Wave Generating Machine for Swimming Pools

GLENFIELD PLANT

During the last decade, remarkable develop­ment has taken place in the design of covered swimming baths and open-air bathing pools and the amenities now ordinarily provided leave very little to be desired.

The popularity of artificial swimming and bathing pools has increased enormously following the introduction of modern hygienic practices, and this popularity has been still further stimulated in some pools by the emulation of the bathing conditions of natural beaches. The generation of waves to traverse the length of the pool and break at the shallow end, gives the greatest similitude, and when a sloping beach is provided under the breakers the illusion is complete.

The exhilarating effect of bathing in a pool in which waves are running is very great, and the innovation has been highly valued by the public who have had access to such pools. Waves and breakers have the additional advantage of ensuring the fullest aeration of the water in the pool, a condition which many medical men have declared to be definitely beneficial to the health and fitness of bathers, and the water massage effect of the waves breaking against the body is also valuable.

The Generation of Waves

There is nothing new in the idea of generating artificial waves in tanks and pools. Wave-making plant has been used for many years in tanks, for the testing of ships’ models. The first application of such plant to swimming pools was on the Continent, where its success was remarkable. With the modernisation of swimming facilities in Britain and following the increasing number of pools provided in all parts of the country, Messrs. Glenfield and Kennedy, Ltd., concluded that a field existed for wave-generating machinery, and accordingly they undertook a considerable amount of experimental work on scale models of swimming baths. As a result of this work, they have perfected a new design of machinery for producing artificial waves.

The natural waves of the sea are not monotonous-they are always somewhat irregular in height and form, and the inclination at which they approach the shore varies considerably. In a wave bath, waves are produced artificially by robust machinery, usually electrically driven, creating periodic forced oscillations in the water, each impulse building up a wave crest which then travels down the length of the pool in accordance with the natural law of gravitation. The wave exhausts itself by breaking on the shelving bottom at the shallow end of the pool. It is a compara­tively simple matter to produce a succession of uniform waves in a rectangular pool, but if the waves are to appear like those of the sea, then it is necessary that the wave-generating machinery shall produce waves of continually varying character: such waves enhance the general appearance of the pool and add considerably to the pleasure of bathers, for it is generally agreed that regular uniform waves very soon become monotonous.

The Glenfield wave-generating plant, which is fully protected by British patent No. 428394, and which is also patented abroad, has the extremely interesting feature of varying the appearance of the waves. No two waves following one another down the pool are exactly alike; the wave crest is generally highest on one side and lowest on the other, and gradually changes until the wave is uniformly high across they width of the pool, then gradually it changes until the form is the opposite of that first observed. The wave form then slowly changes back again throughout a complete cycle. A series of waves, each of which differs in character from the preceding and following waves is produced in regular succession, and this series is repeated as long as the machinery is kept running.

In practice it is usual to arrange periods of about 20 min. of ware action, followed be about 20 min. of still water, thus providing the maximum variety of bathing conditions, and also revealing the remarkable! contrast between moving and still water in the pool.

Glenfield wave-generating machinery for pro­ducing these effects can be designed for any swimming bath or bathing pool, and will, it is claimed, produce the maximum wave effects with the minimum of power consumption.

When a new swimming pool is to be designed in which -, wave-generating machinery is to be incorporated, then the pool can be given the most suitable shape and appearance for a wave bath; nevertheless, it is possible to fit wave-generating machinery to many existing swimming baths, and to obtain highly- successful results. It is best when the length of the bath is of the order of 100/10 ft., with a width of 40/60 ft.; the shallow end should have a wave glacis of about 1 in 15, and in order to get the maximum breaker effect the glacis should run above top water level in the bath, to resemble a natural beach, or otherwise steps should be provided to give an approximate beach effect.

The height of the waves generated is about 2 ft. 6 in., measured from crest to trough and usually three waves can be observed together in a pool of normal dimensions. Higher waves can be produced, but are not recommended, as they^– might prove dangerous to bathers. The waves do not run squarely down the pool; the effect of the varying height of the wave across the width of the pool is to cause the waves to twist towards their lower ends.

Wave-generating machinery has been adopted with great success in several European countries, and has been in operation for some years in a number of well-known pools, some being open-air pools and others covered-in baths in the centres of large cities.

Messrs. Glenfield and Kennedy welcome inquiries relating to their wave-generating plant, and a questionnaire of wave bath particulars will be gladly sent upon application to their offices at Kilmarnock. They are always pleased to prepare designs and make recommendations for the installation of their plant in swimming pools either existing or to be constructed.

The, firm have model swimming pools fitted with wave-generating machinery in which wave pro­duction can be demonstrated. These models are not merely for demonstration purposes, but are constructed to scale and enable experimental wart: to be conducted, based upon the well-known principles of scale model investigations, so that actual wave phenomena in any pool can be predicted with considerable certainty.