London treaty Gunboat Challenge

[Gollevainen]

I decided to modify the entry card giving it proper room for 3-view (side, top and front) layout: all contensant that have submitted their work on the original one can edit their work accordingly if they choose so.

[Themax]

The Evelard de Lascon class was intended and built to fulfill the critical need of a gunboat for the Three Rivers navy which had bought foreign territories few years before and was willing to secure the valuable ressources and to neutralise potential insurrections . The Evelard de Lascon class would never serve the second role as all 3 ships of the class would be sunk in a naval battle against the Japanese navy, the Marquise de Laureil is the last ship of the class, built with 4 5.9" main guns, it also implemented a decent amount of mg as well as a 0.7" autocanon , meaning it lacked a good medium caliber canon .
However, Three River tried to outsmart the Washington treaty with the addition of a rocket launcher, but as this technology was at it's beginning, they lacked accuracy and range, and would never be scrapped for a canon as planned as the 3 ships would sink before .
It would later be known as the gunpowder bin because of how unsafe the ammunitions storage were .


Displacement: 1,850 tons standard
Speed: 19.6 knots
Range: 4,600 miles at 11 knots
Armament:
4 x 5.9" /150mm main gun (2x2)
4 x 0.7" auto canon(1x4)
7 x 12.7mm machinegun (7x1)
12 x 160mm rocket launcher (1x12)
Crew: 168

[Perky50]

Bird Class Brig

Within the rules and protocols of the London Naval Treaty of 1930 were allowances for what would be generally known as gunboats. Every signatory nation would have their own idea of what would be preferred, and the various final results would be as diverse as the nations participating.

The British, who were at that point in their history beginning efforts that would lead to the independence of her colonies, had concerns with the titling of these group of ships as gunboats, and would settle on the older traditional title of Brig as a result.

For Great Britain the choice in the case of the Bird class was not so much to build a large and specialized dreadnought gunboat, but rather to evolve a multipurpose vessel that could fulfill various duties on distant stations and still be cost effective.

While some have argued that the role portrayed for these new brigs might well have been better served simply by building more sloops, there would be certain flexibilitiy's in these designs that would have entailed major modifications in the existing sloop designs.These flexibility's would include such items as provisions for extended deployments and independent operations,and the option to easily reconfigure for a diverse range of duties.

The points of interest ranged from basic patrol and escort duties, through colonial patrol and protection. As well more mundane duties such as fleet dispatch and training would be popular usages as well.

With a view for deployments to colonial postings, there were provisions in the design for the carriage of a reinforced Royal Marine Light infantry platoon, complete with a pair of 3.7” mountain guns, a pair of Vickers machine guns, and a four-man sapper squad.

When deploying with the Royal Marines, the variable depth charges would in most cases be landed so as to provide space for their guns, equipment and other supplies. Provisions were also included to allow for securing the Royal Marines heavy weapons on the top of the cabins aft of the funnel so that they might be fired from the ship if the opportunity or need arose.

This class could also be configured for mine sweeping duties with a basic rig available which would replace the variable depth charge mountings and weapons while configured for that duty.

An integral part of their colonial deployments was assisting in the training of local personnel in the ways of the Royal Navy and Royal Marines as a result of the British Empire beginning to prepare many of their colonial holdings for independence in the 1930’s.

With the opening of the Royal Navy’s East African Naval Academy in Mombasa in 1933 , HMS Mudhen would have included in its various duties hands on training duties for those studying there from all across the British Empire’s African colonies. While overshadowed in some ways by her larger sisters that would be present for that formal occasion, HMS Mud Hen, resplendent in her formal fleet colours, would steal the show among the warships in harbour that day.

While they were never as popular as the various sloop classes in northern waters, by nature of their being designed initially for warmer colonial climes, they would be popular with their crews on station across great swaths of the empire, delivering good service until the end of the war.

Armament:
2 x 4”DP
1 x 12 pdr
2 x 2pdr pom pom
Various pedestal mounts for MG’s
12 variable depth charges
Displacement: 1200 tons
Speed: 18 knots

[reytuerto]

Oh! Two candidates with a clear overkilling capability (and not only powerful artillery, the overkilling capability is turreted!) !

[superboy]

Hi, i love small vessel armed 10 guns.


Spica-Class Fast Attack Gunboat



Specifications:
Builder: CRDA At Monfalcone Tieste Italy
Displacement: 575 tons
Dimensions: 72.9 x 6.95 x 2.58 m
Propulsion: 1 Steamturbine, 9,580 bhp (Parsons geared turbines, Yarrow boilers)
Speed: 29.5 kts Shaft: 2 shafts
Endurance: 1780nm (15 kts)
Crew: 70

Armament:
2x150mm SK L/45 C/16 single guns
4x76/40 QF 18 ctw single guns
2x20mm Flak Medsen single guns
1x20mm Flak Medsen twin gun
8xNaval mines
1x3m Rangefinder
-----------------

And this is Spica-Class Fast Attack Torpedo Boat, the neverbuilt design for export.

[Gollevainen]

At this point of the race i like to point out that if the design fails to fit the given criteria (from the treaty text itself) I wont include it in the judging poll at all. Idea of this challenge is to work within the design treaty parameters.

Also: EDIT: I decided to be bit more lax in the requirments for the country vs. signatory. since quite many AUs disregards such treaties and I dont like to make single nation(s) spesific challenges. The technical requirments Still aply.

[Charguizard]

Technological Showcase: Gier-class Sloop

Having the Batavian Navies Naval Staff settled on dividing destroyer types into defender (gun) and attacker (torpedo) variants, Secretary Comptroller Dumas decided that he wanted a general-purpose sloop, convertible between escort (ASW) and minesweeping. He asked Chief Constructor Van Haarlem for a combination of three types: colonial gunship, convoy escort and coastal minesweeper. Constructor replied that harbour and coastal minesweeping was incompatible with the other two because a ship designed to fulfill these would displace over 1,500 tonnes and draw more than 2.5m. However, if the ship was allowed to grow well beyond this figure, she could carry ASW gear and minesweeping gear at the same time, while also being able to perform as fast oceanic sweepers for the fleet. Commander, NEI, Admiral Garland requested to implement a new innovation he was sponsoring, experimental Siemens-Spyker active stabilizers, which promised to improve gunnery on small, lively platforms. The designers provided about 2.5m in length for this purpose. This decision in turn transformed into a cost spiral as the Staff took turn to add more innovative equipment that had been witheld from the austere destroyer construction of the late ‘20s. In July 1934 Comptroller allowed growth to a maximum of 2,000 tonnes and curbed the number of ships to three, in order to evaluate the equipment implemented before releasing it for future construction.

This convoy escort was by far the largest yet, and was to be powered by a steam plant using just one destroyer boiler feeding two turbines for a total of 6,000hp, for a design speed of 19 kn, considered necessary when pursuing a submarine (It was soon to be known that the latest Louisiainnean cruiser submarines could easily reach 20kn surfaced). She would end up displacing 1,960 t standard on 95m and 2,400 t deep. Standard displacement included two stern depth charge racks and a Y-gun (minimum ASW compliment for an escort) and also minesweeping gear (two paravanes). If required, she could land the minesweeping gear and ship additional depth charges and stick bomb launchers. The ship could not meet the minesweeping requirement because she drew 3.9m deep. Nevertheless, they were still earmarked to supplement destroyers on minesweeping duty.

The design was submitted in January 1935. A powerful 5.5” (14.2 cm) 50 caliber gun developed from the 42 caliber gun of the light cruisers was chosen, at least three guns would be installed. This new gun used a fully RPC mount that elevated to 65° for anti-aircraft fire. It had integral hoists served from a shell room below the mount, one for shells and one for propellant cases. The gun breech was served by a spring rammer that was cocked pneumatically and recocked by the gun’s recoil. The guns were directed by a Model 1933 director which was triaxially stabilized and included it’s own rangefinder. Concerns about the main battery’s ability to deal with aircraft at medium and short range prompted the addition of two twin 7.1cm/42 guns, these would eventually be replaced during construction by twin 3.9cm an 2.6cm autocannon, only a single 7.1cm gun left to fire starshell.

ODSI (SONAR) was clearly essential for the escort mission, and was provided for including an operator room below the bridge. The desired depth charge battery had increased to a six charge pattern, and could be achieved by adding lateral rails or a second Y-gun; provision for this was designed but no ship was ever fitted this way thanks to the implementation of newer ahead-throwing weapons.

Minimum performance was 7,500nm at 12kn with four months’ stores, with a new ideal speed of 20kn when operating against a submarine. The ship had to be able to maintain a speed of no less than 17kn for long periods, to give her a dash capability against a submarine. For good maneuverability the ship needed twin screws. Captain Martadinata of the Naval Staff objected to the low speed; he wanted more than 20kn, but Comptroller objected that treaty restrictions had to be considered still in effect. Consensus was achieved when internal combustion engines were chosen in order to provide quick acceleration, speed in excess of 20kn was to be kept by governing the engines. The ship was no longer considered as a cheap expendable escort or gunboat, and the design was now revised to be powered by four license-built Sulzer diesel engines of 2,000 hp, two on each shaft.

This 1936 Convoy Escort became the Gier class. Three were built under the pre-war 1936 program. A modified version was ordered in 1938 mobilization programme, ten were laid down but one was cancelled once mass production designs started replacing previous, more expensive designs. First of class Rep. Sch. Gier was launched on the 25th of November of 1936 and commissioned on the 29 of May 1937 by Marine Etablissement in Amsterdam. While on speed trials, the ship achieved 20kn on standard displacement while pushing 6,732 hp total, further acceleration was not recorded. Gunnery trials while under support of the active stabilizers showed increased efficiency over destroyer platforms, comparable rather with older open-mount light cruisers. After practice, Gier showed impressive accuracy while demonstrating its abilities to the Chairman of the Council of Guilds of the Netherlands, Dr. Axel Van Buren and his retinue. Later that year Gier would compete against the cruisers of the home squadron and beat Enno Doedes Star by one point, earning it a gunnery efficiency R badge, a first for an auxiliary or flotilla craft.



Gier was awarded to the Batavian Indies Navy and performed station duty at various locations starting in 1938 on the Nieuw Zeeland station. This plate depicts Gier as seen in January 1940 while serving on trade protection duties while in the Formosa station. She is camouflaged in Dazzle Pattern 7B. She is equipped with a half ASW compliment of two depth charge rails with six bombs each, and two Y-gun with twelve bombs total. She also carries a half minesweeping compliment of four paravanes. Her foremast has a Klok-B air warning radar, her main battery director is fitted with Plas-C gunnery ranging radar and her 3.9cm gun mount has an integral Plas-B radar on a triaxially stabilized mount. The 7.1cm starshell gun, 2.6cm gun mount and 13.2mm machine guns weren’t slaved to directors but could receive orders from the target markers on the bridge wings next to the main battery director. Her anti-aircraft armament proved to be insufficient and she was sunk by bombers while operating off of Quelpaert in August 1940.

[emperor_andreas]

Love that camouflage!

[Hood]

My entry:



Castle Class sloop

During the late 1920s and the early 1930s the Admiralty was concerned about the rise of Japan and began to plan a fleet that could operate to protect its Far Eastern territories. The arms limitation treaties of the era and financial stringency made the provision of a large fleet powerful enough to fulfil all of the Admiralty's needs was difficult.
Large sloops were seen as ideal escort vessels and the 1930 London Treaty opened the way for more unrestricted smaller combatants. So began the genesis of the Castle-class.

Several innovations were included to create a sloop capable of defending convoys from aerial and submarine threats as well as the surface threat from armed merchant cruisers and surfaced cruiser submarines. Long range was also required. The new class would carry two dual-purpose gun mounts, pom-poms, depth-charges and be fitted with ASDIC. Power would come from diesel engines for long range.
Plans for 24 sloops were curtailed by costs and problems with the engines, the class suffering from vibration and smoking diesels, but they would form a useful group of vessels for the Second World War and five of them were lost to enemy action during that conflict as they sought to keep open Britain's sea lines of communication.

Class
HMS Farnham Castle, commissioned September 1935
HMS Leeds Castle, commissioned December 1935
HMS Pembroke Castle, commissioned March 1936
HMS Scarborough Castle, commissioned August 1936
HMS Hedingham Castle, commissioned September 1937
HMS Guildford Castle, commissioned December 1937
HMS Portchester Castle, commissioned March 1937
HMS Shrewsbury Castle, commissioned August 1938

Displacement
1,200 tons (standard)

Dimensions
295 ft 6 in (oa), 292ft 6 in (wl) long, 37 ft beam, 9 ft 6in draught (normal load)

Armament
2x2 4.7in/45 Mk.X (400 rpg) in BD Mk.II turrets
1x4 2pdr pom-poms (1,000 rpg)
1x4 0.5in Vickers machine-guns
36x depth-charges

Fire-Control
One HACS main director and one secondary HA/LA rangefinder
ASDIC and hydrophones

Machinery
2x 2,300hp Admiralty diesels
19.5kts max speed
Range 8,500nm at 10kts

[Blackbuck]

Slúpa Patrún 35



The first of a series of closely related designs, the Pat.35 appeared out of a necessity to better safeguard trade routes against an ever-militant Dayashinese Empire. As convoy escorts the vessels wouldn't need to be particularly fast, just enough to leave and rejoin convoys, this meant a 5 or so knot advantage over the convoy. As a result the 35ers were the first Glasic surface combatants to employ diesel-propulsion. Four 1,200 horsepower I8 engines, two to each shaft provided enough power to achieve the treaty-defined maximum speed of 20 knots.
As convoy escorts the 35ers were initially schemed to receive four 120mm single mounts but changing threat assessments resulted in a pair of 105mm twins and a pair of 75mm singles substituting the 120s during the design process, as a result the 35ers would after the breakdown of the treaty framework lose their 75mm guns for another twin 105 in X position and a 40mm multiple AA mount in B position.

Displacement
1,250 tons (standard)
1675 tons (full load)

Dimensions
300ft (oa), 296ft 6 in (wl), 35ft beam, 12ft draught (deep load)

Armament, as-built
Two twin 4.1in/50 Pat.34 (400 rpg) in CÚ.35 mountings
Two single 2.95in/50 Pat.30 (250 rpg) in UA.30 mountings
Two single 23mm Pat.33 cannon (1,250 rpg)
12+4 stern-launched depth-charges (200kg), 2+4 side-mounted depth charge throwers (100kg).

Fire-Control
One 13-foot HA/LA director
One 6-foot HA/LA auxiliary rangefinder
ASDIC and hydrophones

Machinery and Endurance
4x 1,200hp (de-rated to 975hp) Sulzer 8LD34 diesels for 19kts
2x 130hp AEC diesels for hotel and emergency usage
10,000nm range at 12kts
10,000nm at 12kts