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Viaduct Bridge Project

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Viaduct Bridge Project
Posted by Track fiddler on Saturday, January 9, 2021 10:50 PM

I had a thread a while ago on Bridges.  All the Bridges posted were appreciated by me. 

Since that time,  I have removed all of my constructed Bridges and replaced them with temporary Bridges on my layout so I can lay my track soon.

Bear posted a Viaduct Bridge that I was fascinated with.  If I forgot to pay him a compliment,  I pay that nowYes

Because of his post,  I decided to delete the plan of a double Trestle Bridge to be replaced with a double Viaduct Bridge on my Layout.

The plan is in the works and the stencils have already been traced.

I call it the Bridgemuda Triangle

It's getting quite late now.  I will be hitting the rack soon and getting back to this tomorrow.

 

 

 

TF

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Posted by doctorwayne on Saturday, January 9, 2021 11:26 PM

I've known a few women with curves like that, TF.....proceed with caution, and enjoy the ride. Smile, Wink & Grin

Wayne

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Posted by Track fiddler on Saturday, January 9, 2021 11:30 PM

LaughLaughLaugh

I haven't hit the rack yet Wayne.  A sense of humor before the presentation is always goodYes

 

And that was a good oneLaugh

 

 

 

TF

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Posted by Track fiddler on Sunday, January 10, 2021 10:32 AM

Originally I started making a stencil for the double line Viaduct Bridge.  

A break was left in the stencil so I knew where to place the arch over the tracks below while designing the sides.

The legs for the viaduct we're positioned symmetrically to the radius.  The rear of the legs were wider.  The angle of the tracks below did not allow enough clearance.  You can see the angle on the diagram above.

At that point I decided to Center the front stencil arch and use the same stencil centered over the tracks on the back as well.  This gave me enough clearance.  An addition came to mind at that time, that I could add a radius to run a separate line Into the Roundhouse servicing area.

This would allow me a separate line for a coal tower, a water tower and a sanding tower.

To be continued.  I just started this project yesterday and will continue after Sunday brunchDinner

 

Thanks for lookingSmile, Wink & Grin

 

 

TF

 

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Posted by NorthBrit on Sunday, January 10, 2021 11:52 AM

TF.  Bridge builder extaordinaire!      Well done.

 

David

To the world you are someone.    To someone you are the world

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Posted by mbinsewi on Sunday, January 10, 2021 12:53 PM

Great way to get the design started with the mock-up.

Mike.

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Posted by Track fiddler on Sunday, January 10, 2021 1:59 PM

Thanks David, Thanks Mike!  I always appreciate a complimentYes

 

Well,  After brunch I transferred the rough template to poster board and added 3/16 to the side radiuses for the new cutout.  These radiuses are appx. 21 to 22 that go over the viaduct.

My smallest radius on my layout is 18" and I did a test with my 4-8-4 Northern.  This locomotive's nose sticks out the most on outside curves of all my Steamers, even the Challenger.  3/16" outside the edge of the cork gave plenty of clearance.

I laid the side stencils on the Masonite for reference.  The bottom one is the original that needed to be changed.  7/8" looked a little beefy to me as I thaught 5/8" would look more cosmetically correct.

I also needed to subtract 1/4" as the inside Arch panels will be 1/8" on either side.  Reducing the foam legs gave me a quarter inch larger radius for more clearance is a plus.  I left the ends of the side panels run wild a little thicker than they will eventually be.  That way I can cover, or trim them to suit when I am doing scenery.

I think later this afternoon I'll transfer the templates to the 1/4" foam panels and take it from there. 

I'm kind of winging it here.  Fabricating the parts is the easy part of this project.  I'll probably need some participation when I have to put this thing together.  I have some question marks rattling around in my head on choice of assembly methods.  I'll be picking your guys's brains when I get to that pointYes

 

Thanks for looking

 

 

 

TF

 

 

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Posted by York1 on Sunday, January 10, 2021 2:05 PM

Nice work, TF!  I wish I had the knowledge and the room to attempt some of the things you are doing.

York1 John       

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Posted by Track fiddler on Sunday, January 10, 2021 4:26 PM

Good evening

Thanks John.  By the look of your scratch built building coming along on WPF and some other ones I've seen you build.  Looks like you're doing great to me with your modelingYes  I especially like that one cabin you built on the Mountain top.

 

I got the foam side panels going this afternoon.

I did screw up royally though.  After I got all the vertical lines done on one, it occurred to me I didn't take into account how many pannels I have to do.  A total of sixTongue TiedSad.  

It isn't exactly like doing brick lines on two twin portals.  The square inches is probably more like twenty of them.  A random stone pattern would have been much better as it's about ten times as quick and looks just as good, if not better.  You just scribble quickly,  little circles, little rectangles, little squares, thin one, thick one and before you know it you're done.

And I didn't take into account I have to cross all the outer T's on the inside arch panels after they are installed or they'll overlap the sailor course. 

I created way too much work for myself.  I'm screwed! LaughIndifferent

 

 

TF

 

 

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Posted by Track fiddler on Sunday, January 10, 2021 11:50 PM

I'm flipping this!

There's always a solution and I'm not going to let a 22" long piece of 1/4" foam get the best of me.

The other side of the foam is rough from the blade of the table saw because the operator was nervous. 

I will take some 80 grit on the orbital sander and resurface it kind of like the Zamboni resurfaces the hockey rink and have a fresh slate tomorrowYes as I claw the thin iceWhistling

 

MusicAll in all I'm not doing Bricks in the WallMusic Laugh

 

 

 

PiratePF not TF

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Posted by SeeYou190 on Monday, January 11, 2021 2:40 AM

Nice project.

I have always liked the looks of viaducts, but I have never attempted to build one.

Please keep the updates coming.

-Kevin

Wink Happily modeling my STRATTON & GILLETTE RAILROAD. A Class A line located in a personal fantasy world of semi-plausible nonsense on Tuesday, August 3rd, 1954.

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Posted by Track fiddler on Tuesday, January 12, 2021 8:15 AM

Good morning

Thanks Kevin,  will do

 

Well,  my first attempt on the assembly of the bridge failed.  The foam framing uprights that dried overnight are in place and holding.  I had a problem attaching the 1/4" arched side pannels. 

The resilience of the narrow top areas of the arches were weaker than the triangular sections in between that had more retention.  The flow of the curve was too inconsistent.

Two-in-one poly seam seal was not an aggressive or quick enough setting glue to hold with the T pins to offset the inconsistency.

Imgur is not working for me this morning or I would have posted pictures of the failure.

The problem with foam safe adhesives is they dry on the outside edge and stay wet in the center for sometimes weeks.  More aggressive setting adhesives melt the foam.  I cleaned things up with a damp cloth but I still have a bunch of question marks rattling around in my head, ...Flustered hereTongue TiedSad

Hopefully I painted a good enough picture without pictures to make things understandable.  Any ideas or suggestions are definitely welcomed hereYes

 

Thanks for your input in advance.

 

 

TF

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Posted by doctorwayne on Tuesday, January 12, 2021 11:13 AM

Track fiddler
Any ideas or suggestions are definitely welcomed here

Never having made a viaduct similar to what you're attempting, my choice of material would be styrene.  It can be bought in 4'x8' sheets, and in several different thicknesses.

For the amount you're doing, buy a gallon of MEK, as it's a great choice for bonding styrene, and the joints will harden quickly.

You can do straight cuts with a utility knife, and perhaps curved ones, too, but another option for the curved cuts might be a very fine blade in a jig-saw.
 
When doing the assembly, the joints can be filed or sanded shortly after the bond has hardened. 

As-is, a coat of paint can make it look like concrete, or you could use the utility knife to score-in mortar lines - one or two passes with the blade, then another with the back of the blade to make it more distinct.

The other advantage of styrene, especially when built in the shapes you're creating, is the strength once the joints have hardened.

I do realise that each individual usually has their own favourite medium for scratchbuilding, so this is only a suggestion for an alternative.

Wayne

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Posted by Track fiddler on Tuesday, January 12, 2021 7:30 PM

Good evening

Nothing really done on the model today except for rounding up a few things.

Thanks for the suggestion Wayne.  Styrene and styrene solvent always worked well on my truss bridges.  I am going to use your suggestion for a large portion of the project.  Now I decided to scrap all the foam panels. 

I went and picked up some plastruct Dressed Stone sheets #91590.  I like the uneven stone pattern and it looks like a pretty good size for N-Scale.  Unfortunately they only had one package so I ordered another one off ebay.

I think I'm going to leave what I have done so far and use 3M high-strength 90 contact spray adhesive to attach the styrene side panels to the Masonite base and the foam uprights.  Then I will have the edges of these panels to fuse to the inner styrene pannels to.

 

Great idea Wayne.  I think you probably saved me a lot of time and frustration with your suggestionYes

 

Thanks

 

 

TF

 

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Posted by doctorwayne on Tuesday, January 12, 2021 8:44 PM

Thanks TF.  I'm looking forward to following your progress.

Wayne

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Posted by "JaBear" on Wednesday, January 13, 2021 2:54 AM
Gidday Mr.TF, I feel kinda guilty that I may have led you down the garden path. The viaduct that I built was HO scale double track, straight, and made from a shaped timber core and covered with 1/8” MDF which apart from the laser cut brickwork at the top, the stone work was hand done using a dentist’s bit in a Dremel type tool. The raised “Keystones” are card.
 
Of course, none of the above is relevant to what you’re trying to achieve!
 
I’ve also not worked with foam either so I don’t know how the dissimilar materials would bond, so I’m not sure why you just wouldn’t build the whole structure from styrene.
As Wayne has intimated, done properly the joint strength is there. He also said we have our own favourite medium for scratch building, so feel free to completely ignore me!Smile, Wink & Grin
 
Cheers, the Bear.Smile

"One difference between pessimists and optimists is that while pessimists are more often right, optimists have far more fun."

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Posted by Overmod on Wednesday, January 13, 2021 6:12 AM

If you build the 'faces' in styrene, consider gently pre-bending them with heat before cementing.  Make some templates the shape of the transverse curve that you can 'drape' the styrene over and heat lightly with a hair dryer so that when it cools it will harden up in precisely the right complex curve.  (These templates might then 'double' as things to use to hold or weight the sheets compliantly while the glue sets up)

I think I would try something like E6000 or Goop to hold the sheets.  Or low-temp hot glue.  In a pinch if the face bonds turn out not to hold right, you could drill away some of the 'bottom' and reinforce the edges of the joints between foam and styrene from the back -- that might be very strong.

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Posted by Track fiddler on Wednesday, January 13, 2021 9:45 AM

Good morning

Thanks for your reply Bear.  Not relevant to the project I'm doing now as you stated.  I can still appreciate the method of construction you used on your bridge project.  I found it quite interesting and can relate to quite a few similarities to a project I once did years ago.

I put sheetrock panels over sheetrock to make the appearance of Roman slabs of stone.  Rounding the sheetrock panels with a quarter round bit with my router,  the neighbors thought I was quite insane kicking up all the dust in the driveway.  I'm sure they did not appreciate all the sheetrock dust all over their cars eitherLaughWhistling

Originally it was going to be a 150 gallon saltwater aquarium that would be serviced in the other room.  I spent a lot of money on the aquarium and the saltwater equipment but unfortunately I never finished that job before I sold the house.  A large mirror was installed and it was just painted instead of the stone faux finish.

 

Well, here is the theory I have switched my focus to after Wayne's suggestions.

I'm going to trace the templates onto Plastistruct stone stamped modeling sheets.  The 3M contact spray adhesive terrifies me.  I got pretty good with this stuff over the years with countertops.  But that's when you could leave a half inch overage to allow for misplacement.  I don't have that luxury for this small model.  A missalignment could be costly for lost time and materials.

Overmod,  I'd like to Thank you for your suggestion.  I'm not familiar with E6000 but I did some research on the internet.  I found nothing but Raves by other modelers on the ease of workability of this product. 

Apparently you have 10 minutes of working time for adjustments and it sets up in 20 minutes.  Sounds good to me!  This is exactly what I am looking for so I have time to achieve exact placement.  

Looks like it's back to the Hobby Store for some E6000Yes

 

Thanks everyone for your participation so far.  Your suggestions are definitely helping me out on this projectYes

 

 

TF

 

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Posted by Track fiddler on Wednesday, January 13, 2021 6:40 PM

Post Hog !

 

Am I allowed to do that on my thread?  Laugh

I think I can?  Although, I think someone else should.

 

Today I had a nuclear meltdown!  Seriously!  That's the only way I can look at things today.  Things are not going good here. 

Why is it that all my bridge projects get so complicated.

 

So I went to the Hobby Store to get E6000 per Overmods suggestion that I liked.  My luck at the hobby store was not good.  They were sold out as they are not doing a good job restocking as business is slow.

 

The other day while I was driving around and picked up the plaststruct stamped brick sheets and the contact Super 90 spray adhesive. 

I told Judy while I was driving I was not familiar with 90.  Can you look it up and see if it is foam safe?

Otherwise I was going to stop at Home Depot and pick up Super 74, .............She looked it up and said it was foam safe.

 

IT WAS'NT !!!!!!!!! IndifferentTongue TiedSad

The two on the right,  Hot Pink Purple! instead of soft pink, are the ones still melting.  The three white ones on the left are the ones I'm fixing with Fast & Final.  I send in that little "Sweeper Guy" Laugh

Good thing I taped everything off before I sprayed the 3M 90 Nuclear spraySad  The tape acted as a repair stencilLaugh

Well,  That's another 24 hour set back.  I'll let you know when things are going smoother.

 

I'll get this Kids!  Have a little faithWink

 

 

 

 

IndifferentTF

 

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Posted by York1 on Wednesday, January 13, 2021 7:06 PM

That's too bad, TF.  On the bright side, all of them didn't get ruined.

This hobby is supposed to be relaxing and enjoyable?

York1 John       

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Posted by Track fiddler on Wednesday, January 13, 2021 7:21 PM

All of the sides of the uprights did get ruined.

It Ain't So Bad John.  It is still relaxing and enjoyable. 

I've been so bored with the corona these days!  When something goes south I look at it as another challenge and I love challenges.  I'm the type of guy that says bring it on when a piece of material starts to argue with me.

I must say, things have not been going smoothly the last two or three days.  But they willPirate

 

That's why they call it "Trial and Error", ....... Bring it on I always sayYes

 

 

 

SmileTF

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Posted by Track fiddler on Wednesday, January 13, 2021 7:53 PM

Interesting

Sometimes chemical reactions of product work to your benefit.

It seems the meltdown of the foam from the super 90 is accelerating the Fast & Final repair job I'm doing. 

I just put on the second coat a half hour ago and it's drying faster.  I think I'll get the third coat on soon and I'll be back in business to continue in the morning.

 

 

 

PH

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Posted by Track fiddler on Friday, January 15, 2021 2:01 PM

Good afternoon

I decided to let the Fast & Final repair job on the melted foam dry a few days before continuing.  I definitely don't want to have any more problems.

I taped off the faces of the side panels to protect them from the adhesive.

I got them installed with the E6000 edhesive this afternoon.  it worked good.  I have a few discrepancies to iron out but no big deal.  I plan to cut some strips of thin styrene and glue them to the bottom sides of the legs and in the middle of the arche tops.  I will need to cut some thin pieces of foam for spacers in some areas.

This will provide a solid base for the styrene solvent to attach the inside arch panels.

Then it's hurry up and wait for my other panels to come in the mail from eBay.

 

I appreciate all the suggestions so far.  I've had a bit of a rough road but things are going smoother now.

 

 

 

TF

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