Category Archives: Mortars

3,180 shots at Fort Sumter between August 3 and 14, 1864: Third Major Bombardment continues

On August 16, 1864, Lieutenant-Colonel William Ames, Chief of Artillery of the Northern District (Morris and Folly Islands), Department of the South, provided an in progress report for the Third Major Bombardment of Fort Sumter.  The bombardment, which started on July 7, was at that time in its sixth week.  Ames provided this tally for the ordnance expended:

I have the honor to report the following number of projectiles and guns as expended in the bombardment of Fort Sumter from August 3 to August 14, inclusive: Three 200-pounder Parrott guns; 304 30-pounder Parrott shells, 299 100-pounder Parrott shells(*), 772 200-pounder Parrott shells, 13 300-pounder Parrott shells, 219 10-inch columbiad shells, 1,465 10-inch mortar shells, 108 13-inch mortar shells; total, 3,180.

The Third Major Bombardment had exceeded both previous “major” bombardments in terms of duration.  But it remained behind the Second Major Bombardment in terms of number of shots fired at Fort Sumter.  The problem facing the Federals was the amount of ordnance on hand – both guns and projectiles.  Already the Army was forced to borrow from the Navy.  And the Army lost three 200-pounder (8-inch) Parrotts during the first half of August.

The breakdown of rounds fired also illustrates some changes in the type of fires.  Recalling Ames’ reports from July 26 and August 1 for comparison, consider the proportions.  First from the period from July 7 to July 22:

ShellsFired_July7_July22

More than half of the shots fired were from 100-pdr and 200-pdr Parrotts (that would be 6.4-inch and 8-inch for those who prefer the bore diameter designation… like me).  The mortars provided a quarter of the shots fired.  In the minorities were 30-pdr Parrotts, 300-pounder Parrotts, and the columbiads.

Then from July 23 to August 1:

ShellsFired_July23_Aug1

The mortars increased in proportion to nearly a third.  The 30-pdr Parrotts provided a quarter of the rounds fired.  Triple the number of 300-pdr (I mean 10-inch) Parrotts.  Four times increase in the proportion of the columbiad contribution.  And decreasing noise from the 100-pdrs and 200-pdrs.

And from August 2 to August 14:

ShellsFired_Aug2_Aug14

Now the mortars shouldered half the load.  The 200-pdrs fired nearly a quarter of the shots.  The columbiads sustained nearly the same ratio of shots fired.  But decreases from all the other Parrotts.  I’d love to see a breakdown of this on a day-by-day basis.  Furthermore, a similar breakdown, even if week-t0-week, for the other major bombardments would be interesting.

What these charts are demonstrating is the nature of the Third Major Bombardment. By the start of the second month of work, the Federals turned increasingly to vertical fires.  Some of the same reasons Federals at Petersburg brought up their mortars were at play.  Recall the Second Major Bombardment turned to mortars in the later part of November. However, the Third Major Bombardment of Fort Sumter was burning out resources faster than they could be replenished on Morris Island.

∗The “printed” official records indicate this as “200-pounder Parrott shells” but given the sequence and other information surrounding this report, I think that is a misprint and sh0uld read “100-pounder Parrott shells.”

(Citation from OR, Series I, Volume 35, Part II, Serial 66, page 241.)

Mortars and shells wanted at the front: Importance of horizontal fires at Petersburg

We often read the Petersburg siege demonstrated the emergence of “modern war” in some fashion.  The “coffee table book” history draws the the comparison between Virginia trenches of 1864-5 to French trenches of 1915-8.  There is some resemblance, but no more than any functional nature would derive.  Men can only dig a hole in the ground for protection in a finite number of combinations.  Nice surface comparison, but for the most part the trenches are not exactly a mountain of evidence for the “modern war” argument.

If looking to draw positive connections between Petersburg and the tactical nature of warfare in 1915-18, there are two aspects I suggest we examine – the increased use of vertical fires and  changed operational tempo.  That latter point – what we call OPTEMPO in modern parlance – I’ll save for a later post.  But I have mentioned vertical fires earlier this year in relation to the Overland Campaign… particularly Cold Harbor.  And of course, mortars were heavily employed to support the assault after the mine went off.  In the late summer of 1864, the mortars took on added importance at Petersburg. A series of correspondence on August 14, 1864 demonstrates this. That morning, Brigadier-General Henry Hunt wrote to his capable subordinate, Colonel Henry L. Abbot in charge of the siege artillery, directing mortars to the front:

Four 10-inch mortars with a proper supply of ammunition are wanted in the battery near the Taylor house to control a battery of 32-pounder rifles just beyond the crest, distance from 1,200 to 1,500 yards. It would be well to get them out to-day ready to move; they may be ordered into battery to-night. I will inform you then whether to send them. Please answer.

Hunt’s request was to meet a specific tactical need – silencing a Confederate battery that occupied a particularly troublesome position.  The answer to this problem was not direct, or horizontal fire.  Rather he proposed using heavy mortars to fire indirectly, or vertically, onto the Confederate position.  Abbot answered almost immediately that morning and set in motion actions to place the mortars that night. Abbot later suggested a specific position for the mortars, based on earlier experience along that line:

If the 10-inch mortars are ordered forward, I would earnestly request that they be put in the fourteen-gun battery where Pratt’s 4½-inch guns were. The range is essentially the same. The approach to this battery is very good, and to the old battery very bad, a matter of great importance in supplying 10-inch ammunition on account of its great weight; and, moreover, this battery is well made and the old battery very ill constructed, constantly caving under mortar fire.

 Looking back at Hunt’s map illustrating the artillery support during the Battle of the Crater, Pratt’s battery is indicated by the number “24″ and circled in blue below:

PlateLXIV_3D2

The correspondence does not specify which Confederate battery was the target.  For the map above, I’ve highlighted one such battery, which would be “beyond the crest” and approximately 1,500 yards distant.  Notice the close proximity to the mine crater. The range cited was well within the capabilities of field pieces. The Confederate guns mentioned were indeed large caliber weapons.  But the Federals might have concentrated the fires of several batteries to damage the battery.  However, having read about the thousands of shells dumped on Fort Sumter, we must ask how long and at what cost would that be completed? 

There is no mention if Hunt required the use of 10-inch case shot from the mortars, as used during the Battle of the Crater.  That particular projectile, of experimental nature, would have done well to silence the Confederate battery while field pieces demolished the earthworks protecting the guns with direct fire. 

Concurrent with the correspondence with Hunt, Abbot also opened a request for more mortar ammunition… and not just a routine request… to Captain Theodore Edson, Ordnance Officer at Fort Monroe:

I am out of my supply of Coehorn mortar shells and the rebels are taking advantage of it. Please send me any shells and wooden plugs which you can possibly procure, on the mail boat, telegraphing me when they start. I don’t care for prepared ammunition. Time is very important.

Backig this up, Abbot further explained the pressing need for mortar ammunition to Brigadier-General George Ramsay, Army Chief of Ordnance in Washington and indicted this was a long standing request:

I have sixteen Coehorn mortars in position and not a shell in depot for them. The rebels keep up a constant mortar fire on us. I don’t care for prepared ammunition; all I want are shells, fuse-plugs, and paper fuses. These must be received very shortly or the army will suffer. I wrote on 15th ultimo, and telegraphed on 19th ultimo and 11th instant for a large supply. Please inform me at once whether I am to be supplied. Please also send 2,000 Parrott time-fuse plugs for siege guns.

The Confederates had also learned the value of vertical fire, and were now in position to employ some of the heavy mortars from Richmond along with some expedient weapons.  And at the same time, the Confederates were commencing production of their own Coehorn mortars.

Fast forward to 1917. When preparing the American Expeditionary Force for combat in France, American officers found themselves short of artillery in general.  But most acutely they called for howitzers and mortars capable of high angle fires.  Henry Abbot would have given them an “I told you!” look.  Vertical fires would become the dominant form of artillery support on the battlefield.

(Citations from OR, Series I, Volume 42, Part II, Serial 88, pages 182-3.)

 

Artillery support when the Petersburg mine went off

As you might guess, when thinking of the Crater at Petersburg, a subject which crosses my mind is the use of artillery in the operation.  Not to diminish the other aspects of the battle, but the artillery of the Army of the Potomac played an important role there… and is somewhat overlooked in my opinion.  I’m not an expert in the battle.  So I would direct you to one of many folks who have written book length treatments of the battle.

My schedule has prevented me from writing up more on Petersburg up to this time.  Likely, given the sesquicentennial pace, I’ll have to put that on my “after April 2015″ stack.  But I did want to mention the artillery’s role and provide a graphic depiction, by way of Brigadier-General Henry Hunt’s map:

PlateLXIV_3

The map, and a busy map it is, includes a table breaking down by battery the type and number of guns engaged on July 30, 1864:

PlateLXIV_3A

For those who are squinting, the roll call is eighteen 4-½-inch rifles, two 20-pdr Parrotts, fifty-two 3-inch rifles (3-inch Ordnance or 10-pdr Parrotts), thirty-eight 12-pdr Napoleons, ten 10-inch mortars, sixteen 8-inch mortars, and twenty-eight Coehorn mortars.  Grand total is 164 guns and mortars brought to bear on the Confederate lines in support of the assault.

Some of that number were in the 18th Corps sector and not firing directly in support of the assault.  Others were, likewise, firing on the 5th Corps front well to the south of the crater.  But all were firing at some time that morning to suppress or pin down the Confederates in conjunction with the assault.  For comparison, the “great bombardment” by the Confederates on July 3, 1863 during that “contest” at Gettysburg involved about 140 guns.

Hunt’s map indicates not only the battery positions, but also what the targets were.  This adds to the “clutter” on the map. But this is an incredible resource for determining his intent with respect to the fires placed upon the Confederate lines.

PlateLXIV_3B

The snip above looks at the area of the mine, and just south.  Notice there are more dashed blue lines leading to the Confederate redoubt south of the mine than there are the redoubt above the mine.  Suppression of the Confederate line was the intent there.

Another Federal position worth noting is that of Company C, 1st Connecticut Heavy Artillery.  Battery number 8 on Hunt’s map contained ten 10-inch mortars.  Circled here in blue.

PlateLXIV_3C1

Those mortars fired on approximately 1,000 yards of the Confederate front, to the south of the crater (blue shading in the snip above).  Recall, these mortars were firing, for at least part of the day, case shot as constructed under Colonel Henry Abbot’s instructions.  Battery Number 19, Company B, 1st Connecticut, with six 4-½-inch rifles, located north-east (center-right on the snip above) of the mortars also covered a large section of the Confederate lines.

One problem with these arrangements is that suppressing fire requires a high rate of ammunition expenditure.  Suppressing fire cannot be sustained, even by a master artillery chief such as Hunt, for longer than a few hours.  At some point, fresh ammunition chests must be rotated in.  The assault had to quickly achieve the initial objectives, or lose the suppressing fire support.