Building field fortifications requires a lot of “consumable” materials. Even in modern times, when the soldiers fortify a position, they tend to displace a lot of earth and use stockpiles of building materials. One material that comes in high demand is the lowly sandbag. In 1863, engineers on Morris Island recorded using over 46,000 sandbags in just one portion of the siege lines. Reporting on that operation, Major Thomas Brooks described the standard sandbag of the time:
The dimensions of the filled sand-bags, when laid, varied from 6 by 10 by 24 inches to 5 ½ by 11 by 23 inches, and contained .85 of a cubic foot of damp sand, weighing about 85 pounds; hence 32 to the cubic yard.
So 32 sandbags made up one cubic yard of earthwork. (Check my math as I check Brooks here – 0.85 cubic feet is 0.0314 cubic yards… and 0.0314 goes into 1 cubic yard 32.2 times. Seems right?) And 32 sandbags filled with 85 pounds of earth weigh 2,720 pounds – one and a third short tons.
For those commencing the siege of Petersburg, just under a year later, the sandbag was likewise an important commodity. On June 25, 1864, at 2:45 p.m., Major-General Ambrose Burnside had a pressing need for sandbags:
We have commenced a mine that will reach the batteries of the enemy in our front by a reach of 115 yards. I have given orders for all the necessary changes of the line to make the work ordinarily secure. We want about 7,000 sand-bags or more. I think we can break the line of the enemy in due time if we can have the necessary facilities. We want heavy guns very much. Can we have the sand-bags?
That mine, in particular, would require a lot of sandbags. Major-General George Meade responded promptly, granting that request for sandbags:
I have directed Duane to send you an engineer officer and a company of sappers, and Hunt to send you sand-bags and siege guns. I am delighted to hear you can do anything against the enemy’s line, and will furnish you everything you want, and earnest wishes for your success besides. I would have been over to see you to-day, but certain movements of the enemy on the left have kept me here.
“Delighted!” The slow turning siege could grind forward, but needed just a few thousand sandbags. Now time for staff officers to do what they get paid for. Brigadier-General Henry Hunt, the Chief of Artillery, became the “stuckee” on the sandbag tasking request, as he was also directing the siege operations and generally kept sandbags around to support the artillery positions.
Hunt first inquired, at around 6 p.m. that day, to Brigadier-General John Barnard, running engineering operations out of City Point, specifically requesting that Brigadier-General Henry Benham provide the required sandbags. Barnard, no slouch for military protocol, pointed out that Benham came under Meade’s orders, but “There ought to be 100,000 sand-bags somewhere.” He also suggested inquiries with Brigadier-General Godfrey Weitzel, of the Army of the James. But, hold that for a moment.
Upon receipt of Barnard’s reply, Hunt sent the request for sandbags directly to Benham. And Benham, as he did so often with such matters, replied at 8:10 p.m. that the materials were not exactly at arm’s reach:
All my siege materials, as I have kept General Meade fully advised, have been retained at Fort Monroe. On receipt of your dispatch to General Barnard, through Colonel Porter, I at once sent an aide down in a steamer to bring it up, and I expect it to-morrow afternoon or evening, and will send them out to you at once, if you then wish them, of which please advise me.
So Benham had sandbags, but he just didn’t have them around at that moment. Maybe tomorrow or the next day….
We hear all sorts of references to the Federal war effort featuring an over-abundance of resources. But such abundance means nothing if the resources are not at the right place for use. Barnard estimated 100,000 sandbags were “around.” So now a capable staff officer needed to secure a small draft of that sandbag stockpile for use on the line.
Enter Colonel Cyrus B. Comstock, aide-de-camp on the staff of Lieutenant-General U.S. Grant. While Hunt conversed with Benham, he also communicated with Comstock, who was also working this “tasking.” At 6:10 p.m., Hunt related to Burnside:
Have heard from Comstock. He says General Benham has sand-bags. I have telegraphed to General Barnard to have 7,000 or 8,000 sent you to-night either by Benham or Abbot.
Ah, Colonel Henry Abbot also might have sandbags. Comstock inquired with Abbot. And promptly Abbot responded with an affirmative, but with limitations:
I made requisition for 25,000 sand-bags–5,000 for each gun, excluding the 100-pounders. How many were actually obtained I cannot say without seeing my ordnance officer, who is now at Broadway Landing. I have no transportation for them. I would suggest that you direct General Ingalls to send transportation to the Broadway Landing (one mile below the pontoon bridge), and let the wagon-master carry an order for Capt. S. P. Hatfield, ordnance officer of siege train, to issue the required number of bags to General Burnside. I think this plan would save much time. These bags, I hope, will be replaced, as I find I shall be obliged to supply them for my embrasures.
Abbot also suggested, within separate correspondence to Barnard, to inquire with Weitzel, on the Bermuda Hundred line. So that’s how Barnard knew to reference Weitzel, perhaps? At any rate, that’s where the draft of sandbags would come from. That evening, Weitzel sent word to Burnside:
I have just ordered 8,000 sandbags to be sent to you from my depot at Bermuda Hundred with all possible haste. I imagine they will reach you about 1 o’clock.
So Burnside got his sandbags the following morning. Soon the troops would be employed filling those sandbags. Mind you those 8,000 would only provide 250 cubic yards of sandbags – be that reinforcing or revetments. Oh, but that was 340 short tons of earth to be moved. Sieges are indeed labor intensive operations.
The main reason I bring all this up is not to impress the reader with the number or weight of sandbags used, but to demonstrate how a good staff functions to support the commander. While commanders can designate the point of attack or defense, it is often up to staff officer to ensure the resources are arranged to support that command. Hunt, Comstock, Abbot, and Weitzel demonstrated just that function on June 25. A small episode of the war, not something to command a paragraph in any history of the battle. But the complex nature of any battle, particularly a siege, required hundreds of such small episodes – thankless staff work – in order to reach a successful conclusion.
There would be many more “sandbag days” at Petersburg. 100,000 sandbags would not be enough.
(Citations from OR, Series I, Volume 40, Part II, Serial 81, pages 406-7, 417, 418, and 422-3.)