Fortification Friday: Don’t for get the door! Gotta get in and out of the fort

So you’ve built a strong fortification in accordance with Mahan’s instructions.  The fortification has wonderful fields of fire, properly sized parapets, protected batteries, and bombproofs for everything to include the commander’s liquor stash.  Great!

But sooner or later the fort’s garrison has to wonder outside the works.  Say for maintenance of the works, or patrolling the outskirts, or simply for resupply.  So there needs to be a passage to the exterior somewhere in the plan.  Mahan called these outlets:

Outlets are passages made through a parapet, or an enclosure of a gorge, for the service of the work.  They should, in all cases, be made in the least exposed part of the work.  Their width need not be more than six and a half feet, when used only for the service of the work; but when they serve as a common passage for wagons, &c., in the case of the intrenchment crossing a road, they should be at least ten feet wide.

Clear definition.  And some clear specifications with the idea width established at either 6 ½ feet, for “walk out” outlets, or ten feet, for “ride out” outlets.  That established as a rule of thumb, we turn to the structural components and advice for building these outlets:

When cut through the parapet, the sides receive a slope of three perpendicular to one base, and are riveted with sods, &c.

A gate, termed a barrier, serves as an enclosure to the outlet.  The framework of the barrier is made like an ordinary gate, consisting of two uprights, or stiles, a cross-piece, or rail, at the top and bottom, and a swinging bar, or a diagonal brace. Upright palisades, about seven feet long and four inches thick, are spiked to the frame about four inches apart; they are finished at top with spikes. A barrier, thus constructed, will not offer a shelter to the enemy should he attempt to cut it away.  The barrier is hung on hinges like an ordinary gate.  The posts of the framework should be very solidly braced to support the weight of the barrier.

Figure 41 illustrates such a barrier:

PlateVIFig41

Yes, they sell these as pre-fabricated products at Home Depot and Lowes.  Well… not exactly to military specifications.  But you get the point, the base form is a simple gate. For the annotations, Mahan offered:

  • A A – posts to which the gate is swung.
  • B B – the uprights of the gate.
  • c c’ – the upper and lower cross pieces. (c’ seems to have been left off).
  • D – the diagonal brace.
  • E – the bar of the gate.

Note also the mention of spikes on the gate. Specifically palisades.  These were not intended to impale an attacker, but rather to keep the attacker’s reach away from the structure of the gate.  So drop all those Medieval notions there.

Continuing, Mahan offered,  “A cheval-de-frise is sometimes used for a barrier, it presents but a trifling obstacle.”  So let us relegate that to the level of lazy engineering.

But just keeping the enemy at arms length was not enough.  One also had to protect the outlet from cannon fire. Toward that end:

The outlet should be covered by a mask, thrown up either on the interior, or on the exterior, to prevent the enemy from firing through it into the work.  A traverse is thrown across it, if placed on the interior.  Sufficient space should be left between the traverse and the parapet for the passage of a gun.  The length of the traverse is arranged to prevent the enemy from firing into the work, by an oblique fire through the outlet.  The traverse may be of earth or of wood; in either case it should be arranged for defense to enfilade the outlet. In some cases, and it would generally be safest, a barrier is erected between the parapet and the traverse, on each side of the outlet.

Figure 42 provides us Mahan’s suggested layout of the masking traverse:

PlateVIFig42

From the key for this figure:

  • O – the passage or outlet through the parapet.
  • P – (to the left of “Fig. 42.”) the passage between the parapet and the traverse
  • T – the traverse

Note Mahan gave us 6 ½ feet between the parapet and traverse for “P”.  We also see the prescribed cross fires built across the passage.

Mahan went on to suggest more elaborate defensive arrangements to protect important passages.  “In very frequented passages, a redan or a lunette, is thrown up on the exterior to cover the outlet, and thus ensure its safety in case of surprise.”  These arrangements followed the standard configurations for faces and flanks.  No doubt, such added more work for the defender’s labor force, as they would be clearing and leveling both front and rear.

The important take away with respect to passages is how a necessary weak spot in the defenses would be turned into a strong point by way of barriers, traverses, and other cover.

(Citations from Dennis Hart Mahan, A Treatise on Field Fortifications, New York: John Wiley, 1852, page 61-2.)

Winter Encampments… where armies are reforged for battle

Three years ago I started a series of posts discussing the 1864 Winter Encampment of the Army of the Potomac, focused through the diary entries of Colonel Charles Wainwright.  In that series, I often called for readers to broaden considerations.

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We tend to study military history from battle to battle.  The “in between” is often summarized in short paragraphs.  Almost as if the armies were machines to be turned on when battle nears, then turned off once out of musket range.  Such fails to present the reality of armies in being.  These are bodies of men which must be fed, equipped, trained, and led.  Armies don’t just stand around waiting for a switch to be thrown.  Armies are a constant buzz of activity, even if not directly confronting an enemy.  In fact, even more abuzz when not within range of an enemy!

Under conventions used during the 19th century, armies were supposed to go into “winter quarters” during the months of January, February, and March…. at least in the Northern Hemisphere… and at least prior to the mechanization of logistics… and at least so long as the weather precluded active campaigning.

When studying the Civil War, specifically, we must put those last two caveats into the mix. During the Revolutionary War, we might point to Valley Forge and Morristown as examples of winter encampments.  We also must acknowledge there was much campaigning in the Carolinas through those same periods, as the fairer weather allowed such (and armies were reluctant to exert themselves in those areas in the days before whole-scale mosquito control). Secondly, a driving factor for 18th century armies to “winter” had to do with sustenance. With the arrival of the railroad, one important constraint on an army’s winter activities was at least alleviated… though depending on the situation might still be tenuous.

But even if the armies were not starving and shivering, as their forebears at Valley Forge, the winter encampments of the Civil War were indeed important periods of activity for our study.  When “sitting still” armies focus on replenishing, refitting, re-equipping, training, and reorganizing.  And those all require substantial resource expenditures… namely time!

During the Civil War, replenishment activities, as alluded to above, benefited from products of the industrial revolution.  While railroads provided a far more efficient way to provide bulk resupply in the field, industrialization as a whole provided an economy of scale to the overall benefit of the armies. Even in the supposedly non-industrial Confederacy, factories well to the rear worked to provide substantial quantities of ammunition or other consumables used by the armies in the field.

One might figure refitting and re-equipping to be one and the same.  But words have meanings here.  Refitting is to repair or directly replace what is on hand.  Say… like.. replacing worn out 6-pdr field guns with new 6-pdr field guns.  But re-equipping is to replace with something, hopefully, better.  As in a new, shiny set of 12-pdr Napoleons. And those activities must be considered from weapons all the way down to tent flaps.  Replacement or upgrade of equipment is, analytically speaking, reflects an improvement of combat efficiency.  Refit brings the army back to full capacity.  Re-equipping reflects an incremental upgrade in combat power.

Nothing in an army is as precious and perishable as the skills of soldiering.  Veteran individuals might know the drill, but the net evaluation of veteran status is not bestowed upon the unit by individual assessment.  Rather the whole of the unit must perform at the required level.  Such is why armies standing still tend to spend great deals of resources engaged in training, even for veteran formations.  Soldiers must operate in a predictable manner, when ordered. As such, training is the preventative to the disorder, confusion, and chaos of battle. The net effect of prolonged periods of training is an incremental improvement of combat efficiency, which might also reflect onto combat power (thinking things like increased rate of fire, better use of weapons, etc.).

Reorganization is often related in light of some personal or political components.  Certainly, one way to remove an incompetent subordinate, or one who has fallen into political disfavor, is to dissolve a command. But from the practice of military science, reorganization applies to situations where command structures are inefficient or unnecessarily complicated.  I contend, at least in the context of the Civil War, such was more so the case. Sometimes just a designation change carried more weight than simply bringing forward a replacement in command.  Re-designation from “wings” to numbered corps at Murfreesboro in the winter of 1863, for example.  Such gave subordinate commanders more latitude, but more importantly gave soldiers a unique entity to identify with.  Arguably the reverse occurred in the winter of 1864 with the Army of the Potomac, as storied formations were dissolved with consolidation of corps.  Both reorganizations improved command and control of the force.  (I know some will argue that point in regard to the Army of the Potomac… but that is what comments are for.)

The result of these five categories of activities during those encampments had a cumulative effect.  Armies were reforged in those camps.  Sometimes better.  Sometimes for the worse.  And those reforged armies were almost immediately put to the test when spring campaigns launched. I’m often amazed someone has not put together a full, proper study of the winter encampment experience of the Civil War.  There’s plenty of material.  Consider:

  • The first winter of the war, with Confederates across Northern Virginia and Federals around Washington.  These witnessed the birth of major armies, which would play important roles in the war.
  • Also in the first winter of the war, the complex of camps around Cairo, Illinois.  Likewise, the birthplace of armies.  We might extend that study to consider other western theater camps such as around Columbus, Kentucky and Cincinnati, Ohio. In some cases, arrangements were made that worked well into 1865 (i.e. Grant-Sherman)… and others that wouldn’t work past a few months.
  • The Federal winter camps in Stafford during 1863.  Burning question – was this a successful winter?  Did it setup failure at Chancellorsville?  Or success at Gettysburg?  Or both?
  • Likewise, cross the Rappahannock that winter to the Confederate camps outside Fredericksburg.  The thread I’d pull on there, and have before, is logistics, reflecting on the resupply, refitting, and re-equipping activities. One might argue a general failure in those three activities brought on the need for a Gettysburg campaign.
  • Oh, but let us not forget the winter encampment which completely consumed Murfreesboro, Tennessee.  Certainly a “reforging” of an army to consider, with good and bad to evaluate.
  • We might also consider Milliken’s Bend for the same winter, for Grant’s force operating on Vicksburg.  Particularly in regard to reorganization of an army, morphing a cumbersome Thirteenth Corps, with additional forces tacked on, into a proper field army.  But we might also study that encampment in regard to modern warfare lessening the need for a winter pause.
  • The Winter Encampment… as I prefaced this post with, that of the Army of the Potomac in 1864.  A wealth of material to study in this regard.  Major activities conducted across all the activity categories.  Historians such as Clark “Bud” Hall, John Hennessy, and others have blazed a trail here, offering a template that can be applied to other winter encampments.  Hopefully, with the establishment of a Culpeper Battlefields State Park, we can see a time when students can venture into the field for study of these encampments.
  • The counterpoint winter encampment… that of the Confederates on the south side of the Rapidan during the winter of 1864.  Again, a wealth of material to consider.  And.. a wealth of extant field locations, though mostly still on private property.
  • Sherman’s armies winter around the Chattanooga area.  This, I would complain, has slipped under the nose of most.  The Atlanta Campaign as a whole, perhaps, gets “just enough” attention from historians, in my opinion.  And that winter’s experience is often summarized with the Grant-Sherman correspondence.  As if the soldiers were “on ice” the whole time. Given the decisive nature of the victory at Atlanta, would it not be good for us to connect some dots?
  • Sherman’s very brief winter pause at Savannah of barely three weeks, from Christmas 1864 into January 1865.  It was a winter encampment of sorts.  Certainly all those activities we mention above occurred before Sherman launched his march through South Carolina in mid-January. However, consider what this said about the notion of a winter pause… both at Savannah and at other points such as Petersburg, that winter.  Was a winter encampment an obsolete practice in modern war?

Well.. I started out to make a short list.  But my fingers kept going.  There are several others worth noting (for instance, the winter of 1863 around Charleston, which I’ve discussed in much detail across several posts).  But you get the idea.  We need to look into these winter activities with more than passing reference.  These were places and times when armies were reforged.  What was made right, or not as the case may be, would serve those armies well into campaigns that followed.

Fortification Friday: Stoccades as a supplemental interior arrangement

As we continue the walk through Mahan’s description of interior arrangements for fortifications, we turn next to the use of stockades.  As a defensive structure, stockades dated back to ancient times.  Stockades were quite popular on frontiers (not just the American frontier) where resources were short and adversaries were not expected to use heavy siege weapons.  As such, we tend to see more stockading in American fortifications… not just those Civil War structures we focus on here, but also for those outposts across the west.

Mahan mentioned stockades and stockading at several intervals in his instruction.  It is important to differentiate between stockading as a form of construction, in particular used for obstacles, and stockades as a defensive structure.  For reasons I cannot determine, Mahan used the archaic spelling “stoccade” to describe the latter.  And I will perpetuate that here, if for nothing else to preserve what may have been a subtle point, lost on us today.  Same material, just used in a different manner.  And toward the use of a stoccade, Mahan returned to a “… we’ll detail that later…” section of the earlier discussions.  Specifically, what to do with the back-side of those open works or on the gorge of bastions within enclosed works:

Enclosures for gorges and outlets.  A stoccade is the best enclosure for the gorge of a work.  The outline, or plan of the gorge, should be a small bastion front, for the purpose of obtaining a flank defense.

Mahan refers to Figure 39 as an example of such a plan:

PlateVIFig39

A basic lunette, but with an enclosure wall across the gorge.  I’ve taken the liberty of outlining that addition in red.  Notice how, as Mahan suggested, this is a portion of a bastion in terms of plan arrangement.  We have the curtain in the middle, a pair of flanks, and a pair of faces.  This offers a cross fire across the rear of the fortification.  Not something that would stop a determined defender.  But at least something to cause pause.

And keep in mind, this enclosure wall was not just earth.  Rather the intent was something that might be placed without heavy labor or use of precious resources.  A wood stoccade wall:

The trunks for the stoccade should be ten or twelve inches in diameter, and eleven feet in length.  It will be best to square them on two sides, so that they may have about four inches of surface in contact.  The top of the stoccade should be at least eight feet above the ground.  To arrange it for defense, a banquette is thrown up against it on the interior; the height of the banquette one foot nine inches. A strip, about two feet in length, should be cut from the top of two adjacent trunks, wit ha saw, so that when they are placed side by side there shall be an opening at top, between them, eight inches wide on the interior, and two and a half inches on the exterior; this opening, through which the muzzle of the musket is run out, in firing, is termed a loop-hole. The distance between the loop-holes should be three feet.  In this arrangement the bottom of the loop-holes will be six feet above the ground, on the exterior, to prevent the enemy from closing on them to stop them up, or to use them in the attack.

Figure 40 illustrates this arrangement:

PlateVIFig40

Notice this is across line n-m on Figure 39.  So basically across a face of the bastion.  Consider the interior arrangements described.  First, look to “n”, on the left.  We see a small banquette built as described, providing a footing for our garrison.

Consider the matching of requirement to form in the design of the stoccade wall.  The holes provided for these trunks ensured the tops extended eight feet above the ground, and thus six feet, three inches from the tread of that banquette.  Certainly sufficient to provide protection from direct fire for the man standing on that banquette.  But then we have the loop-holes, extending from the top down to six feet above the ground, which corresponds to five feet, three inches above the tread of that banquette.  So… for the guy on the inside, the loop-hole is at the right height for easy handling of a musket, through that nice little embrasure, if I may.  But… for the guy on the outside, the loop-hole is just above eye level for a man of average height and thus a little more cumbersome to reach and utilize.  Applied math!

Now what about the exterior face?

About four feet in front of the stoccade, a ditch is made twelve feet wide and three feet deep.  The earth from the ditch is thrown up against the stoccade, in a slope, to the level of the bottom of the loop-hole, to prevent the enemy from attempting to cut down the stoccade.

And we see that arrangement laid out in profile.  Again, the form matches to requirements with almost elegant simplicity.

Something easily replicated for the stage of a western movie in the 20th century.

(Citation from Dennis Hart Mahan, A Treatise on Field Fortifications, New York: John Wiley, 1852, page 60-1.)