New Gran Colombian Ships for 1917

[The Rock Doctor]

I know, we're still mired in late 1916...

The deployment of the protected cruiser Guyana and blimp A-9 to the Indian Ocean was a test of the concept of aerial scouting for the Armada.  In general, Rear-Admiral Ramsey found the pairing to be quite useful, from spotting refugee boats and scouting coastal cities to (later) watching for RRC warships transiting the Strait of Malacca.  On the other hand, Guyana's support facilities were somewhat modest, and A-9 was consequently exposed to a lot of wear-and-tear, eventually being destroyed during a storm in September 1916.

Although planning for a new blimp-carrying cruiser does continue, the Armada's follow-up plans have concentrated on a "mobile aerodrome" concept in which a Type 0 airship hanger would be mounted on an auxiliary-type hull.  Such a vessel would be used as a based for blimp or airship operations in regions where no such facilities existed ashore.  It could also support blimps being forward-deployed to airship cruisers.

Notional plans for a smaller vessel with a large, rolling, shuttered roof were put forward, but arguments were made about the feasibility of constructing and maintaining such a device.  Its ability to support loads (the blimp, service crews, etc) was also questioned.  In the end, a conventional hanger, with doors facing aft, was settled upon, though a longer hull would be necessary to accommodate the landing deck aft.

The Yubarta will have a modest defensive armament, though it is recognized that the bulk of the hanger will make her a very inviting target in the event of a surface engagement.  Ideally, her role in combat will be taken from a safe anchorage well out of sight of any enemy forces.



Yubarta, laid down 1917 (Engine 1916)

Displacement:
   6,345 t light; 6,516 t standard; 7,665 t normal; 8,585 t full load

Dimensions: Length overall / water x beam x draught
   446.73 ft / 436.35 ft x 91.86 ft x 11.15 ft (normal load)
   136.16 m / 133.00 m x 28.00 m  x 3.40 m

Armament:
     1 - 5.51" / 140 mm guns in single mounts, 83.72lbs / 37.97kg shells, 1912 Model
     Breech loading gun in a deck mount with hoist
     on centreline forward
     4 - 2.56" / 65.0 mm guns in single mounts, 8.38lbs / 3.80kg shells, 1912 Model
     Anti-aircraft guns in deck mounts
     on side, all amidships, all raised mounts - superfiring
     6 - 0.31" / 8.0 mm guns in single mounts, 0.02lbs / 0.01kg shells, 1912 Model
     Machine guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 117 lbs / 53 kg
   Shells per gun, main battery: 250

Armour:
  - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.98" / 25 mm   0.98" / 25 mm      2.95" / 75 mm
   3rd:   0.98" / 25 mm         -               -
   4th:   0.39" / 10 mm         -               -

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 7,414 shp / 5,531 Kw = 16.36 kts
   Range 12,000nm at 12.00 kts (Bunkerage = 2,068 tons)

Complement:
   409 - 532

Cost:
   £0.273 million / $1.092 million

Distribution of weights at normal displacement:
   Armament: 15 tons, 0.2 %
   Armour: 9 tons, 0.1 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 9 tons, 0.1 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 276 tons, 3.6 %
   Hull, fittings & equipment: 4,816 tons, 62.8 %
   Fuel, ammunition & stores: 1,321 tons, 17.2 %
   Miscellaneous weights: 1,229 tons, 16.0 %
   -1,050 t:  Facilities for two SSZ type blimps, including hanger, hydrogen cracker, hydrogen storage, mooring mast, workshop & stores
   -100 t:  Air group workspace (weather office, photo development, etc.)
   -54 t:  Weight reserve
   -25 t:  Long-range wireless

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     88,276 lbs / 40,041 Kg = 1,054.4 x 5.5 " / 140 mm shells or 9.1 torpedoes
   Stability (Unstable if below 1.00): 1.14
   Metacentric height 5.7 ft / 1.7 m
   Roll period: 16.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.02
   Seaboat quality  (Average = 1.00): 2.00

Hull form characteristics:
   Hull has low forecastle, rise forward of midbreak, low quarterdeck
   Block coefficient: 0.600
   Length to Beam Ratio: 4.75 : 1
   'Natural speed' for length: 20.89 kts
   Power going to wave formation at top speed: 36 %
   Trim (Max stability = 0, Max steadiness = 100): 35
   Bow angle (Positive = bow angles forward): 10.00 degrees
   Stern overhang: 6.56 ft / 2.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      21.65 ft / 6.60 m
      - Forecastle (27 %):   21.65 ft / 6.60 m (67.59 ft / 20.60 m aft of break)
      - Mid (68 %):      67.59 ft / 20.60 m (21.65 ft / 6.60 m aft of break)
      - Quarterdeck (16 %):   13.78 ft / 4.20 m (21.65 ft / 6.60 m before break)
      - Stern:      13.78 ft / 4.20 m
      - Average freeboard:   39.23 ft / 11.96 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 32.2 %
      - Above water (accommodation/working, high = better): 746.7 %
   Waterplane Area: 29,317 Square feet or 2,724 Square metres
   Displacement factor (Displacement / loading): 402 %
   Structure weight / hull surface area: 102 lbs/sq ft or 499 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.77
      - Longitudinal: 10.56
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is excellent
   Ship has slow, easy roll, a good, steady gun platform
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

[Walter]

Whoever came up with that design ought to be shot!  :o

[The Rock Doctor]

Because of how useful it could be, or because of how ugly it is?

[Walter]

He should get a medal for the usefulness of the vessel but should be shot for the hideous look of the vessel. :D

[The Rock Doctor]

Consider it a defensive measure - it will be difficult to target her if she's that repulsive.

[maddox]

France hires that genious immediatly.

So ugly, it becomes magnificent.

[Walter]

Consider it a defensive measure - it will be difficult to target her if she's that repulsive.

It's more likely going to be a shell/bomb/torpedo magnet. Trying to sink the ship as fast as possible so the ugly stain is removed from the surface of the ocean. ;D

[Korpen]

I would be worried about how she would behave if there would happen to be blowing any form of wind (and that has been known to happen at sea). With such a huge surface area working as  sail I would suspect that she can start to behave quite oddly in even moderate winds, and have problem holding course in some side winds.

[The Rock Doctor]

I agree - that could be a problem.  On the other hand, it wouldn't be any worse than a small aircraft carrier would face, would it?

[ciders]

I agree with Korpen. This ship will be very vulnerable in a storm.

EDIT : yes Rock, but your ship is very high. An aircraft carrier is more small on the water, more aerodynamic. Without wanting to hurt you, your Republican Highness ? :)

[The Rock Doctor]

No offence taken, if that's what you mean.  I'm just trying to gauge how serious a problem this would be.

[maddox]

A very serious problem, her draugth is shallow compared to the hull.  So not even the resistance of the seawater would help her a lot against the wind.

Imagine the effect of an iceberg ,but reversed.

[Korpen]

I agree - that could be a problem.  On the other hand, it wouldn't be any worse than a small aircraft carrier would face, would it?

It would, as cider say, she catch more wind. Also, a carrier usally had allot mor power to push with, even a fairly normal 10m/s wind would most likely be felt by this ship I think.

[The Rock Doctor]

Excellent - so I have a white elephant in the making.

[Guinness]

I hate to pile on, but I agree that her shallow draft, combined with that tall sail area might be a problem.

I expect the beam is fixed by the width of the hanger.  I wonder if a radically different hull design might be necessary instead. Possibly a stepped down hull with more freeboard forward, but less aft, so that the hanger itself is more "nestled" in the hull?

In general, I think you need to go for even more reserve buoyancy to account for what is probably more of a topweight issue than SS realizes. At least that's my opinion.