I want to create a similar

I want to create a similar scene to this, but it is doing to be a challenge, as the track is curved and close to the back part of the layout.

I have a bridge kit that gives me the option of a ballasted deck instead of an open deck, but I will need to kit bash the deck to make it wider to accommodate a 42" radius. The kit's deck is too narrow for my longest passenger car and RDC.

I probably can split the deck down the middle and put in a spacer.

I positioned the narrow river

I positioned the narrow river behind the bridge coming from a future module. The estuary taking up about one third of the module.

Your bridge scene is possible ....

You just have to make a small section of straight track for the bridge.

Thanks Steve,With good

Thanks Steve,

With good easements of both sides of the bridge I can see this is possible. 

Somewhat of a problem is not knowing what space I will have in another room in the future plus I haven't decided on the great options that have been presented to me by forum members for the other module.

I need to keep the track simple and probably removable to the  left side of the bridge in case one day I need to tear it up to accommodate a future module's track plan.

Looking Good

Yes. That's a great looking idea. A shorter bridge like in the proto picture. In fact, why don't you do the girder bridge. That solves any problem with length of loco/cars. I realize you already have a bridge to use. But a girder can be scratch built. Just my usual 2¢ worth. I still love what you are accomplishing.

Morgan, I'll look up what a

Morgan,

I'll look up what a girder bridge is. I can always find a home for the kit I have; perhaps the fourth module.

I always value you 2 cents worth.

Girder bridge

Is what you have in your proto picture. That is a girder under, so that the track is clear above. Other girders are on top, or beside the track. The picture you show is exactly what I meant. It may be that you'd have to have a straight track over the bridge? So it wouldn't be a steady curve. (Similar to what we had to do with toy train track. You'd have 2 or 3 curves/9" long? a straight section and more curves to complete the curve you desired.) 

Dee: Re Bridges,

deck girder - the surface the ties of the track are laid on is in line with the upper edge of the girders. 

through girder - the surface the ties of the track are laid on is in line with the lower edge of the girders, such that the girders form two walls the train must pass between; these result in clearance restrictions, among other things; not just for big loads, but also for plow and other MOW purposes.  They're also more easily damaged in a derailment.

ballasted deck girder - the surface of the bridge, whether it be a through or deck type, is closed, usually as a concrete trough in order to contain ballast, in which the ties of the track are subsequently laid.  Much more common in modern construction, and usually configured as a deck girder, though I'm sure there are through girder examples.

A deck girder is likely the most efficient (I'm no engineer, though), because the girders can be spaced closer together, with subsequently less bracing and decking; it's also easier to allow (slight) curvature in the track, as there are no outer 'walls' to contend with.  Deck girders are generally preferred, while through girders appear more often in locations where the elevation above surroundings required more clearance under the bridge than a deck girder would allow.

Blair

Curves on

deck bridges aren't a big issue, within reason, though they often result in speed restrictions due to lateral forces.

Consider this bridge (photo credit Chris Van der Heide):

http://trainweb.org/algoma/Images/Locations/montrealfalls/trestle2.jpg

A speed restriction limits the train to 5 mph.

Each segment is, of course, straight, with the rail curve above it; the RR achieves more than 90 degrees of curvature from one side to the other, with a straight segment in the middle.

Hope this helps,

Blair

Blair,The kit I have gives

Blair,

The kit I have gives me the option of making it a ballasted deck.

I can eliminate the "walls' by building up the height of the deck with some homasote

plus track on it brings the it almost flush with the top of the girders so overhang from passenger cars will not hit any thing.

and the 42 radius appears to look good.

Morgan,I'm going to tweak

Morgan,

I'm going to tweak the bridge to have the girders almost flush with the track.

See previous page.

Experimenting with tweaking

Experimenting with tweaking the bridge before assembling it.

Deck is what I meant

Dee: I do like the way you are going about this, but I still like the deck bridge as you showed in your proto picture of what you originally intended. It was fairly short and would look nice in that sketch you showed that had the bridge in the corner. You might even be able to put the foreground with both water and the inlet that is dried up. i.e. Make the water extremely shallow almost like a creek with lot's of silt. i.e. Combine the proto photo with your sketch and the "inlet with the tide out". All in one module. You certainly should have the depth for a deck. The through girder just don't look right to me. However, in all honesty, when you get the module finished, I'm sure it will be nice. You have good modeling skills and will get a result that will satisfy you. Even if it's a through girder!

Tweaking the bridge.

   Hi Dee,  A deck girder bridge usually has the two long deep girders spaced to be under the rails with the bridge ties extending out beyond the girders a couple of feet ( more if they wanted a walkway beside the rails). The problem with putting a curve on a deck girder is you can't keep the rails above the girder, so would be easier to insert a length of straight track at the bridge location. If the left side of the durve could be straighten to aim more toward the center of the next module you could put the straight section and creek over to the left a bit.? .....DaveB

DaveB, So this is a deck

DaveB,

So this is a deck girder?

and the one in this pic is a through girder, as the ties are just below the the walls and inside them?

Morgan, I'm finally figuring

Morgan,

I'm finally figuring out the definitions of the bridges.

Shallow water like a creek sounds good.

Quote DaveB: The problem with

On deck bridges the girders are usually farther apart then the rails. According to UP standards the girder centers are between 7' and 9' apart depending on bridge span. I've seen others where the distamce is 6'-6''. The ties carry the rail loads to the girders, on reason for the closer bridge tie spacing.

If you have a curve on a deck bridge the bridge remains straights. The girders are set so far apart that the rails remain between the girders: https://model-railroad-hobbyist.com/sites/model-railroad-hobbyist.com/files/users/Selector/IMG_4513rr.JPG

The photo is from a MRH thread called Curved Bridge which has more examples: https://model-railroad-hobbyist.com/node/35251

Yes, it is a through girder bridge. A railroad would build one where the clearance beneath gets too small for a deck girder bridge. The deck girder is cheaper to build as it lacks the floor construction of the through girder bridge.
Regards, Volker

Volker,The kit I have is a

Volker,

The kit I have is a through girder bridge and I think I can adjust it to look more like the one in the photo in regards to the look of having the ties just below the girders. I can build up the deck a bit.

Dee... If you need the

Dee...

If you need the clearance below the bridge then use it in stock form, ie the plates above the rails. If not then you can convert it to something that has the plates below the deck. The plates would benefit from small changes though. If the deck is wide enough then with such a large radius curve I think you could pull it off.

Sorry Yannis, I don't quite

Sorry Yannis,

I don't quite understand. When you refer to plates, do you meant side girders?

Yes

Dee: Now you are on the right "track"! LOL/pun intended. The bridge you show on the proto is just about perfect for you. The girders are really just attached to the sides (speaking about a model, they don't have to be structurally sound) And like I also mentioned, the track might be straight through that bridge. Your bridge model appears to be longer than the proto, but that only means that the track if straight, will be longer. Just make the adjustment in the diagram. i.e. Place the bridge where you want it. In the middle, on the left, or wherever.

  "and the one in this pic

Hi Dee, Yes it appears that photo is a through girder bridge with the track level up near the top of the girders instead of lower down between them as is more common.If you can raise the deck level of your kit you should come out looking close to the prototype bridge. You might also look in to trimming the curved top ends of the girder so it has square ends like the photo.....DaveB 

I raised the deck to look

I raised the deck to look more like the one in the photo.

I still have to put the plates on the girders and bridge shoes on.

And a shot of a 42" radius, which I will not probably use.

Still, doesn't look that bad,

Time to put the plates on the

Time to put the plates on the girders and to think about what colour to paint it and how to weather it.