Not sure if this helps but some boat howitzers were used by the army and perhaps they used a limber. There were some boat howitzers made by wiard very similar to dahlgrens.
Army use of boat howitzers
Aside from use in naval service, boat howitzers saw service with the land forces as well. The boat howitzers were occasionally used in artillery batteries, but were more often used in infantry units, in a role that would later be called infantry support guns.
At First Bull Run, two boat howitzers were manned by Company I of the 71st Regiment, NY National Guard. The unit had trained on boat howitzers while deployed at Washington D.C., and when called to Bull Run, brought two of them attached to I Company. The guns unfortunately had to be left behind during the unit's withdraw and were captured by Confederate forces.
During the Antietam campaign, the 9th NY Infantry (Hawkins' Zouaves), Company K (Whiting's Battery) employed 5 Dahlgren Boat Howitzers (two rifled and two smoothbores) They fired on Confederate skirmishers at Snavely's Ford and suppressed them . The Confederate Grimes' (Portsmouth) Battery had 2 smoothbore Dahlgren Boat Howitzers, with which they fought near Piper's Stone Barn . The boat howitzers appeared to be popular - when Grime's battery was forced to turn in one of its guns, it chose to turn in a 3-inch Ordnance Rifle rather than one of its Boat Howitzers .
The 1st Regiment, New York Marine Artillery also armed themselves with boat howitzers, using it for its designed use of amphibious expeditions. The unit participated in 16 raids along the North Carolina coast employing their boat howitzers. The New York Marine Artillery was issued twelve 12-pounder rifled boat howitzers made by Norman Wiard out of semi-steel, a low-carbon iron alloy. Other than the material used, the Wiard boat howitzers were identical to the Dahlgren 12-pounder rifled boat howitzers. The Wiard howitzers were not made in large numbers .
Boat howitzers were used in the western theaters also. The Indiana Brigade used a Dahlgren boat howitzer in fighting near Grand Prairie, Arkansas on July 5, 1862. .
While boat howitzers were never commonly used by either army, by the end of the war their use by land forces was ....