A Military Dictionary and Gazetteer / Comprising ancient and modern military technical terms, historical accounts of all North American Indians, as well as ancient warlike tribes; also notices of battles from the earliest period to the present time, with a concise explanation of terms used in heraldry and the offices thereof. The work also gives valuable geographical information. Compiled from the best authorities of all nations. With an appendix containing the Articles of war, etc.

by Thomas Wilhelm

By Conversion.—The position of the bridge having been determined, and the width of the stream accurately measured, a suitable place at some distance above the position of the abutment is selected for the construction of the bridge. This place may be at a considerable distance from that which the bridge is to occupy; it is frequently on some tributary of the stream to be bridged, out of sight of the enemy’s shore.

The bridge is constructed parallel to the shore; side-rails are lashed on all except the extreme bays. The balks, chess, etc., for the abutment bay on the enemy’s side, are embarked on the next to the last bay of the bridge; a ponton is lashed to the last ponton in the bridge; this contains, in addition to the articles necessary for constructing the abutment, two strong pickets. The up-stream anchors are deposited in the bows of the boats on the wheeling flank, 10 or 15 yards of their cables coiled, the remainder stretched along the bridge. Two strong spring-lines are extended and lashed, the one over the bows, the other over the sterns of all the pontons; these lines should be considerably longer than the bridge, and the ends coiled on the platform. The bridge is then allowed to float down to within 15 yards of the first abutment.

The material for the first abutment and bay is brought down in a ponton. Two strong pickets are planted to receive the spring-lines and two to receive the shore-lines, which are coiled on the platform between the first and second pontons.

The wheeling flank is pushed off, and men are stationed in the bow and stern of each ponton with oars and boat-hooks to increase or retard the progress of their ponton, as may be necessary. A detachment is stationed at the first abutment to manœuvre the spring-lines; another to prevent the pivot flank from touching shore; a turn of the shore-line is also taken around the mooring-post of the ponton, and this line is eased off, as the case may require. The anchors are cast as the pontons in which they are carried come in their proper places, and their cables are shifted to the pontons to which they are to be attached. The progress of the bridge is checked when it arrives opposite the abutments, which should be constructed during the conversion of the bridge, if the force be strong enough.

The down-stream anchors are cast by the spare pontons, as in the bridge by successive pontons.

Flying Bridge.—This term is applied to any floating support anchored to a fixed point (usually in the stream), and driven from shore to shore by the oblique action of the current on its sides.

Although these bridges do not afford a continuous communication, yet they possess some decided advantages, viz.:

They are readily established, even over the most rapid streams.

They require but little material for their construction.

They may be worked by very few men.