The Pa.r.s.eval airship was delivered to this country and became known as No. 4; a second ship of the same type was also building when war broke out; needless to say this ship was never delivered. At a later date Messrs. Vickers, who had obtained the patent rights of the Pa.r.s.eval envelope, completed the other two ships of the order.

The Forlanini ship was completing in Italy on the declaration of war and was taken over by the Italians; Messrs. Armstrong had not commenced work on the other two. These ships, although allocated numbers, never actually came into being.

Pa.r.s.eVAL AIRSHIP No. 4

This airship deserves special consideration for two reasons; firstly, on account of the active-service flying carried out by it during the first three years of the war, and, secondly, for its great value in training of the officers and men who later on became the captains and crews of rigid airships.

The Pa.r.s.eval envelope is of streamline shape which tapers to a point at the tail, and in this ship was of 300,000 cubic feet capacity. The system of rigging being patented, can only be described in very general terms. The suspensions carrying the car are attached to a large elliptical rigging band which is formed under the central portion of the envelope. To this rigging band are attached the trajectory bands which pa.s.s up the sides and over the top of the envelope, sloping away from the centre at the bottom towards the nose and tail at the top.

The object of this is to distribute the load fore and aft over the envelope. These bands, particularly at the after end of the ship, follow a curved path, so that they become more nearly vertical as they approach the upper surface of the envelope. This has the effect of bringing the vertical load on the top of the envelope; but a greater portion of the compressive force comes on the lower half, where it helps to resist the bending moment due to the unusually short suspensions. A single rudder plane and the ordinary elevator planes were fitted to the envelope. A roomy open car was provided for this ship, composed of a duralumin framework and covered with duralumin sheeting. Two 170 horse-power Maybach engines were mounted at the after end of the car, which drove two metal-bladed reversible propellers.

These propellers were later replaced by standard four-bladed wooden ones and a notable increase of speed was obtained.

Two officers and a crew of seven men were carried, together with a wireless installation and armament.

This airship, together with No. 3, took part in the great naval review at Spithead, shortly before the commencement of the war, and in addition to the duties performed by her in the autumn of 1914, which are mentioned later, carried out long hours of patrol duty from an east coast station in the summer of 1917. In all respects she must be accounted a most valuable purchase.

Pa.r.s.eVAL AIRSHIPS 5, 6 and 7

Pa.r.s.eval No. 5 was not delivered by Germany owing to the war, so three envelopes and two cars were built by Messrs. Vickers on the design of the original ship. These were delivered somewhat late in the war, and on account of the production of the North Sea airship with its greater speed were not persevered with. The dimensions of the envelopes were somewhat increased, giving a cubic capacity of 325,000 cubic feet.

Twin Maybach engines driving swivelling propellers were installed in the car, which was completely covered in, but these ships were slow in comparison with later designs, and were only used for the instruction of officers and men destined for the crews of rigid airships then building.

An experimental ship was made in 1917 which was known as Pa.r.s.eval 5; a car of a modified coastal pattern with two 240 horse-power Renault engines was rigged to one of envelopes. During a speed trial, this ship was calculated to have a ground speed of 50 to 53 miles per hour.

The envelope, however, consumed an enormous amount gas and for this reason the ship was deflated and struck off the list of active ships.

This digression on Pa.r.s.eval airships has antic.i.p.ated events somewhat, and a return must now be made to earlier days.

Two more Astra-Torres were ordered from France, one known as No. 8, being a large ship of 4,00,000 cubic feet capacity. She was fitted with two Chenu engines of 240 horse-power, driving swivelling propellers. This ship was delivered towards the end of the year 1914.

The second Astra was of smaller capacity and was delivered, but as will be seen later, was never rigged, the envelope being used for the original coastal ship and the car slung to the envelope of the ex-army airship Eta.

On January 1st, 1914, an important event took place: the Army disbanded their airship service, and the military ships together with certain officers and men were transferred to the Naval Air Service.

Before proceeding further, it may be helpful to explain the system by which the naval airships have been given numbers. These craft are always known by the numbers which they bear, and the public is completely mystified as to their significance whenever they fly over London or any large town. It must be admitted that the method is extremely confusing, but the table which follows should help to elucidate the matter. The original intention was to designate each airship owned by the Navy by a successive number. The original airship, the rigid Mayfly, was known as No. 1, the Willows airship No.

2, and so on. These numbers were allocated regardless of type and as each airship was ordered, consequently some of these ships, for example the Forlaninis, never existed. That did not matter, however, and these numbers were not utilized for ships which actually were commissioned.

On the transfer of the army airships, four of these, the Beta, Gamma, Delta and Eta, were given their numbers as they were taken over, together with two ships of the Epsilon cla.s.s which were ordered from Messrs. Rolls Royce, but never completed. In this way it will be seen that numbers 1 to 22 are accounted for.

In 1915 it was decided to build a large number of small ships for anti-submarine patrol, which were called S.S."s or Submarine Scouts.

It was felt that it would only make confusion worse confounded if these ships bore the original system of successive numbering and were mixed up with those of later cla.s.ses which it was known would be produced as soon as the designs were completed. Each of these ships was accordingly numbered in its own cla.s.s, S.S., S.S.P., S.S. Zero, Coastal, C Star and North Sea, from 1 onwards as they were completed.

In the case of the rigids, however, for some occult reason the old system of numbering was persisted in. The letter R is prefixed before the number to show that the ship is a rigid. Hence we have No. 1 a rigid, the second rigid constructed is No. 9, or R 9, and the third becomes R 23. From this number onwards all are rigids and are numbered in sequence as they are ordered, with the exception of the last on the list, which is a ship in a cla.s.s of itself. This ship the authorities, in their wisdom, have called R 80--why, n.o.body knows.

With this somewhat lengthy and tedious explanation the following table may be understood:

No. Type. Remarks.

1. Rigid Wrecked, Sept. 24, 1911.

2. Willows Became S.S. 1.

3. Astra-Torres Deleted, May 1916.

4. Pa.r.s.eval Deleted, July, 1917.

5. Pa.r.s.eval Never delivered from Germany.

(Subst.i.tute ship built by Messrs. Vickers).

6. Pa.r.s.eval Built by Messrs. Vickers.

7. Pa.r.s.eval Built by Messrs. Vickers.

8. Astra-Torres Deleted, May, 1916.

9. Rigid Deleted, June, 1918.

10. Astra-Torres Envelope used for C 1.

11. Forlanini Never delivered owing to war.

12. Forlanini Never delivered owing to war.

13. Forlanini Never delivered owing to war.

14. Rigid Never built.

15. Rigid Never built.

16. Astra-Torres See No. 8.

17. Beta Transferred from Army.

Deleted, May, 1916.

18. Gamma Deleted, May, 1916.

19. Delta Deleted, May, 1916.

20. Eta Transferred from the Army.

Fitted with car from No. 10.

Deleted May, 1916.

21. Epsilon Construction cancelled May, 1916.

22. Epsilon Construction cancelled May, 1916.

23. Rigid 23 Cla.s.s.

24. Rigid 23 Cla.s.s.

25. Rigid 23 Cla.s.s.

26. Rigid 23 Cla.s.s.

27. Rigid 23x Cla.s.s.

28. Rigid 23x Cla.s.s. Never completed.

29. Rigid 23x Cla.s.s.

30. Rigid 23x Cla.s.s. Never completed.

31. Rigid 31 Cla.s.s.

32. Rigid 31 Cla.s.s, building.

33. Rigid 33 Cla.s.s.

34. Rigid 33 Cla.s.s.

35. Rigid Cancelled.

36. Rigid Building.

37. Rigid Building.

38. Rigid Building.

39. Rigid Building.

40. Rigid Building.

80. Rigid Building.

In August, 1914, Europe, which had been in a state of diplomatic tension for several years, was plunged into the world war. The naval airship service at the time was in possession of two stations, Farnborough and Kingsnorth, the latter in a half-finished condition.

Seven airships were possessed, Nos. 2, 3 and 4, and the four ex-army ships--Beta, Gamma, Delta and Eta--and of these only three, Nos. 3, 4 and the Beta, were in any condition for flying. Notwithstanding this, the utmost use was made of the ships which were available.

On the very first night of the war, Nos. 3 and 4 carried out a reconnaissance flight over the southern portion of the North Sea, and No. 4 came under the fire of territorial detachments at the mouth of the Thames on her return to her station. These zealous soldiers imagined that she was a German ship bent on observation of the dockyard at Chatham.

No. 3 and No. 4 rendered most noteworthy service in escorting the original Expeditionary Force across the Channel, and in addition to this No. 4 carried out long patrols over the channel throughout the following winter.