MODIFIED CHRISTMAS RIG
TANDEM RIG
HONOLULU RIG
TOWING IN TANDEM
When towing more than one barge astern, it is referred to as tandem towing. In a pure sense, tandem means one behind the other. Within the tandem rig are three other methods called the Honolulu rig, Christmas tree rig, and Modified Christmas Tree rig.
When towing more than one barge astern, it is referred to as tandem towing. In a pure sense, tandem means one behind the other. Within the tandem rig are three other methods called the Honolulu rig, Christmas tree rig, and Modified Christmas Tree rig.
TANDEM RIG
In this method, the tug is connected to the first tow. The first tow connects to the second, and so on if additional units are towed. The intermediate hawser, connecting the first tow to the second, must be streamed and allowed a proper catenary depth. The surging action must be eliminated between tug and first tow and between first tow and second tow.
In this method, the tug is connected to the first tow. The first tow connects to the second, and so on if additional units are towed. The intermediate hawser, connecting the first tow to the second, must be streamed and allowed a proper catenary depth. The surging action must be eliminated between tug and first tow and between first tow and second tow.
HONOLULU RIG
In this method, the first tow is connected to the main tow wire. The second tow is connected, with an auxiliary tow wire, to the bitts on deck. The Honolulu rig allows independent connection of the two tows. Disconnecting and control are readily workable.
In this method, the first tow is connected to the main tow wire. The second tow is connected, with an auxiliary tow wire, to the bitts on deck. The Honolulu rig allows independent connection of the two tows. Disconnecting and control are readily workable.
CHRISTMAS TREE RIG
In this method, all of the barges tow from a single towing hawser. This is done by means of pendants shackled to flounders (sometimes called bale or fishplates) inserted in the towing hawser.
In this method, all of the barges tow from a single towing hawser. This is done by means of pendants shackled to flounders (sometimes called bale or fishplates) inserted in the towing hawser.
MODIFIED CHRISTMAS TREE RIG
In the modified Christmas Tree rig, all of the tows are towed from a common flounder, but the last barge will tow as a separate unit
In the modified Christmas Tree rig, all of the tows are towed from a common flounder, but the last barge will tow as a separate unit
Note: Christmas Tree rigs are preferred for multiple tows. They are stronger and any one unit can be taken from the tow at anytime without disrupting the whole tow. The assistance of another tug is usually required to break up the Christmas Tree rig before entering port.
