Raising a Keel-Stepped Mast

Sliding Mast Sleeve

When I got my Daysailer, it came with a keel stepped mast, using a mast jack. It also came with a curious "sliding sleeve", hinged to a metal plate bolted to the deck over the partners and with a hole for the mast profile. The sleeve was clearly home made, using a grooved wooden block and a piece of bent sheet-metal (aluminum), roughly forming a channel that fits the mast profile (see photo and the detail drawing below).

Mast Sleeve and Disk.

The sleeve should not fit
too tight, and could be waxed

The disk is a good platform to
mount additional hardware

Sleeve made from
wooden block
with bolted on
sheet metal

The hinge is
drawn upside
down (oops)

Aluminum Disk 1/8",
held by 6 bolts through deck,
with plywood backing plate.

Use T bracket as
additional reinforcement
from underneath

To raise the mast, one would slide the mast foot into the sleeve, then stand in the cockpit, grab the mast about 8' from the sleeve and push it up and then finally forward. The point of the hinged sleeve is solely to give a pivot. When the mast is all the way vertical, the foot lines up with the opening in the deck: from then it slides down through the deck, and needs to be guided onto the pin (1" threaded stock) of the mast jack. With a bit of practice, it's straightforward to do that sigle-handed, but it helps if you are really strong and tall. Having a second person on the cuddy top to assist makes the job simpler.

Pushing the mast overhead is hard and controlling it from the cockpit can be challenging at times, so I started looking around for alternatives. What I came up with is described below and is shown in operation here (see also the detail drawing below).

Total height is about
2" above the ring on
the mast, before the
mast is dropped.

A 1:8 block and
tackle is fastened
with a shackle
to the eye for
the jib
tack.

A single block is suspended
from a piece of wood held
by hinges between
the three legs.

The hinge remains
in place with
the mast
raised
up.

The mast
slides in the
sleeve once the
holding pin is pulled.

Mast
sleeve detail
showing holes for pin

← Pull here

← Bolt with wing nut

Procedure

Secure mast in hinged sleeve with pin (as shown) and attach line at ring
Raise to vertical with block and tackle
Remove pin
Let mast drop down to mast step (mast jack) by letting out block and tackle
Unstepping proceeds in reverse

When raising the mast this way, it's necessary to manually prevent the mast from swaying horizontally, but no lifting is required. Once vertical, the mast can no longer move sideways. When lowering it through the deck to the mast step, gentle forward pressure is needed to keep the mast (nearly) vertical.

The pin is not needed when unstepping the mast: once tipped, the mast cannot slide out of the sleeve until it's almost horizontal. It could slide forward once the mast is nearly horizontal, but letting the mast drop onto its cradle with a smooth motion is enough to prevent that.

Notes

The front leg is a bit longer, and is held by a cotter pin. The two other legs are about 8' long. I used milled maple from the lumber store, so the dimensions are approx 1" x 2" for the cross section. Because the front leg had to be longer than the longest piece I could find, it's doubled near the top and I doubled the bottom end as well.

Two small holes in the sleeve and matching holes in the mast allow the use of a pin which prevent the mast from sliding in the hinge until it's vertical. If you tried to raise the mast without the pin, the slow pull is at such an angle that the mast would slip horizontally rather than being raised. The pin is not needed for lowering, as long you tilt the mast quickly enough when it comes down; it rarely slides more than a foot if you lower it briskly.

I use a 1:8 block and tackle that I got cheaply at some hardware store, but I replaced the rope with an old halyard for smoother operation. A main halyard is about long enough. I attach the working end to the ring on the mast.

The sleeve of the mast hinge remains in place after the mast is stepped.

It's possible to raise the mast single-handedly, especially if you have a cleat on the cuddy top to belay the rope, for example while you pull out the pin. However, its even easier with a helper as shown in the photos (BTW, that's not me in the photos, I'm pulling on the line that goes off to the side in the middle picture, bottom)

One person is in the boat, who can steady the mast against sideways motion and, when it's already vertical, makes sure that it doesn't tip back when you try to drop it in the hole. The guiding takes a lot less force than raising the mast directly. Using a 1:8 purchase makes that easy, too. Once the mast is dropped to where it's low enough for the mast foot to be close to the mast step on the bottom, you can let go of the mast above and grab the foot to guide it onto the mast jack - the mast won't fall at that time, being held in the partners.

I've used this contraption now about a dozen times. It's definitely easier on my back, but it requires a little extra time. A small jam cleat on one of the legs to keep the block and tackle under tension when not in use is a planned improvement. The three legs make it very sturdy, and it doesn't require level ground, for the trailer (although I'd avoid a strong sideways slope.)

After the season has started and I've built up the requisite muscles again, I usually don't bother with the tripod, but it's nice to have if the ground slopes the wrong way, or I'm simply tired.

~ green ~ lake ~ ~