ARTICLE VII
7-1 Modifications: It is the intent of this rule is to
provide guidelines for and limitations to
approved modifications. All modifications should
maintain the integrity of the one design
and improve longevity.
7-2 A measurement certificate will be invalidated by structural
alteration, replacement of components, and or major repairs. Yachts must be remeasured
with respect to the affected
parts or areas, before a new certificate will be issued.
7-3 Cabin top stiffener: One athwartship stiffener may be added to the
interior area of the
cabin top. This stiffener shall be attached to either the front or
rear surface of the mast
compression post. The lowest point of the stiffener shall not
extend below a horizontal
plane defined by: the intersection of the interior surface of
the cabin side with the underside
of the deck. Maximum thickness of the stiffener shall
not exceed 3/4". The intent of this
modification is to allow installation of a
stiffener to the interior cabin top, preventing
compression failure of the cabin top under
the mast step. See figure 1 attached for
installation guidelines.
7-4 To reduce mast post compression of the hull, one of the following
modifications is
allowed:
7-4.1 Fiberglass reinforcement (GRP), centered under the mast post may be
added. This reinforcement may extend up to, but not above the intersection of the hull and
deck. 3/4" foam may be used to fill the low areas in hull contour, created by the
bottom core and hull stringers. The foam must follow the contour of the hull, and may not
exceed a width of 8". The total width of reinforcement may not exceed 12" fore
and aft. Thickness of the layers may not exceed the equivalent of 3 layers of 24 oz woven
roving. See figure 2 attached for installation guidelines
7-4.2 A partial bulkhead, positioned athwartship and adjoining the aft
or forward surface of the mast compression post, may be attached to the hull. The bulkhead
shall not extend above a horizontal plane defined by a straight edge laid between the
highest point of the port and starboard lower hull stringers. The maximum thickness of the
bulkhead shall be 3/4". The bulkhead shall be constructed of wood, plywood, or foam.
The following laminating schedule should be observed:
A. Athwartship pad under the bulkhead not to exceed 6" in width
fore and aft, or 1/8" in depth.
B. Foam spacer or fillet may be used under the bulkhead; height not to
exceed 1/2" and width not to exceed 1".
C. Secondary bonds on fore and aft surfaces of the bulkhead, not to
exceed 3" per leg, or 1/16" in thickness.
D. The bulkhead must be securely attached to the mast compression post.
7-5 Additional forward bulkhead
7-5.1 A vertical athwartship bulkhead can be added in contact with the
aft side of the mast conpression post. Construction of this bulkhead may be created by
using one or more framing pieces, subject to the thickness tolerance indicated below.
Placement of the new bulkhead shall be inline with the vertical athwartship plane created
by the aft side of the mast compression post. Bulkhead may be structurally bonded to the
hull and underside of the deck. Materials used in bulkhead construction shall be limited
to either cored or non-cored material, with a maximum finished thickness of 3/4".
Material type is limited to: plywood, fiberglass layers, or fiberglass sandwich using
either foam or wood core. Installation should use the following the laminating schedule
and be subjected to the limitations indicated:
A. Fiberglass reinforcing layers running athwartship may be added under
the bulkhead, layers are not to exceed 6" in width fore and aft, or 1/8" in
depth.
B. Foam spacers or fillet may be used between the bulkhead and its
contact point to the hull. Fillet/spacer height not to exceed 1/2" and width not to
exceed 1".
C. Secondary bonds on fore and aft surfaces of the bulkhead, not to
exceed 3" per leg, or 1/16" in thickness.
D. The bulkhead must be securely attached to the mast compression post.
7-5.2 An opening must be provided in the bulkhead to allow access to
the bow area. This opening shall be a minimum of 38" in width, 13" in height to
allow access to bow area. The opening should be sealed with a solid door, Hypalon cover,
or other water resistive barrier.
7-5.3 Installation of these bulkheads is not to be considered as a
substitute for air bags. Air bags are still required as indicated in paragraph 5-1 A.
7-6 Bulkhead caps: Any of the three possible mid hull partial bulkheads
may have caps of
no more than 2" wide nor 1 3/4" deep.
7-7 A 6" by 9" triangular knee may be added to the rear of
the mast post at the top of the
cabin. The maximum thickness shall not exceed 3/4".
The knee should be securely attached
to the mast post and cabin top. The intent of this
modification is to support the section of the
cabin top, under the mast step, not
supported by the mast compression post.
7-8 Additional aft bulkheads
7-8.1 To improve floatation, the installation of 2 light weight,
watertight bulkheads may be added to the interior. These bulkheads should be located in
the following areas:
A. At the rear edge of the cockpit and running
athwartship, and
B. At the front edge of the cockpit or 12" aft, also running
athwartship.
Bulkheads shall be sealed on all edges to the hull and deck creating an
airtight chamber under the cockpit.
7-8.2 For the purpose of this rule, lightweight shall be defined as
either cored or non-cored material, with a maximum thickness of 3/4". Materials
allowed in construction include: plywood, fiberglass layers, or fiberglass sandwich using
either foam or wood core.
7-8.3 Drain plugs and inspection ports may be added as long as the
chamber can be made watertight while racing.
7-8.4 Installation of these bulkheads is not to be considered as a
substitute for air bags. Air bags are still required as indicated in paragraph 5-1 B.
7-9 Equipment mounting pads: Pads are allowed under deck equipment to
provided proper
lead angles. The maximum width and length of mounting pads shall not
exceed an overall
dimension 2" greater than that of the equipment being supported.
These pads are not intended
as structural members or stiffeners.
7-10 No holes over 1/2" may be drilled in the deck unless filled
by equipment which is
permanently installed and sealed in place. It is the intent of this
rule that all holes are to be
filled by either equipment, fasteners, or repair material.
No unfilled holes that breach the
deck or hull are to be allowed.
7-11 Backup plates and fender washers are limited to a maximum of
1" greater than the
width and length of the fitting being installed.
7-12 Disclaimer: Modifications to any Wylie Wabbit, performed by the
owner or his agents
after delivery, shall be the sole responsibility of the owner; and
shall not subject the manufacturer
or association to liability for resulting injury. Any
planned modification should be in accordance
with this article. One design eligibility
will be reviewed per paragraph 2-2 and 2-5.
|
home
