Entrenchments in river/bridge hexes and/or airfield hexes.

[Brett Nicholson]

I have currently begun a scenario ('South Africa's War' #1: South African Armour) where the defending player is allowed to place 3 entrenchments during intial deployment. I looked through the annotated rules and didn't see any restrictions about placing entrenchments and there aren't any mentioned in the scenario rules. My main concern is if I am allowed to place an entrenchment at the bank of the bridge would the defenders get additional defensive bonuses during the first round of an assault as there are no engineer units on either side. Meaning a total of (-4) v.s. an assault with (-2) for the entrenchment and another (-2) for being a river/bridge hex (re:rule 5.75)? I am not sure whether the bridge negates the river hex assault modifier or not. Also, the airfield hexes provide a natural (-1) modifier but if I am allowed to place an entrenchment there would the modifier jump to (-3)? A final question arises about the river. It is my first time using 'Eastern Front' maps (map in question is EF#3) and the scenario instructions do not indicate whether the river is major or minor, only mentions the bridge. In this case should I assume that the river is major since there is a bridge? There is one AAR written for this scenario but I couldn't find any answers there.