lobes, one above and two below, which when viewed end on gives it
a trefoil appearance. The internal rigging is attached to the
ridges formed on either side of the upper lobe, where it meets
the two side lobes. From here it forms a V, when viewed cross
sectionally, converging at he ridge formed by the two lobes on
the underside of the envelope which is known as the lower ridge.

To the whole length of the top ridges are attached the internal
rigging girdles and also the lacing girdles to which are secured
the top and side curtains. These curtains are composed of
ordinary unproofed fabric and their object is to make the
envelope keep its trilobe shape. They do not, however, divide
the ship into separate gas compartments. The rigging girdle
consists of a number of fabric scallops through which run strands
of Italian hemp. These strands, of which there are a large
number, are led towards the bottom ridge, where they are drawn
together and secured to a rigging sector. To these sectors the
main external rigging cables are attached. The diagram shows
better than any description this rigging system.

Ten main suspensions are incorporated in the Coastal envelope, of
which three take the handling guys, the remaining seven support
the weight of the car.

The horizontal fins with the elevator flaps, and the vertical fin
with the rudder flap, are fixed to the ridges of the envelope.

The car was evolved in the first instance by cutting away the
tail portion of two Avro seaplane fuselages and joining the
forward portions end on, the resulting car, therefore, had