Main Sheet Traveler

The San Juan 28 has a single aluminum rail mounted just behind the cabinway in an indentation in the forward bulkhead of the cockpit. The mainsheet is attached to a single aluminum car. The car rides the rail on steel bearings and is held in place with a 3:1 pulley system, which is locked into position with clam cleats mounted on the cockpit bulkhead port and starboard. A single line is used.

For the most part, this is a simple system that has lasted well over the years. The only reason I have for replacing it is that it has seen better days. The aluminum rail has pitted badly in the area where the bearings run, causing movement to be less than smooth. I have found that cleating the single line using clam cleats is less than desirable. The line constantly falls free of the cleat, or is locked on the wrong side when I need it loose.

There are a number of good replacements for the old system. I decided to take it a bit further and selected the Harken Windward Sheeting Traveler System.

http://www.harken.com

Parts List: 1
2
1pr
1
- 247 CAR-SB WINDWD SHEET 1250 using a 3:1 ratio.
- 258 TRAV CTRL-SB DBL
- 174 Small Boat Hi-Beam End Stops
- 155.48 TRK-SB HI-BEAM 48 IN.(1.22M)

A couple of things you'll need to know. The Low-Beam is too low, the car will bang into the cockpit. The Hi-beam works just fine and the 48 inch beam fits, with the caps, length wise without cutting.

Positioning the beam in the cockpit required drilling new holes. The fore and aft alignment changed. This does create a small problem, in that, some of the holes exit below in a bad spot.

Before positioning the beam you'll need to put the car on the rail. Harken provides a little blue bracket to hold the bearings in place during shipping. Not enough can be said about saving this bracket. Notice the left side has notches. This is used to replace bearings. When putting the car on the rail be sure to unclip the other side (right).

After removing the appropriate clip, slide the rail into the car. Be sure to keep the bracket firmly against the rail as you slide the rail into the car.
Once the car is on the rail take get care not to let the car slide off.

After positioning the beam on the boat(with the traveler in place)test it by moving the car from one end to the other. Make sure it has room near the lazarettes. Drill all holes through. I used a 1" hole saw on the inside to make a flat surface for the washer and nut. A dremel tool was used to remove the material the hole saw left. Note: I only drilled up far enough to create a flat for the washer and nut. Only one hole had to be freehanded using only the dremel.
The old holes were cleaned, filled and sanded flush. I primed and painted the new cuts to match the gelcoat.

Next you need to position the end caps and control blocks. The directions from Harken, for the control block hole, don't account for the end caps. Put a piece of masking tape on both ends of the rail for marking the new hole positions. Put the end cap on and mark two hole positions. One for the alignment nipple. Drill a hole the same size as the nipple.

The second hole is for the screw. This hole needs to be taped, so find a screw and locate the appropriate tap and drill.

At this point the Harken directions will work if you measure from the inside edge of the end cap for the control block hole. Harken provides two sets of screws to secure the control block. Be sure to use the longer of the two for the high rail.
From this picture you can see how the line is run.

I used a 3:1 setup. The line lengths (2 lines) were calculated by taking the rail length times 3 plus the length of the cockpit. Works out to be 18 feet each. 5/16" Sta-Set was used

There it is, all set to go...

William R Sindt, Last updated: August 3, 2002

	Before positioning the beam you'll need to put the car on the rail. Harken provides a little blue bracket to hold the bearings in place during shipping. Not enough can be said about saving this bracket. Notice the left side has notches. This is used to replace bearings. When putting the car on the rail be sure to unclip the other side (right).
	After removing the appropriate clip, slide the rail into the car. Be sure to keep the bracket firmly against the rail as you slide the rail into the car. Once the car is on the rail take get care not to let the car slide off.
	After positioning the beam on the boat(with the traveler in place)test it by moving the car from one end to the other. Make sure it has room near the lazarettes. Drill all holes through. I used a 1" hole saw on the inside to make a flat surface for the washer and nut. A dremel tool was used to remove the material the hole saw left. Note: I only drilled up far enough to create a flat for the washer and nut. Only one hole had to be freehanded using only the dremel. The old holes were cleaned, filled and sanded flush. I primed and painted the new cuts to match the gelcoat.
	Next you need to position the end caps and control blocks. The directions from Harken, for the control block hole, don't account for the end caps. Put a piece of masking tape on both ends of the rail for marking the new hole positions. Put the end cap on and mark two hole positions. One for the alignment nipple. Drill a hole the same size as the nipple.
	The second hole is for the screw. This hole needs to be taped, so find a screw and locate the appropriate tap and drill.
	At this point the Harken directions will work if you measure from the inside edge of the end cap for the control block hole. Harken provides two sets of screws to secure the control block. Be sure to use the longer of the two for the high rail. From this picture you can see how the line is run.
	I used a 3:1 setup. The line lengths (2 lines) were calculated by taking the rail length times 3 plus the length of the cockpit. Works out to be 18 feet each. 5/16" Sta-Set was used