How to build bridges during battles?

[Yorrick]

So Im fighting on the Antietam map and I see what looks to be a grey-out pontoon bridge of some kind next to the ford on the southwest side of the battlefield. is it buildable? How do I do that and what are the requirements?

[mogami_99]

place a unit with engineer capabilities on the spot and select build option. Some leaders are engineers

[Yorrick]

Sorry but that answer didn't work. What wound up happening was during the deployment phase I was able to build one bridge but not another, nor could I build the other bridge during the battle itself with any of my brigades or battalions, or even when I had an engineer leader on top of it.

[mogami_99]

during deployment phase in lower right hand corner of map you have Engineer points listed. I think you used all yours on that one bridge. (Brown box) You should get more every morning while battle lasts