Heavy artillery TO&E

[Carronade]

Does anyone have information on the organization of the Union heavy artillery regiments? I've been able to patch together a few bits; they usually seem to have had twelve companies, sometimes subdivided into three battalions, and a total strength of about 1800 men. The troops had some basic infantry training since, unlike field artillery, they could not always expect to operate in company with infantry; this facilitated their employment in that role in 1864-65.

What was the "break point" between light and heavy artillery? I know guns up to 20lb Parrotts were routinely employed with the field armies. Thanks for any info.

 

[Red Harvest]

From what I found in a quick read is that early in the war company size was around the standard 100 for infantry and company count was 10. This was the case for Union and CSA. But both went to 150 man companies later, and the Union also went to 12 companies per regiment.

The break point between light and heavy artillery was around the point where siege carriages were required. Siege artillery was heavy artillery and moved behind the army. Some field pieces (such as 12 pdr howitzers, etc.) would be part of the siege train for flank protection in emplacements.

12 pdr guns, 20 pdr Parrotts and 24 & 32 pdr howitzers were about the heaviest pieces that could be mounted on field carriages. 30 pdr Parrotts, 4.5" Ordnance rifles, 8" siege howitzers, and 24 & 32 pdr guns were mounted on siege carriages. The extra weight required either 8 or 10 horses per carriage depending on the piece, rather than the standard 6 of field batteries. In addition, the caissons took 8 horses instead of six as well. (This from Maj. Joseph Roberts' Manual of Heavy Artillery.)

I see some reference in the 1864 Field Artillery Tactics manual to 12 pdr guns (the heavy ones) requiring 10 horses although not explicitly stated. It shows 96 horses specifically for the 6 caissons and 6 guns, and an additional 36 for 6 additional caissons. So the guns themselves would have 96 - 36 = 60 horses per 6 guns, or 10 per gun. Extra draught animals were required for the bigger guns. I recall reading that 600 lb/horse was the standard, so really the heavy 12 pdr should only require 8 horses on a field carriage.