In the series, which seems to favor the attacker, the bridge defense is difficult to bust but it can be done.
There are several bridge attacks in Napoleonic history that come to mind:
Lodi 1796 - the French attack into the teeth of the Austrian artillery and eventually take it after several assaults.
Landshut 1809 - the Austrians have to take a bridge to cross over the river and keep their advance going.
Ratisbon 1809 - the Austrians again have to take a bridge .....
Look at each of those and you will see that it did take time to take a bridge if it was aggressively defended.
In my games if someone tries to defend a bridge by being ON the bridge I just open up on that unit with artillery. Pretty soon it routs. If my opponent uses a "gamey" tactic of keeping a unit at the exit well there isn't much I can do about that. You could say that there was a "mob" on the bridge and that it was blocked to all traffic ...
But truly that is the one case where I think a House Rule could solve that problem. if the unit routs then the defending player cannot block the exit.
Other than that a bridge was hard to take if it was actively defended.
I am sure that other examples are there to be found ... the three I cite are some of the most famous. Oh add in Ebelsberg 1809 too ... sorry, forgot about one of the most heroic of them all. The French storm across a 300-400 meter bridge into a fortress-town no less! (Petre referred to Ebelsberg as one of the best defensive positions in Austria).
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Generalfeldmarschall Wilhelm Prinz Peters von Dennewitz
3. Husaren-Regiment, Reserve-Kavallerie, Preußischen Armee-Korps
Honarary CO of Garde-Ulanen Regiment, Garde-Grenadier Kavallerie
NWC Founding Member
For Club Games: I prefer the Single Phase mode of play. I prefer to play with the following options
OFF:
MDF, VP4LC, NRO, MTD, CMR, PR, MIM, NDM, OMR (ver 4.07)