Naphtha engine

A naphtha launch, sometimes called a "vapor launch", was a small motor launch, powered by a naphtha engine. They were a particularly American design, brought into being by a local law that made it impractical to use a steam launch for private use.

By the 1880s, the small steam engine was well established as a power unit for small steam launches, as well as for large boats. However US law, prompted by some past boiler explosions, required that all steam boats carry a licensed engineer at all times. Although this was no difficulty for a commercial craft, it prevented small steam launches from being used for personal and recreational purposes. Becoming such an engineer required an apprenticeship of two years beforehand.

A more popular alternative to the steam launch was the naphtha launch, which used an alternative power source. Advertisements of the period used the deliberate phrase, "Every Man His own Engineer!" to highlight this legal restriction.

The first naphtha launch appears to have been British, reported in the French journal La Nature in 1888. This launch, Zephyr, was the invention of Alfred Yarrow, a well-known builder of steam launches for some years previously. Similar launches were produced in the same year by the Swiss company Escher Wyss AG. One of these was Alfred Nobel's graceful aluminium-hulled sloop Mignon, of 1892. Another, also of aluminium, was the Aluminia of 1894.

The first American naphtha launches recorded were those of the Ofeldt company of New York, who would later become well known as makers of naphtha engines. They described this as the 'Essh' system, and may have been licensees of the Escher Wyss patents. As well as Ofeldt, complete launches were also offered by the Gas Engine and Power Co. of New York. By 1890 they claimed to have sold over 500.

The typical naphtha launch was an open launch of around 24' length. These were pleasure craft intended for use on fine weather excursions. After all, a commercial boat with a professional crew would not suffer from the regulatory problem that led to their invention. Naphtha launches appeared in the finest circles, in the best yacht clubs and under the ownership of some celebrated names.

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Wikipedia