Sail Models
Sail/Yachts
This section includes any model powered either in full or in part by the wind. The club specialist is Alan Horne, phone number is 07969 538626 and email alan@alanhorne.co.uk
Alan has created and developed the popular J Class model yacht and can help with design, build and the set up of sailing craft.
The hulls of sail boats will generally fall into two types. The first is a "finned keel" hull where the ballast weight, normally a torpedo design, is located below the hull on a fin and the second where the ballast is incorporated within the hull and the keel line is part of the hull itself.
This is an example of a sailing boat with a finned keel with the lead ballast at the bottom of the fin. This design, in all its variations, is more efficient in the water as there is less wetted surface (so less resistance) and the centre of gravity is lower. This means that less weight can be used to counterbalance the sails and a lighter boat will go faster!
This is an example of a sailing boat with a full keel (awaiting restoration). There is a greater surface under the water so more resistance and the ballast is higher up in the hull so more weight is required to counter the force from the sails. This design is likely to be slower under the same sail power as a finned keel boat. This yacht design is generally older than the finned keel yacht which is a more modern design.
So, a yacht with a finned keel will be lighter, faster and more efficient through the water but there are some advantages to a model with a full keel.
The first, and primary advantage is that many of our sailing venues are affected by weed in varying degrees in the summer. Even the smallest amount of weed wrapped around the keel or rudder will significantly affect the performance, handling and control of a model with a finned keel and ensuing frustration will make summer sailing an unsatisfactory experience. The smoother underwater lines of the full keel make this design a more practical model for all year round sailing. Provided there is sufficient wind to power the sails a model with a full keel will make progress through even relatively thick patches of weed.
Second, a model with a finned keel will be more twitchy in the water and the hull will be less forgiving of a poor sail setup. The additional weight and longer keel design of a model with full keel make it smoother on the water and more forgiving of poor sail setup.
The sails. Model yachts are generally available with two main types of sail design. The Gaff Rig and the Bermuda Rig.
The Gaff Rig is generally associated with a full keel hull and is an older, historic, design for a rig. The mainsail, behind the mast, is split by the gaff boom into two parts with the lower part being referred to as the mainsail and the top part as the top sail.
This design is less efficient than a Bermuda rig but looks very pretty on the right hull. It also offers the advantage that the topsail can be removed as windspeed increases to reduce sail area without replacing the entire rig.
This rig is also better for those looking for scale on their model. As the rig is less efficient than a Bermuda rig, the gaff model can carry a greater sail area without compromising a scale look. A scale model with a scale Bermuda rig will only useable in the lightest winds and even then handling and control will be compromised.
This is an example of a Bermuda Rig. This rig is more efficient than a Gaff Rig of similar sail area and can be better tuned for maximum performance on a racing yacht. The mainsail is a single sail, normally panelled to create a better aerodynamic shape and a hull with this rig will point into the wind better than a Gaff rig. Racing yachts will normally come with three rigs, the A rig with the biggest sail area for light winds, a medium B rig and a smaller C rig for stormy conditions.
The club is the "home" of the J Class model and they can be seen wearing various rigs and in various lengths from 48 inches to 90 inches long. Its a stylish model with a full keel that can cheat the weed in the summer.
The club is also home to a wide range of other sailing yachts representing most of the classes available. The current club racing yacht is the Micromagic which offers a good mix of performance and ease of transport.