Heeling and rail meat

Archives
1

Posted by Rees Midgley (rmidgley@…>)

A large number of posts over the years have suggested that most
Freedoms do best at a heel angle of 15 degrees. When the wind rises,
one way to maintain this heel angle is to let out the traveler.
Another approach is to load up the windward rail with people hanging
out, “rail meat.” Sailing friends have often recommended that we
carry a number of additional crew just for this purpose.

However, each added person will lower the boat further into the water
thereby increasing resistance on all points of sail.

Does anyone have any thoughts on the relationship between number of
bodies (movable weight), wind speed, and direction of sail? I would
expect that any advantages of rail meat would come on a reach with
wind exceeding 15 knots and that in all other angles of sail that
added bodies would be a detriment. If true, any gain or loss in one
point of sail might be lost on another.

  • Rees (Off Island, 1986 F36/38)
2

Posted by lance_ryley (lance_ryley@…>)

The definitive answer on this is ‘it depends.’

The idea behind putting the rail down 15 degrees (or 20, or whatever
is optimum for your boat) is that it creates a longer waterline.
Technically, the longer the waterline on a displacement hull, the
higher the theoretical hull speed - somewhere around 1.33 * SQRT
(waterline length). If your waterline is 25’, your THS is around 6.65
knots. but if your overall length is 30’, and by putting the rail
down the beam of your vessel increases the effective waterline to
28’, the THS goes up to 7 knots.

The effect of net crew weight on displacement-related drag is
probably negligible on a 30’ or larger sailboat, but placement is
still important. The reason again has to do with hull shape. 4 people
sitting on the rail are essentially sitting on the end of a lever.
the farther out they hike, the more leverage they have to keep the
boat level. The tricky part is the balancing act: the farther over
you heel, the less efficient your rudder, keel and sailing rig are.
The boat tends to want to round up, which means you have to put the
rudder ‘down’ which causes drag. The keel is no longer pointed
straight up and down, so it isn’t as efficient. The rig isn’t
straight up and down, so the angle of attack isn’t as efficient.
Leveling the boat out reduces weather helm. Generally, if you have
two similar boats going upwind (and assuming enough wind to drive the
boat - forget light air days which are completely… umm… off topic
for today :), the flatter boat will point higher and go faster. In
fact, downwind you might actually be aiming for a slight windward
heel in order to balance out the helm and the sails.

Ok… fingers are tired. That is all for now. Hope it clarifies things
a bit.

Lance


— In FreedomOwnersGroup@yahoogroups.com, Rees Midgley
<rmidgley@…> wrote:

A large number of posts over the years have suggested that most
Freedoms do best at a heel angle of 15 degrees. When the wind
rises,
one way to maintain this heel angle is to let out the traveler.
Another approach is to load up the windward rail with people
hanging
out, “rail meat.” Sailing friends have often recommended that we
carry a number of additional crew just for this purpose.

However, each added person will lower the boat further into the
water
thereby increasing resistance on all points of sail.

Does anyone have any thoughts on the relationship between number
of
bodies (movable weight), wind speed, and direction of sail? I
would
expect that any advantages of rail meat would come on a reach with
wind exceeding 15 knots and that in all other angles of sail that
added bodies would be a detriment. If true, any gain or loss in
one
point of sail might be lost on another.

- Rees (Off Island, 1986 F36/38)
3

Posted by twales@… (twales@…>)

The real problem with too much rail meat is that you have to feed them and
provide the beer. Can get a bit pricey…
TW

Original Message:

From: lance_ryley lance_ryley@…
Date: Wed, 03 Oct 2007 19:02:19 -0000
To: FreedomOwnersGroup@yahoogroups.com
Subject: [FreedomOwnersGroup] Re: Heeling and rail meat


The definitive answer on this is ‘it depends.’

The idea behind putting the rail down 15 degrees (or 20, or whatever
is optimum for your boat) is that it creates a longer waterline.
Technically, the longer the waterline on a displacement hull, the
higher the theoretical hull speed - somewhere around 1.33 * SQRT
(waterline length). If your waterline is 25’, your THS is around 6.65
knots. but if your overall length is 30’, and by putting the rail
down the beam of your vessel increases the effective waterline to
28’, the THS goes up to 7 knots.

The effect of net crew weight on displacement-related drag is
probably negligible on a 30’ or larger sailboat, but placement is
still important. The reason again has to do with hull shape. 4 people
sitting on the rail are essentially sitting on the end of a lever.
the farther out they hike, the more leverage they have to keep the
boat level. The tricky part is the balancing act: the farther over
you heel, the less efficient your rudder, keel and sailing rig are.
The boat tends to want to round up, which means you have to put the
rudder ‘down’ which causes drag. The keel is no longer pointed
straight up and down, so it isn’t as efficient. The rig isn’t
straight up and down, so the angle of attack isn’t as efficient.
Leveling the boat out reduces weather helm. Generally, if you have
two similar boats going upwind (and assuming enough wind to drive the
boat - forget light air days which are completely… umm… off topic
for today :), the flatter boat will point higher and go faster. In
fact, downwind you might actually be aiming for a slight windward
heel in order to balance out the helm and the sails.

Ok… fingers are tired. That is all for now. Hope it clarifies things
a bit.

Lance


— In FreedomOwnersGroup@yahoogroups.com, Rees Midgley
<rmidgley@…> wrote:

A large number of posts over the years have suggested that most
Freedoms do best at a heel angle of 15 degrees. When the wind
rises,
one way to maintain this heel angle is to let out the traveler.
Another approach is to load up the windward rail with people
hanging
out, “rail meat.” Sailing friends have often recommended that we
carry a number of additional crew just for this purpose.

However, each added person will lower the boat further into the
water
thereby increasing resistance on all points of sail.

Does anyone have any thoughts on the relationship between number
of
bodies (movable weight), wind speed, and direction of sail? I
would
expect that any advantages of rail meat would come on a reach with
wind exceeding 15 knots and that in all other angles of sail that
added bodies would be a detriment. If true, any gain or loss in
one
point of sail might be lost on another.

- Rees (Off Island, 1986 F36/38)




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4

Posted by twales@… (twales@…>)

The real problem with too much rail meat is that you have to feed them and
provide the beer. Can get a bit pricey…
TW

Original Message:

From: lance_ryley lance_ryley@…
Date: Wed, 03 Oct 2007 19:02:19 -0000
To: FreedomOwnersGroup@yahoogroups.com
Subject: [FreedomOwnersGroup] Re: Heeling and rail meat


The definitive answer on this is ‘it depends.’

The idea behind putting the rail down 15 degrees (or 20, or whatever
is optimum for your boat) is that it creates a longer waterline.
Technically, the longer the waterline on a displacement hull, the
higher the theoretical hull speed - somewhere around 1.33 * SQRT
(waterline length). If your waterline is 25’, your THS is around 6.65
knots. but if your overall length is 30’, and by putting the rail
down the beam of your vessel increases the effective waterline to
28’, the THS goes up to 7 knots.

The effect of net crew weight on displacement-related drag is
probably negligible on a 30’ or larger sailboat, but placement is
still important. The reason again has to do with hull shape. 4 people
sitting on the rail are essentially sitting on the end of a lever.
the farther out they hike, the more leverage they have to keep the
boat level. The tricky part is the balancing act: the farther over
you heel, the less efficient your rudder, keel and sailing rig are.
The boat tends to want to round up, which means you have to put the
rudder ‘down’ which causes drag. The keel is no longer pointed
straight up and down, so it isn’t as efficient. The rig isn’t
straight up and down, so the angle of attack isn’t as efficient.
Leveling the boat out reduces weather helm. Generally, if you have
two similar boats going upwind (and assuming enough wind to drive the
boat - forget light air days which are completely… umm… off topic
for today :), the flatter boat will point higher and go faster. In
fact, downwind you might actually be aiming for a slight windward
heel in order to balance out the helm and the sails.

Ok… fingers are tired. That is all for now. Hope it clarifies things
a bit.

Lance


— In FreedomOwnersGroup@yahoogroups.com, Rees Midgley
<rmidgley@…> wrote:

A large number of posts over the years have suggested that most
Freedoms do best at a heel angle of 15 degrees. When the wind
rises,
one way to maintain this heel angle is to let out the traveler.
Another approach is to load up the windward rail with people
hanging
out, “rail meat.” Sailing friends have often recommended that we
carry a number of additional crew just for this purpose.

However, each added person will lower the boat further into the
water
thereby increasing resistance on all points of sail.

Does anyone have any thoughts on the relationship between number
of
bodies (movable weight), wind speed, and direction of sail? I
would
expect that any advantages of rail meat would come on a reach with
wind exceeding 15 knots and that in all other angles of sail that
added bodies would be a detriment. If true, any gain or loss in
one
point of sail might be lost on another.

- Rees (Off Island, 1986 F36/38)




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