THE “GIERPONT”.

The “Gierpont” (flying bridge) allows a stream to be crossed as follows:

The operating cable is attached at one end to an anchor put down upstream near the middle of the river and at the other end to the middle of the upstream side of the boat. The two ends of the pontoon are then fastened by special lines to the swinging cable. The pontoon can, in this way, be made to lie at an angle to the current. The component of the current normal to the side of the boat causes it to cross in describing an arc of a circle around the anchor as a centre and with the length of the cable as a radius. The speed is regulated by changing the angle which the axis of the pontoon makes with the direction of the current.

In order to assist the action of the current on the pontoon, two or four lee-boards are fastened to the upstream side, that is: the side next to the cable, one or two of them serving to cross the stream to the right bank, the other one or two, to the left bank.

In order to diminish the resistance of the cable in the water, it is supported by a few small boats called “onderlegaakjes”.

A “Gierpont” of this kind works, among others on the Meuse, at the Gravenbicht-Rothem (Limbourg) and Grave crossings.