AN INTRODUCTION TO THE OPTIMUM

with

Details provided by the Designer and Supplier, John Taylor.

 

Optimum Centre Deck

Since Optimum's introduction early in the 2000 season, the design has remained somewhat unknown to many of the Six Metre Class enthusiasts. The Designer launched Optimum to try to challenge the dominance and success of many of the designs produced by Graham Bantock.

 

To date there has been a quiet and steady increase in the Optimum hulls being produced. With boats now sailing as far apart as Southend on Sea, Windermere and the Lee Valley. Optimum's successes have been steady but few and far between. The best performances in its first season, were to finish in 3rd place in the 6 Metre Championship at Milton Keynes, and to be the best performing yacht for the Scottish team against England in the annual Karachi Cup match. In the 2001 season, an Optimum won the Midland District Championships held at Bournville.

Optimum is described by its designer as a dual purpose yacht, and he thinks that it is the only one of its kind. A Dual Purpose yacht has the tremendous advantage of being able to sail as a vane yacht as well as a radio controlled yacht. This to most Skippers surely represents a good money saving idea. The Designer has decided to build another of his own Optimum designs, and has kindly sent pictures of how he progressed, accompanied by descriptive text. The hull as displayed is partly finished to give a better understanding of how the boat is made. The standard moulding, is one layer of 200 gramm/sqrmtr of carbon cloth and one layer of 90 gramm/sqrmtr of kevlar cloth. The kevlar cloth gives the hull strength and prevents it splitting when the inevitable collision with another yacht occurs. The deck is made from 2 materials. Nomex (which looks like honeycomb), represents the core of the deck and is extremely light. Either side of the Nomex is a layer of thin carbon cloth moulded in epoxy. The Nomex sandwich formation gives the yacht a very light but robust deck. The hull is vacuum moulded at high temperature. The vacuum enables excess epoxy resin to be squeezed out from the hull. The high temperature allows the epoxy to form a very hard outer shell. Therefore the end result is a very light and robust hull. The fin and rudder are also moulded in the same manner using Nomex and carbon cloth.

Optimum Foredeck

Within the Optimum hull various Nomex/carbon pieces are inserted for added strength. A triangular section is built in just behind the mast position. This is designed to transfer the strain applied from the shrouds, away from the hull flanges and down into the bottom of the boat and keel. The result is that more rig tension can be applied without distorting the hull. At the foredeck, a solid piece of Nomex runs across the deck, which helps to spread evenly the load applied by the Jib, ensuring no damage to the boat. Also as a feature there is a moulded trench for the Jib track. This allows the Skipper to fit the Jib onto the boat keeping the boom as low and close to the deck as possible for maximum rig efficiency.

The positioning of the radio equipment is somewhat different compared with other 6 Metre yachts. The winch is positioned on its side, into the fin inside the hull. The rudder servo is situated behind the rudder tube, which keeps the tiller arm short. The Optimum can be adapted for the RMG winch upon request. Refer to pictures further down this page.

Optimum Aftdeck

Optimum hulls have various access hatches on the deck, this makes building easy and also keeps the hull weight down to a minimum. Hulls can also be constructed using glass / epoxy. The Nomex comes as standard. THE DESIGNERS OWN BOAT WITH ALL OF THE MAJOR MOULDED WORK COMPLETED, CAME TO A TOTAL WEIGHT OF 2lbs 3oz OR 1kg.

Optimum Skeg

As this Optimum is being built as a dual purpose boat, the hull incorporates not only a rudder tube, but a moulded skeg box for sailing with Vane gear. Both the rudder and skeg can easily be detached by loosening the fixing bolt. Access for this is a small hole in the deck. Obviously hulls built for radio only, will not have the skeg box built in.

Optimum TopsidesOptimum Winch Mounting Method

Nearly all Skippers use the conventional above the deck sheeting method for their yachts. However, the Designers own dual purpose Optimum hull uses a system that enables operation underneath the deck. This system works better when your chosen rig utilises a deck level gooseneck. Shown in this picture is a Whirlwind winch which is installed on its side and is fitted into the fin. RMG winches can also be used in an identical manner.

 

Optimum Winch Sheeting Method

The winch line runs towards the after end of the inside of the yacht, to a fixed position pulley. The winch line becomes a continuous loop, using elastic.

From the pulley, the main and jib sheeting split from the continuous loop. The main sheet runs forward to an eyebolt positioned at the base of the fin inside the hull. Once through the eyebolt, the main sheet appears above the deck through a PTFE fitting, and then eventually to the main boom. The jib sheet line also runs forward to another pulley situated on the carbon strengthening frame.

Optimum Winch Sheeting MethodOptimum Winch Sheeting Method

From here the line runs upwards and appears through the main deck again through a PTFE deck fitting. This system is very neat and also most importantly, it prevents any interference with the rig through snagging. The only disadvantage of this system which needs to be considered, is that of line breakage. ( A potential hazard with all systems ). However, if a slightly stronger sheeting line was to be utilised, the breakage potential is minimised. The Designer uses this system on all of his yachts in other classes and has experienced no problems.

Optimum side view

A dual purpose Optimum hull now incorporates a different keel. Those made for Radio Control have a larger tapered fin. This helps the yacht to float higher in the water, thus keeping the waterline shorter and maximizing sail area.

 

Dual purpose hulls like the Designers personal yacht incorporates a significantly smaller straight fin. This allows the yacht to sit lower in the water, increasing its waterline by 20mm. For Vane sailing this increase is important, because these yachts rely upon longer water lines.

Optimum side view

Obviously, sail area will be effected because of the Rules of the Class. It is therefore important for dual purpose yachts to be measured twice. Once for Radio sailing and secondly for Vane sailing. Previously described and depicted was the Designers alternative sheeting system. The main and jib booms are set up as follows.

A deck level gooseneck supplied by Bernie McNulty

Note that the mainsheet comes through the deck and connects to the mainsail boom.

 

The low level gooseneck (as supplied by Bernie McNulty) rotates around the mast on two stainless steel bushes that are fixed in position. Adjustment of the boom is made by the thumbwheel. A strengthened mainsail boom is applied to the gooseneck. This is made from 12mm c/f tube inserted into a 14mm c/f spar. The strengthening is required to prevent the boom flexing under pressure.

A deck level gooseneck supplied by Bernie McNulty

Note that the jib sheet comes through the deck and connects to the jib boom.

The jib swivel supplied by Sails Etc

The jib boom hooks onto a swivel (supplied by Sails Etc) that has been incorporated within the moulded track well built into the deck. This design feature allows free movement of the jib boom. Also the moulded well keeps the jib as low to the deck as possible for maximum rig efficiency.

 

The jib swivel supplied by Sails Etc

This low rig system is very efficient. Wind flow over the deck is caught by the sails, rather than being lost through the space created by a conventional gooseneck and kicking strap system.

 

The performance of a yacht does improve by having the rig lowered.

 

During measurement of this dual purpose Optimum yacht, the sail area achieved was 1040 Sqr Ins. An Optimum built for Radio only, gives a normal sail area of 1080 Sqr Ins. Even though dual purpose hulls have less sail area, the waterline length (LWL) is much longer than that of its Radio counterparts. This can be a significant factor when sailing in greater wind speeds.

 

Optic racing hard

The finished product. "Optic" a dual purpose Optimum 6 Metre. If only I were skilful enough to win all the races !.

!

!

copyright 2012 cooperman.talktalk.net, all rights reserved.

CNC is only limited by our imagination.

Tweakie.CNC

Rounded Rectangle: CNC Home.
Rounded Rectangle: Construction 1.
Rounded Rectangle: Construction 2.
Rounded Rectangle: Construction 3.
Rounded Rectangle: Construction 4.
Rounded Rectangle: Construction 5.
Rounded Rectangle: Routing & Cutting.
Rounded Rectangle: Vinyl Cutting.
Rounded Rectangle: Lithophanes.
Rounded Rectangle: Engraving.
Rounded Rectangle: Making a Vinyl Cutter.
Rounded Rectangle: Soft & Hard Issues.
Rounded Rectangle: Micro Stepping.
Rounded Rectangle: Bob the Mill.
Rounded Rectangle: Making Printed Circuits.
Rounded Rectangle: Making a 4th Axis.
Rounded Rectangle: Tool Position Setting.
Rounded Rectangle: Low Power Lasers.
Rounded Rectangle: Gallery.
Rounded Rectangle: Related Links.
Rounded Rectangle: Site Map.
Rounded Rectangle: Sam.
Rounded Rectangle: Optic.
Rounded Rectangle: The X Files.
Rounded Rectangle: Bertie.
Rounded Rectangle: The Rover Jet Engine.
Rounded Rectangle: The New Laser Project.
Rounded Rectangle: The RF Laser.
Rounded Rectangle: