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Micro Engineering bridge tower height adjustments?

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  • Member since
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  • From: Bradford, Ontario
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Posted by hon30critter on Sunday, December 16, 2018 9:42 AM

7j43k
In the towers above, the diagonals should be tied to intersections of vertical and horizontal members.  They're there to keep the structure from racking.  On the left tower, there are parts of the verticals that descend below the last diagonals.  Those "legs" could bend and fail because of the lack of diagonals.

That's what I was thinking when I first saw the picture.

Thanks for your help.

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

  • Member since
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Posted by 7j43k on Sunday, December 16, 2018 9:20 AM

7j43k

 

In the towers above, the diagonals should be tied to intersections of vertical and horizontal members.  They're there to keep the structure from racking.  On the left tower, there are parts of the verticals that descend below the last diagonals.  Those "legs" could bend and fail because of the lack of diagonals.

Either the foundations should have been built higher, up to the lowest horizontal; or the dimensions of the lower story should have been modified: lower the right horizontal, add a lower horizontal on the left, connect four corners of panels with diagonals.

Wayne has an example of assymetrical base stories.  And one too long "leg".

 

 

Ed

 

 

 

 

 

 

  • Member since
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  • From: Bradford, Ontario
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Posted by hon30critter on Sunday, December 16, 2018 9:06 AM

Hi Wayne,

The bottoms of our towers on the long bridge will be visible because they will be in the middle of an industrial scene. They will be on level ground so if we have to do 2 1/2 storey towers at least the bottom beams will be parallel to the others.

We could kitbash the towers so that all the storeys are the same height, but that would be quite a project considering that we have four towers on one bridge alone.

We will also have some towers in a deep valley so I will keep your methods in mind. I didn't plan on using quite that much foliage however.

Thanks for the pictures.

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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  • From: Canada, eh?
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Posted by doctorwayne on Sunday, December 16, 2018 3:48 AM

7j43k
...This one, for example, has a left tower that looks funny, down towards the bottom....

It looks plausible to me, Ed, but if you wanna talk about "funny", here ya go...

...and the other end of the same bridge...

The concrete piers on the one in the front are okay, but that bridge in the background musta been separated at birth from the first one shown.

The first one got the lipstick-on-the-pig treatment, and is now just a scenic view for passengers on the trains...

If I ever get the projects I'm working on done, that high bridge will get a similar treatment, and maybe some "water" in the Speed River, too.

EDIT:  I almost forgot:  if you need to shorten the bridge piers, always do so from the bottom.  I built all of the bridges shown by constructing them, upside-down, on the equally upside-down 3/4" plywood subroadbed which originally spanned those chasms.  Since the terrain was already in place, I had to trim each leg of each tower to suit, and then place the concrete footings wherever the legs were going to end-up, all because some wacko engineer didn't bother to properly prepare the site.  Now I gotta be an arborist just to cover up his mistakes. Bang HeadWhistling

By the way, all of those bridges are removeable as single units.

Wayne

  • Member since
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  • From: Bradford, Ontario
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Posted by hon30critter on Saturday, December 15, 2018 8:35 PM

7j43k
and this one looks "righter":  

Thanks Ed,

I think you may have answered my question. The second picture shows concrete piers of different heights below the towers.

The area below the bridge will be mostly flat because we want to model some industries there. One of the towers may end up sitting partially on a slope at the far end of the bridge so the second picture helps a lot.

FYI, the bridge will be about 600' (83") in total. It will start with a Central Valley 200' through truss bridge sitting on an abutment on one end and a stone pier on the other. That will be followed by a Micro Engineering 85' plate girder bridge and then a series of four ME towers with 50 plate girder bridges between them. The bridge is curved but it doesn't have constant radius. The tightest radius is 32".

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

  • Member since
    May 2004
  • 7,500 posts
Posted by 7j43k on Saturday, December 15, 2018 8:16 PM

Dave,

 

I was about to make a pronouncement, and then thought that maybe I really didn't know.

I believe these towers TEND to be modular in height, but then they do have to solve problems of up and down terrain. 

So, I'd suggest going online and looking at prototype photos.  And see how THEY did it.

One thing I'm pretty sure about is that the diagonal pieces always intersect the verticals at connections with horizontals.  That means they don't just land "mid-span".

This one, for example, has a left tower that looks funny, down towards the bottom.  That's funny as in wrong:

 

and this one looks "righter":

 

 

 

Ed

 

 

 

 

  • Member since
    July 2006
  • From: Bradford, Ontario
  • 15,797 posts
Micro Engineering bridge tower height adjustments?
Posted by hon30critter on Saturday, December 15, 2018 6:41 PM

Hi again gang,

How do you adjust the height of a Micro Engineering bridge tower? The towers come as three storeys and they are 10" tall. Our track will be 9" above the scene below. Do we just go with two storeys and put the base on a raised platform or pilings?

Also, when they say "10 inches", I'm assuming that that doesn't include any type of bridge structure that will sit on top of the towers. Is that correct?

Thanks as always,

Dave

 

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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