Update - Cumulus Takes Fleet By Storm

2002, ‘03 & 04 saw all major Fireball Championships dominated by sailors using the Cumulus section mast.

A huge amount of work was carried out on the taper size and shape of the Cumulus to be best suited to the Fireball. With the section offering the optimum bend characteristics. The custom taper gives the mast a better resonance (the rate at which the tube returns to its original shape after bending).

The mast can be controlled easily to suit a wide range of crew weights using spreader angle and strut position.

All masts are supplied in 2004 with ball bearing main halyard lead blocks.

Results

• 1st - 6th Fireball World Championships 2001, 2002, 2003 & 2004
• 1st - 6th Fireball National Championships 2001, 2002 & 2003

World Champions 2003, Chips Howarth (67kg), Vyv Townsend (82kg) using Cumulus with 30mm pre-bend.

National Champions 2001, Vince Horey (70kg) and Jonney Midred (90kg) using a Cumulus with 20mm pre bend.

Why Seldén?

Choose a Seldén mast and you will find many performance enhancing features unique to our products, for example:

• The Seldén tapering system ensures that our tapers are minimum size and weight. This gives low windage, centre of gravity and topmast weight. This maximises your speed by enabling the topmast to react quickly to gusts and waves giving better acceleration, a smoother ride upwind and, ultimately, more races won!
• Automated welding keeps excess heat out of the taper for guaranteed consistency and performance. The weld produced is so perfect that there is no need to mechanically grind the weld (which can induce inconsistencies). This means that once we have finalised a winning design, you can be sure that your spar will perform identically to the champions.
• All masts are heat treated in our purpose-designed oven. This artificial hardening ensures that you get maximum performance from the high performance aluminium alloy.
• Our spars pass through a purpose-developed bead-peening machine. This gives the mast a perfect satin finish that dramatically improves fatigue properties, giving you a mast that will perform reliably for many years.
• Top quality fittings such as our fully adjustable spreader bracket and highly durable cast gooseneck ensure speed and reliability on the racecourse.

Sections Available

Mast	Cumulus
Boom	2633

Mast Specification - Cumulus

The mast is supplied with tenon heel plug with slots for halyard exits, ball bearing turning block for main halyard, spreaders with adjustable angle and length, and ball bearing sheaves for spinnaker halyard and pole lift. The Cumulus is standard with a 2:1 jib halyard (upgrade option) and a protector sleeve at the spreaders. All masts are supplied with drawlines for all halyards for rapid fitting of rigging pack.

Boom Specification - 2633

2633 section has an unrivalled stiffness to weight ratio, allowing maximum performance through vang and mainsheet control without excess weight. Outboard end of boom is cutaway as standard, and boom is supplied with inboard and outboard ends with sheaves, plus three boom slides which allow direct attachment of kicker and mainsheet blocks for efficient centrelining in medium conditions.

Spinnaker Pole Specification

42mm tapered pole is constructed from especially drawn (not extruded) tube for the ultimate in stiffness coupled with light weight, supplied with two piston ends.

Rigging Specification

Rigging includes 2.5mm wire main halyard, kevlar pole lift, 3mm wire shrouds, 3mm jib halyard, trapese wires and spinnaker halyard.

Tuning Tips

	Crew in Boat	Semi-trapezing	Full trapezing	Overpowered	Very Overpowered
Wind Speed (knots)	5-8	9-11	12-15	16-20	20+
Mast Foot Position (from c/b bolt)	Max forward allowed by Class rules
Spreader deflection to aft side mast Spreader L = 415mm)	Deflection set via achieving required pre-bend
Mast rake	6910mm	6910mm	6860mm	6810mm	6810mm
Rig tension (Loos, on shroud)	39	39	39	39	39
Pre bend, natural (no chocks)	27mm	27mm	35mm	42mm	42mm
Chocks (15mm), from neutral	N	N	+1	N	-1
Jib car (athwart)
Centreboard	Forward	Vertical	5° up	10° up	15° up
Jib Car Vert	Top line	Top line	Top line	Mid line	Mid line
Kicker	No	No	med	full	full
Cunningham	No	No	25%	75%	100%
Outhaul	15mm ease	10mm ease	Full	Full	Full