Mast Raising System for O'Day 240
The system that I use to single-handedly raise the mast on my O'Day 240 is based on the system for the O'Day 25 (described on the link below). The 240 system is totally self-contained, e.g. it works on the water or on the trailer. O’Day 240 Mast Raising System To build the 240 system: 1. I added an eye strap on the bottom of the boom -- as close to the clew-end as possible. 2. I added a duplicate gooseneck on the aft side, and as low as possible, near base of the mast. 3. I bought 80 ft. of 3/8 double braid to replace original line in the 4-purchase boom vang. 4. I bought about 25 ft. of 5/16 double braid to make a "bridle" to stabilize the boom. 5. I pinned a short (maybe 5 in.) tang to the backstay chainplate. (The turnbuckle remains in place and just swings out of the way when raising or lowering the mast.) In order to easily attach the boom vang (see step 9, below) I enlarged the non-pinned hole in this new tang. To use the system to raise the mast: VERY IMPORTANT: To become familiar with this system, and to check it out, initial use of this system is to raise the mast, rather than lower it. (This sounds much more complicated than it really is; I just wanted to avoid overlooking any detail.) 1. Roll the mast forward and support it on the bow pulpit. 2. Tie a temporary head-stay from masthead, to one of the bow cleats. (My boat has an extra halyard that I've pre-marked to proper length to act as a head stay until I connect the jib roller-furling.) 3. Insert forward hinge pin at base of mast. 4.Attach boom to the new gooseneck (the one at the base of the mast), and lay it across the boat, on lifelines so it's 90 deg. to mast. 5.Tie topping lift around tip (clew end) of boom and beyond the new eye-strap. (Mark the tie-off point with tape, so you’ll know the length to tie it from now on.) 6.Tie other end of topping lift around mast so that the boom will be held perpendicular to the mast when using boom as gin pole. 7.Tie main halyard through new eye-strap on bottom of boom. 8.Tie other end of mail halyard around mast and below new gooseneck so that the main halyard is the line the carries the load, rather than the topping lift. (The topping lift is for back-up in case that the halyard would part.) 9. Connect boom-vang (with 80 ft. line) to the new tang at the aft chain plate (where the back-stay normally attaches). 10. Connect other end of boom-vang to the eye-strap on the bottom of the boom. 11. Tie mid-point of 5/16 double-braid new eye-strap on the bottom of the boom. 12. Measure approx. 10 ft. 6 in. and tie one end of 5/16 double-braid to loop in casting at base of the life-line stantion that's closest to base of mast. 13. Use other tail of 5/16 double braid to pull boom into vertical position and tie tail to base of opposite stantion. This will keep the boom from flopping from side to side as the mast comes up. The bridle should be taunt when the mast is lying down and the boom is standing vertical; it will slacken as the mast becomes upright. (Note: For the bridle in steps 11,12, & 13, I have heavy-duty, screw-type chain links tied at the bridle mid-point and ends. That way, after initial set-up, no more measuring or guessing on bridle length is needed.) 14. Use boom-vang to raise mast. 15. When mast is nearly vertical, grab boom, or boom-vang line, to finish raising mast to vertical position. 16. Connect main-sheet to boom (Pull it tight to carry load that the boom-vang was doing.) 17. Connect jib roller-furler and untie temporary head stay. 18. Disconnect boom-vang from aft chainplate. 19. Connect and tension back-stay. 20. Replace boom-vang line with working length line. 21. Connect boom to original ("working") gooseneck and rig topping lift and main halyard to normal, working, positions. Note: If you need extra leverage, the 80 foot line on the boom-vang is long enough to reach one of the jib sheet winches. To lower the mast, reverse the process. Again,I recommend that you initially test and try this system by raising the mast, rather than lowering it.
