Fortification Friday: Bombproofing according to Wheeler

I trust you are observing Veterans Day, Remembrance Day, or Armistice Day in the manner you feel appropriate today.

But as today is Friday, my blog-writing assignment is to talk about fortifications.  So I turn to the words of a veteran, writing an instruction for cadets in the post-Civil War era – Junius B. Wheeler.  And also keeping within the line of thought from previous posts, I want to emphasize how the veteran’s experience (or should that be veterans’… as in plural?) brought forward changes in the instruction.  What we’d say today were changes in tactical doctrine.

As mentioned earlier, Wheeler defined a wider variety of shelters for use in fortifications.  And those shelters were designed to resist different types of threats when compared to pre-war instructions.  In Wheeler’s text, bombproofs were not simply a place to store ammunition.  Rather these were a general class of shelter, designed to resist the effects of shells, in which ammunition, supplies, equipment, or personnel might be protected. Allow me to work through some of these particulars:

Construction of bomb-proofs. – Bomproofs may be built during the construction of parapets, or after the parapets are finished.  The latter is the most usual method.

The position in a field work occupied by a bombproof depends on the size of the work, the kind of trace, degree of exposure of the interior of the work, the convenience of the position, etc. Hence, bombproofs are sometimes placed under the parapet; sometimes in the gorge of a half-closed work; sometimes in the middle of the parade, etc.’ the position being determined by the circumstances of each case.

We have this figure from Wheeler to illustrate a bombproof:


Notice how this sits in cross section, which Wheeler would discuss as he continued.  And also notice the dashed line and arrow from left to right.  This is not incoming fires, but the line of protection afforded from incoming fires:

Fig. 43 represents a cross section of a bomb-proof into which the men can retire and be safe from the effects of a direct plunging or curved fire.


Wheeler continued on to describe the particulars for building this form of bombproof.  The excavation, placement of particulars, and such do not differ greatly from Mahan’s instructions.  The technical nature of digging earth did not change after the Emancipation Proclamation, after all.  Five feet of earth was considered sufficient to protect against shells – field artillery shells, I would point out, as this was not a permanent structure. What did change were the facilities for the troops:

Ingress and egress of the men using the bombproof may be facilitated by cutting steps into the side of the trench, as shown in the figure.  The part of the bomb-proof resting against the side of the trench should be revetted by a covering of plank, fascines, or other suitable material, to keep the shelter dry, and to make it more comfortable.  Guard beds should be constructed, when the bomb-proof is wide enough, so that the men can lie down at full length; if not wide enough, benches can be made which will allow the men to assume easy positions.

Notice Wheeler’s emphasis on making these shelters “livable.”  A far cry from earlier views on this subject and reflection of the experience of long, hard work in the trenches at Vicksburg and Petersburg, to name a few.

Wheeler closed this section noting a bombproof as depicted in the figure could “easily be placed under the banquette.”  Notice how, in profile at least, Wheeler’s bombproof figure resembles Mahan’s later-day splinterproof.  You know, the one from Morris Island.  Wheeler clearly offers an upgrade in status, if not in construction.

Wheeler continued to identify a class of shelter not mentioned in pre-war manuals:

Blindages. – Any construction used in field works which has for its object the protection of the men and material against the effects of artillery fire from overhead, is termed a blindage. The preceding construction, therefore, is a blindage.

Yes, I’ve paced you around to this point.  Had I introduced blindages earlier in this thread, you’d think it was some new innovation.  It was not.  What we have is the “old ways” being employed to meet different requirements.  In the post-war assessment, overhead protection took on more importance. The term blindage was a tip of the hat to those perceived needs, not a new form of construction.

To that point, Wheeler next discussed splinter-proofs, which were not to be proofed against shells, but would have some overhead protection:

Splinter-proofs. – Shelters which are not exposed to the impact of the projectiles of the enemy, need not be so strong as the bomb-proof. It will be sufficient if they are proof against the splinters and fragments of shells, produced by the enemy’s fire.

This, of course, is no departure from Mahan’s post war discussions.  And we’ve seen how splinter proofs took on more importance, based on wartime experience.  Wheeler offered Figure 44, so we could ponder these splinter proofs:


Shelters of this kind are usually constructed in inclined positions. (Fig. 44). They are made by placing strong timbers, or bars of railroad iron, in an inclined position against the surface to be protected, and in juxtaposition, and then covering them with earth sufficient to make the interior safe against the fragments which may strike the shelter.

Again, note the dashed line and arrow, being the line of protection.  In addition, we see the overhead cover furnished with this splinter proof.  Particulars of the construction:

The inclination of the timbers will be equal to, or less, than the natural slope of the earth thrown against them.  It is well to cover the pieces with raw-hides or tarpaulin before the earth is thrown against them, to make the shelter water-tight.

A thickness of two feet of earth is sufficient to resist the fragments of shells fired from field guns.  In many cases the earth is placed upon the shelter by piling sand bags filled with earth against it.

Entrance to the shelter is provided for by openings at the ends, sometimes by openings left at intervals.

Again, not a significant change in the technique, but rather a change in the application of the construction of those techniques.  As for where these practices of splinter proofs were employed:

Splinter-proofs, from their nature, are placed in those situations where they are not exposed to a direct fire.  They are much used to protect doors, entrances, etc., which are exposed to the effects of bursting shells; to protect vertical walls liable to injury from the same cause; etc.

So we are back to the pre-war notions, to some extent, for placing splinter proofs at doors and entrances. But as we see from the illustration and description above, the arrangement was altered to afford protection from high angle… or as Mahan called it, curved … fires.

Now these shelters discussed thus far by Wheeler were generic shelters.  He set aside any specific discussion of magazines.  This is because, again, we see wartime experiences prompting evolutions in the practice.  We’ll consider Wheeler’s magazines next.

( Junius B. Wheeler, The Elements of Field Fortifications, New York: D. Van Nostrand, 1882, pages 135-9.)



One thought on “Fortification Friday: Bombproofing according to Wheeler

  1. […] Last week, we saw that Junius B. Wheeler’s post-war text (for cadets studying fortifications) included an emphasis on building shelters for troops within the fortifications.  Not that the arrangements featured new building techniques.  Rather the emphasis on what was protected, and how it was protected, shifted.  That last post looked at shelters for the troops.  But Wheeler also updated guidance for building magazines to store, and protect, ammunition.  And as with the evolution of troop shelters, there were new classifications of magazines based on operational requirements (realized… as I grid this ax… on wartime experiences): […]

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