Wednesday, February 6, 2008

ALONGSIDE TOWING



For tugs working inside harbors and for towing short distances or in confined areas where constant control is required, towing alongside or the hip tow is the preferred method. A hip tow can be made up on either the port or starboard side of the tug. There are various ways of making up a hip tow, here are some standard things to keep in mind.

Making Up a Hip Tow
Three lines should be used, the spring line, the bowline, and the stern line. For large or heavy tows, you may want to double up on the towlines and also use a bow breast line. Before the tug goes out to make up for a hip tow, the towing lines must be inspected and made ready. Inspect the lines for signs of chafing and the eyes and the eye splices for fraying or breaks. Check the towlines for wear and breaks. If you find a line damaged or one that you have doubts about, point it out to the operator. When selecting the lines to be laid out, the usual procedure is that the best line is used for the spring line. This serves as the towline and takes the greatest strain. The second best line is used for the bowline, and the third best line is used for the stern line. The lines are then faked down (they are laid out so that they are free of kinks and obstructions). They can then be paid out rapidly when they are needed.
DETERMINING WHICH SIDE TO MAKE UP TO
The tug secures to one side of the tow with her own stern abaft of the stern of the tow. This will increase the effect of the tug’s screw and rudder. The side chosen depends on how much the tug must maneuver with the tow.

If all turns are to be made with the tug’s screw going ahead, she will be more favorably placed on the outboard side of the tow, the side away from the direction toward which the most turns are to be made.

If a sharp and difficult turn is to be made under headway, the tug should be on the side toward which the turn is to be made. Here she is placed for backing to assist the turn, because as she slows, the tow’s bow will turn toward the side the tug is on.

If a turn is to be made under no headway, the tug is more efficient on the starboard side of the tow. When the tug backs to turn, the port send (side force) of her screw will combine with the drag of the tow to produce a turning effect greater than that which could be obtained with the tug on the port side.

The best position for a long back in a straight line is to have the tug on the port side. Then the drag of the tow tends to offset the port send of the backing screw.
SECURING THE TOWLINES
The towing line or spring line, usually a 6-inch (or larger) hawser, is led from the forward towing bitts on the tow side of the tug to the aft set of bitts on the tow. This line is secured first. Then the tug eases ahead with her bow turned in to take out all of the slack.

Next the bowline or backing line is paid out over the outboard side of the bow stem or king post and lead to a bitt on the forward end of the tow. Once the bowline is secured on the tow, all the slack is taken in and the bowline secured. This will bring the tug into proper position, slightly bow-in to the tow. When backing down, the bowline becomes the towline.

The stern line or turning line is lead from the tug’s stern to the outboard side of the tow’s stern. The purpose of this line is to keep the tug’s stern from drifting out. The three lines, when properly secured and made taut, will make the tug and tow work as one unit.

Note: If for some reason the stern line cannot be fair led and secured to the outboard side of the tow, it is then secured to the inboard bitt on the stern of the tow.

A fourth line (optional), the bow breast line, can also be used for greater control when making up to a heavy tow. Check all the lines to ensure that they are as taut as possible. Perform this by easing the tug forward, then aft, to see that all the towlines are secure. The tug and the tow should be made up as a single unit.

CAUTIONS:

1. When securing these towlines, remember, NEVER secure the line so that it cannot be thrown off quickly and easily.

2. The tug and tow seldom pitch in the same manner. When both start pitching the lines take a heavy strain and may part. When equipped with a rudder the tow assists in steering. Size and loading of the tow may obstruct the view of the tug’s operator. In that case, a lookout is stationed aboard the top who keeps the operator informed of activity and hazards in the blind area.