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Assessment of Earthworks:

Assessment of the Principal Earthworks:

The Federal "Fish Hook" Line, Petersburg, VA


The "Fish Hook" at Petersburg National Battlefield preserves examples of late war siegeworks that occur no where else. During fall 1864 and winter 1865, Federal engineers designed a line of fortifications that could be held by a minimal number of troops and eventually by the garrisons of the enclosed forts alone. Fort Fisher was the keystone of this line, but each redoubt had a role to play in the defense. Guns were sited to create interlocking fields of fire that could systematically sweep all of no-man's land with shell and canister. Multiple lines of fraise, abatis, and wire entanglements were constructed to slow any attacking force, to give the guns time for execution. It was a lethal design that cannot be understood by studying individual redoubts or trench lines in isolation.

Confederate engineers did not adopt a system of mutually supporting, enclosed forts along this section of their defenses, perhaps for lacking sufficient field artillery. The siege might have been lengthened if they had. As it occurred, the military architecture preserved on the Fish Hook line contributed materially to Federal victory at the Siege of Petersburg.

The Fish Hook line within the boundaries of Petersburg National Battlefield consists of one bastioned fort, five redoubts, and a siege battery-all connected by rifle trenches. This line was entrenched after September 30, 1864, as Federal forces sought to consolidate gains made during the fighting on Peebles and Pegram farms and improved almost continuously until the end of the siege. In general, these earthworks are located in wood lots of various sizes and maturity. The best preserved earthworks are located in the most mature forest conditions, while the least preserved have been cleared of trees in the recent past, then allowed to grow up in woody scrub and pines. The surface cover of the parapets is almost exclusively leaf litter. The park's boundaries in every case lie close to the earthworks providing little if any buffering from activities on adjacent private property.

In April 1998, Cultural Resources GIS conducted a systematic GPS survey of the principal artillery earthworks on the Fish Hook line-Forts Urmston, Conahey, Fisher, Welch, Gregg, Wheaton, and the Siege Battery. The earthworks were assessed according to 1) clarity of surviving details, 2) amount of damage observed in the field, and 3) integrity of setting. The scores assigned to each earthwork are summarized in the table above and described in more detail in the following discussion. Scoring ranged from 5, being best in the category, to 1, being worst.

The overall integrity rating is the sum of the three assessment categories and provides a comparative indicator of the earthworks' condition (10-15 good, 5-9 fair, 1-4 poor). The perfect score (15), for example, might be assigned to an earthwork that remained undisturbed in an area where woods grew up soon after the end of the war and were never extensively logged and where the soils resisted erosion.
The results of the assessment are summarized in the table below and discussed in more detail in following sections.

Clarity of
Detail +
Observed +
Setting =
FORT WELCH 4 4 4 12 good
SIEGE BATTERY 4 4 4 12 good
FORT FISHER 4 4 2 10 good
FORT GREGG 3 2 4 9 fair
FORT WHEATON 3 3 2 8 fair
FORT URMSTON 2 1 1 4 poor
FORT CONAHEY 1 1 1 3 poor

During the three-day survey of the Fish Hook line, two CRGIS crews mapped a variety of earthworks and other features:

artillery platforms, 51
artillery embrasures, 27
artillery ramps, 20
traverses, 7
balks, 13
magazines, 7
miscellaneous holes (primarily foxholes), 17
banquette (firing step), 181 meters
park trails, 646 meters
boundary markers, 32

Crews mapped 33 parapet segments, totaling 3,242 linear meters. The relief of parapets (distance from top of parapet to bottom of ditch) ranged from 0.3 to 4.6 meters, the average being 2.23 meters. Parapet width ranged from 2.13 meters to 7.3 meters, the average being 4.6 meters. The condition of 2,726 meters of parapet was assessed as good, 295 meters as fair, and 221 meters as poor. Ditch-in-front construction was used for 93 percent of these earthworks.

In addition, 105 assessment points were taken, at which the following information was collected: predominant surface cover of the parapet (leaf litter, moss, native grasses, heavy undergrowth, turf grass), percent of bare soil, plant species diversity (within the surrounding square meter), and observed damage (animal burrowing, human digging, tree throw, erosion, compaction, intrusion, or none). Leaf litter was by far the predominant parapet cover and provided greater than 80 percent coverage in most locations. As a result of the poor surface soils and thorough covering of leaf litter, plant species diversity (at least in April) was very low.

The principal earthworks are discussed in the following section in order of integrity-from best to worst condition and recommendations for treatment are offered based on the integrity of resources and setting and observed damage.

Fort Welch is a small redoubt with steep slopes and well defined angles that is filled with interesting survivals--nine gun positions with platforms and ramps, four embrasures with good definition, a magazine, and segments of surviving banquette (firing step) connecting gun platforms. The redoubt is difficult to access with its steep sides and water-filled ditch and is thus rarely visited. This has contributed to its high rating. Little damage to the interior was observed, although animals are burrowing into the parapet in at least four places, primarily in the northwest face. This infestation might easily worsen and begin doing serious damage to the parapet. The redoubt's deep, water-filled ditch and steep slope have prevented extensive timbering. The interior is dense with larger pines and hardwoods and heavy undergrowth.
The terrain in the immediate vicinity has remained largely undisturbed and thus retains high integrity. Much of the acreage between the National Park and the boundary of Pamplin Park Civil War Site was clear cut and sown in new pines, making the area nearly inaccessible. Because of the nature of the clear-cutting, it is assumed that surviving picket lines, covering Fort Welch and the Siege Battery were destroyed or badly damaged. Because of its integrity, Fort Welch is an ideal candidate for a forest husbandry approach.

The Siege Battery (number 27 in the line of Federal batteries) has benefited from its relative obscurity. It is highly overgrown in summer months, and its features are not readily readable to the casual observer even in the winter. It is a well-preserved example of an artillery position constructed late in the war. The battery has a clean profile with well-defined angles. It is rich in detail with four large traverses, all sharply defined, eight positions for large caliber guns which retain their platforms and embrasures, two platforms for field guns, and a probable mortar platform, as well as two magazines constructed behind the parapet in the angles of the traverses. Little damage was noted in the interior, except for a large animal burrowing in the magazine adjacent to gun #8. The rear of the platform of gun #1 was truncated when the hiking trail came through. The Pegram House site, located within a hundred yards or so from the Siege Battery would be an important archeological site and interpretive location.
The Siege Battery should probably be maintained in forest cover. If, however, additional easements could be acquired to allow interpretation of the Pegram house site and Battle of Pegram's Farm, a selective portion of the battery might be cleared and interpreted. This would be preferable to clearing Fort Welch.

Fort Fisher is a large bastioned fort with a steeply sloping parapet and fairly well defined angles. Its size has tended over the years to minimize the effect of impacts and intrusions. Despite the fact that a portion of the ditch of the southwest bastion was filled in for road improvements and that some logging has occurred, the earthwork retains high integrity. Once inside, the sense of place is palpable. The interior is rich in legible detail. There are positions for nineteen field guns, two with recessed platforms, four ramps leading to guns in the bastion angles, a large oblique traverse with a collapsed magazine, two smaller traverses in the northeast and northwest bastions, each with a large collapsed magazine, long segments of surviving banquette, particularly in the northeast bastion, and the remnants of the fort's drainage system. The drainage system is a particularly rare survival. Shallow ditches run from the fort's two northern bastions, conjoin, and then drain into a sump adjacent to the western face. The ditch of the central traverse drained into this sump, as well. A collapsed portion of the parapet next to the sump might be evidence of a culvert (wooden) that passed water out of the fort into the outer ditch. A similar slumping was observed on the opposite face. Isolated spots of erosion were seen in several places in the parapet. Two compacted areas appear to have been caused by animals, particularly in the northeast bastion near gun #12 where a trail was worn along the outer edge of the parapet. Only one example of tree throw was found, adjacent to the parapet but causing little damage.

When surveyed in April 1998, Fort Fisher received a higher mark for setting, despite its location at the intersection of Church and Flank roads. The terrain to the north and northeast was largely intact. On a follow-up visit in May, it was apparent that new construction on private property adjacent to the park had degraded the setting within the fort's northern and eastern fields of fire. Trees can be replaced but the contour of the land cannot be rehabilitated in any historically meaningful way.

Fort Fisher is a likely candidate for selective interpretation. It is large enough to enable moderate visitation with low impact, so long as visitation is properly channeled. The logical access point would be through the sally port by means of a drawbridge, rather than through the existing intrusion in the southwest bastion. The drawbridge could be raised at dusk to deter nighttime visitation. As an example, a trail could lead visitors past the central traverse up the gun ramp and onto the platform of a cleared and planted northeast bastion. Railings would be needed to keep visitors off the parapets and the magazines. To view the outside of the fort, visitors would follow a hiking trail around the ditch perimeter. After some years, the effects of visitation could be examined and the relative integrity of features in the northeast and northwest bastions compared. This would provide a valuable case study for determining the long-term efficacy of hydro seeding for resource preservation.

Fort Gregg has interesting features that have been blurred by erosion over the years. The design itself-featuring a dentate face--is fairly unique. Each of four gun platforms was sited within a parapet 'V' that directed oblique fire to the northwest or southwest. This was one technique used by engineers to coordinate the fire of guns from adjacent redoubts to create interlocking fields of fire. Six gun platforms are visible but outlines are indistinct. Two gun ramps are fairly well defined. The magazine outline has been blurred by erosion.
The setting retains a high amount of integrity, particularly within the redoubt's fields of fire to the west and southwest. The area is mature woodland. Clear-cutting on private property adjacent to the park, however, would likely degrade the fort's setting. The ground to the rear of the fort (east) has been more disturbed over the years, probably by agriculture. Originally, parapets connected Fort Gregg to adjacent earthworks. Faint traces of one segment of these connecting parapets were tentatively identified but not mapped.

Animal burrowing is a severe problem. Foxes or ground hogs have dug at least seven large burrows and appear to have a system of linked tunnels within the parapet. This could lead eventually to a collapse of the parapet from within. Several eroded areas in the southern face may have resulted from old burrows. The animals should be removed, the burrows filled and tamped with an imported soil (to differentiate from original construction), and the scar covered with the excavated spoil and leaf litter. The parapets fronting the west face have experienced past erosion, almost to the level of the gun platforms. A now unused social trail enters the fort at gun #2. There was evidence of recent relic hunting in at least two locations-between guns number 1 and 2 and in the outside of the north face.

Although Fort Gregg is farthest removed from a public access point, it has been visited heavily over the years, probably by local children and more recently by relic hunters. Logging occurred, perhaps in the 1960s, but was not heavy-handed. The redoubt retains a strong sense of place, but its small size tends to magnify the negative effects of damage. After repairs, Fort Welch should be maintained by forest husbandry techniques.

This redoubt was built by Confederates as Fort Archer, captured by Griffin's division of the V Corps on September 30, 1864, then refaced and renamed Fort Wheaton. The earthwork has experienced an overall softening of angles due to past erosion. There has been a great deal of casual visitation over the years, though little currently. The redoubt's basic features remain intact, but it is encroached upon from all sides. The park boundary follows the outer perimeter of the ditch. The neighboring landowner recently clear-cut right up to the park boundary, perhaps even burying or uprooting one of the property markers. Heavy equipment ruts come up to the edge of the redoubt's ditch at one or two places and may have caused some slumping of the counterscarp. The area has been sown in new pines that have grown into an impenetrable thicket. While the sense of place within the redoubt is strong, from without the viewer feels cramped and disoriented. The ground adjacent to gun platform #3 was disturbed by past logging or human digging. The original sally port of Fort Archer (filled in when the redoubt changed hands) has eroded out, though erosion does not appear ongoing. The surrounding landscape has not been recontoured; meaning that some integrity of setting could be reclaimed.

As the last intact Confederate fort on the Squirrel Level Road Line, Fort Wheaton has high interpretive value. It was captured by Federals in the fighting at Peebles Farm and refaced. The fort could be instrumental in telling the story of that battle. Its location, however, precludes interpretation unless additional land or easements could be acquired. This redoubt would be maintained by forest husbandry.

Fort Urmston contains four gun platforms, two of which are very clear, and four gun ramps, three of which are in decent condition. The site was cleared within the last twenty years in a manner that was insensitive to surviving features, and the parapet has suffered serious erosion. Angles are blurred, and earth from the parapet has slumped into the water-filled ditch at several points. Undergrowth is heavy. The southern face was destroyed at some point by road construction, taking most of two gun platforms and ramps with it. Two old social trails cross the ditch and enter the redoubt at guns 3 and 5, causing severe compaction and subsequent erosion. A shallow ditch (drainage or relic hunting) was dug at some point behind gun ramps 2 and 3, and much of the spoil was thrown onto gun ramp #3. Tree throw has damaged the parapet in one place in the north face. The setting appears to have been at least moderately degraded for years. There is evidence of ground disturbance, probably due to logging, in the fields of fire to the north.

Erosion has advanced to the point, that Fort Urmston would benefit from clearing and planting in grasses. Architectural details will not be compromised.

Fort Conahey was a bilevel redoubt built out from the slope of the hill, rather than on its crest. Four guns were sited in the lower (western) tier to fire through gun ports pierced all the way through the parapet then roofed over with logs and earth. The lower tier gun positions can only be described as "casemated," a technique used in permanent masonry fortifications but rarely seen in the field. In this case, ad hoc materials were substituted for masonry to completely enclose the guns. The second story collapsed onto itself many years ago, burying many of these original features. Two gun platforms in the east face are better defined. At some point, the western portion of the ditch was filled in by work on Flank Drive.

The site was cleared of trees in the recent past and then allowed to grow up in pines and woody scrub. This tree clearing set off serious erosion, compounded by visitation that has removed the cover of leaf litter and compacted the earth on the northern face. Because large segments of the parapet are showing greater than 40% bare earth, erosion would appear ongoing. Two gun platforms in the dentate north face are visible but poorly defined. There was evidence of recent relic hunting activity (at least three large holes).

The setting of the redoubt has been seriously degraded by new construction adjacent to the park, which has completely reshaped the terrain, removing all historic integrity right up to the park boundary. Flank Road encroaches from the rear. This unique redoubt appears to have suffered unnecessarily from tree clearing without the appropriate follow up. In its current condition, it would be best to clear Fort Conahey again and hydro-seed it as soon as possible.

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