The Heavy Mortarer is a 3rd-tier class introduced in Valkyria Chronicles 2. They can be promoted from Mortarers as part of the Lancer Class Tree. They wield more powerful heavy mortar lances at the cost of lower mobility. Other than having lower AP, they are an upgraded version of mortarers.
Gallian Heavy Mortarers
Heavy mortarers did not exist in Valkyria Chronicles.
Valkyria Chronicles 2
Their role and equipment are the same as their Gallian counterparts.