When setting up a Petticrows Dragon there are some basic
steps to follow. This way you can be sure the boat is set
up in a “standard” way. If you use these settings
as a base reference you can then experiment to find out exactly
what suits your sailing
1. Set the jumper tension
If you have fixed jumpers then set the tension prior
to stepping the mast. An average setting would be 8
on a Loos Tension gauge. Check the mast is straight
sideways. On adjustable jumper systems mark the overall
tension control rope with 6,8 and 10. (this can only
be measured
when the mast is up and from a ladder) |
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2. Mark the forestay
Put the mast up in the boat, so that it is standing
vertically. Measure from the deck -up the mast 81cm
and make a mark. (max class rule is 81mm, min79mm) This
will probably be at the top of your black band. Pull
the forestay down the mast and mark the forestay at
the mark which is 81cm up the mast. The mark on the
forestay is your reference |
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3. Establish the mast rake.
Connect the forestay. Do not connect the mast ram bottle
screw or shrouds. Get some tension on the forestay with
a little runner or backstay
tension. Measure from the mark on the forestay to the
deck. This measurement is your mast rake. The average
mast rake measurement should be 122cm. In heavy winds
the mast can be raked aft so that the mast rake measurement
is 123cm. In light winds. The mast can be raked forwards
so that the mast rake measurement is 121cm If the rake
is incorrect it can be altered by changing attachment
point of the forestay.
It is a good idea to tape above and below the most commonly
use holes. |
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4. Find station 4 line
On the topsides of the boat just below the edge of the
deck there are small spots which show the position of
measurement stations. Station 4 is about 1200mm in front
of the mast With a straight edge and some tape join
the station 4 marks across the deck of the boat. This
line across the deck will be your reference for your
mast, forestay and shroud position. |
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5. Find shroud positions
Measure from station 4 line perpendicularly to the front
face of the upper shroud. This measurement should be
82 cm Measure from the station 4 line to the front face
of the lower shroud. This measurement should be 85cm
It is normal to have the shrouds inline with the front
of the mast when sailing upwind. Moving them aft from
this position has the effect of making the mast bend
less. Forward of inline and the mast will bend more. |
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6. Find forestay measurement plate position
Measure from station 4 line to the front of the forestay
plate. This measurement should be 104cm The plate can
be 75mm long The forestay must be within the front and
back of this plate.
We always put the forestay at the front of this plate. |
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7. Find mast measurement plate position
Measure from station 4 line to the aft of the mast measurement
plate. This measurement should be 82cm. This plate is
50mm long. |
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8. Check the “J”
measurement
The J measurement is the distance between the front
of the forestay measurement plate and aft of the mast
measurement plate. This should be a maximum of 186 cm
as per class rules
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9. Mast step position and pre bend
Without connecting the mast ram bottle screw
OR shrouds And with the mast rake at 122cm
Push the mast aft so that the forestay has some
tension. You can use a little runner tension to
achieve this. Do not bend the mast. Normal position
of the mast is that the front face
is level or aft of the aft end of the mast measurement
plate. If the front of the mast is level there will
be no pre bend when you connect and adjust the mast
ram bottlescrew. If you are ( as an example ) 5mm behind
, you will have 5mm of prebend when you connect and
adjust the bottlescrew. It is normal to have between
0 and 10mm of prebend. If the mast is more than 10 mm
behind the aft end of the mast easurement plate , this
indicates the mast step pin needs to be moved FORWARD.
If the mast is in front of the mast measurement plate
, this indicates the mast step pin must be moved AFT. |
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10. Connect Shrouds and adjust
Mast Ram Bottle-screw.
Connect the shrouds in the chosen shroud position and
wind the upper shroud nut to achieve a tension of 15
on the Loose gauge. Make sure the shroud calibration
marks are equal port and starboard. Connect the lowers
in the next hole aft and wind the shroud nuts to achieve
a tension of 10. Again make sure the calibration marks
are equal. Connect the Mast Ram Bottlescrew to the mast.
Pull tension on the runners. Adjust the bottlescrew
open or closed so when the lever is pulled maximum aft
the front of the mast is level with the aft of the Mast
Measurement plate. Using the locking nuts fix bottle
screw in this position. Sight up the mast and if the
mast step position is correct the mast will be straight
fore/aft or have a forward bend of up to 10mm . (The
Pre-bend.). To check the forward movement of the mast
ram. Release the runners and backstay. Uncleat the mast
rope controlling the lever so the bottlescrew
pushes the mast forward. In this position the front
of the mast must not be further forward than the front
of the Mast Measurement Plate.
If it does then you must restrict it from xceeding the
class rule maximum movement of 50mm.
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11. Measure the shroud tension
Using a Loos Model PT-2M tension meter set the
shroud tensions depending on the weather conditions.
Measure directly onto the wire.
The figures given are for boats newer than 2008, in
older models of boat the hull is not so stiff so up
to 30% more tension is required |
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12. Mark your Maximum Runner Tension.
Attach a Loos Gauge to the forestay. Pull on the runner
until the tension is 32. Put a mark on the runner wire
where it enters the deck. This can be used as a guide
to runner tension while
sailing 32 is the absolute maximum in
strong winds. |
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