A Brief History of the Rating Rules used by Model Yachtsmen in the UK

Introduction

Any competition between sailing craft needs to take account of the fact that big boats are faster than small ones. Some way of measuring the ‘size’ of a boat is needed, either to place boats in roughly comparable groups (level rating), or to determine handicaps that would, theoretically, even out the size differences. While full size yachting has tended to favour handicaps, modellers, with few exceptions, have preferred the concept of level rating.

The competitive sailing of model yachts has existed in Britain since at least the mid 1820s. At that time races were run ‘for trifling wagers’ by the London artisans who sailed their models on the Chelsea Water Company’s reservoir that stood at the high point of Green Park, just behind where the tube station is now. We don’t know what Rule they used to determine the ‘size’ of their boats, but we can be sure that they had some system designed to ensure that racing did not become a procession.

Local Rules

For most of the 19th century, Rule making was a matter for individual clubs or informal groups of modellers who sailed together and there was no serious attempt to co-ordinate Rating Rule practice. A wide range of Rules are known to have been used at particular times and places, including length, measured in a variety of ways, weight, as at Dundee, and various formulae which sought to take account of all three dimensions of the hull. None of these systems made any attempt to measure the sail area of the boat, any more than did the Rules then used by full size yachtsmen. So far as we know, none of these earlier model Rules directly followed full size Rating Rule practice until the early 1880s, when there is some evidence that members of the Liverpool club were using the ‘94’ Tonnage Rule. As this club was dominated by a group of well heeled Liverpool merchants, some of whom may well have had full size yachts, a direct link to full size practice is possible. We have so few designs and boats from this period of model yachting that it is not possible to say anything useful about the effect of the Rules on design practices, Even when boats from this period turn up, it is often impossible to determine what Rule they were built to, or whether they were to a specific Rule at all.

As there was no organisation above club level and very little interclub competition, clubs were able to persist with their own local Rules for long periods, and evidence of this can be found as late as the turn of the 20th century. Even where clubs began to adopt Rules of wider acceptance, many continued to use their local Rules in parallel, or added local riders to more widely adopted Rules.

The ‘1730’ Tonnage Rule

The first Rule to have more than a local acceptance among modellers was the so-called ‘1730’ Rule. This was a Tonnage calculation introduced for full size yachts in 1881, by the relatively new Yacht Racing Association (YRA) founded in 1875. It was an attempt to deal with the dissatisfaction felt with the existing Tonnage Rules, which were not uniform between clubs and were thought to lead to the development of an unsatisfactory form of yacht, deep and narrow in hull form and unsuitable for use in later life as a cruiser. The concepts of ‘a proper yacht’ and ‘a wholesome form of hull’ begin to be bandied about at this time among full size sailors and to have a baneful effect on the development of racing craft. This influence spread, despite its irrelevance and illogicality, to the discussion of model Rules, with equally unfortunate results that persisted until well into the 20th century.

The YRA formula was

(L+B)2 x B
1730

where L was the waterline length, B was the greatest breadth, wherever found.

Dimensions were taken in feet and the resultant of the top line divided by the 1730 constant to give a measurement in ‘Tons’. There was no necessary relationship between the boats ‘tonnage’ measured in this way and her ‘tonnage’ for customs purposes, let alone her actual displacement. Full size yachts were given handicaps based on their tonnage, though level rating races were also offered for the smaller classes at 5, 10 and 20 tons.

The effect was not what the Rule makers had expected or wanted. Far from curbing the ‘undesirable’ effects of the previous Tonnage Rule, this exacerbated them. Including beam three times over in the calculation put a very heavy tax on it, while leaving depth unmeasured encouraged designers to go steadily deeper to regain stability lost by narrowing the hull. That this Rule more or less coincided with the general adoption of outside ballast in full size yachts only made things worse. The result was characterised as a ‘plank on edge’, or ‘lead mine’. The French referred to them as ‘couloirs lestées’, ‘ballasted corridors’.

Model yachtsmen had been using outside lead ballast since at least the 1830s when ‘Cooper the gunsmith’ produced the first recorded example. Their adoption of the ‘1730’ Rule came a few years behind that of the full size fllet and more or less coincided with the appearance of the first magazine to devote regular coverage to the sport. The Model Yachtsman and Canoeist was edited from Hull and was keen to promote interclub racing and the development of regional and, hopefully, national organisation of model yachting. Interclub racing required a common Rule and the ‘1730’ Rule had the advantage of being the full size Rule also, thus catering to the preferences of those modellers who wished their competitions to be as much like the full size sport as possible. It enabled designers to believe that they, like the full size designers of the day, were contributing to the development of naval architecture.

Modellers used the same formula as full size yachtsmen, but measured in inches rather than in feet. Their boats, freed from considerations of safety or comfort, tended to be even more extreme than their full size counterparts and some clubs, such as Liverpool and South Shields, introduced additional elements to limit the draft of boats and, in the case of Liverpool, to enforce a minimum freeboard, to require the use of bulwarks and of rigs comparable to those used on full size yachts. These local riders to the ‘1730’ Rule may have been more widespread than these two clubs, but no evidence has so far come to light.

The effect of the Rule on model yachting was twofold.

First, it produced models that closely paralleled the style produced in full size designs; long, narrow, deep and heavily ballasted. Many designs were published without sail plans, leaving it to the builder to decide how much his boat could carry. Sail area was unmeasured and top suits were very big. Sail reduction was possible by substituting a jib headed topsail for the jackyard style carried with the top suit, and by dousing the flying jib. The next stage was to remove the topsail and jib and sail under main and staysail alone, Even so, all serious competitors had a number of different smaller rigs to suit different wind strengths. Generally, these were complete with a separate mast and spars.The illustration below shows the sail plan for a typical 10 Tonner. Even the smallest option from this suit is over 800 square inches, on a hull less than 40 inches on the waterline and a displacement of about 20 pounds

Second, the general acceptance of the Rule and the existence of the magazine meant that for the first time a reasonable sequence of designs to a common Rule is available, enabling some conclusions to be drawn about the development of design ideas.

The ‘1730’ Rule lasted only five years in full size yachting and was replaced by the Length and Sail Area Rule in 1887. Modellers had only just started to use it when it was replaced, and, having tasted the benefits of a common Rule, were slow to give it up. It continued in vigorous life among modellers for many years. Model designers, or at least some of them, were well aware of the results of William Froude’s tank tests that showed the importance of skin friction as a component of resistance. Like full size designers, they started to cut away the forefoot and deadwood of their hulls so as to reduce the wetted area, though sophisticated thinkers like Stansfield-Hicks maintained that this process could not be carried as far in models as in full size craft which had an on board helmsman. He believed that models needed a fair amount of deadwood to ensure that they ran straight and were not too much affected by variation in wind strength. In those parts of the country where the ‘1730’ Rule lasted longest, the Northeast and on the Clyde, the late form of boat to the Rule was rather different. The hull, while remaining very narrow, or even becoming narrower, became shallower, so that it closely resembled that of a rowing wherry. The lead ballast remained at its original depth and was connected to the hull by a deep fin.

1907 boat designed by A Long, a shipyard draughtsman and member of the Gateshead club. This is not a particularly extreme example

 

1908 West Hartlepool boat

The illustration above of a 1908 boat from West Hartlepool shows the style of boat that persisted in the North East until at least the late 1920s. Some examples in Scotland, and possibly elsewhere, used twin fins to help the tracking of the attenuated hull. This development is discussed more fully in the context of the LSA Rule below.

rules menu top lsa rules linear rules