Features February 1, 1998 Issue

Offshore Log:
Do You Know Where Your Emergency Tiller Is?

To see how well production boatbuilders plan for the unexpected use of emergency tillers, we inspected numerous boats and set them up. A few are clever and well-done, most have one or more shortcomings.

The great racing sailor, Paul Elvstrom, preferred the superior sensitivity of tiller steering to wheel steering even on larger offshore boats. Elvstrom, however, seems to have been the exception as most modern boats over about 27' are equipped with wheel steering.

Despite the many advantages of the basically foolproof tiller steering system (including: lower cost, lighter weight, and with the addition of a hiking stick, better visibility), wheel steering has never been more popular. The common argument for wheel steering is that the sweep of the tiller can, if not properly designed, take up too much space in the cockpit.

The popularity of wheel steering—beyond feeding the owner’s ego— is also due to the mechanical advantage inherent in the common cable-quadrant system, which requires much less work for the helmsman. For example a 24" wheel with a 2.2" chain sprocket and 12" quadrant would be comparable to a tiller length of close to 11'. Increase the wheel size to 32" and the tiller would need to be 14' 6" long. Crew fatigue is an important safety consideration, and wheel steering may well be justified on this basis alone.

Cable Can Fail
Because the services of a professional contortionist are usually needed to work on most steering system installations, the required, routine inspection and adjustment of the slack that inevitably develops in chain and cable systems is often left undone. Because most steering sheaves are poorly guarded and quadrants often have shallow grooves, the steering cable can easily jump the system.

So, if you have wheel steering, you still need an emergency tiller as a backup. They are required by Lloyd’s as well as by many race committees. Boats with tillers would also be wise to carry a spare tiller and rudder head fitting.

Easy Access
Work done under stress, in an emergency situation such as loss of steering, requires simplicity. Emergency tiller installations should be easily understood, even by crew members who have limited experience. We can’t ever remember seeing a deck plate marked emergency tiller, even though deck plates marked diesel, water, and waste are the norm.

Then there is the issue of the deck plate key. Will you or a member of the crew be able to locate it quickly in an emergency situation? Deck plates that accept a winch handle in lieu of a key are becoming more common, and this is a step in the right direction. Winch handles are typically more numerous and easier to locate than a deck plate key. Additionally, inexperienced crew may have no idea what a deck plate key looks like.

The most commonly seen deck plates are made of bronze and are often chrome plated. These plates are rarely opened, so the ability to loosen a corroded plate is paramount. Many keys are sadly lacking in the torque department and the common wire deck plate key distorts easily, becoming ineffective under any load. The best choice is a plastic deck plate that does not corrode or require tools and can be broken away if cross threaded or jammed.

Assuming that you’ve been able to remove the deck plate or otherwise gain access to the top of the rudderstock, where is the emergency tiller? Hopefully it’s in the lazarette or in one of the cockpit lockers. And what does it look like?

Design
Often the lowly emergency tiller is a crude length of welded or bent mild steel or aluminum pipe, although wooden emergency tillers are also common. Ideally, the emergency tiller should be nonmagnetic or remain far enough away from the compass so as not to cause any deviation while being used. No tools should be required for installation. Typically, installing the tiller requires nothing more than sliding its socket- type receiver end on to the squared-off top of the rudder stock. Better systems also have a method to securely attach the tiller to the rudder stock.

Because the rudder stock is commonly found just aft of and in rather close proximity to the pedestal, helmsman seat and other cockpit structures, the tiller is often undersized and may require the removal of the steering wheel or require the helmsman to steer backward or athwartships. Imagine doing this for the first time in a tight situation such as docking, negotiating a narrow channel, or in a crowded harbor!

The Leverage Problem
The actual force required to keep a course will depend on the interaction of many factors, including the wind and sea state, displacement of the boat, how well balanced the boat is generally, rudder size—including its distance from the center of lateral plane (leverage)—and whether or not the rudder itself is balanced. The interrelation of these factors is difficult if not impossible to assess from the dock, particularly with the wide variety of possible points of sail and sail combinations that need to be factored in.

In general, the average modern 30' sailboat will handle reasonably with a tiller that swings a radius of 3' while boats approaching 50' will require 4' 6" or more. These dimensions should only be considered a rough guide as the age and general health of the crew must also be considered. From the study of human factors engineering, we know that a 60-year old person, for instance, has only 60% of the strength he or she had at age 30.

In a situation where tight maneuvering is not required, an undersized tiller can be rigged with a block and tackle or a line to a winch. If you are within motoring range of a safe harbor, powering will be your best option, as the rudder under power (except when backing down) is under much less load than when sailing. If motoring is not an option, reducing sail while retaining good balance will help to relieve some of the strain.

As you are most likely to use an emergency tiller in windy conditions, the common metal tiller will quickly conduct heat out of your hands making steering that much more uncomfortable and fatiguing. A leather-covered tiller end or a pair of gloves stored with the tiller is a good idea. In some installations, adding a hiking stick may be appropriate. Clinging on to a tiny tiller in the bottom of a deep cockpit may substantially limit visibility and further contribute to fatigue.

In the event that your emergency tiller fails, which happens, a wrench—Vice Grip, monkey, crescent or perhaps, best of all, a socket wrench with a properly sized socket—can be attached to the top of the rudder stock. You can use what’s left of the broken emergency tiller, a boat hook, or block and tackle to provide the added leverage that will be needed.

Because of the complexity and inherent problems of the typical emergency tiller installation, consider staging a drill so crew members can familiarize themselves with emergency tiller steering and its idiosyncrasies. The drill is the time to check for such things as sharp edges and burrs (remember you will be performing this task quite quickly), what tools may be required, and how to add leverage while assuring that the tiller can still swing through the needed 70° arc. You may even discover to your horror that your boat was shipped from the factory with an emergency tiller belonging to a different model boat and subsequently doesn’t fit on the rudder stock, or worse yet, find that you don’t have an emergency tiller at all.

This drill also will acquaint you with the force required to steer the boat with a stubby tiller. In most cases, we think you’ll be shocked.

Conclusion
We’ve focused on chain and cable systems, as this type of steering is used on more than 90% of the sailboats with wheel steering installations. Much of what we said, however, also can be applied to non-cable steering systems.

On most other types of steering, the rudderstock will not freewheel upon loss of steerage. Hydraulic systems will require the ram to be disconnected from the tiller arm, while rack and pinion and worm gear steering will require dismantling much of the gearing system to get the rudder not only to freewheel, but in some cases to gain access to the rudder stock. The good news is that these systems, if properly installed, are much less prone to failure than a cable-quadrant.

Lastly, we searched for emergency tillers on a number of new and used boats and on some we simply could not find them. Emergency tillers, apparently, are sometimes a new boat option!

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