HMS Neptune (BB-1911)


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First Royal Navy battleship with a superfiring turret. The lozenge arrangement meant that it was possible for the side mounted turrets to be able to fire to both sides. When the centre turrets were fired across the ship, the blast effects ripped up the wooden deck and blew it over the side. Class of 5 with 3 Royal Navy and 2 Australis Navy ships. All 5 remained in service in training and other ancillary duties, the Australis ships being made into Area Defence Vessels, two RN ships as training ships the last as a training aircraft carrier. All of the conversions had one thing in common. They were to reduce the ships to the point where the Washington/Geneva Treaties did not recognise them as battleships. Thus they would not count against the allowable amount of battleship tonnage/numbers. The same applied to the Neptune.

As training ships the RN vessels were given different supperstructure that mimicked the types of vessels seaman and officers would be trained for. These conversions were of the most modern ships being built for the RN at the time. Majestic Class, Cornwall class. The fore and aft 12" were kept with a range of 5.5", 6", 4" and the modern 2pd AA guns. Aircraft handling facilities were added (where possible) to the training ships during the 1930's.

The training ships were often used as heavy escorts to the faster 12-15 knot convoys that normally carried more important material from Nova Scotia to Liverpool. The aircraft carried were of great use on milder days when they could be launched and recovered without putting the ship at risk. In the darkest days of the Atlantic with no aircraft carriers and before the escort carriers were available, two Hurricanes were loaded aboard and were one shot fighters sent after the Condors that tracked the convoys.

The Hercules and Colussus replaced the old armoured cruisers of the County type in the training ship role. These were the ocean going training ships. There normal round trip would take them across the Atlantic into the Caribbean Sea visiting the Commonwealth Islands. Three trips a year plus coastal trips in between gave the cadets a good grounding in sea conditions. Having the ships look like modern ships did pay dividends on occasion. Once when a German cruiser was looking to attack a convoy the Hercules was escorting, the cruiser took the Hercules to be a Majestic class and took off.

While the Neptune had been considered the weakest of the three RN conversions, by 1930 it was the most valuable. While only able to carry up to a dozen aircraft of its own, these aircraft were split into six bomber and six fighter aircraft for self protection. It was as the fleets Training Carrier that the Neptune was so valuable. Most of the pilots that fought in WW2 or commanded aircraft carriers of their own had probably done their landing training aboard HMS Neptune. Neptune was also used for training mechanics to service aircraft at sea. From the basic conversion completed in 1924, further and further additions and new equipment was added. An extra elevator/lift was added, AA guns, a bridge superstructure, HACS to control the 4" AA, 4x2pd AA, arrester wires, upgraded wireless/aerial configuration and many more minor details. The 11" and other side/belt armour was removed and the deck armour was kept.

The whole thought behind the Area Defence Vessels was to be able to park the ship in a lagoon of some island and the ship would provide the defence of the area. The ship would also be able to act as a mothership for the big flying boat squadrons (Catalinas, Sunderlands) while air support around the area could be provided by the ships own half dozen seaplanes. Like the RN's training ships, during the early part of WW2, the ADV's spent a lot of their time at sea as convoy escorts. These two ships were very important in the Indian Ocean when Australis and Zealandia were sending their troopships through to the Western Desert theater. Having aircraft buzzing around the convoy meant there would be no unwelcome surprises from enemy shipping.


Displacement 20,000 tons std, 23,500 tons full load
Length 566 ft
Breadth 85 ft
Draught 26.3 ft
Machinery 4 shaft , steam turbines, 25,000shp
Speed 22 knots
Range 6000 miles at 12 knots
Armour 11" side, 2" deck, 11" turrets. (belt removed on Neptune and ADV's reduced to 3")
Armament Neptune (as CVE)

6 x 4" (6x1)
4 x 2pd (4x1)
from 1940
8 x 20mm (4x2)
Colussus (as TS)

6 x 12 (3x2)
4 x 6" (4x1)
6 x 4" (6x1)
4 x 2pd (4x1)
Hercules (as TS)

6 x 12" (3x2)
10 x 5.5" (10x1)
6 x 4" (6x1)
16 x 2pd (4x4)
Auckland (as ADV)

4 x 12" (2x2)
4 x 4" (4x1)
8 x 2pd (2x4)
Aircraft 12 2 to 3 2 to 3 6
Torpedoes nil 6 x 21" (2x3) nil nil
Complement 905 (with aircrew) 780 (815 as flagship) 800 (830 as Flagship) 750
Notes HMS Neptune 01/1911

HMS Colussus 07/1911

HMS Hercules 08/1911

HMAS Auckland 10/1912

HMAS Gascoyne 01/1913

Above: HMS Hercules ready to anchor.  Below: Foredeck, turret and bridge superstructure of Hercules

Side view of Colussus class: Note the Dreadnought clones in the background.

Old drawings of the three Neptune/Colossus class battleships.


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