together to form a single finished beam.

I will be joining X-braced beam halves to solid beam halves to form the vertical and diagonal beams. I will be joining two x-braced beam halves together to form the horizontal beams and joining two V-braced beam halves together to form the horizontal cross supports.

So, in total, each kit will have enough parts to form 10 solid beams, 10 X-braced beams, and 10 V-braced beams. My estimate is that I will need 232 individual parts to build the two tower superstructures. So, that means that I will need to purchase 8 kits.

This will be tedious work because I need to paint the inside of each half beam before gluing the half beams together to form single finished beams. The insides of the joint beam halves need to be painted, since they will be visible through the lacings.

Rich