Adding Adjustable Shrouds and Forestay, and other Rerigging

Updated 24 January 2003

by Ali Meller, with Mike Goldstein and Jen Schwade

I recently worked with Mike Goldstein and Jen Schwade, owners of Ballenger 505 7356, to rerig some of the boat's control systems and add adjustable shrouds. The boat had non adustable shrouds and a Harken magic box in front of the mast, on the mast step, for forestay tension. 7356 is a "stuff-luff" rigged 505.

Buzz Ballenger built 505s from about 1976 through 1983, first near Chicago and then in Santa Cruz CA. 505 construction technology -- at least with some builders -- was advancing rapidly during this time, and Buzz worked hard to improve his boats. He changed his moulds multiple times -- refining the hull shape, experimented with different layups and resins, and his late boats differ markedly from his early boats. 7356 was one of the last boats he built, in 1983. We have not yet determined what the resin system is, but the boat is fully cored with Airex foam, and has thin skins. It has a forward thwart that looks quite a bit like that on the latest Fremantle 505s (though narrower) and a low thwart at the back of the CB trunk that is really just a centerboard trunk brace, as it merges with the floor rather than going all the way to the seat tanks.

My first 505 was Ballenger 6615, a well-built hull for 1978. 7356 is a much better built boat than 6615.

After adding the new forestay and shroud control systems and altering some of the other controls, the boat was unofficially weighed, and was ten pounds underweight (good job Buzz!).

Mike was able to track down a used Waterat non-high aspect ratio centerboard in very good condition. Though the board that was in the boat looked OK, having a standard foil in the boat should make it easier to compare speed with other US 505s, most of which use the Waterat non-high aspect ratio centreboard.

The shroud extension starting at
the chainplate, going up to the
Harken 300 block on the bottom
of the shroud, then back through
another Harken 300 shackled to
the chainplate, then over the
crown of the tank to a Harken
wire bullet block on an eye
strap that turns it down towards
the mast step can be seen to port.
Starboard side shroud tackle.
Just below the triple block, a
single handing on a spectra strop
turns the line coming out of the
port side shroud tackle aft.
A similar single block just aft of
the triple -- and partly obscured
by the spinnaker pole topping lift
tail, turns the starboard side line
aft. They meet at the thimble.
The fender washers on the bulkhead
just under the edge of the centreboard
cap are where the plate with the two
Harken Micro standup blocks is
A closer view of the starboard
shroud blocks. The single that
turns the shroud line coming
from the port side is the one
aft of the triple, on a spectra
strop coming from the diagonal
bulkhead. The single turning
the starboard side line is on
a shorter strop hung from the
same fitting as the
Port side shroud tackle.
Upper aft line is run through
a hole through the centerline
The line turning around the Ronstan
single on the eye strap is the
forestay tail. From this single it
runs aft to a double where both ends
are turned forward. They run through
the diagonal bulkhead through a limber
hole behind the single, and are split
to go to either side on the other side
of the diagonal bulkhead. The lime
Marlow prestretch on top of the
forstay tail is the auto-adjust end
of the jib cloth tension halyard.
It is tied to the 2:1 block on the
forestay cascade, just a little to the
right of this image.
An aluminium plate was fabricated
to support the two highly loaded
Harken Micro standup blocks. The
starboard stand up is shrouds, the
port one is forestay. The inner
mounting screws are not yet fitted.
Another view of the aluminium
plate. The forestay tackle is
partly a cascade, which required
a vectran line end to be attached
on the forward face of the aft
The forestay tackle is a 2:1, 2:1
cascade with a 4:1 final purchase,
for 16:1. The floating double block
is part of the 4:1.
The red/white Swiftcord tail is the
existing vang/kicker control line.
The green line going through the
cheek block is the pre-existing
centreboard down line.
The shrouds are a 2:1, 7:1, 2:1
system. The floating block is the
last 2:1. The purple line is the
shroud tail going forward to be
split to either side.
The Harken cleat and red line are
the spinnaker halyard. I prefer
a horizontally mounted cleat with
a block behind it, so you can pull
the spinnaker up, or uncleat it,
from either side.
The diagonal bulkheads and mast
step, taken from under the foredeck,
port side.
The two Harken standup blocks just
below and to the right of the photo
centre are splitting the forestay
tails to either side of the boat.
The equalization and of the jib
cloth tension halyard also goes
through the limber hole and is tied
to the second block in the forestay
tackle, so that the jib cloth tension
is automatically adjusted as the
forestay is adjusted.
another view taken slightly more
from the side.
Diagonal bulkheads and mast step
taken from under the foredeck,
starboard side. The purple
lines are either end of the
shroud tackle being turned
to either side by the Harken
micro standup blocks.
The loosely mounted cheek block
is keeping the starboard forestay
tail clear of the two Harken
standup blocks
The forestay extension emerges
ABOVE the mast step on this
Ballenger. The Harken 300 wire
block is the first 2:1 in the
forestay tackle. The next 2:1
block -- another 300 -- is
floating aft of the diagonal
bulkheads. The vertical purple
line is the existing spinnaker
pole downhaul (foreguy)
Aft of the mast step. Jib cloth
tension halyard is cleated in the
Clamcleat against the diagonal
bulkhead on the port side of the
centreboard cap. The Harken
double airblock is on a long shackle
so it clears the forestay tackle
The spinnaker pole topping lift is
now led to a Clam cleat on the
starboard side of the centreboard cap.
A jacket will be sewn or spliced to
the spectra once the correct length
is determined.
Port side control lines led through
the forward thwart. Forestay is on
top, shrouds below.
The design of the Ballenger tank,
and the way the forward end of the
tank ends in a bulkhead, meant
the Harken double bullet standup
block had to be mounted further
inboard than was ideal. Bushings
will be installed in the forward
face of the thwart to turn the
the control lines the slight
angle they need to turn there.
Port side control lines led through
the diagonal bulkhead. A Harken
bullet double standup turns them
up and inboard along the forward
face of the diagonal bulkhead.
For final installation, the bolt
heads will be aft, going through
large fender washers. The nuts
will be on the inside.
The centreboard up line block can be seen
at the top left
Dress warmly!
Early February may not be the
optimum time for outdoor boat
The view from inside the SSA
clubhouse, where is was much
warmer! We should have taken
the boat off the trailer and
left it on the trolley to make
it easier to work on the inside.
The Pronto (similar to Rapide)
trailer is quite low, but it is
still a reach to the inside of
the boat.
We weighed the boat last, just
before packing it all up to trailer

Influenced by the rerigging on Rondar 7080, we adapted the forestay and shroud controls for the Ballenger. We also increased the forestay mechanical advantage from 8:1 to 16:1, so it would be easier to pull the rig more upright.

Mike wrote me:

"Before I saw the 7080 article, I didn't think it was possible to rig the adjustable shrouds/forestay on 7356."

The Plan

By leading shroud and forestay tackles aft and then turning them forward and splitting the tails to either side, the tails can be run along the seat tank-floor join, rather than along the centreboard trunk-floor join. This allows them to be turned up to a cleat on the seat tank wherever is deemed appropriate, rather than at the aft thwart, or simply crossing the cockpit floor in the open.

We left the current vang system as it was, even though it DOES cross the floor of the boat in the open. It does this in a location that would probably not be stepped on by either crew or skipper in normal sailing. The vang system could be modified to go along the seat tank-floor join -- as on a Waterat -- in future.

We were working around existing systems, some of which worked well and we did not want to change. The spinnaker halyard was already led to the starboard side, and this prompted us to run the forestay tackle -- which was going to run ABOVE the mast step -- to port so as to avoid any interference with the spinnaker halyard. The forestay tackle to port meant the shroud tackle should go to starboard, and other positioning decisions such as jib halyard/cloth tension being to port followed. It is sort of a "ripple" effect.


As on the Rondar 505 7080 rerig, we went with a Harken 300 wire block on the bottom of the shroud, and a 2:1 shroud extension of 1/8" flexible wire led from the chainplate, up through the block on the shroud, down to second Harken 300 wire block on the chainplate OVER the crown of the seat tank to a Harken wire bullet block on an eye strap, which turns it down along the diagonal bulkhead, and then to a Ronstan Series 20 triple with a becket paired with a Ronstan Series 20 triple on center line. So the tackle is led diagonally down along the diagonal bulkhead to just behind the mast step, just clear of the aft face of the diagonal bulkhead. Having the tackle on the AFT face of the diagonal bulkhead may not look as neat as when it is hidden in front of the bulkhead, but it is easier to install, and easier to see if any part of it needs maintenance. The line through the triple blocks is 1/8" vectran.

The vectran line from one side needs to cross centerline to join the vectran line from the other side. This was most easily accomplished just aft of the triple block anchoring point, and was much easier than on Rondar 7080, as the centerline web was simply a piece of marine plywood, rather than the sealed fiberglass structure on 7080. The vectran lines are joined at a closed sailmaker's thimble. Another vectran line is spliced to the thimble and led aft to the aft thwart. An aluminium plate was constructed and mounted on the aft face of the aft thwart with two Harken micro stand up blocks to turn the forestay (port side) and shroud (starboard side) tackles, respectively. The shroud vectran line (extension of the line that the lines coming out of both primary shroud tackles are attached to, is turned forward at the Harken Micro standup block and ends in a floating Ronstan Series 20. Shroudd tails are reeved through that floating block, led forward through a limber hole in the diagonal bulkhead and split to either side by Harken Micro standup blocks mounted on a custom fit aluminium reinforcing plate. This split takes place to starboard of the mast step. The line end going to starboard is simply led down along the forward face of the diagonal bulkhead to a Harken double bullet standup block (Micro sized doubles are not made, and Ronstan does not make a standup block). The port line end is led over the mast step and then down to the corresponding Harken double bullet standup block.


7356 was rigged with a forestay and a stuff luff. The forestay adjustment system was a Harken magic box mounted on the mast step, in front of the mast. This limited the mechanical advantage and the travel. The magic box was removed and a 16:1 tackle, consisting of 2:1, 2:1 and 4: 1 was devised. As with the shroud system, the tackle is turned around at the back end of the centerboard case. On 7356 we mounted a Ronstan Series 20 double, matched with a Ronstan Series 20 single on an eye strap on the diagonal bulkhead, underneath the centreboard cap. The actual forestay tails come forward off the double, and are split to go to either side by Harken Micro standup blocks. The tails are led forward through a limber hole in the diagonal bulkhead underneath the centreboard cap on the port side. They are mounted on a custom fit aluminium reinforcing plate. The starboard forestay tail needed to clear the Harken Micro standup blocks installed for the shroud tackle, so is led above them by a cheek block mounted on the diagonal bulkhead.

Other Rigging Changes

The boat had been rigged with larger heavier fittings, and some were on the centreboard cap where the crew tends to sit. To clean up this area, the jib cloth tension/cunningham cleat was mounted on the port side of the centreboard cap, directly behind the diagonal bulkhead. The line leads to the cleat through a hole drilled in the diagonal bulkhead. The spinnaker pole topping lift is led to a similar cleat on the starboard side of the cap, mounted slightly further aft.

The existing mast ram down Clam cleat was removed and replaced with a Ronstan cam cleat on an angled Holt Allen cam cleat base. When both mast ram up and mast ram down controls are rigged, I believe both should be cleated in cam cleats rather than Clam cleats, so that one does not recleat while you are pulling on the other. 7356 currently uses a pin stop rather than a ram up control, but may eventually have a ram up, hence the cam cleat for the ram down.

The main cunningham was rigged to the port side of the centreboard cap, close to the mainsheet swivel jammer. This allows easier access when reaching in heavy air (the cunningham is an excellent depower string when reaching).

The centreboard up control line bullet block was moved right to the aft end (starboard side) of the centreboard trunk cap so it would be easier to grab when blast reaching. The centreboard down control will eventually be moved aft near the back end of the centreboard trunk cap for the same reason.

The mast was rigged for the long luff spinnaker by raising the spinnaker halyard by installing a new spinnaker halyard sheave box at the maximum height. The spinnaker pole topping lift was raised by removing the old sheave box and running the topping lift out that hole, up to a block hanging on a "p" eye strap hanging from the lower rivet of the jib cloth tension sheave box.

Doing the Work

All the work shown in the images was done in four cold six-to-eight-hour days, outside, in early January of 2003, at Severn Sailing Association in Annapolis. Hot soup for lunch and more hot soup, stew, and hot alcoholic beverages for supper kept the team functioning.

SSA is very close to Annapolis Performance Sailing (APS). All or nearly all new fittings were bought at APS. Most fasteners were purchased at Chesapeake Marine Fasteners, while odd sizes that we only needed a few of were purchased from APS.

Still To Be Done

A number of holes through wood or foam core need to be epoxy sealed. A number of fasteners need to be epoxy or silicone sealed in.

A hole was cut through the thin plywood centerline frame that extends from the mast step to the front of the centreboard case. That hole has to be epoxy sealed. The shroud tackle anchoring points on the same plywood centerline frame, just forward of the hole, need to be reinforced by bonding in additional plywood and glass. All holes through foam core or wood that have lines in them, either moving control lines, or line used to hang blocks, need to be epoxy sealed as both wood and foam core will soak up water. I suggested to Mike that he could epoxy seal all holes where machine screws (bolts) are mounting fittings. Silicone seal would also work here. All sealing will be done with epoxy and Cab-O-Sil (West System calls Cab-O-Sil Colloidal Silica, filler #406). Holes that will be used for lines will be sealed with a thin mixture intended to coat the sides of the hole, not fill it. A slightly thicker mixture will be used to mount machine screws. I have heard that machine screws mounted in a West epoxy resin and Cab-O-Sil mixture are easier to remove than those mounted in West epoxy without any fillers.