New GC ships for H1/1906

Started by The Rock Doctor, March 21, 2007, 07:57:45 PM

Previous topic - Next topic

The Rock Doctor

One new proposed class for Gran Colombia in 1906, although it happens that the Havoc class torpedo-boats will be built in Jamaica.  

The design history is a bit quaint; it was originally a GC design intended to supplement the Battle Fleet's torpedo forces.  However, the priority for torpedo forces is now to replace the earliest, small and somewhat flimsy IC-era torpedo-boats retained in post-amalgamation service.  Jamaican naval shipwrights have analyzed the design, and made the modifications necessary for domestic production.  

Whereas the Gran Colombian design would have fielded a pair of 100 mm and three 65 mm guns, this design features five 76.2 mm guns, plus two banks of torpedoes.  One gun is forward, two abreast the funnels, one aft of the funnels, and one at the stern.  The torpedoes sit between the midships and aft guns.

Havoc differs slightly from its five sisters in that the midships 76.2 mm gun has been omitted in favor of a wireless shack to allow better coordination with larger fleet units and shore commands.  Havoc's design thus adds 5 t of miscelleaneous weight, 0.01 seakeeping, and is $0.1 less expensive than her five sisters.

The design posted below is for the five standard units; Havoc can be posted separately if requested.

Note:  the class is somewhat based on American "Flivver" type destroyers of ~1909.  Thus I'm happy that the armament and three screws can fit on the hull.

Hurricane, laid down 1906 (Engine 1905)

Displacement:
   699 t light; 723 t standard; 814 t normal; 886 t full load

Dimensions: Length overall / water x beam x draught
   276.51 ft / 275.59 ft x 26.25 ft x 9.84 ft (normal load)
   84.28 m / 84.00 m x 8.00 m  x 3.00 m

Armament:
     3 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1906 Model
     Breech loading guns in deck mounts with hoists
     on centreline ends, majority aft
     2 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1906 Model
     Quick firing guns in deck mounts with hoists
     on side, all amidships
     2 - 0.31" / 8.0 mm guns in single mounts, 0.02lbs / 0.01kg shells, 1906 Model
     Machine guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 68 lbs / 31 kg
   Shells per gun, main battery: 200
   4 - 18.0" / 457 mm above water torpedoes

Armour:
  - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1.18" / 30 mm   0.79" / 20 mm      1.18" / 30 mm
   2nd:   1.18" / 30 mm   0.79" / 20 mm      1.18" / 30 mm

Machinery:
   Coal fired boilers, steam turbines,
   Direct drive, 3 shafts, 13,500 shp / 10,071 Kw = 27.91 kts
   Range 2,500nm at 10.00 kts (Bunkerage = 162 tons)

Complement:
   76 - 99

Cost:
   £0.097 million / $0.386 million

Distribution of weights at normal displacement:
   Armament: 8 tons, 1.0 %
   Armour: 10 tons, 1.3 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 10 tons, 1.3 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 465 tons, 57.1 %
   Hull, fittings & equipment: 203 tons, 25.0 %
   Fuel, ammunition & stores: 115 tons, 14.1 %
   Miscellaneous weights: 12 tons, 1.5 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     179 lbs / 81 Kg = 13.3 x 3.0 " / 76 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.36
   Metacentric height 1.2 ft / 0.4 m
   Roll period: 10.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.22
   Seaboat quality  (Average = 1.00): 1.01

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.400
   Length to Beam Ratio: 10.50 : 1
   'Natural speed' for length: 16.60 kts
   Power going to wave formation at top speed: 63 %
   Trim (Max stability = 0, Max steadiness = 100): 69
   Bow angle (Positive = bow angles forward): 5.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      10.50 ft / 3.20 m
      - Forecastle (20 %):   10.50 ft / 3.20 m
      - Mid (50 %):      10.50 ft / 3.20 m (10.17 ft / 3.10 m aft of break)
      - Quarterdeck (15 %):   10.17 ft / 3.10 m
      - Stern:      10.17 ft / 3.10 m
      - Average freeboard:   10.33 ft / 3.15 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 194.1 %
      - Above water (accommodation/working, high = better): 83.0 %
   Waterplane Area: 4,453 Square feet or 414 Square metres
   Displacement factor (Displacement / loading): 35 %
   Structure weight / hull surface area: 24 lbs/sq ft or 119 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.25
      - Overall: 0.54
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is cramped
   Ship has slow, easy roll, a good, steady gun platform


The Rock Doctor

#1


Hurricane; as noted, Havoc's midships gun would be replaced by a small radio shack and aerial.

P3D

Range and coal bunker size is apparently a big limiting factor on these ships.

I played with my DD design, and found that increasing draught from 2.4 to 3m did not increase cross-sectional strength at all! Reducing range, however, from 3000 to 2000nm, helped a lot.

But Orange unfortunately needs long-range destroyers,
The first purpose of a warship is to remain afloat. Anon.
Below 40 degrees, there is no law. Below 50 degrees, there is no God. sailor's maxim on weather in the Southern seas

The Rock Doctor

It does seem that way; on the other hand, I don't think they were intended to be long-ranging or ocean-going craft for several more years.  Given that most of GC operations will be taking place within a few hundred miles of the coast, I think the range is adequate for the time being.