The ammendements listed below were
modified after discussions between the New Zealand and Australian
Associations before being included in the official Class Rules.
They are included here for interest,
and historical purposes only.
NEW RULE 11.5 - ASYMMETRICAL
Objective: To provide sufficient change to the class restrictions
to allow development of asymmetrical type spinnakers
11.5.1 A retractable spinnaker boom, mounted in a permanently
fixed position through or on the bow may be used. Boom shall
not project more than 1800 mm from bow stem head, when fully
extended. Boom shall not project more than 700 mm from bow stem
head when fully retracted. Boom shall be kept in a fully retracted
position while spinnaker is not in use.
A fixed pole was disregarded for the following reasons:
- too cumbersome (and dangerous) on a startline and in general
- completely changes the look of the Javelin hull which we are
trying to avoid
- minimal cost savings compared to a retractable pole setup
A retracted pole length of 700 mm was required to enable all
boats to fit a pole that does not extend aft of the mast position
11.5.2 A bow sprit may be fitted solely for the purpose of
launching an asymmetrical spinnaker boom, but shall not project
more than 400mm forward of bow stem head.
A reinforcing strop may be fitted between bowsprit and bow stem.
Strop may be made of any material provided its dimensions are
no greater than 50mm x 12 mm. Lowest end of strop to be not less
than 50mm from lowest point of bow or projection
Whist a bow sprit is not essentially required to fit a retractable
spinnaker boom, it was felt that it would assist the conversion
of older style hulls. A bow sprit will provide additional support
for the spinnaker pole, reducing the need for the use of exotic
materials in its construction. A bow sprit reduces the total
length of spinnaker boom required by reducing the size of supporting
tube required to be fitted inside the hull and therefore reduces
the amount of pole projecting forward of bow when the pole is
retracted. Reinforcement of the bow sprit makes the bowsprit
stronger. The 50mm measurement is to ensure the effective length
of the hull is not compromised, when the reinforcement is attached
to the bow stem.
11.5.3 Forestay may be attached to the bowsprit, provided
the point of attachment is no more than 20mm from bow stem.
Currently the forestay attachment cannot protrude forward of
the bow stem. Once a retractable pole is fitted, the strongest
method to attach the forestay is to utlise the bow sprit or its
extensions. This measurement makes it easier to fit the forestay
11.5.4. The asymmetrical spinnaker halyard must be led from
the spinnaker firstly through a sheave or fair lead placed on
the mast in such a way that when the halyard is held tightly
perpendicular to the mast, the projection of the halyard shall
intersect the mast no higher than 5825 mm above the sheerline
level measuring band, and the forward edge of the sheave or fair
lead shall not extend further than 64 mm from the forward side
of the mast. Other sheaves or fair leads after this first one
are not restricted.
Hoist height increased to fit the larger asymmetrical spinnaker.
A hoist height any greater than this would require the use of
additional rigging (ie. uppers) to control the mast, which we
want to avoid.
11.5.5. Spinnaker to be measured with the head, tack and clew
stretched out simultaneously so as to tension the three edges
of the sail equally. The total length of the luff, leach and
foot shall not exceed 17500 mm.
It was felt that some sort of measurement rule was required to
place some additional control over the size of the spinnaker
(instead of relying upon the hoist height and pole length to
control what size spinnaker could be fitted). Formulas to control
the area of the kite were considered but were felt to be too
complicated and too restrictive. A perimeter measurement was
felt to be a happy medium. The 17500 mm measurement allows a
relatively deep kite to be constructed with an area of approximately
200 sq ft.
11.5.6 The measurement rules contained in Rule 11.5.4 and
11.5.5 may only be applied to a spinnaker flown from a spinnaker
boom of type described in Rule 11.5.1.
Do not want to allow a larger conventional symmetrical spinnaker
to be used.