The ABCs of safe towing
Posted on 31 October 2012
Written by Eric Sorensen
You may need to tow someone or be towed someday, so it’s important to know how to rig a bridle to attach the hawser if you are doing the towing.
Towing from a single stern cleat will make it difficult, if not impossible, to control the boat’s heading if the tow is anywhere near the size of your boat. The bridle lets you change course without having to pull the tow ahead, much like having a tow post 20 or 30 percent of the boat’s length forward of the stern.
Braided or laid nylon line will stretch 40 to 50 percent before it parts — with enormous destructive force — so don’t let anyone stand in the path of a line under strain. If you wonder whether you have enough line out offshore in bigger seas, you probably should pay out more because the added weight and length absorbs shock better.
Regarding tow speed: The faster you go, the more strain you put on the hawser and its attaching points. So if you’re in doubt, slow down. Towing at 6 to 8 knots is usually safe as long as the hardware on both boats and the hawser are strong enough. On a long-distance tow I would put the passengers in the tow vessel so they are safe if the tow broaches or sinks and perhaps leave one person to steer if the conditions aren’t bad.
Always hook the tow line to the tow right at the bow at the forward-most cleat; the boat will keep its heading better when pulled from the forward-most fixed point. With a small boat, try to attach the tow line to the towing eye that you hook the trailer cable to. A lower tow point tends to pull the boat down by the bow less, reducing yawing, and this eye is probably stronger than the bow cleats. Offshore, 400 to 600 feet of line is a good length for many situations. When approaching a bar or channel or congested waters, shorten it up since you’ll need better control of the tow. When you enter congested waters, shorten the tow to about 100 to 200 feet so you can control the tow’s direction and position in the channel more precisely.
Once you approach the marina or harbor and are in calm water, you’ll get the most control by bringing the tow alongside. Put plenty of fenders over the side, clustering them where the hulls contact. Position the boats so your stern is 20 to 40 percent of its length abaft the tow’s stern so you can turn away from the tow. The bigger the tow in relation to the tug, up to a point, the farther astern the tug’s stern should be.
Set up a tow line leading aft from your bow or forward spring cleat to the tow’s spring or stern cleat, drive ahead on this line slowly to tension it, and turn toward the tow. Secure the bow line as a breast line to snub the bow in with the boats toed toward each other at 10 or 20 degrees, if possible. This will help you turn away from the tow once you’re all tied up.
Last is the stern line, which should be run from the tow’s outboard stern cleat to the tug’s inboard stern cleat to lock in the toe angle. Tension this line by turning away from the tow while running ahead slowly as the stern line is being secured.
When you’re done, and with the engines out of gear, the boats should be toed toward each other, with all lines tight and stretched slightly to create a single unit; slack in the lines will make the tow harder to control and can cause damage to both boats. Three tow lines is all you should need if this is done correctly, with the stern line acting as a backing line, but feel free to add more springs if you want. Have someone stand on your bow or even on the tow’s bow if you can’t see where you’re going.
See related article:
- 7 critical elements of the seaman's art
November 2012 issue