Help with the Cresson Bridges

[Specter3]

I am going to splice a couple of Atlas bridges for the main span. Looking for ideas for the other two.

[davefoxx]

Take a look at Micro Engineering's bridges and see if there's anything there that will work for you.  I have a half-built 80' plate girder bridge that I can no longer use that you are welcome to.  They also make 40' plate girder bridges, too.

DFF

[sirenwerks]

There's a two article series in NSM (11-12/92 and 1-2/93) that may help, on a multispan bridge that is part thru plate and part girder viaduct.  PM if you want copies.

[Specter3]

Thanks guys. Oh and if anyone has better pics of the other bridges I would appreciate them as well.

[jimmo]

Are you planning to make the bridges to exact prototype scale or selectively compress them?

How many tracks are you planning on crossing in this scene?

From some of the other pics on the Conrail Historical Society site, the longest bridge appears (to me) to be about 100 feet or so. If you are going to compress the scene, Micro Engineering's 80 foot plate girder will work. But you're going to have to build the thru version yourself because they only make thru girder bridges for HO-scale. Their 40 foot plate girder would work as the second bridge and the last bridge appears to be an even smaller thru plate girder at maybe 30 or less feet. I would look for a z-scale bridge for that one since I'm not aware of any smaller plate girders in N-scale. I wouldn't recommend cutting down a larger bridge because it would be a model of a bridge that is engineered to be the length it is. Splicing two Atlas 60+ foot bridges will make a model that is too light for a railroad bridge. It would need to be a much taller girder.

[Specter3]

It will cross 5 tracks at ntrak spacing. The second will cross a road. It will be sized to look ok on the module crossing those tracks. The large span does have an imposing height to it. I wonder if there is an HO bridge that could be used and perhaps cut down the middle and narrowed. I got a nice article on scratching from Sirenwerks and could if given time make some pieces, but time is really short and a suitable stand in may be used for a while. And anyway the PRR signals attached are going to be hard to get as well so the big bridge with decent signals may be a phase 2 proposition.

[jimmo]

It will cross 5 tracks at ntrak spacing. The second will cross a road. It will be sized to look ok on the module crossing those tracks. The large span does have an imposing height to it. I wonder if there is an HO bridge that could be used and perhaps cut down the middle and narrowed. I got a nice article on scratching from Sirenwerks and could if given time make some pieces, but time is really short and a suitable stand in may be used for a while. And anyway the PRR signals attached are going to be hard to get as well so the big bridge with decent signals may be a phase 2 proposition.

Sounds like you could use some CAD/Shapeways magic.
 

[Specter3]

Think that girder is 13 feet high?

http://www.modeltrainstuff.com/Central-Valley-Model-Works-HO-72-Girder-Sections-p/cvm-1903-1.htm

HO scale bridge

[sirenwerks]

Think that girder is 13 feet high?

A good way to figure that out is to look at some other photos and reference the girder height to other details in the scene.  For instance, this photo:



https://www.flickr.com/photos/91503777@N04/15781202630/in/photolist-po6c3u-po6txy-qhNDQq-qk5CEz-q3wMJw-pok3se-pojMog-q3FhRv-po6B4A-qk5USK-qjUWeD-q3DFs8-qk61QM-po6Jtq-q3F5Mv-po6wyd-q3wBFq-po6aAm-qk2h2J/

Compare the girder height to the railing height or the dims of the signal head.  The signal head's size is probably standard and easy to find out from those in the know (hey, Conrail queens!).

[jimmo]

Think that girder is 13 feet high?

http://www.modeltrainstuff.com/Central-Valley-Model-Works-HO-72-Girder-Sections-p/cvm-1903-1.htm

HO scale bridge

Looks more like 10 feet to me, judging by the hopper under (or almost under) the bridge that is 10 feet wide. That also means your prototype is about 97 feet long. Your HO-scale bridge at 72 feet is about 132 feet in N-scale.

[ Guests cannot view attachments ]

You might consider cutting the HO bridge down to size since you are going to have to modify it quite a bit anyways.

[jimmo]

That's a great view of the other end of the bridge. I took a piece of the pic and adjusted it to where I could see the short span detail better. It actually is a deck girder with a walkway extension to match the other spans. It kind of looks like canvas in between the walkway and the deck girder.

[ Guests cannot view attachments ]

Great little modeling challenge.

[jimmo]

IMHO (if it were to be a compressed scene), I would go with a Micro Engineering 80 foot for the big span, an Atlas 60 foot for the center span and a Micro Engineering 40 foot deck girder for the short span.

To add to the fun, it appears that the bridges are skewed as well. Can anyone verify (or deny) this?

[jimmo]

I just discovered that Kato makes a 100 foot thru girder bridge in N-scale.

[Specter3]

Yes it is skewed. Sirenwerks, thaks for that pic of the other end. That is a lot of detail I was missing. Followed the link and looked at his pics. That guy just made my life a lot easier.

[John]

Yes it is skewed. Sirenwerks, thaks for that pic of the other end. That is a lot of detail I was missing. Followed the link and looked at his pics. That guy just made my life a lot easier.

the internet is such a great resource for stuff like this..