Comprise:

/1 two cylinder disconnecting compound engines fitted on board the twin screw tug "Walrus", 1877;

/2 [as above] fitted on board the paddle tug "Etna", 1880;

/3 four cylinder disconnecting triple expansion engines fitted on board the twin-screw steamer "Arabian", 1884;

/4 four cylinder disconnective quadruple expansion engines fitted on board the screw steam yacht "Myrtle", 1887;

/5-6 six cylinder disconnective quadruple expansion engines fitted on board the screw steam yacht "Rionnag na Mara", 1886.