In building my high steel trestle on a curve from ME I have run into another problem that may or may not solve itself and only you who have built one will know. What the problem is that when I build the bents, no mater how hard I try to keep them straight, they tend to bend slightly and I want to know if this will correct itself when actually installed as then it will have a full bottom and top and as a bent, it dose not! Also of note, the plan is to do single bents instead of towers. On another note I would like to extend two of the bents with the materials at hand, anyone done that as I will have some extra bents if all goes well.
You have a picture of it?
Nothing really to show yet!
Is this similar to what you are looking to build?
When you say they come out bent are you refering to them not lining up exactly straight, top or bottom? I would build them side by side to better insure they are identical. You will likely have to sand a little here and thee to make them match so when you glue in your girder spans they will be less likely to go astray. I am sure there are others here with more experience than me on my one bridge.
Hope this helps at least as reference.
Love the way you ended the bridge on the left side. What I am planing is single bents (yours are double) and from top to bottom when I build them, they curve (not much but noticeable) but I have not installed them yet but if installing will not fix the curve, then I need to come up with another solution.
I assume that by “curving” you mean that the the bents do not remain perfectly vertical, that they bow outward like a “C”.
One of the reasons real civil engineers didn’t use single bents on tall structures without sway bracing. 
I doubt that the bents can actually be load bearing, the plastic isn’t rigid enough and without some form of sway bracing it will bend. You can add sway bracing or run a piece of brass strip up through the inside of the vertical beams as a stiffener.
nice pict & bridge John is it Ho or N ?.. and Im having a bit a trouble following this maybe cause Im some what green but ,is the term" bent "discribing a part of the tower or is it discribing the tower itself.?..Jerry
The bent is the vertical parts, a term left over from long ago.
That’s exactly what I mean, might fix it with the wire and turnbuckle bit but I saw one with just single bents and that is the way I am trying to go. The reason for the question is alot of times things that are crooked get straightened upon installation.
Thanks Jerry. Are you Jerry who I met at the Great Train Expo recently. I think we spoke at the N scale Inland Pacific layout for a spell. That said you probably figured that this scene is N scale. It is part of my home layout.
As described before the term bent is refering to the upright supports.