Summary Statement, 1st Quarter, 1863 – Pennsylvania’s Independent Batteries

The method used by the Ordnance Department for designating and tracking returns from Pennsylvania’s independent batteries leaves a lot to be desired.  In their defense, the state did not aid their administrative endeavors with simple unit designations.  The way I organize these units, in my mind at least, involves recognizing there were “Independent Batteries” which were given lettered designations as such.  And there was a second set which, due to various reasons, were identified by battery commander – some not existing long enough to gain the lettered designation; some being reorganized and placed in heavy regiments; and some simply escaping any “regimented” designation.

That in mind, here’s a list of the former:

  • Battery A – Schaffer’s Battery
  • Battery B – Stevens’ or Muehler’s Battery
  • Battery C – Thompson’s Battery
  • Battery D – Durrell’s Battery
  • Battery E – Knap’s Battery
  • Battery F – Hampton’s Battery
  • Battery G – Young’s Battery – not listed above.
  • Battery H – John Nevin’s Battery
  • Battery I – Robert J. Nevin’s Battery (not formed until June 1863)

With those in mind as sort of a translation table, let’s sort out the first quarter, 1863 summary of returns:

0140_1_Snip_PA_Ind

And a lot of sorting we will need.  Notice that only seven of the fifteen batteries indicated posted returns.  And one of those seven had a posted date of April 10, 1864.  So there are a lot of gaps to start with.

  • Mlotkowski’s Battery – Battery A – Reported at Fort Delaware, Delaware, but with no cannons.  The duty location and commander’s name matches to a 1st Pennsylvania Battery (also cited as Battery A Independent Heavy Artillery), under Captain Stanislaus Mlotkowski. If so, this was previously listed under Captain Frank Schaffer.
  • Durrell’s Battery – Battery D, of the independent batteries mentioned above. – No return. Captain George W. Durell commanded.  Assigned to Second Division, Ninth Corps.  Following the “Mud March” the battery accompanied the division to the west, to a posting in Kentucky at the end of the winter.
  • Roberts’ Battery – No return. this may be a reference to a battalion of heavy artillery organized by (then) Major Joseph Roberts.  The four batteries in the formation later became Companies C, D, F, and (part of) K in the 3rd Pennsylvania Heavy Artillery Regiment, with a date of February, 1863.  However, a formation called the 3rd Pennsylvania  Heavy Artillery Battalion was reported at Camp Hamilton (outside Fort Monroe) under Major John A. Darling (who was later a staff officer in the 3rd Regiment, so this is likely the same unit).
  • Illegible to me, but I think this is Nevin’s Battery– Battery H – Listed as at Fort Whipple (Fort Myer), in the Washington Defenses, but no assigned pieces.  Captain John I. Nevin would spend the war around Washington, DC.
  • Keystone Battery – Reported at Centreville, Virginia with six 10-pdr Parrotts.  I would match this to Captain Matthew Hastings’ battery, assigned to Casey’s Division and part of the Washington defenses.
  • Hampton’s Battery – Better known as Battery F – Posted to Aquia Creek, Virginia with six 10-pdr Parrotts.  Captain Robert B. Hampton’s battery was assigned to Second Division, Twelfth Corps.
  • Jones’s Battery – No return.  If I’ve transcribed the name correctly, this must be Captain Paul I. Jones’ Independent Heavy Artillery, which became Company L, 2nd Pennsylvania Heavy Artillery (November 1861).
  • Knap’s Battery – Battery E – Paired with Hampton’s Battery F (above), also posted to Aquia Creek and with six 10-pdr Parrotts, in Second Division, Twelfth Corps.  Captain Joseph M. Knap served as the division’s Artillery Chief, with Lieutenant (later Captain) Charles A. Atwell assuming the battery position.
  • Schaffer’s Battery – Battery A – No return.  I think this is a duplicate with Mlotkowski’s Battery (above).
  • Schooley’s Battery – No return – This is most likely Captain David Schooley’s Independent Company Heavy Artillery which was later designated Company M, 2nd Pennsylvania Heavy Artillery (also occurring in November 1861).
  • Thompson’s Battery – Battery C – At Falmouth, Virginia with four 3-inch Ordnance Rifles. Captain James Thompson’s battery supported Second Division, First Corps.
  • Ulman’s Battery – No return.  As mentioned for the last quarter, my best guess is this being Captain Joseph E. Ulman’s independent battery.  The battery ceased to exist in March 1862, but apparently lingered as a ghost on the paperwork.
  • Stevens’ Battery – Battery B – No location given but with four 6-pdr field guns and two 3.80-inch James Rifles.  Captain Alanson J. Stevens’ battery supported Third Division, Twenty-first Corps, then stationed at Murfreesboro, Tennessee.
  • Young’s Battery – Battery G – No return. Captain John J. Young’s battery was assigned to Fort Delaware at this time.  (Sometimes cited as the 2nd Independent Battery Pennsylvania Heavy Artillery.)
  • Muehler’s Battery – No return. Charles F. Muehler was the original commander of what became Stevens’ Battery B.  So this looks to be a duplicate entry line.

Good news here, most (six of seven) batteries with returns posted are easily matched to lettered independent batteries.  Of course, the bad news is that I’m offering you a lot of “best guesses” here to round out the rest.  Worth noting, also listed at Fort Delaware for this reporting period was the 1st Pennsylvania Marine and Fortification Artillery, Batteries A and B, under Captains John S. Stevenson and Franz von Schilling, respectively.  Those batteries would become part of the 3rd Pennsylvania Heavy Artillery, and thus fall outside our scope.

While requiring a lengthy administrative explanation, because of the scarcity of reports, there is not much to discussion in regard to ammunition:

0142_1_Snip_PA_Ind

Just one battery reported smoothbore cannon, and that was Stevens’ out west:

  • Stevens’ Battery B – 448 shot and 200 case for 6-pdr field guns.

Starting on the rifled artillery, we have only one with 3-inch Ordnance rifles, and that is reflected with the Hotchkiss-patent on hand:

0142_2_Snip_PA_Ind

  • Thompson’s Battery C – 82 canister, 99 percussion shell, 144 fuse shell, and 505 bullet shell for 3-inch rifles.

On the next page, we can narrow the focus down to just the Parrott-patent columns:

0143_1A_Snip_PA_Ind

  • Keystone Battery – 684 shell, 607 case, and 219 canister for 10-pdr Parrott.
  • Hampton’s Battery F – 600 shell, 480 case, and 144 canister for 10-pdr.
  • Knap’s Battery E – 657 shell, 396 case, and 159 canister for 10-pdr.

And on the next page, we find but one entry to consider:

0143_2_Snip_PA_Ind

  • Thompson’s Battery C – 100 Schenkl shells for 3.80-inch James rifles.

That brings us to the small arms where six batteries reported items on hand:

0143_3_Snip_PA_Ind

By battery:

  • Nevin’s Battery H – 150 Springfield muskets, twenty-seven Army revolvers, and sixty horse artillery sabers.
  • Keystone Battery – Fourteen army revolvers and 150 horse artillery sabers.
  • Hampton’s Battery F – Twenty Navy revolvers, sixty cavalry sabers, and ten horse artillery sabers.
  • Knap’s Battery E – Thirty-seven Navy revolvers and eight horse artillery sabers.
  • Thompson’s Battery C – Thirty-two Navy revolvers and six cavalry sabers.
  • Stevens’ Battery B – Seventeen Navy revolvers and five cavalry sabers.

We see substantial small arms in the two batteries serving in the Washington Defenses, which is to be expected.

While I’m not absolutely certain about the identification of batteries listed in this portion of the summary, I am confident those which reported ordnance on hand are properly set in context.  Not to diminish the service of those at Fort Delaware, but those units likely only serviced the garrison artillery… if they serviced them much at all.

Dahlgren on Shrapnel, part 2: “these results are only to be considered as general terms”

As discussed earlier, while working on a system of boat howitzers to equip the US Navy, John Dahlgren conducted a detailed study of the behavior of shrapnel.  He identified three factors which governed the performance of shrapnel, from a target point of view, and thus would provide the requirements for the practice of fire for such projectiles.  Those were the range, the time of projectile flight, and height of burst above the ground. And those were the same requirements we saw in the illustration from other pre-war manuals.

OwenPlate20Fig6

What Dahlgren’s study offered was a “schooled” approach to the problem, as he felt the behavior should be scientifically defined to provide a reliable reference to the gunner.  Dahlgren determined shrapnel was most effective when exploding 50 to 130 yards in front of and 4 to 15 feet above the intended target.  So the next question – how to make a shrapnel projectile’s burst to occur with such regularity that the gunner could achieve a result within that “most effective” space.  The key to achieving such results would be accurately setting the burn time of the fuse.

But that was easier said than done, as Dahlgren observed:

The shrapnel fired from cannon may have a velocity in the different parts of its trajectory, amounting to as much as 1200 or 1500 feet per second, and hence a difference in the burning of the fuze, almost inappreciable in time, will be made very perceptible by the variations in the distances at which the explosion occurs; thus, with the 1200 feet per second, a fourth of a second will produce an error of 100 yards:  if the velocity be 600 feet per second, the difference in distance will still be fifty yards.

Keep in mind at the time of writing, most services used paper fuses.  In the use of such, the length of the paper was cut, using a rule calibrated to the burn rate of the fuse, for the desired burn time.  The Bormann fuse was just coming into use.  But in either case (and the case for most of the other types in use) the smallest time measure provided was the quarter second.  What Dahlgren was telling us is that quarter second could produce an error of between 50 to 100 yards.  In other words, this would produce an unacceptable variation which might serve to throw shrapnel completely outside the optimal window, if not the marginally effective zone.

Dalgren went on to point out another factor, which fell outside the gunner’s control, was the consistency of fuses.  Regularity in burn rate was a problem at the time.  Furthermore, the set of the fuse would often change the performance, in some cases leading to misfires and other problems.  So the bottom line this was not simply a case of selecting a fuse length and firing the shrapnel.  More thought was required.

Dahlgren did point out that British practice was to provide each shrapnel with four fuses.  These were defined by the ranges allowed based on the fuse burn time – 650 yards, 900 yards, and 1100 yards, with a fourth left to be cut based on tactical needs.  Not specifically stated, but assumed, is these allowed the gunner select a fuse based on where he wanted the shrapnel balls to hit the ground.  In other words, the 650 yard fuse would cause a burst at around 500 yards, with balls proceeding forward another 150 yards.. .give or take.

Though Dahglren spent some time describing the nature and functionality of various fuses available at the time, he shorted the discussion with a “might be too much elaborate this brief sketch” … so allow me to follow that lead at time time.  He simply noted that in US service (both land and sea) the standard was to provide shrapnel with fuses pre-configured for 1, 2, 3, 4, and 5 seconds (color coded).  It was not desirable to modify those fuses in order to shave off fractions of a second. And while he provided for some modifications or fabrications, those were considered impractical for field service.  Instead, the focus should be, he felt, on precise employment of the standard fuses (again, not only burn time but placement in the projectile to reduce the chance of misfire, failure to fire, or other derived irregularities).

What this leads us to is a somewhat fixed practice of fire.  A gunner would seek to fire shrapnel when the target was at a range which matched to the burn time of those configured fuses.  Granted, that might be inconvenient as battles are too often fought at odd ranges (you know… were four map sheets join and all).  But this plays upon that 50 to 130 yard fall of the balls after the shrapnel burst.  To be blunt, this was horseshoes and hand-grenades work.  So long as the time of burn was within that desired  50 to 130 yard, an effect could be felt.

Now the critical point fell upon the sighting arrangements of the cannon.  Given that fuses were working on a “set” time, and from that the gunner derived the zone in which the balls would fall, he had to work back to ensuring the gun tube was properly oriented to push the projectile on the desired flight path.  Azimuth… the easier part of that problem.  Elevation was the question mark.  Dahlgren explained the functioning of the fuse and elevation as such:

… the elevation is given to the piece which is required to carry the projectile to the proper distance, while the fuze adjusts the explosion to the time which the projectile occupies in traversing this space.

Given those fixed fuses, Dahlgren suggested the British method would work best for sights:

The sight in this method is graduated to the intervals of time which will carry the projectile to its desired position; and each graduation is accompanied by the two distances which include the spread of shrapnel balls.

Thus if the fuze be adjusted to 2″, and the piece elevated by the sight, raised to the line on it marked 2″, then the shrapnel will burst about 500 yards from the piece, and spread its balls from that point a considerable distance farther – effectively, at least 150 yards.

Note here the use of the symbol (“) for seconds, as opposed to referencing inches.  Select a measured fuse to fire at a measured distance and use a set elevation on the sight.  The gunner was to trust the equipment and ordnance provided to perform with regularity.  No need to know the science here.  Just basic rules of thumb – target at 650 yards, select a two second fuse, elevate gun to the two second mark on the sight.  Fire.

Dahlgren admitted that the factors necessary (range to burst, elevations, etc.) for this arrangement needed refinement, agreeing his department needed to work out those details.  Still, he concluded:

Even when obtained, these results are only to be considered as general terms that are to guide the intelligent officer to a proper application of shrapnel or of shells, when used upon uncovered troops; there being left in the fractions of seconds, a wide margin for the tact and discretion that are to make his fire more or less effectual.

A bureaucratic way of saying, “We’ll get the gunner in the ballpark, but someone still needs to observe fires in order to hit the target.”

We can actually trace Dahlgren’s practice of fire directly into the manuals.  From The Ordnance Instructions for the United States Navy of 1860, we have this paragraph regarding shrapnel from boat howitzers:

Similar terms are used in marking the sight and the fuze.  Thus, if the fuze be adjusted to 2″, and the piece elevated by the sight raised to the line on it marked 2″, then the shrapnel will burst about 500 yards from the piece and spread its balls from that point to a considerable distance farther – effectively at least 150 yards.

So by 1860, the observation became the rule. A “practice of fire” described in one paragraph.

However.. you know there was going to be a “but… ” here…. There is a problem with this practice of fire.  Aside from that paragraph in the Instructions, there is no table in that manual detailing the particulars for three second, four second, or five second settings. Now there was a separate set of manuals detailing how the Navy wanted sailors to use boat howitzers.  And there we find this table (The Naval Howitzer Ashore, 1865):

BoatHowitzerTable

This is “good stuff” but not the raw inputs needed for the “practice of fire” for shrapnel.  We don’t find table increments for seconds as defined on the sight.  Instead we have degrees of elevation, with ranges and time of flight provided.  But notice this is broken down, were available, for shrapnel and shell.  While not directly supporting the “practice of fire” we can see how the figures given in the practice play out.

Turning again to the two second time of flight, we see a close approximation at 1.9 seconds associated with a range of 500 yards for shrapnel from a 12-pdr smoothbore howitzer (the caliber and type Dahglren cited in his tests).  That occurs with a 1º elevation.

Notice if we go down a line to the particulars for shells, the two second time of flight would fall somewhere between 516 yards and 730 yards, likely around the midpoint between those two.  With an elevation between 1º and 2º.This requires some bending of the mind around the ballistics, but I submit the ranges given for shrapnel coincide with the range where the burst occurs, not where the balls would fall.  However, that given for the shell is where the projectile hits ground (and the gunner wants it to explode).  Thus, I’d submit we are reading different definitions for “range” on those lines accounting for the different uses of projectile types.

That “but….” presented within this table lingers over the “practice of fire” like a cloud in battle obscuring the target.  Yes, Dahlgren defined the practice in clear terms before the war.  And yes, those practices were incorporated in the pre-war (1860) manual.  However, at least by 1865, the tables provided failed to give the gunner such “tolerable approximations” that Dahlgren sought in 1852.  One gets the impression that shrapnel was just not that important after all!

(Citations from John A. Dahlgren, A System of Boat Armament in the United States Navy, Philadelphia: A. Hart, 1852, pages 56, 69-70; Ordnance Instructions for the United States Navy, Washington: George W. Bowman, 1860, page 109.)

 

Fortification Friday: Bombproofing according to Wheeler

I trust you are observing Veterans Day, Remembrance Day, or Armistice Day in the manner you feel appropriate today.

But as today is Friday, my blog-writing assignment is to talk about fortifications.  So I turn to the words of a veteran, writing an instruction for cadets in the post-Civil War era – Junius B. Wheeler.  And also keeping within the line of thought from previous posts, I want to emphasize how the veteran’s experience (or should that be veterans’… as in plural?) brought forward changes in the instruction.  What we’d say today were changes in tactical doctrine.

As mentioned earlier, Wheeler defined a wider variety of shelters for use in fortifications.  And those shelters were designed to resist different types of threats when compared to pre-war instructions.  In Wheeler’s text, bombproofs were not simply a place to store ammunition.  Rather these were a general class of shelter, designed to resist the effects of shells, in which ammunition, supplies, equipment, or personnel might be protected. Allow me to work through some of these particulars:

Construction of bomb-proofs. – Bomproofs may be built during the construction of parapets, or after the parapets are finished.  The latter is the most usual method.

The position in a field work occupied by a bombproof depends on the size of the work, the kind of trace, degree of exposure of the interior of the work, the convenience of the position, etc. Hence, bombproofs are sometimes placed under the parapet; sometimes in the gorge of a half-closed work; sometimes in the middle of the parade, etc.’ the position being determined by the circumstances of each case.

We have this figure from Wheeler to illustrate a bombproof:

WheelerFig43

Notice how this sits in cross section, which Wheeler would discuss as he continued.  And also notice the dashed line and arrow from left to right.  This is not incoming fires, but the line of protection afforded from incoming fires:

Fig. 43 represents a cross section of a bomb-proof into which the men can retire and be safe from the effects of a direct plunging or curved fire.

See?

Wheeler continued on to describe the particulars for building this form of bombproof.  The excavation, placement of particulars, and such do not differ greatly from Mahan’s instructions.  The technical nature of digging earth did not change after the Emancipation Proclamation, after all.  Five feet of earth was considered sufficient to protect against shells – field artillery shells, I would point out, as this was not a permanent structure. What did change were the facilities for the troops:

Ingress and egress of the men using the bombproof may be facilitated by cutting steps into the side of the trench, as shown in the figure.  The part of the bomb-proof resting against the side of the trench should be revetted by a covering of plank, fascines, or other suitable material, to keep the shelter dry, and to make it more comfortable.  Guard beds should be constructed, when the bomb-proof is wide enough, so that the men can lie down at full length; if not wide enough, benches can be made which will allow the men to assume easy positions.

Notice Wheeler’s emphasis on making these shelters “livable.”  A far cry from earlier views on this subject and reflection of the experience of long, hard work in the trenches at Vicksburg and Petersburg, to name a few.

Wheeler closed this section noting a bombproof as depicted in the figure could “easily be placed under the banquette.”  Notice how, in profile at least, Wheeler’s bombproof figure resembles Mahan’s later-day splinterproof.  You know, the one from Morris Island.  Wheeler clearly offers an upgrade in status, if not in construction.

Wheeler continued to identify a class of shelter not mentioned in pre-war manuals:

Blindages. – Any construction used in field works which has for its object the protection of the men and material against the effects of artillery fire from overhead, is termed a blindage. The preceding construction, therefore, is a blindage.

Yes, I’ve paced you around to this point.  Had I introduced blindages earlier in this thread, you’d think it was some new innovation.  It was not.  What we have is the “old ways” being employed to meet different requirements.  In the post-war assessment, overhead protection took on more importance. The term blindage was a tip of the hat to those perceived needs, not a new form of construction.

To that point, Wheeler next discussed splinter-proofs, which were not to be proofed against shells, but would have some overhead protection:

Splinter-proofs. – Shelters which are not exposed to the impact of the projectiles of the enemy, need not be so strong as the bomb-proof. It will be sufficient if they are proof against the splinters and fragments of shells, produced by the enemy’s fire.

This, of course, is no departure from Mahan’s post war discussions.  And we’ve seen how splinter proofs took on more importance, based on wartime experience.  Wheeler offered Figure 44, so we could ponder these splinter proofs:

WheelerFig44

Shelters of this kind are usually constructed in inclined positions. (Fig. 44). They are made by placing strong timbers, or bars of railroad iron, in an inclined position against the surface to be protected, and in juxtaposition, and then covering them with earth sufficient to make the interior safe against the fragments which may strike the shelter.

Again, note the dashed line and arrow, being the line of protection.  In addition, we see the overhead cover furnished with this splinter proof.  Particulars of the construction:

The inclination of the timbers will be equal to, or less, than the natural slope of the earth thrown against them.  It is well to cover the pieces with raw-hides or tarpaulin before the earth is thrown against them, to make the shelter water-tight.

A thickness of two feet of earth is sufficient to resist the fragments of shells fired from field guns.  In many cases the earth is placed upon the shelter by piling sand bags filled with earth against it.

Entrance to the shelter is provided for by openings at the ends, sometimes by openings left at intervals.

Again, not a significant change in the technique, but rather a change in the application of the construction of those techniques.  As for where these practices of splinter proofs were employed:

Splinter-proofs, from their nature, are placed in those situations where they are not exposed to a direct fire.  They are much used to protect doors, entrances, etc., which are exposed to the effects of bursting shells; to protect vertical walls liable to injury from the same cause; etc.

So we are back to the pre-war notions, to some extent, for placing splinter proofs at doors and entrances. But as we see from the illustration and description above, the arrangement was altered to afford protection from high angle… or as Mahan called it, curved … fires.

Now these shelters discussed thus far by Wheeler were generic shelters.  He set aside any specific discussion of magazines.  This is because, again, we see wartime experiences prompting evolutions in the practice.  We’ll consider Wheeler’s magazines next.

( Junius B. Wheeler, The Elements of Field Fortifications, New York: D. Van Nostrand, 1882, pages 135-9.)

 

Dahlgren on shrapnel (case shot): “… even a tolerable approximation … not likely to be undervalued…”

As I’ve opened the ball here, I feel bound to continue the discussion about the practice of case shot… and in particular how this was related to those training to man the guns.  Let me say again for emphasis – the conundrum here is that very little is offered in the manuals (US manuals, but if we want that extends across to the British manuals of the period), yet the type of projectile was seen as a vital component in the ammunition boxes. Specifically, we do not see specific instructions, firing tables, or other such details offered in the texts available to new artillery officers.  I would contend in the context of 1861, with hundreds of volunteer officers grasping guidons as brand-new battery commanders, what was in those manuals was of extreme importance.  And all this in light of experiments and tests in which some very good minds determined shrapnel / case shot should not be handled simply as any old shell.

I mentioned John Dahlgren as one of those looking the performance of shrapnel.  So let us turn to his 1852 “A System of Boat Armament in the United States Navy.”  Now keep in mind that work was more so a justification for the concepts incorporated in the boat howitzer system (which exceeded expectations, mind you).  So there is some carry over of that intent.  But the part we want to consider here is within the section discussion ammunition for those boat howitzers:

Within the last fifty years, another projectile, the shrapnel shell, or spherical case shot, has been contrived, partaking somewhat of the nature of the shell and the canister, and in a great measure superseding the plain shell, where troops are fairly open to its action.

Dahlgren continued on, continuing to slight the projectile class with the label of “novelty”, while discussing the evolution of shrapnel – from Napoleonic times up to the 1850s.  But this was not to say Dahlgren did not rate shrapnel of use.  He found shrapnel of value beyond the range of canister.  And he added that specifically applied to naval operations, shrapnel was useful, even within canister’s normal range, to support landing operations.

As to the use of shrapnel:

It is designed to burst the shrapnel in front of the troops exposed to it, and at just such a distance and height as to disperse the charge of balls among them.

Here the difficulty lies.  If the shrapnel burst too high, too near, or too fr, then it is alleged by the objectors that its power is lost, or so far diminished as to be trifling.

The conditions to an execution so exact are said to be: –

  1. In appreciation of the distance.
  2. In timing the explosion.
  3. In adjusting its height above the object.

When bodies are moving with velocities of several hundred feet in an instant, spaces of time which it seems ridiculous to attempt the appreciation of by ordinary means, become not only important, but very plain to the perception, by the differences in the explosion.

Yes, we see the same issues discussed in my earlier post, but yet simply related by way of illustration.  Dahlgren was picking at this problem….

The importance of knowing the distance can hardly be over estimated, and the difficulties of making even a tolerable approximation to the truth are not likely to be undervalued by artillerists.

Emphasis mine.  Given that assessment, Dahlgren approached the problem in his typical manner – starting with an analysis to define just what the problem was.  With respect to the first point, distance, he noted practices that might be employed to train crews to better determine range.  Furthermore, he pointed out the naval gunners had the advantage of seeing water thrown up by the shrapnel, an advantage over shrapnel fired over land.  And he added:

The adjustment of the fuse to the distance, and the altitude of explosion, are regulated to the elevation; and therefore, the three conditions to good effect may be said to depend mainly on a correct knowledge of the distance.

With that established, he saw the need to test….

Considerable experiment will be indispensable to determine accurately the proper regulations of elevation of gun, time of fuze, and height of explosion; and systemic practice must be resorted to afterwards in order to familiarize officers to the use, and enable them to make effective application, of the shrapnel.

Or in other words, put this down in a manual so all can be trained on the practice and the practice be made repeatable.  Yes, the brass ring of all doctrine writers!

But this was not simply an exercise in establishing range tables and providing range estimation training.  Shrapnel behaved differently than shot and shell.  And that was not necessarily a bad thing:

It is in the peculiar dissemination of its balls that the shrapnel promises some corrective for errors in the estimation of distance.  Following the course of the trajectory, with a velocity not less than that of the shrapnel at the instance of explosion, they radiate from the case in the form of a cone; and, when projected on the horizontal plane, take an elliptical figure, the greater axis of which coincides with the continuation of the trajectory, and is much elongated, particularly at the low elevations.

We might call this a “shotgun pattern” of sorts. Dahlgren called it a “jet of balls”, adding the pattern was tighter the closer one is to the point of the burst.  In order to fully understand this behavior, Dahlgren cited some test data:

Three muslin screens were stretched on upright frames over the water, fifty yards apart.  In dimensions, they were twenty feet long and ten feet high.

DahlgrenShrapnelPlate5

A frigate’s launch, carrying a 12-pounder of 750 lbs. in the bow, was placed 545 yards from the nearest screen.

Its charges were one pound.  The elevation by sight 1.3 inches.  The motion of the boat precluded the use of an instrument for this purpose.

The shrapnel (charged) averaged 11.4 lbs., containing 80 musket balls (17 to the pound), and four ounces of powder.

The fuzes were two seconds, and such as are issued to the service.

Eight rounds were fired with the following results: –

DahlgrenShrapnelTable

The gradual increase of the dispersion with the distance is exemplified by the number of balls in each screen, the mean of these eight rounds reducing the effect one-third for 50 yards, and two-thirds for 100 yards.

Dahlgren went on to work on variables which caused variations with the distance of the burst.  And he provided some insight into the behavior of ricochets.  But, while cautioning the test was a small sample size, he did offer a third party observation:

From the data above, the distances of 60 to 150 paces in front of the object (50 to 129 yards), with heights of four to fifteen feet, have given good results with cannon, apart from the ranges.

So here we have a planning figure – shrapnel should explode 50 to 129 yards in front of the target at a height of 4 to 15 feet in order to achieve the best effect, given dispersion of the balls.

As for performance of the balls on the target, Dahlgren observed:

The force of the balls was sufficient, in every instance, to pass through pine boards one inch thick, placed behind the screens, the distance of the third screen from the explosion being sometimes 150 yards.

So we add to the planning figure the effective range of shrapnel – 150 yards beyond the burst.

Dahlgren departed analysis of the test results and moved on to summarize opinions about the merits of shrapnel, which was certainly a spirited debate among military authorities of the time.  At the end he suggested a conclusion (as Dahlgren, being somewhat a “staff officer” at this time, was not the decision maker):

Is it not more judicious to improve its operation to the utmost, by thorough experiment and practice, and to look to the results of actual service for a settlement of the several issues raised; neither blindly confiding in the alleged superiority of the new projectile, nor, on the other hand, allowing its probable merit to be depreciated by a too ready skepticism?

Let us put a healthy highlight on Dahlgren’s suggestion.  On one part, we see tacit admission the behavior of shrapnel was not well documented.  On the other part, he exposes a situation we, removed from things 150 years, may not appreciate – Not all authorities, Army and Navy, were convinced shrapnel was worth the trouble.  That’s important!

However, let’s close this on the technical side.  Dahlgren determined shrapnel was most effective when bursting 50 to 130 yards (I’m rounding) in front of and 4 to 15 feet above the intended target.  That’s the factor we seek to apply to practice… or more accurately for the purposes of discussion, that is the factor we want to see evidence of being applied to instructions given to gunners.  Got it?

(Citations from John A. Dahlgren, A System of Boat Armament in the United States Navy, Philadelphia: A. Hart, 1852, pages 37-50.)

 

Summary Statement, 1st Quarter, 1863 – 1st Pennsylvania Light Artillery

From Ohio, we move one state to the east for Pennsylvania.  As related for the previous quarter, the 1st Pennsylvania Light Artillery began with eight batteries, A through H.  Battery I was added near the end of the war.  So for the first quarter, 1863 we only have those original batteries to discuss.  Of those eight, the clerks recorded seven returns:

0140_1_Snip_PA1

None of those “odd” or “obsolete” weapons.  These batteries were all Napoleons, Ordnance Rifles, and Parrotts:

  • Battery A: No return.  This battery was kicked around all winter.  In January, Lieutenant John G. Simpson’s battery was in Third Division, First Corps at Belle Plain.  In February, the battery went to Third Division, Ninth Corps, then transferring to Fort Monroe.  When the corps was reassigned to Kentucky, the Third Division (Getty’s) was left behind, later being brought under the Seventh Corps. A good excuse for no report!  Somewhere along the way Simpson was promoted to Captain.  The battery had four 12-pdr Napoleons.
  • Battery B: Belle Plain, Virginia with four 3-inch Ordnance Rifles.  Assigned to Third Division, First Corps battery.  Captain James H. Cooper commanded.
  • Battery C: White Oak Church, Virginia with six 10-pdr Parrotts (an increase from the last report). During the winter, Batteries C and D were consolidated, under Captain Jeremiah McCarthy (Battery C), remaining with Third Division, Sixth Corps.
  • Battery D: At White Oak Church, Virginia with four 10-pdr Parrotts.  As indicated above, consolidated with Battery C.  Captain Michael Hall, being a junior captain, mustered out.  So here’s where the clerk’s numbers come into question.  Were the two new guns for Battery C transferred from Battery D?  And if so, were do we reconcile the quantities given on the line below for Battery D?  I’ll just transcribe… you debate….
  • Battery E: At Yorktown, Virginia with four 12-pdr Napoleons. Captain Thomas G. Orwig commanded this battery, assigned to the Artillery Reserve of Fourth Corps.
  • Battery F: At Belle Plain, with four 3-inch Ordnance Rifles. Lieutenant R. Bruce Ricketts commanded this battery, which supported Second Division, First Corps.
  • Battery G: Also at Belle Plain and with four 3-inch Ordnance Rifles.  Commanded by Captain Frank P. Amsden and assigned to Third Division, First Corps.  (Of note, Batteries G was soon to be attached to Battery F, but later in the spring.)
  • Battery H: At Gloucester Point, Virginia with four 12-pdr Napoleons. Captain Andrew Fagan commanded this battery, which was part of the Artillery Reserve, Fourth Corps.

Moving to the next page, we find smoothbore ammunition on hand is a simple pair of lines:

0142_1_Snip_PA1

  • Battery E: 176 shot, 64 shell, and 192 case for 12-pdr Napoleon.  The entry of 80 canister for 6-pdr field guns is likely a transcription error, which should be on the Napoleon column.
  • Battery H: 182 shot, 54 shell, 162 case, and 64 canister for 12-pdr Napoleons.

Of course, nothing for Battery A, which had reported 239 shot, 181 case, and 92 canister for 12-pdr Napoleon the previous quarter.

Moving to rifled projectiles, the first page covers Hotchkiss patent types:

0142_2_Snip_PA1

These are all for 3-inch rifles:

  • Battery B: 20 canister and 380 bullet shell for 3-inch rifles.
  • Battery F: 80 canister, 80 percussion shell, 56 fuse shell, and 504 bullet shell for 3-inch rifles.
  • Battery G:  223 fuse shell and 420 bullet shell for 3-inch rifles.

The next page of rifled projectiles, I’ll break down into segments.

0143_1_Snip_PA1A

Battery G reported 80 3-inch Dyer’s canister on hand.

Moving right to the Parrott columns:

0143_1_Snip_PA1B

The consolidated Battery C and D had two lines:

  • Battery C: 292 shell, 523 case, and 145 canister for 10-pdr Parrott.
  • Battery D: 299 shell, 503 case, and 96 canister for 10-pdr Parrott.

So plenty of ammunition for that consolidated battery.

Not much more to consider for the Schenkl columns:

0143_2_Snip_PA1

  • Battery B: 285 shell for 3-inch rifles.
  • Battery G: 97 shell for 3-inch rifles.

Moving over to the small arms:

0143_3_Snip_PA1

By battery:

  • Battery B: Sixteen Navy revolvers and seventeen horse artillery sabers.
  • Battery C: Seventeen Navy revolvers and fourteen horse artillery sabers.
  • Battery D: Fifteen Navy revolvers and twelve horse artillery sabers.
  • Battery E: Eight Navy revolvers, twenty-four cavalry sabers, and eight horse artillery sabers.
  • Battery F: Eight Army revolvers, ten Navy revolvers, one cavalry saber, and four horse artillery sabers.
  • Battery G: Eleven Army revolvers and ten horse artillery sabers.
  • Battery H: Fourteen Navy revolvers and eleven horse artillery sabers.

That completes a relatively short entry for the 1st Pennsylvania Light Artillery.  But up next is what promises to be a lengthy entry on the independent batteries from the state!

Case shot and practice of fire: A conundrum?

Consider this figure:

OwenPlate20Fig6

This particular figure appeared in “Elementary Lectures on artillery: Prepared for the use of the gentlemen cadets of the Royal Military Academy” by Captains Charles Henry Owen and Thomas Longworth Dames, published in 1861.  And as “Royal” implied, these were English officers and not Americans.  Still, the technology was the same and applied in much the same manner.  It is similar to illustrations appearing in American texts of the same period.  I simply chose this source because the basic illustration was cleaner.

Basically, this illustration explains the practice for firing shrapnel.  The target, on the far right, is a box labeled “Column of Men.”  And we see four examples where shrapnel was fired.  Only one of which was accurate and would achieve the desired result.  Labeled “a”, I’ll put a star on that point and show the respective coverage of the balls after bursting:

OwenPlate20Fig6A

The perfect shrapnel burst – at the right time of flight; at the right height; at the right angle of flight.  The momentum of the shrapnel shell (case shot… for us not subject to His Majesty) imparted forward progress to the balls after the burst.  So we see the expected pattern would place fragments and balls across the formation of infantry.

If the the fuse was set for too short a time of flight, then the shrapnel burst too soon.  At this case, point “b”:

OwenPlate20Fig6B

The payload falls well “short” of the target. Not to mention, and not depicted here, it was also possible for the burst to be “long”, with the payload landing well beyond the target.  So setting the fuse

But the fuse timing was just one of :

OwenPlate20Fig6C

Or if the projectile is fired too low:

OwenPlate20Fig6D

This brought the burst too low and well in front of the target.

Not illustrated in this figure is the angle of flight.  But you might get a feel for that looking at bursts “c” and “d”.  However, as case shot/shrapnel was fired primarily from guns, sometimes howitzers, and not mortar.  So this was somewhat a “goes without saying” consideration.

Still we see depicted two of the three necessary components of a proper shrapnel burst.  The right height being the darkest of the three trajectories depicted.  We see points “a”, “c”, and “d” being the right time of flight.  Allow me to “box” these to highlight:

OwenPlate20Fig6X

Hopefully nothing entirely new to artillery enthusiasts.  Just depicting the desired work of the shrapnel… er… case shot… in combat.  As we well know, the artillerist would need estimate the range to target.  From that, he would derive the necessary elevation.  That, of course, considering the desired height of burst.  And the artillerist would need to calculate time of flight to the optimum bursting point.  That being used to properly cut or set the fuse.   And…. goes without saying the artillerist would also need to point the gun toward the target (a factor not easily depicted in the two-dimensional world of the illustration).

Great!  So the artillerist had to do a lot of computations in the heat of combat.  One might think the manuals would have a lot of tables and guides as to how one should compute bursting height and time of flight.

Given such complications, one might think that manuals of the period would devote much space to instructions.  Well…. The brand new “Field Artillery Tactics” of 1861, from the minds of William French, William Barry, and Henry Hunt, mostly covered how to maneuver the battery.  Though unofficial, John Gibbon’s “Artillerists Manual“, with a wealth of insight for the gunners to consider.  Yet it also lacks any details on the practice of firing case shot.  Even Owen and Dames, from which these illustrations are taken, did not discuss the practice in any length.  They felt an illustration would suffice, apparently.

These references would offer elevations, range, and, perhaps but not always, time of flight for selected weapons.  But none would offer details of the ballistic behavior for shrapnel at the point of the burst.   Such was not simply derived by extending the trajectory out to the ground.  Rather one had to consider loss of momentum of those balls, fragments, and sub-projectiles, which fell off at a greater rate than a complete projectile.  And I’m just scratching the surface of the data needed for one to compute a “good” firing of case shot.

There are very few recorded experiments conducted at the time to learn how case shot behaved (Dahlgren’s experiments for boat howitzers come to mind, but there were some US Army and British experiments in this regard).  Yet, very little of what was learned went into the manuals.

That, I would submit, is a conundrum.

Fortification Friday: Bomb Proof shelters, as in “force protection”

Last week I pointed to a change… if we may, an evolution… in military practice based on experiences of the Civil War.  In that case, we saw a new class of “semi-permanent” fortifications introduced.  And beyond that, we saw several improvements and refinements of the facilities constructed for fortifications, be those temporary or semi-permanent.

Now let us look at another evolution, just as subtle.  But one I would submit was a major change in the function of fortifications.  In his 1870 instructions, Mahan moved immediately from discussion of magazines into a similar structure with different function:

Bomb Proof Shelters.  Bomb and splinter proof shelters of wood have also been carefully built in the interior of some of these enclosed works, and in the gorges of those open to the rear; both may be arranged with loop-holes for defense. These are mostly constructed in the manner shown in Fig. 39, bis.

This brings us back to reference the shelter built on Morris Island the shelter built on Morris Island in the summer of 1863:

MahanFig39bis

As related before, this was not necessarily a “new” structure.  Rather this was the use of a type of structure in a different manner, addressing an evolving requirement on the battlefield.  In this case, on Morris Island, the requirement was protection from shells and shrapnel delivered from high-angle or, as Mahan called it, curved, fires (or as I sometimes relate – fires acting on the vertical plane).  Overhead cover, we’d call it today.

Mahan gave a general description as to the construction of these shelters:

The exterior side is of heavy logs placed in juxtaposition, resting on a ground-sill and capped at top.  Parallel to these is another row, which may also be in juxtaposition or at short intervals apart and capped like in the outside row.  The roofing, consisting of heavy logs laid in juxtaposition and covered by thick jointed boards, rests on the capping.  The back face may be sealed on the inside to obviate the dampness from the earth resting against the back; and some simple method of drainage, by fascines or tiles, is arranged to carry off the water from the earthen covering.  This last should be the same as for the powder magazines.

So, these shelters were “like” magazines, but were not magazines.  The purpose of these shelters was to protect the troops, supplies, and equipment.  We’d call this force protection today.

But there is scant mention of this in the pre-war courses.  Here’s what I think (as in my thoughts… make sure you don’t get the idea I’m putting words in Mahan’s mouth…) – prior to the war, doctrine did not envision a situation where a field army would remain in postion subject to prolonged attriting fires.  Prolonged, as in more than a few hours.  Yes, things like mortars and howitzers existed prior to 1861.  And yes, during battle armies would be subject to fires from those type of weapons.  But, prior to 1861, the general perception was that sort of exposure would be limited, depending on the situation.  Perhaps only in a situation where an army was preparing a large scale assault… or preparing to receive a large scale assault.  So such exposure would be limited to a phase in a particular battle.

However, wartime experience brought with it a new perspective.  Entire campaigns would be fought with soldiers almost constantly in contact and exposed to attriting fires.  For emphasis, let’s just say in 1861, William T. Sherman led his command toward Manassas with the notion his troops would only be under fire (save some minor delaying actions) for a limited period of time on the battlefield.  But in 1864, he led a much larger force through Northern Georgia fully expecting the troops to be under fire every single waking hour.  An army could no longer afford to simply “lay in the open” waiting for the signal to attack. That wait might be for days, if not weeks.  And the artillery, of both sides, would not be idle.  We can offer many reasons this change occurred.  Regardless of cause, the effect was a need for better protection of the force.

Applied to practice of field fortifications, this brought a need for structures that would afford relief to the infantry.  Again, this is not to say such shelters did not exist prior to 1861.  Rather, such shelters were of little concern, prior to the war, for those constructing temporary, field fortifications.  However, by the summer of 1863, witnessed on Morris Island, these structures became necessary.  So much that a significant amount of manpower was diverted from other tasks in order to ensure “force protection” was given as the siege lines advance.  Oh… and so much that the defenders in Battery Wagner spent more time on shelters than on erecting more batteries.

And speaking of the defenders, Mahan added, with respect to the shelters:

It is highly important that these works should be so organized as to afford a retreat for the garrison should the main work be carried.  This might be done in some cases, by masking, with earth, only the lower portion of the side looking on the interior of the work, and covering the exposed timber with iron plating with loop-holes, to sweep all the interior space.

This sounds very much like a safety redoubt or keep…. but “sounds like” is not “the same as” in this case.  In his pre-war writing, Mahan proposed safety redoubts and keeps for field fortifications.  And he retained, those designations, even going further to elaborate on the construction of blockhouses as a form, even when proposing these shelters with arrangements for retreat.  The difference between here is the employment.  The keep was intended for a fortification with large interior capacity and for use as a last line of defense.  The shelters described, in the paragraph above, were employed even in smaller fortifications and were not necessarily the “last line” to defend.  The point being – shelters would protect the soldiers AND offer them a position from which to fight in conjunction with the localized defense within the fortification.  A keep was a shelter from which to rally and reform for the final defense of the entire fortification.

Not quite the trenches of World War I.  But the concept was in the air.

(Citations from Mahan, An Elementary Course of Military Engineering: Part 1: Field Fortifications, Military Mining, and Siege Operations, New York: John Wiley & Son, 1870, page 54-5.)