Most model sailboats use a cantilevered jib boom which develops tension in the jib leech. In many sailing conditions, this is perfect, but in light wind sailing, you may find that a jib topping lift will allow your jib to set better.

In models, like the Seawind that use cantilevered jib booms, the jib topping lift is very important as it alleviates the mechanical load transmitted by the jib boom.

The jib boom transmits, in part, the tension of the forestay (through the jib boom fulcrum point) to the aft edge of the jib (leech). In light air sailing, this tension keeps the jib leech too tight for good air flow through the slot between the main and the jib.

A jib topping lift is noting more than a line that supports the end of a boom - usually to keep the weight of the boom from affecting the set of the sail.

The rules do not allow the use jib topping lift or a extended boom. So an alternative, is a removable jib boom extension which gives us the best of both world. When a topping lift is permitted during a regattas slip the extension in. when not permitted during official regattas slip it out. NO extensive changes are made to the boat keeping it legal for all official regattas.

EXTENDING THE JIB BOOM

A removable 1-1/4" Jib boom extension can be easily made out of two pieces of aluminum tubing. (The boom is extended, so the topping lift will clear the leech of the jib)

MAKING THE TOPPING LIFT

Take a length of line about 60" long. At one end, tie in a small snap swivel which can be snapped into the plastic end of the jib boom. On the other end install a bowsie and a snap swivel. last tie the open end to the bowsie. I use a small fishing leader snap swivel available at any fishing shop. The reason for the snap is so you can undo the topping lift while sailing in moderate to heavy winds.

INSTALLING THE TOPPING LIFT

Snap one end of the topping lift to jib haul up, the other goes to the end of the jib boom.

What you now have is a topping lift that can easily be adjusted while your boat is in the water or removed while your boat is out of the water for official regattas.

ADJUSTING THE TOPPING LIFT

Adjust the tension in light air so that the leech of the jib approximates the curve of the closest part of the mainsail. When it blows harder, unsnap the topping lift line at the boom, and re-snap to the front of the boom. That will keep it out of the way until needed
again.

A jib boom extension\topping lift kit is available ( On The Boat Store page )

Photo of the Jib Boom Extension\Topping Lift Installed