McClellan's siege train

[MikeyB]

If Mac was able to do what he wanted to do, and bring up his siege train, and the Confederates did what Mac wanted to and dug in and took it, would he have been successful?

What would have been different here versus Grant's experience at Petersburg? Why was the siege train so ineffectual in 1864? Or would it have been equally ineffectual in 1862?

Were the level of entrenchment in 1864 at Petersburg something no one could have fathomed in 1862? Is that the difference?

 

[67th Tigers]

Grant simply didn't try to use the siege train to batter the fortifications.

 

[trice]

If Mac was able to do what he wanted to do, and bring up his siege train, and the Confederates did what Mac wanted to and dug in and took it, would he have been successful?

What would have been different here versus Grant's experience at Petersburg? Why was the siege train so ineffectual in 1864? Or would it have been equally ineffectual in 1862?

Were the level of entrenchment in 1864 at Petersburg something no one could have fathomed in 1862? Is that the difference?

Siege Artillery in the Campaigns Against Richmond
With Notes on the 15-inch Gun, Including an Algebraic Analysis of the Trajectory of a Shot in Its Ricochets Upon Smooth Water
By Henry L. Abbot · 1867
Link: https://www.google.com/books/editio...e_Campaigns_Against/1HMDAAAAYAAJ?hl=en&gbpv=1

 

[Belfoured]

Siege Artillery in the Campaigns Against Richmond
With Notes on the 15-inch Gun, Including an Algebraic Analysis of the Trajectory of a Shot in Its Ricochets Upon Smooth Water
By Henry L. Abbot · 1867
Link: https://www.google.com/books/editio...e_Campaigns_Against/1HMDAAAAYAAJ?hl=en&gbpv=1

It's unclear to me, based on Abbott's report, that Grant apparently forgot that he had a siege train:

"The aggregate number of rounds fired during these three months was thus 26,912, amounting to about 545 tons of iron. The total expenditure of ammunition from the beginning of the campaign to October 31 was 44,973 rounds, amounting to 870 tons of iron. Upon the Petersburg lines the firing has been so frequent as to render it difficult to select special instances for mention. At all hours of the day and night sudden artillery battle have occurred, often involving the entire line and demanding the expenditure of many tons of ammunition. This has usually arisen from the position of the right of our line, which is necessarily enfiladed from the Chesterfield Heights, and advantage that has given the rebel batteries there a strong temptation to open fire."

Abbott included a series of charts regarding guns and placements, and much more, in his report, which is in OR XL, Part 1, p. 655.

 

[trice]

It's unclear to me, based on Abbott's report, that Grant apparently forgot that he had a siege train:

"The aggregate number of rounds fired during these three months was thus 26,912, amounting to about 545 tons of iron. The total expenditure of ammunition from the beginning of the campaign to October 31 was 44,973 rounds, amounting to 870 tons of iron. Upon the Petersburg lines the firing has been so frequent as to render it difficult to select special instances for mention. At all hours of the day and night sudden artillery battle have occurred, often involving the entire line and demanding the expenditure of many tons of ammunition. This has usually arisen from the position of the right of our line, which is necessarily enfiladed from the Chesterfield Heights, and advantage that has given the rebel batteries there a strong temptation to open fire."

Abbott included a series of charts regarding guns and placements, and much more, in his report, which is in OR XL, Part 1, p. 655.

I suspect what had changed was the extensiveness of the earthworks and the recognition of their effectiveness against the existing heavy artillery.

Gillmore's reduction of Fort Pulaski outside Savannah (April 10-11, 1862) was the death-knell of the masonry fortification. You might think Fort Sumter had decided that, but Sumter was not adequately defended and there was no detailed account of the bombardment for the military professionals to study. Gillmore knew the world was watching, that his report would be studied by artillerymen worldwide (as it was). He produced a methodical account of every step for scientific study.

I think that had an impact on what followed. Two-plus years later, the view of the dominance of heavy guns was undoubtedly different. The siege of Vicksburg, the siege of Port Hudson, and the siege of Charleston would probably be the examples that had the biggest impact. Sherman's ongoing siege of Atlanta would have been concurrent with the siege of Petersburg in the summer of 1864.

I think the lessons of those two years led to an understanding that well-constructed earthworks could stand up to heavy artillery (see Charleston, the bombardments there, and the attack on Fort Wagner that included the 54th Massachusetts in July 0f 1863). In Spring of 1862, there was reason to believe that well-used heavy artillery and regular approaches could dominate the field. By June 1864, there was a significant doubt that the 1862 approach would work.

 

[Lubliner]

In Spring of 1862, there was reason to believe that well-used heavy artillery and regular approaches could dominate the field. By June 1864, there was a significant doubt that the 1862 approach would work.

There really were no regular approaches at Charleston to allow such domination, even by sea. Fort Pulaski was a sitting duck without proper lines of support and communication with the mainland, and easily approached by the vessels Gilmore used. The difficulties faced in attacking either fort are significantly different.

but Sumter was not adequately defended and there was no detailed account of the bombardment for the military professionals to study.

There was plenty of detailed reports during the bombardment of Charleston Harbor, and continual ideas being tried to overcome the unique obstacles Montgomery faced when there in command in 1864. The preceding three years surely gave them experience and practical knowledge for laying out a sound plan of action, IMO.
Lubliner.

 

[Josh The Lighthouse Guy]

Charleston isn't a good comparison. Fort Sumter was a masonry fort blasted to rubble by rifled artillery from Morris Island. The Union had to take Batteries Wagner and Gregg on Morris Island to make this possible, but a low-lying sandy barrier island isn't a place for classic siege approaches.

Fort Pulaski was a similar situation to Sumter, except that Tybee Island was undefended.

Grant did use classic siegecraft at Vicksburg so he was well aware of its capabilities. So why not at Petersburg?

Grant may have been disenchanted by their usefulness after Cold Harbor (Rhea's book discusses their implementation after the June 3 debacle), and especially after the Crater. Grant may have felt that, after the Overland Campaign, the winning strategy was to get the Confederates out of their earthworks not simply try to break through part of them efficiently.

I also recall someone once suggesting to me there are issues with the soil and/or topography, but I'm fuzzy on the specifics so take this with a grain of salt.

Maybe the biggest issue with relying on a siege train at Petersburg is vulnerability. Grant's left flank and rear were exposed, as evidenced by the Beefsteak Raid. Grant may have concluded that extensive siege artillery would have tied up too much of his infantry keeping them well-defended and impaired his ability to launch flanking offensives, which he correctly concluded could make Petersburg and Richmond logistically untenable. Especially after VI and most of Sheridan's cavalry were sent to the Shenandoah. This paragraph is purely speculative on my part.

 

[Belfoured]

Charleston isn't a good comparison. Fort Sumter was a masonry fort blasted to rubble by rifled artillery from Morris Island. The Union had to take Batteries Wagner and Gregg on Morris Island to make this possible, but a low-lying sandy barrier island isn't a place for classic siege approaches.

Fort Pulaski was a similar situation to Sumter, except that Tybee Island was undefended.

Grant did use classic siegecraft at Vicksburg so he was well aware of its capabilities. So why not at Petersburg?

Grant may have been disenchanted by their usefulness after Cold Harbor (Rhea's book discusses their implementation after the June 3 debacle), and especially after the Crater. Grant may have felt that, after the Overland Campaign, the winning strategy was to get the Confederates out of their earthworks not simply try to break through part of them efficiently.

I also recall someone once suggesting to me there are issues with the soil and/or topography, but I'm fuzzy on the specifics so take this with a grain of salt.

Maybe the biggest issue with relying on a siege train at Petersburg is vulnerability. Grant's left flank and rear were exposed, as evidenced by the Beefsteak Raid. Grant may have concluded that extensive siege artillery would have tied up too much of his infantry keeping them well-defended and impaired his ability to launch flanking offensives, which he correctly concluded could make Petersburg and Richmond logistically untenable. Especially after VI and most of Sheridan's cavalry were sent to the Shenandoah. This paragraph is purely speculative on my part.

I think you allude to a relevant factor. Petersburg was not Vicksburg, as even a look at maps will show. Just for one, at Petersburg Grant was also trying to keep Richmond in play. Second Deep Bottom and New Market Heights/Chaffin's Farm were threats to Richmond, for example. There was also the question of railroads. At Vicksburg he had a completely encircled for. Once the May 19 and May 22 assaults were tried, it was a simple matter of weeks.

 

[thomas aagaard]

I think the lessons of those two years led to an understanding that well-constructed earthworks could stand up to heavy artillery (see Charleston, the bombardments there, and the attack on Fort Wagner that included the 54th Massachusetts in July 0f 1863). In Spring of 1862, there was reason to believe that well-used heavy artillery and regular approaches could dominate the field. By June 1864, there was a significant doubt that the 1862 approach would work.

I would argue that the prussians proved in 1864 that heavy siege artillery can blow earth fortifications into piles of dirt at the range of 1.7 miles. (2,7km) And systematically destroy the defending artillery.
And a classic regular approach with parallels can allow the infantry to storm a very strong position.

But they had impact detonated shells for their "30 pound" rifled cannons that worked well for the job.
Without this, the job become a lot harder.

 

[MikeyB]

I would argue that the prussians proved in 1864 that heavy siege artillery can blow earth fortifications into piles of dirt at the range of 1.7 miles. (2,7km) And systematically destroy the defending artillery.
And a classic regular approach with parallels can allow the infantry to storm a very strong position.

But they had impact detonated shells for their "30 pound" rifled cannons that worked well for the job.
Without this, the job become a lot harder.

Perhaps this is easier said than done, but why isn't enfilading fire devastating to trenches? A couple of well placed solid shots down the line and don't you take out an entire company of tightly compacted men? Or, massed firing of exploding shot overhead, doesn't that also nullify the defensive advantages of the trench?

 

[MikeyB]

I suspect what had changed was the extensiveness of the earthworks and the recognition of their effectiveness against the existing heavy artillery.

Gillmore's reduction of Fort Pulaski outside Savannah (April 10-11, 1862) was the death-knell of the masonry fortification. You might think Fort Sumter had decided that, but Sumter was not adequately defended and there was no detailed account of the bombardment for the military professionals to study. Gillmore knew the world was watching, that his report would be studied by artillerymen worldwide (as it was). He produced a methodical account of every step for scientific study.

I think that had an impact on what followed. Two-plus years later, the view of the dominance of heavy guns was undoubtedly different. The siege of Vicksburg, the siege of Port Hudson, and the siege of Charleston would probably be the examples that had the biggest impact. Sherman's ongoing siege of Atlanta would have been concurrent with the siege of Petersburg in the summer of 1864.

I think the lessons of those two years led to an understanding that well-constructed earthworks could stand up to heavy artillery (see Charleston, the bombardments there, and the attack on Fort Wagner that included the 54th Massachusetts in July 0f 1863). In Spring of 1862, there was reason to believe that well-used heavy artillery and regular approaches could dominate the field. By June 1864, there was a significant doubt that the 1862 approach would work.

Was Johnston building earthworks or breastworks from fences and rail in 1862? If earthworks, would McClellan have been pretty surprised at how ineffectual his big siege guns were?

 

[Josh The Lighthouse Guy]

Perhaps this is easier said than done, but why isn't enfilading fire devastating to trenches? A couple of well placed solid shots down the line and don't you take out an entire company of tightly compacted men? Or, massed firing of exploding shot overhead, doesn't that also nullify the defensive advantages of the trench?

Trenches are supposed to zigzag precisely for the reason of preventing enfilade fire from devastating the troops there.

EDIT: clearer wording

 

[MikeyB]

Trenches are supposed to zigzag imprecisely so enfilade fire doesn't devastate the troops there.

So what exactly is the artillery strategy for attacking trenches?

Is it exploding shot, take out infantry from overhead?
Is it howitzers and mortars and trying to precision land a shell down into the trench in an arc?
Is it just pound it with whatever you got and hope to bury the trench in and on itself so it isn't providing cover?
All of the above? Just fire as much lead and see what happens?

 

[DaveBrt]

So what exactly is the artillery strategy for attacking trenches?

Is it exploding shot, take out infantry from overhead?
Is it howitzers and mortars and trying to precision land a shell down into the trench in an arc?
Is it just pound it with whatever you got and hope to bury the trench in and on itself so it isn't providing cover?
All of the above? Just fire as much lead and see what happens?

The approach trenches are only FULL of troops just before the attack. Prior to that, mortars would try to hit the assembly area to get as many diggers as possible when they are out of the trenches.

Use shot and shell to attack the head of the approach trenches (here the diggers are) and where the trench is not full depth. Try to blow away the facines being used to cover the diggers, making the diggers much more vulnerable. Mortars are used against the whole line of approach trenches -- to keep life interesting for the diggers and support people.

Artillery was used along with trench raids to slow the work.

 

[trice]

There really were no regular approaches at Charleston to allow such domination, even by sea. Fort Pulaski was a sitting duck without proper lines of support and communication with the mainland, and easily approached by the vessels Gilmore used. The difficulties faced in attacking either fort are significantly different.

I would say that you are right in the sense of Vauban style approaches. Looking at something like Fort Wagner will not really show that in practice, no constant creeping closer of the lines before the assault. What we see there is more of a straight charge up the beach to overrun the enemy, who had supposedly been suppressed by artillery fire. The earthwork fortifications and bombproofs allowed the Confederates to survive the hours of pre-assault bombardment, then scramble out to smash the assault when the bombardment lifted.

My Dad did a lot of that type of assault in his war, on Leyte and Okinawa. I remember him telling me about his regiment's attack on Kakazu Ridge (his division's second attack, the 383rd having lost about 300 in the first attempt). The "softening up" consisted of bombardment by all the division's artillery, the Corps artillery, naval bombardment that included the 8" guns of a heavy cruiser and close air support. The Japanese came out of their holes when the bombardment lifted. The battle went on all day with the Americans repulsed at the end. Then the Japanese counterattacked that night. Dad's regiment took about 400 casualties, and Dad told me once that his life was saved by a man named Buford T. Anderson, who was later awarded the Medal of Honor.

What I think about earthworks, siege artillery and the Civil War was that the change of scale to massive and continuous trench warfare, with multiple lines to provide depth and bombproofs to allow the defenders to survive, had finally put an end to the calculus of the Age of Vauban. Breeching batteries (the type that McClellan was so intent on developing at Yorktown) would not cause wide ruptures in the defensive front for attackers to pour through. Defenders were becoming inured to that type of fighting and would continue to resist. The guns themselves could still plough up the earth and smash a single position, but they could not simply blast their way through the opposition.

There was plenty of detailed reports during the bombardment of Charleston Harbor, and continual ideas being tried to overcome the unique obstacles Montgomery faced when there in command in 1864. The preceding three years surely gave them experience and practical knowledge for laying out a sound plan of action, IMO.
Lubliner.

This is exactly what was happening. Field fortifications have long been known. Roman legions entrenched their camp every night on campaign in the days of Julius Caesar. Abercrombie incompetently smashed his army into Montcalm's position (trenches with wooden breastworks and an abatis out front) at Ticonderoga in 1758 -- the bloodiest battle of the French and Indian War. The American Rebels dug in on Bunker (Breed's) Hill in 1775.

What is really changing in 1862-65 is that large armies are developing experience with technologically more advanced weapons. Other technological advancements and trends allow them to support those large armies in the field over long periods of time. RRs and steamboats keep the troops supplied with food and ammunition. The entrenched positions become stronger and more resistant to fire. The troops become more used to this type of warfare. Movement and breakthroughs become more difficult. Building up siege batteries could blow your way through a point -- and the enemy would pull back to another point, just as strong as the one you just took, and you'd have to move the battery and try again to gain a few hundred yards.

 

[Lubliner]

What is really changing in 1862-65 is that large armies are developing experience with technologically more advanced weapons.

I see the biggest jump in tactical maneuvering to have begun in the Mexican War with the amphibious landings and support troops. Montgomery was full of ideas once he took over at St. Helen's Island (Helena?), sending in a few examples of what might be possible. Even in the Mexican War, bombardment from off-shore vessels were used to soften the points of attack. By the way, there is a very detailed book called 'Siege Train' by Edward Manigault on the Charleston front in the rebel encampment. I recommend it highly!

Siege Train: The Journal of a Confederate Artilleryman in Defense of Charleston: Manigault, Edward, Charleston Library Society (S. C.), Ripley, Warren: 9780872494916: Amazon.com: Books

Siege Train: The Journal of a Confederate Artilleryman in Defense of Charleston [Manigault, Edward, Charleston Library Society (S. C.), Ripley, Warren] on Amazon.com. *FREE* shipping on qualifying offers. Siege Train: The Journal of a Confederate Artilleryman in Defense of Charleston

www.amazon.com

Lubliner.

 

[Belfoured]

I would say that you are right in the sense of Vauban style approaches. Looking at something like Fort Wagner will not really show that in practice, no constant creeping closer of the lines before the assault. What we see there is more of a straight charge up the beach to overrun the enemy, who had supposedly been suppressed by artillery fire. The earthwork fortifications and bombproofs allowed the Confederates to survive the hours of pre-assault bombardment, then scramble out to smash the assault when the bombardment lifted.

My Dad did a lot of that type of assault in his war, on Leyte and Okinawa. I remember him telling me about his regiment's attack on Kakazu Ridge (his division's second attack, the 383rd having lost about 300 in the first attempt). The "softening up" consisted of bombardment by all the division's artillery, the Corps artillery, naval bombardment that included the 8" guns of a heavy cruiser and close air support. The Japanese came out of their holes when the bombardment lifted. The battle went on all day with the Americans repulsed at the end. Then the Japanese counterattacked that night. Dad's regiment took about 400 casualties, and Dad told me once that his life was saved by a man named Buford T. Anderson, who was later awarded the Medal of Honor.

What I think about earthworks, siege artillery and the Civil War was that the change of scale to massive and continuous trench warfare, with multiple lines to provide depth and bombproofs to allow the defenders to survive, had finally put an end to the calculus of the Age of Vauban. Breeching batteries (the type that McClellan was so intent on developing at Yorktown) would not cause wide ruptures in the defensive front for attackers to pour through. Defenders were becoming inured to that type of fighting and would continue to resist. The guns themselves could still plough up the earth and smash a single position, but they could not simply blast their way through the opposition.



This is exactly what was happening. Field fortifications have long been known. Roman legions entrenched their camp every night on campaign in the days of Julius Caesar. Abercrombie incompetently smashed his army into Montcalm's position (trenches with wooden breastworks and an abatis out front) at Ticonderoga in 1758 -- the bloodiest battle of the French and Indian War. The American Rebels dug in on Bunker (Breed's) Hill in 1775.

What is really changing in 1862-65 is that large armies are developing experience with technologically more advanced weapons. Other technological advancements and trends allow them to support those large armies in the field over long periods of time. RRs and steamboats keep the troops supplied with food and ammunition. The entrenched positions become stronger and more resistant to fire. The troops become more used to this type of warfare. Movement and breakthroughs become more difficult. Building up siege batteries could blow your way through a point -- and the enemy would pull back to another point, just as strong as the one you just took, and you'd have to move the battery and try again to gain a few hundred yards.

The irony of Breed's (Bunker) Hill is that the biggest problem the British encountered was the fences along the American left, at the base of Breed's over to the Mystic River. Once they had been hammered a few times at that location, they took a step back, attacked the redoubt directly, and took it. Technically the Americans also had a redoubt of sorts on the actual Bunker Hill to the rear, but its role may have been to impede getting reinforcements quickly to the forward redoubt.