A further two boats of this class, AE1 and AE2, were built at Barrow for the Royal Australian Navy and these sailed to the Antipodes under their own power. One of these actually accomplished 30 000 miles before a complete refit of her propelling machinery was thought to be desirable.
Boats ordered before the war took 20 to 30 months to complete, but, E19, ordered in November 1914, was built, equipped and handed over in the record time of eight months, setting the pace for several later boats. This achievement was aided by the fact that the class were fitted with engines being built at the time by Vickers for the newly-ordered G Class submarines.
