Fortification Friday: Barriers, Bridges, and Ramps … the fort “communications” infrastructure

Writing the instructions for cadets, almost two decades after the Civil War, Junius B. Wheeler focused more on the functional requirements of outlets in the fortifications, as opposed to the important details of construction.  The nuances here are, I think, important.  Mahan presented the outlet had important operational uses within fortifications, but proceeded to discuss the particulars assuming the student would understand what those uses were. Wheeler focused on the uses up front, citing communications as the need and outlets as the remedy. And we must broaden “communications” a bit, perhaps our 21st century writers might say “traffic” and refer to movement of personnel, supplies, as well as messengers carrying communication.

Wheeler added to Mahan’s instructions with mention of “turn back” traverses at the mouth of outlets (to reduce the area under enemy lines of fire) and wider outlets for sorties.  But for the most part, the construction techniques remained the same.  Likewise, Wheeler identified the same supplemental structures as Mahan – barriers and bridges – while adding a few embellishments.

First off, we have the barriers. Which were… well… gates:

Barriers. – The outlets are usually arranged so that they can be quickly closed, to guard against surprise. The means used is a gate, technically termed a barrier.

The gate is made with two leaves, hanging on posts by hinges, and made to open inward.

The frame of each leaf is composed of two uprights, called stiles; two cross pieces, one at the other at the bottom, called rails; and a diagonal brace, called a swinging bar.

The leaf of the barrier may be open, by spiking stout upright pieces, with intervals between them, to the pieces of the frame; or it may be made solid, forming what is known as a bullet-proof gate.

Yes, something you might purchase, pre-fabricated, at the home improvement store.  But note that Wheeler offered two versions – a light “open” leaf version with spaces between the uprights AND a heavy “bullet-proof” version with no spaces.  The latter was illustrated in Figure 52 of Wheeler’s book:

WheelerFig52

Wheeler added some practical observations about the construction of these heavy gates:

Since the gate must be strong, the leaves of it are necessarily very heavy.  The leaves must be hung upon stout posts, firmly braced into the ground, to sustain the great weight of the gate.

The top rails of all barriers should not be less than six feet above the ground.

In the barriers with open leaves, the vertical pieces are usually extended from eighteen inches to two feet above the top rails, and their upper ends sharpened.

In those which are solid, it is usual to arrange some obstruction upon the top rail, such as sharp pointed spikes, broken glass, etc., to interfere with persons climbing over the top. It is usual to provide apertures in the leaves, through which the men can fire upon the ground outside.

Gotta love those details.  From having a “peephole” to shoot out from to having broken glass atop the gate.

Bridges were another supplement to the outlet’s composition:

Bridges. – When the ditch has been completed along that part of the work in front of the outlet, it is usual to carry the roadway across the ditch by means of a bridge.

The ditches of field works are, as a rule, quite narrow, and the bridges used to span them are very simple constructions.

A common method of building the bridge is to lay three or more sleepers across the ditch, and cover them with planks laid transversely.  If the span is sufficient to require intermediate supports, these are obtained by using trestles placed in the ditch.

A bridge built in this way can be quickly removed and speedily re-built, if there be any necessity for it.

We might consider this a temporary bridge without any means for retracting or removing, save dismantling.  Thus it was kept to the bare minimum arrangements.

Wheeler mentioned that other “hand-books on military engineering” described the use of draw bridges or rolling bridges in fortifications. He only briefly discussed the former, being basically as that detailed by Mahan in earlier texts.  The latter were designed to be “… pushed out from the work, and drawn back into it.” Both sort of bridges were,

… known as movable bridges, are useful to guard against surprise, to prevent stragglers from entering, and to keep the garrison in the work.  As a defense against an assault of a field work, they are of but little value.

To belabor that point:

The best method, is to have no ditch in front of an outlet, but let the roadway be on the natural surface of the ground.

Of course, operational needs might vary. But you get the point.

Wheeler offered one more supplemental structure under his heading of communications, but not one that was directly associated with outlets.  This was the ramp.  While all writers on fortifications discussed ramps in some regard, Wheeler saw fit to highlight the structure and its role for interior communications (and again, broaden that definition as mentioned above):

Ramps. – The short roads used in fortifications to ascend from one level to another, are termed ramps.

The width of a ramp depends upon its use, following the rule laid down for the width of passages.  A width of six feet for infantry, and of ten feet for artillery, are the widths generally used.

The inclination of the ramp may be as great as one on six, and as little as one on fifteen, depending upon the difference of level between the top and bottom. The side slopes of earth with its natural slope.

The ramps in a work should be placed in positions where they will not be in the way, nor occupy room which may be required for other purposes.

Steps or stairways are sometimes used instead of ramps. The rule for them is that the breadth of each step, called the tread, shall be at least twelve inches, and the height of the step, known as the rise, shall be about eight inches.

They are substituted for ramps in those places where there is not sufficient room for the ramp.

Nothing new or advanced here.  Ramps and stairs were part of fortifications dating back to the earliest times.  What is noteworthy here is that Wheeler considered them part of the fort’s communication infrastructure… again communication in the sense of how one moves into, out of, and inside of the fort.

(Citations from Junius B. Wheeler, The Elements of Field Fortifications, New York: D. Van Nostrand, 1882, pages 151-5.)

 

Battle of the Bands, part 2: Comparison between Tredegar, Macon, and authentic Parrotts

When discussing Parrott rifles, we really have to focus on the bands.  The bands over the breech end of the cannon are what make the Parrott a Parrott, by type.  Without the band, the Parrott would simply be a gun of cast-iron that generally followed the Ordnance Shape in exterior arrangements.  One that would be prone to bursting.  And thus something not likely to have seen much service.  On the other hand, with the band in place, at least the field gun calibers were actually reputable weapons… relatively speaking.

And it is important to understand the variations of these bands. Some time back I highlighted the difference between the authentic, original Robert P. Parrott-designed, and West Point Foundry produced, guns and those “knock offs” from Tredegar. The Tredegar weapons had longer and thicker bands.  This was due to construction techniques.  In brief, the original, patented, Parrott design called for a single bar to be heated, formed into a spiral, then placed onto the breech (and turned as it cooled).

On the other hand, Tredegar lacked the lavish facilities of West Point Foundry (and one might also say was aloof to some of the advancement in metalworking… but that’s a complex story). So when “copying” the Parrott for Confederate orders, Tredegar modified the technique to construct the band.  In short, Tredegar constructed a set of wrought iron rings or hoops.  When heated, those slipped onto the breech and were butt welded together.  As the rings cooled, they shrunk down onto the breech. Please note the basic technique was similar for Tredegar’s Parrott copies and larger weapons to include Brooke Rifles.  These butt welded bands were not as strong as the spiral welds from West Point Foundry.  So Tredegar allocated more metal to compensate.

As indicated above, Tredegar’s work was aimed at replicating the features of the northern weapon.  Those copies were based on examples purchased just prior to the war (notably by Virginia) and others captured early in the war.  One would suspect the features employed for this replication would be passed directly to other vendors producing Parrott-type rifles for the Confederacy, such as Macon Arsenal.

But such presumption should be given a “field test” with study of surviving pieces.  And the place to do that is along Confederate Avenue at Gettysburg.  There we find a pair of 20-pdr Parrotts from West Point, although a “Navy” weapon with breeching shackle attached:

Gettysburg 13 May 2012 147

A pair of 20-pdr Tredegar Parrotts:

Confederate Ave 30 Jan 10 179

And, recently returned to the field, a pair of 20-pdr Parrotts from Macon Arsenal:

Gettysburg 020

(Yes, I should have stood to the right side of that Macon gun there… but Jim, I’m a blog writer, not a photographer!)

Measuring the length of the bands on these three, starting with the original, Yankee Parrott:

Gettysburg Sept 10 001

Just over 16 inches.  I call it 16 ¼ inches overall.

Now the Tredegar Parrott:

Gettysburg Sept 10 030

Substantially longer. I would call it 21 ¼ inches overall.

And finally, back (on the road) to the Macon gun:

Gettysburg Sept 10 020

Hold the phone there!  Look close at that tape:

Gettysburg Sept 10 022

Despite the “wiggle” in my tape, we have something shorter than the other two.  I call it 15 ¾ inches, round about.  So with three quick measures, we can throw out the presumption about Macon’s products just being straight copies of the Tredegar guns.  Of course, you could probably deduce that by noting the clearance of the band on the standard NPS reproduction carriage.

But is the Macon band thicker, by chance, for compensation?  Let’s start, for a baseline, back at the Federal Parrott:

Gettysburg Sept 10 003

Since the band edge is rounded off, we have to eye-ball this a bit.  I call it at just over 1 ½ inches.  I’ve seen secondary sources state this should be, precisely, 1.625 inches.  But we are “in the field” and the 1 ½ inch measure will be OK for now.

Moving to Tredegar’s product:

Gettysburg Sept 10 028

I’d say this is just about the same thickness.  Just over 1 ½ inches.  Though there are secondary sources that credit the Tredegar band on 20-pdrs as being 2 inches thick.  Let me take an assignment here to survey all surviving Tredegar 20-pdrs at Gettysburg for comparison.  But for now, we have the 1 ½ inch measure to work with for our purposes.

Now back to Macon:

Gettysburg Sept 10 025

So you don’t have to strain the eyes too much, I had a second measure where I fiddled with the ferule a bit measuring the second of the pair:

Gettysburg Sept 10 014

Clearly in both cases the measure is LESS than 1 ½ inches.  Substantially so.  I’d call it 1 9/32 inches.

But you may have noticed that my ruler was “set up” off the actual barrel a bit.  That’s because on both Macon Parrotts there is a “lip” or ring between the band and the barrel.  Let’s look close:

Gettysburg Sept 10 015

The clearance on the first Macon Parrott is tighter, but on the second there is a clear separation between this lip and the other components of the gun.  This is also clearly not a supplemental or inner band.  My first thought was this lip was the remainder of some fitting that limited the advancement of the band during construction.  But the more I looked at the lip, it appeared to be threaded.

And that, perhaps, would explain the different dimensions of the band. Speculation here, only, as no source I know of corroborates this. Perhaps Macon Arsenal threaded the bands onto the breech.  Such also might explain the “scuffs” that appear on the guns today.  If the bands were threaded, perhaps Macon felt the construction imparted additional strength over the butt welded bands and thus reduced dimensions.  But again, I’m only speculating here based on appearances.

By all means, don’t just accept my speculation here.  Go visit the guns and make your own observations. Then circle back to discuss!

Overall, let me offer this table for field measures of these three sets of Parrott rifles:

20pdrParrottComparisons

I would point out the measure taken in the field for both Confederate guns differs from printed secondary references.  So more “field trips” are warranted for conformation.

One other measure to share…. looking at the bore of the Macon rifle:

Gettysburg Sept 10 024

The bore size corresponds to the 20-pdr caliber, properly, at around 3 ¾ inch, in the books supposed to be 3.67 inches.  Notice the well defined rifling.  This piece likely did not see much service.  In all likelihood, the weapon was delivered in the spring of 1864, going to a location in Georgia.  Given the outcome of that summer’s campaign, quite possible this 20-pdr was captured, and spent the rest of the war in some Federal depot.

Wonder what story this gun would tell if allowed to speak?

Two stories I hope are interpreted with the Reconstruction Era National Monument

Officially announced as we entered the Martin Luther King, Jr. weekend, President Obama created the Reconstruction Era National Monument, along with several other monuments at historic sites related to the advancement of civil rights.  From the official fact sheet:

Reconstruction Era National Monument: Located in coastal South Carolina, the new Reconstruction Era National Monument encompasses four sites throughout Beaufort County that tell the vibrant story of the robust community developed by freed former African American slaves in the Reconstruction Era South.  This designation includes the Brick Baptist Church and Darrah Hall at the existing Penn Center on St. Helena Island as well as the Old Firehouse in downtown Beaufort and parts of Camp Saxton in Port Royal where the Emancipation Proclamation was read on New Year’s Day in 1863. These sites establish the first unit of the National Park System focused on telling the story of Reconstruction.

And that brand-new Monument already has its official website.  I’m impressed with the direction taken.  As I’ve pointed out before, there is a tendency to compartmentalize Reconstruction as if a separate, stand-alone chapter.  We should properly see a story-arc that connects the Civil War through to Civil Rights … and right up to our doorsteps today.  And Beaufort County, South Carolina is a perfect place to demonstrate that continuity.   Reconstruction of that county stated during the Civil War.  And the turns of Reconstruction into the post-war era may be traced readily across various sites in the county.

I am pleased to see the inclusion of Mitchelville and Fort Howell in the Monuments list of “Places to See.”  These immediately call to mind the military role within Reconstruction.  We often forget, despite being largely a political event, Reconstruction was in part a military operation.  And one that deserves deep study as a military operation.  Certainly as those military activities often directly contributed, or in some cases detracted from, the advancement of Civil Rights.  Furthermore, many of the military experiences from that period which deserve study.  There are lessons learned applicable even today.  (Dare I remind readers the very lengthy “reconstruction” engagements still ongoing in places such as Afghanistan?)

Several places within the Beaufort Historic District will no doubt get attention. Mention of the Baptist Church brings to mind one important story I’d like to see highlighted with the interpretation. After the battle of Port Royal Sound, November 1861, much of the county was occupied by Federal forces.  Many white residents fled inland, leaving behind a population of former slaves.  Those numbers swelled as more slaves escaped through the lines, or were brought to freedom by the Federals.  And that population turned, as people will in trying times, to their religious convictions for support.  Working among the freemen, Reverend Solomon Peck worked to establish a church, using the Old Baptist Meeting House among other places.  Seeking formal sanction for assuming control of the structures, Peck wrote to President Lincoln.  And Lincoln replied along the lines that if the majority of the members of the church still present (on the island) are indeed loyal to the United States Government, then they are entitled to use the facilities.  After all they would be “the church” in standing.

Doesn’t sound like a big deal. But when you look at it through the lens of history, it is. This is a level of equality not normally extended at that time.  So long as the persons were loyal … says nothing of citizenship, but loyal… then the government would recognize a legal standing.  The government recognized them as the body of a church.  Legally.  And what dovetails nicely in this story is the reading of the Emancipation Proclamation in the church, to freedmen, at the start of January, 1863.

Another story that I would much wish to see used in the interpretation of the new Monument comes from the military side in those Civil War years.  Frederick Denison, of the 3rd Rhode Island Heavy Artillery, recorded an episode that occurred outside Beaufort as the regiment garrisoned the island, in the spring of 1863:

We are here tempted to record a little military anecdote.  While Lieutenant [Edward] Waterhouse was on duty near Beaufort, having occasion to ride across the island in a carriage, he invited a staff-officer of the Regulars to ride with him.  Meeting a private of a colored regiment who paid the required salute, the Lieutenant properly returned it, when the following dialog ensued:

Regular: “Do you salute niggers?”

Lieutenant: “He is a soldier and saluted me.”

Regular:  “I don’t care for the regulations.  I swear I won’t salute a nigger.”

Lieutenant: “I obey the regulations and return a soldier’s salute.”

Regular: “Curse such regulations. I’ll never salute a nigger; and I don’t think much of any one that will.”

Lieutenant: (Coolly reining in his horse).  “You can get out and walk, sir.”

The snob tried his shoe-leather on the sand, a wiser man, we may hope, and with a higher idea of both the Lieutenant and the polite colored soldier.

You see, the Emancipation Proclamation might say the slaves are free. Constitutional amendments might guarantee their freedom, citizenship, and right to vote.  And those freedmen might even wear the uniform and carry a musket.  But real equality is not pressed down by the government.  It’s achieved at the personal level.  When the Lieutenant Waterhouses of the Army saw fit to treat every USCT private in the same manner as any other private in the Army, there is an equality to speak of.

The simple exchange of salutes might seem small in the grand scheme of things.  But that salute was but a small example of a larger sentiment building among those serving in the department.  Those USCT soldiers would earn the respect and admiration of many for deeds on Morris Island during the summer which followed. There would be plenty of those “regular staff-officer” types, at the time and the century that followed, who would not catch on.  Thankfully, over the span of the next 100 years, there were more of the Lieutenant Waterhouses who did.

(Citation from Frederic Denison, Shot and Shell: The Third Rhode Island Heavy Artillery Regiment in the Rebellion, 1861-1865, Providence, R.I.: Third Rhode Island Artillery Veterans Association, 1879, page 150.)

Fortification Friday: Outlets evolved in the post-war instructions

Earlier we considered the pre-war instructions offered by Mahan in regard to outlets, particularly how those would be constructed.  Training cadets before the war, Mahan covered the topic with a few paragraphs.  Later, after the war, he added a section about bridges associated with the outlets.  However, by the 1880s, Junius Wheeler’s instructions to cadets would sprawl over the better part of seven pages.  Maybe this is simply a case where pre-war there was a premium on copy space for printed manuals.  On the other hand, maybe Wheeler felt “his” cadets needed “special help” getting this particular aspect of fort-building in order.  Or perhaps, which I tend to think, wartime experiences prompted the extended emphasis.

The first thing we see with Wheeler’s treatment of the subject is a focus shift.  Before discussing the construction of these outlets, he steps back to discuss what these are used for.  Notably, the section is titled “Communications, barriers, etc.”:

Communications. – The defenders of a closed work must have arrangements made by means of which they can enter or go out of the work when necessary. In the case of continued lines, arrangements should be provided by means of which the defenders can make sorties.

Word choice here.  Mahan’s writing pressed that outlets were important for servicing the works.  Left unstated, implied at best, were other uses for the outlets – communications, logistics, reconnaissance, or simply just getting out to stretch the garrison’s legs. On the other hand, by selecting this sub-heading, Wheeler set different functional requirements… although, much vaguer than Mahan’s.

Wheeler’s second paragraph discussed the basics.  The outlets had to be made through the parapet, and that created a weak point in the work.  To minimize the risk, he insisted the number of outlets be kept to a minimum and built where least exposed.  Specifically, he gave these suggested placements:

In redoubts, the outlets are on the sides least exposed to attack; in half-enclosed works, they are placed near the middle of the gorge; in forts, they are usually placed near the re-entrants.

And that matches well to Mahan’s suggestions from decades before.  But where we see variations is with the size of these outlets, which Wheeler relates based on functional requirements:

A passage for the use of infantry only should not, as a general thing, be less than six feet wide; for artillery, not less than ten feet wide; for sorties, the outlets in continued lines should be at least fifty yards wide.

See what happened here?  Wheeler took Mahan’s two size categories and then added a third, based on an additional use-case.  I think at this passage Wheeler is thinking back to works at Vicksburg or Petersburg or around Atlanta.  And in those campaigns, field works had become part of an offensive operation – be that a very deliberate siege at some levels, but more dynamic than an “According to Vauban” siege.  Again, not to say wide passages for sorties did not exist prior to 1861, but rather to say those took on different emphasis around about 1863-4… at least in the American context.

Demonstrating that the more things change, the more they tend to stay the same, Wheeler offered this diagram for an idea outlet through the parapet with masking traverse:

WheelerFig50

Yes, he ripped off Mahan.  But give him a little credit for adding more notations and giving us that nice profile on the right.  And he offered the lines (c and g, the “crossing” arrows through the middle) which were the enemy’s “extreme lines of fire”.  Those lines, Wheeler instructed, governed the length of the traverse (T).  Note how those lines are drawn off the corner of the superior slope of the parapet.

Toward that, Wheeler did add a lot more to the notion of masking the outlet:

The length of the traverse may be shortened by turning back the interior crest at right angles to its general direction, and extending it as far as the crest of the Banquette.

This “turn back” is indicated by “B” on the figure.  One on each side of the outlet.  Notice how that would send the lines of fire (again, lines c and g) into a tighter intersection, further back in the outlet, and thus reducing the area the enemy might fire upon. Such angles reduced, the traverse need not be so long.  All in all a nice functional flourish to the outlet design.

Beyond that, Wheeler offered other options that would reduce the vulnerability:

Instead of having a road along its entire front, the traverse is sometimes joined to the parapet on one side of the opening, as shown by the dotted lines b d and e f, in Fig. 50.

And such would mean only one “extreme line of fire” need be considered in regard to traverse length.  But that did mean traffic had a nasty chicane to deal with.

This is all good, but how about that fifty-yard wide outlet for sorties?

The method adopted to mask the interior of the work in this latter case, is to place the traverse opposite the outlet on the outside, and beyond the ditch….

The traverse in this case is usually broken, generally a redan in trace, with the profile of a parapet, but commanded by the parapet in rear.

Figure 51 illustrated this manner of masking:

WheelerFig51

Basically, if you have to provide a wide gap in the works, the only viable solution is to build a miniature work in front to cover it.  Keep in mind, such sortie outlets would be placed on less exposed sections of the line.  And of course, these would be covered by strong faces on either side.  Such would reduce the chance the enemy might target the outlet for their own “sortie”.  And the redan covering the front would further reduce the danger of direct artillery fire.  Note, however, you don’t see a traverse in the interior of the works to cover the sortie outlet.  The purpose of this outlet is to allow infantry in wide columns to emerge in quick order. Bad enough, though necessary, to have that redan in the way.  Putting a traverse on the inside would impose yet another choke point for maneuver… and yet another delay in an operation where time was critical.

Before leaving Wheeler’s discussion of outlets, we’ll also examine the evolution of barriers and bridges.  Furthermore, Wheeler introduced the notion of ramps within these outlets.  All interesting facets to consider with respect to the art of military fortifications.

(Citations from Junius B. Wheeler, The Elements of Field Fortifications, New York: D. Van Nostrand, 1882, pages 148-51.)

Loudoun County CW Roundtable 2017 Schedule

We’ve just posted our 2017 schedule for the Loudoun County Civil War Roundtable.  And wanted to re-post here as I know some readers in our area will be interested:

Speakers and Topics Scheduled for 2017

March 14, 2017—George Lewis: 500 Horses a Day

April 11, 2017—James A. Morgan III: Activities of the Joint Committee on the Conduct of the War

May 9, 2017—Mike Block: The Confederate Experience in Culpeper County, Virginia

June 13, 2017—Laura June Davis: Mississippi River Boat Burners

July 11, 2017—Robert H. Moore II: The Summers and Koontz Affair

August 8, 2017—Elizabeth Parnicza: The Looting of Fredericksburg

September 12, 2017—James Hessler: Dan Sickles

October 10, 2017—Gordon Calhoun: The CSS Florida, Operations and Artifacts

November 14, 2017—David Goetz: John S. Mosby and the Lincoln Conspiracy

December 12, 2017—Members’ meeting (TBD)

Note: Meetings are not held in January and February.

If you are not a member of the roundtable but wish to attend, drop me a note.  Would be glad to introduce you to the group.

Other “event” news to note, the 18th Annual Civil War Seminar hosted by Longwood University and Appomattox Court House NHP is scheduled for February 18.  No details as to speakers, but I highly recommend getting this one on your calendar.

A rare pair from Georgia: Confederate 20-pdr Parrotts, Macon Arsenal

Back in the summer, the folks at Gettysburg put a pair of 20-pdr Parrotts back out on the field.  I’m a bit behind in my writing assignments… and it is cold outside… so let me post some summertime photos to warm you up a bit:

Gettysburg Sept 10 027

The location is Captain Robert Stribling’s Battery (the Fauquier Artillery) along West Confederate Avenue. The battery manned two 20-pdr Parrotts and four 12-pdr Napoleons at the time of the battle.  And what we see here are a pair of 20-pdr Parrotts representing the battery at this position. This pair is somewhat unique among surviving weapons, being the only such (that I know of) produced by Macon Arsenal.

Recall Macon Arsenal included one of the government-run foundries setup by the Confederacy. The arsenal is most known for the production of 12-pdr Napoleons.  But the arsenal also produced a small number of iron guns, following the layout of the Parrott rifle system.  In the past, I’ve mentioned a 10-pdr Parrott which is suspected to be from Macon. Arsenal records indicate a handful of 20-pdr and 30-pdr Parrotts were also produced.  Of, probably, five 20-pdr Parrotts produced by Macon, we have these two survivors.  So you can say these had a good survival rate… or be thankful to have two survivors out of such a small production run.

Unlike the 10-pdr at Chancellorsville, there is no doubt as to the origin of the 20-pdrs:

Gettysburg 024

Right there on top – “Macon Arsenal”.  The other stampings read “1864” for the year of production (perhaps matching to April or May in arsenal records); “1660” is the recorded weight, in pounds; “No.1” is the foundry number; and “E.T.” for either the inspector or other official making acceptance.

The gun’s mate has similar markings, but a fair bit clearer:

Gettysburg Sept 10 023

Note the differences here with the weight being 1664 pounds and the foundry number of 3. We also see the rifling – five right handed spiral grooves.

Gettysburg 025

Do watch for the wasps there.

Working our way back from the muzzle, we see a clamp of sorts around the end of the chase, just short of the muzzle swell:

Gettysburg 023

That on No.1 appears to be aligned, while that on No.3 is askew after 150 years of handling. The band itself is a fraction over 1 inch in width:

Gettysburg Sept 10 010

As seen on the right, what appears to be a square pin goes through the strap.  Presumably this is what remains of the front sight. The open end of the strap is fixed by a bolt (seen above).  The other side is hinged:

Gettysburg 035

That is on No.3, where the strap is askew, where the hinge is easier to view.  Notice, to the right, you don’t see the pin that might be the front sight.  This strap is apparently both out of alignment and upside down.

Looking at the barrel itself, thanks to a fresh coat of paint we can see a lot of surface details.

Gettysburg 037

The casting seam may be traced right back through the shoulders to the band.  And very little turning was done to smooth the surface.  This would not pass the Federal inspections but was determined as sufficient for Confederate needs.  Turning just added to the processing time and gave picky inspectors something to fret over… in J.R. Anderson’s opinion, at least.

And we get back to what makes this a Parrott, the band:

Gettysburg 032

I’ve taken the time to collect some rough field measurements.  But I wish to save those for a post comparing the bands of Federal, Tredegar, and Macon Parrotts of this caliber.  That in mind, we’ll save full discussion of the band arrangement for later.  But do note the slight radial line visible about a quarter the way up from the breech.  That may be a trace left over from butt-welding the rings constituting the band.  Also notice a scuff mark just in front of the band. Perhaps a vestige of the work to force the bands onto the barrel?  Or yet another result of bad handling?

Looking at the breech, we see arrangements for the rear sight at the top position:

Gettysburg 021

Just seems like a lot of inherent inaccuracies built in with that front sight on a strap.  But then again, this isn’t a sniping rifle.

Notice the casting seem down the face of the breech.  And we also see a dent in the knob.  Battle damage or mishandling? Probably the latter.

Here is a better view of the rear sight area:

Gettysburg 033

And again we see “scuffs” near where the band is attached over the barrel.

It is good to see these old guns back on the field after many years absence.

Gettysburg 019

Many thanks to those who work restoring these guns and the organizations that aid the park service in this regard.  Very good work with these two rare guns.  And it is good to see them on the field instead of stuffed in a museum. Better to have them on the field, in spite of the risk due to weathering and wear. Cannons were made to point out over a battlefield.  And though these two could not possibly be Gettysburg veterans (due to the date of manufacture), they stand in well in place of those that were.

Fortification Friday: Drawbridges? For field fortifications?

Last week we looked at the use of outlets in the field fortifications.  Certainly it was impractical to insist the garrison stockpile sufficient food and supplies for the anticipated duration of the conflict at hand… not to mention cross their legs the whole time.  Some sort of gate or entrance was required.  However, that presented a weak point that an attacker might exploit.  Thus Mahan urged his students to build additional structures, namely traverses, to cover those entrances.  That reduced the risk to a degree.

But where the point where the outlet crossed the ditch (if it had to cross a ditch, that is) presented a greater problem.  As we’ve seen in detail, one of the important properties of the ditch was serving as an obstacle to any attack.  But the outlet would require a six to ten foot wide path across the ditch.  Thus granting an attacker a potential highway across.  Common sense response to that problem was to simply build some sort of retractable bridge.  But pre-war, Mahan did not offer that as a direct solution (indeed, avoiding mention of the problem altogether).  But in his post-war edition, Mahan offered:

Draw-Bridge. For the usually narrow ditches of field works, either a light rolling bridge may be used for a communication, from the outlet, across the ditch; or else an ordinary wooden draw-bridge.  A very simple one, and of easy construction, was proposed by Colonel Bergère of the French engineers.

I believe this refers to Colonel Pierre Bergère (1785-1868), but I don’t know of a specific work to reference in regard to the bridges in question here.  I find it interesting the more detailed discussion of bridges enters Mahan’s post-war edition with Bergère serving as a reference and introduction.  Either as if the 1861-65 experience simply followed that of the French engineer, or could not be applied directly.  I have my thoughts, but let’s save that for later.

Mahan offered Figure 45, bis to illustrate the proposed bridge:

MahanFig45bis

Technical details followed:

The bridge is a light platform a,a’, of joists and boards, long enough to span the ditch D, and so arranged as to turn around an axle at A, the crest of the scarp.  At the point B, on each side of the platform, an iron gudgeon is firmly attached to it and turns in the eye of a socket at the end of lever C B.  This lever is formed of two pieces of scantling of some tough flexible wood, each about four inches square. The lever has an eye, at the middle point O, which receives a strong iron bolt that connects two ordinary gun carriage wheels.  The two pieces which form the lever are firmly fastened together, as shown in the figure; a weight, consisting of shells filled with sand, or shot, being fastened at the end c, and serving as a counterpoise to the bridge.  Two rails A, of heavy scantling are laid for the wheels to run upon in maneuvering the bridge; which is done simply by one or two men taking hold of the spokes of the wheels, and so, by turning them, causing them to run backwards or forwards, and thus raise or lower the bridge.

The arrangement is a clean piece of engineering.  But nothing novel or particularly advanced, technically speaking.  Noteworthy is the re-purposing of common equipment, such as carriage wheels and projectiles, on hand with the field army.

But I have to throw a flag out here.  If those building the fortification had ample time to build fancy drawbridges, they were more so working as garrison troops and probably not actively campaigning.  The premise behind field fortifications was those would be temporary structures established as part of a field army’s operations.  Not structures to be garrisoned, which should shade more to the permanent fortifications with far more elaborate arrangements all around.  But experience in the Civil War took the American officers away from some pre-war assumptions about how fortifications would be use.  And more importantly how to classify them.  We’ve already noted that Junius Wheeler began classifying semi-permanent and temporary garrison fortifications within the discussion of field fortifications.

Now this is not to say no self-respecting American engineer in 1861 would consider the drawbridge when planning the outlet to a fort. Rather that in 1861, the use of drawbridges were not emphasized in the classroom.  But by 1870, that changed to provide a couple of paragraphs and a nice illustration based on a French officer’s recommendations.  As we will see by looking at Wheeler’s text, by the next decade, those instructions evolved even further.  Pages, mind you, dedicated to the discussion of small bridges!

(Citation from Mahan, An Elementary Course of Military Engineering: Part 1: Field Fortifications, Military Mining, and Siege Operations, New York: John Wiley & Son, 1870, page 57-8.)