Sea Spray October 1951

Sea Spray October 1951

Leander R Class

The Editor,

Dear Sir,

Having just read Onlookers second letter , I feel that a few remarks are called for to answer some of his so-called points.

In the first place this is a class for amateur designers and builders, who do not possess the funds to chase an unlimited class (such as V's), but who desire to try out their own ideas in a class which produces hulls that are easy in lines, cost, and upkeep.

To my mind it fills the need in this country for a fast, keen, open (within the size limits imposed) and progressive National class.

Onlooker doubts that Rs, and for that matter, any boat under 14ft, can really plane for any distance. Has he never sailed a Z in heavy weather? Or even I's? As for speeds attained, there is only one way to prove the claims made, and that is by running trials for the specific purpose. This may come this season, but in case Onlooker is interested I will give a few comparative ratios between International 14's and National 12's, whose performances are well established overseas, and an R class dinghy. These three types are of similar design, although only the R's have the advantage of a spinnaker which, on reaches is considerably more efficient than a mainsail.

1. Displacement Length Ratio - D(tons)/(l/100)^3

2. Power to Weight Ratio (Sq. Ft. Sail Area per lb. weight)

(in both these ratios lower weight enables R's to show favourably).

3. The Wetted Surface to Sail Area Ratio - also has a bearing on planing performance, but here again the R Class shows to advantage and as wetted surface figures are only very approximate. I have not worked them out.

Although the R's show up particularly well on Ratio 2, it must be remembered that a boat must have the power to carry its 210 sq. ft. as tight as a 12 can carry its 90 sq. ft. But the sail is still there which means that the boat will plane earlier, thus gaining extra stability. Furthermore, area in a spinnaker or jib gives drive greatly in excess of similar area in a mainsail on reaches and runs.

Now for a few other points.

Weight - Using orthodox construction, E Rountree built Petite last winter and raced her successfully last season. She weighs 90-100 lbs complete without sails, and cost £15 to build the hull, Petite is still in one piece and shows no greater signs of strain than do boats twice her weight.

Ballast - who wants to build a boat lighter merely for the sake of adding lead skegs? Or, for that matter, unless he is on the shady side of life and wants a safe steady boat, in a lead keel where it is only about one third as effective as weight in crew? These are after all racing not cruising boats.

Outriggers - Nothing in the way of outriggers cost much, and if they can increase a boat's speed why bar them?

As for developing catamarans:

1. The weight of the contraption to fit the stem rule would be excessive.
2. The wetted surface would be excessive - (a catamaran's weakest point)
3. The hull lines would be pure displacement type, and would have to be very deep to acquire the necessary displacement.
4. The 110 sq. ft, allowed would not provide sufficient driving force.
5. The difficulties entailed in keeping the bow up off the wind are bad enough in 18' catamaran (we've had two), let alone trying it in a 12'9" model.