84 lines
5.5 KiB
Plaintext
84 lines
5.5 KiB
Plaintext
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Bridge Destruction
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Bridges are much hard to destroy than buildings, and this is for
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several reasons:
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[1> Most of the bridges to be destroyed will be far larger than the buildings.
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[2> They are built strongly, to last for long periods of time.
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[3> They have many reinforcements that are not visible.
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[4> Everyone realizes the strategic importance of bridges, therefore everyone
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should realize how well guarded they are.
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An important factor to bear in mind, when working on bridge
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demolition, is the extent of real damage desired. Total destruction of a
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bridge is useless, a waste of good explosives. It may even be harmful, since
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there may come a time when friendly force will need the use of that bridge.
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Bridge destruction should therefore be considered a tactical-delay operation.
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It will slow the enemy down, and cause them much expense and time to rebuild.
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Since types of charges differ for different types of brides, I will go into
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specific types of bridge demolitions.
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[Stringer bridges] are the most common type of concrete, steel, or
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timber bridges in existence. They are usually one or more spans, but this
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makes little difference in the actual placement of charges. If more than one
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span is to be destroyed, one should just copy the first placement on the
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second span. The stringer-type bridge is on basically two or three steel
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"I" beams, referred to as stringers. The obvious method is to attempt to
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sever these primary aspects of the entire structure. This can be accomplished
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by placing charges on either side of each stringer. Each charge should be
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tamped either with sandbags or a wooden brace. The result of placing all the
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charges on the same side of the stringer is the twisting and forced warping
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of the steel beams beyond any future use. When dealing with a bridge of
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this type which incorporates more than one span, place the charges along the
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joints of the stringer, since this is the weakest point along the line.
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A [slab bridge] is a simple structure, consisting of a flat slab of
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either concrete or timber held together in such a way that it forms one
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continuous slab, these are the easiest bridges to destroy, since all that is
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required is a diagnol line of explosive charges placed either under, or
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drilled into, the structure itself. If the charges are placed beneath the
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bridge, they should be attached by some means, and tamping should be used.
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The [T-Beam bridge] is very similar to the stringer-type bridge,
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except it is without the bottom reinforcements. This doesn't mean the T-beam
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bridge is any weaker or easier to destroy. This type of bridge is based on
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three or four concrete or steel T-beams, with a large slab of concrete
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covering them. The space between the T-beams on the underneath of the
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bridge is ideal for the placement of explosive charges, since 75% of the
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tamping has already been constructed, by the very nature of the bridge
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itself. This type of bridge may have more than one span but, since bridge-
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destruction is only a tactical-delay operation, the destruction of one span
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should be enough. If you wish to destroy more than one span, just repeat
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the same operation, on the second span, paying close attention to the joints.
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Like the stringer-type bridge, the charges are placed beneath the bridge,
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between the beams themselves. A steel or wooden platform should be
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constructed to so hold the explosives, and direct their force upward into the
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bridge.
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The [concrete cantilever bridge] is probably better known as a
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causeway. It is usually a very low bridge, with many segments or spans
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supported by a series of concrete columns. The same basic procedure should be
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followed as previously outlined, in that one should look for the weakest point
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in the entire structure, and fix the charges at that point. The weakest point
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in most structures is the place where two objects join, so the explosive
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charges should be placed along the joints of the separate sections or spans.
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Place charges of explosives at the foot of the corresponding column to insure
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destruction. The charges placed at the foot of the columns should all be
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tamped and placed on the same side of the respective columns, so as to
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encourage maximum destruction. This type of bridge has many spans, but
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usually it is only necessary to destroy several of the middle sections.
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All charges placed at the foot of the columns should be situated on
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the same side, so as to channel the movement of the destructive force in one
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direction.
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The [truss bridge] is usually used for railroad crossings, and is
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built of steel. This type of bridge is one of the strongest in the world, and
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offers many problems for the saboteur. The best method is to run several
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different explosions at thirty-minute intervals, to that one can see exactly
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what needs destruction, but this is not feasible for the guerilla operation.
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Be very careful when attempting a sabotage operation of this type, especially
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with a truss bridge, since, as it is a train crossing, it will undoubtedly
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be guarded heavily.
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[Suspension bridges] are, generally speaking, the largest bridges in
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the world, and accordingly the strongest. It is a good idea to allow yourself
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three of four separate charges with a time lapse between them. If this is not
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possible, concentrate your charges on the main cables, and the center section
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of the bridge. Six - no less important - charges should be placed on the two
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towers at either end of the bridge and tamped down.
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