attempted by the earlier ships. With experience gained it was
shown that a large fleet of airships of comparatively small
capacity is of far more value for an anti-submarine campaign than
a lesser fleet of ships of infinitely greater capacity. The
average length of patrol was eight hours, but some wonderful
duration flights were accomplished in the summer of 1918, as the
following figures will show. The record is held by S.S.Z. 39,
with 50 hours 55 minutes; another is 30 hours 20 minutes; while
three more vary from 25 1/2 hours to 26 1/4. Although small, the
Zero airship has been one of the successes of the war, and we can
claim proudly that she is entirely a British product.


S.S. TWIN

During the year 1917, designs were submitted for a twin-engined
S.S. airship, the idea being to render the small type of airship
less liable to loss from engine failure. The first design proved
to be a failure, but the second was considered more promising,
and several were built. Its capacity is 100,000 cubic feet, with
a length of 164 feet 6 inches, and the greatest diameter 32 feet.

The car is built to carry five, with the engines disposed on
gantries on the port and starboard side, driving pusher
propellers. This type, although in the experimental stage, is
being persevered with, and the intention is that it will
gradually supplant the other S.S. classes. It is calculated that
it will equal if not surpass the C Star ship in endurance,
besides being easier to handle and certainly cheaper to build.