 Later, it was established that the LCM-6 was too small to serve effectively, and howitzers were positioned on Navy AMMI pontoon barges.When these proved to difficult to move and to have too deep of a draft, barges formed of Navy P-1 pontoons were the workable solution.M101A1, and later M102 howitzers were mounted onto a baseplate welded to the barge deck, allowing the howitzer to be traversed 360 degrees.