Fortification Friday: Wheeler’s magazines – experience brings refinement

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):

Powder magazines, etc. – Shelters in which the ammunition and other stores can be placed and kept safe from the effects of the enemy’s fire, are equally important as the shelters for the men.  The most important of these are the powder magazines, or those shelters intended for the storage of the ammunition.

Read between the lines here.  With the title of this section, we see there are more types of magazines than just powder magazines. We’ll get back to the “etc.” later.  Just keep that in mind for now.  Second, notice the change of priorities here.  Writing after the war, Wheeler has elevated the need to shelter men to equal that of the ammunition.  A contrast from the pre-war manuals in which only ammunition shelters were specifically mentioned in detail.

Wheeler continued:

The rules for the construction and location of bomb-proof shelters for men, apply equally to shelters of this class.  The only difference in construction is the size of the shelter, it being much smaller, as a rule, than that required for the use of troops.

This certainly falls within the range described by Mahan in his post-war description of powder magazines.  And we know these were large, elaborate structures that could cover a large area of the fort’s interior.  To that point:

Large magazines are not constructed in ordinary field works.  They take up too much room, and even the best of them are but poor places in which to store ammunition for any length of time.  The usual method adopted is to construct as many service magazines as may be necessary, near the guns to be served by them, making them large enough to contain the amount required for a definite service of the gun or guns to which they belong.

So now we have a new term to discuss.. and part of that “etc.” we held on to earlier:

Service Magazines. – Magazines of this kind are oftentimes built in the adjacent traverses if there be any; generally under the parapet near the guns; and sometimes under the barbettes.

The conditions to be observed in locating and constructing a powder [OR is this service?] magazine are that it shall be conveniently placed; shall not be exposed to direct fire of the enemy; be made bomb-proof; be well drained; and if practicable, be well ventilated.

I put my interjection in the first sentence, as it seems to me Wheeler meant to say “service magazine” in this passage.  But the actual printed text reads “powder magazine.”  And that would be important, as we see a critical functional difference here with service magazines – being conveniently placed!

Wheeler offered that service magazines might be kept above ground:

WheelerFig45

Or either fully or partly underground: WheelerFig46

The above ground variety is similar to the construction of a powder magazine, in the Mahanian sense.  But the below ground variety offered a few new twists.  Describing a service magazine with passage-way lined with wood frames, Wheeler wrote:

The frames are made of timbers or scantlings of the proper dimensions, each frame consisting of two uprights, called stanchions, a ground sill, and a cap. The interior dimensions of the frame are the same as that of the magazine, or six feet high and six feet wide, the least dimensions given, when practicable, to the width and height of the interior space.

The frames are placed upright, about three feet apart, and in the position which they are to occupy.  Their tops and sides are then planked over; this planking is called the sheeting.

The bottom of the excavation is sloped from the sides to the middle, and from the rear to the front, to allow all water leaking through the magazine to collect in a shallow trench mad along the middle line, and to run off into a drain prepared to receive it, or into a dry well dug near the entrance.  The ground sills are then floored with boards.

Great care should be taken to make the top watertight, before the earth is placed upon it.  This done, it is covered with several feet of earth depending upon the degree of exposure to which it is subjected….

The entrance to the magazine should be closed by a stout door, and the approach to it should be protected by a splinter-proof.  If field artillery is employed to defend the work, the limber boxes are taken off and placed within the magazines.

What we see here is somewhat a miniature version of Mahan’s pre-war coffer-work magazine, to include use of the same materials and parts (stanchions, sheeting).  And, of course, we have a splinter-proof over the entrance.

Wheeler’s service magazine was placed near the guns.  But notice Wheeler did not bore us with details of the depth of earth protecting this magazine. Granted, being below (or partially below) ground alluded to some protection. More emphasis was placed on protecting the magazine from water and moisture.  If you ask me, this was realization, again based on wartime experience, that the most frequently encountered issue with the magazines was water damage.  If the fort was well arranged, the enemy’s guns wouldn’t be in place long enough to fire on the magazine.  One hopes….

The last sentence does circle back to the protection from enemy fires.  One practice seen within fortifications was to stack ammunition in racks or such.  But with field artillery, storing the ammunition in the chests offers some protection (after all, those were designed to sit in the open on the battlefield!).  Not to mention, allows for rapid transition from “garrison” to “field” if the need arises.

A fine point that we need to keep in mind is that Wheeler’s service magazines were not replacing “ready ammunition” that may be stacked near the gun.  We see those frequently in wartime photos:

FJ6_03130a

Some.. more than others.  Though remember this photo  was taken after Fort Johnson was in Federal hands… so some piles may have been stacked as the service magazines were cleared out. Much more a mess, I would say, were the stacks and piles behind Battery Rosecrans on Morris Island.

So we’ve seen Wheeler discussed shelters for the troops and magazines for the ammunition.  How did he suggest sheltering the guns?  We’ll look at that, and some other innovations based on wartime experience, next.

( Junius B. Wheeler, The Elements of Field Fortifications, New York: D. Van Nostrand, 1882, pages 139-43.)

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