River Monitor

Started by Kaiser Kirk, August 16, 2009, 04:51:17 PM

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Kaiser Kirk

The vessel below is meant to do several things
1. transit the Lugwig Canal from Rhine to Danube
       a. depth is controlled by what I could find about the Upper Rhine, which is apparently quite wide but darn shallow along Bavaria's stretch- 4.5 feet or so. Current is apparently as fast as 6knots, so cruise speed has been set at 8.

2. have small enough dimensions to travel as a wide load on a railroad flat car.
       a. Not to sure about European rail freight standards in 1916.  Currently, flatcars used for conversion to bridges are up to 87 feet long, and 8 feet wide (oversized loads would extend past), bearing ~ 60 tons.
       b. If I can manage a monitor transportable by rail, there are all sorts of places I can move them.

3. use an army howitzer as the main gun.
       a. the howitzer in question is the 1904 French Remailho QF 155mm.
       b. the field gun and mount came to 3.3 tons, while the 96mm used came to 3.37tons.

So here is the first effort :
Quote
Bang, Bavaria River Monitor laid down 1916 (Engine 1912)

Displacement:
   51 t light; 60 t standard; 61 t normal; 62 t full load

Dimensions: Length overall / water x beam x draught
   68.90 ft / 65.62 ft x 11.81 ft x 3.94 ft (normal load)
   21.00 m / 20.00 m x 3.60 m  x 1.20 m

Armament:
      1 - 3.78" / 96.0 mm guns in single mounts, 94.58lbs / 42.90kg shells, 1916 Model
     Quick firing gun in deck mount
     on centreline forward
     Main guns limited to end-on fire
      4 - 0.31" / 8.0 mm guns in single mounts, 0.02lbs / 0.01kg shells, 1916 Model
     Breech loading guns in deck mounts
     on side, all amidships
   Weight of broadside 95 lbs / 43 kg
   Shells per gun, main battery: 150

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   0.39" / 10 mm     51.18 ft / 15.60 m   7.58 ft / 2.31 m
   Ends:   Unarmoured
     Main Belt covers 120 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.79" / 20 mm   0.39" / 10 mm            -
   2nd:   0.39" / 10 mm         -               -

   - Armour deck: 0.31" / 8 mm, Conning tower: 0.79" / 20 mm

Machinery:
   Diesel Internal combustion generators,
   Electric motors, 2 shafts, 119 shp / 89 Kw = 10.50 kts
   Range 400nm at 8.00 kts
   Bunker at max displacement = 2 tons

Complement:
   10 - 14

Cost:
   £0.009 million / $0.035 million

Distribution of weights at normal displacement:
   Armament: 3 tons, 5.5 %
   Armour: 12 tons, 19.7 %
      - Belts: 7 tons, 10.7 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 2 tons, 2.7 %
      - Armour Deck: 4 tons, 5.9 %
      - Conning Tower: 0 tons, 0.4 %
   Machinery: 5 tons, 7.8 %
   Hull, fittings & equipment: 30 tons, 49.8 %
   Fuel, ammunition & stores: 10 tons, 17.1 %
   Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     110 lbs / 50 Kg = 4.1 x 3.8 " / 96 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.12
   Metacentric height 0.3 ft / 0.1 m
   Roll period: 9.9 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 2.74
   Seaboat quality  (Average = 1.00): 1.69

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.700
   Length to Beam Ratio: 5.56 : 1
   'Natural speed' for length: 8.10 kts
   Power going to wave formation at top speed: 65 %
   Trim (Max stability = 0, Max steadiness = 100): 42
   Bow angle (Positive = bow angles forward): -12.00 degrees
   Stern overhang: 3.28 ft / 1.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      8.20 ft / 2.50 m
      - Forecastle (20 %):   5.74 ft / 1.75 m
      - Mid (50 %):      5.74 ft / 1.75 m
      - Quarterdeck (15 %):   5.74 ft / 1.75 m
      - Stern:      5.74 ft / 1.75 m
      - Average freeboard:   5.94 ft / 1.81 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 78.5 %
      - Above water (accommodation/working, high = better): 67.9 %
   Waterplane Area: 621 Square feet or 58 Square metres
   Displacement factor (Displacement / loading): 126 %
   Structure weight / hull surface area: 25 lbs/sq ft or 120 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.78
      - Longitudinal: 15.55
      - Overall: 1.06
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is cramped
   Ship has slow, easy roll, a good, steady gun platform
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Main Battery Shell weight too heavy

This is meant to be a riverine gunboat.
The dimensions allow passage in the Lugwig Canal from the Rhine to Danube.
Additionally, the dimensions have been restrained so they can be a wide load on a flatcar and be transported by rail.

The gun is actually a 155mm Remailho QF howitzer.  The Remailho + carraige weighed 3.3 tons., the 96mm gun weights 3.37 tons. Hence the shell weight.
As the Remailho was capable of 15 rpm, 10 minutes fire is carried.
Elevation of the Remailho was +41 and range was 6000yds.

Armor is meant to stop MGs, with the belt extending from freeboard to below water, and the armor deck meeting the top of the belt, at essentially weather deck level.  The freeboard+draft only give 1 deck level below anyhow. 
Did they beat the drum slowly,
Did they play the fife lowly,
Did they sound the death march, as they lowered you down,
Did the band play the last post and chorus,
Did the pipes play the flowers of the forest

maddox

Hmm, that forces me to anticipate. 

But I like the reasoning behind it.

The Rock Doctor

I like the idea and the reasoning around your constraints.

Your operating range seems short to me, particularly if you're attempting to steam upriver against that six knot current.

Walter

Well, as long as it sticks to friendly shores of rivers, it should not be a problem. There would probably be some refueling points along the way.

maddox

2 tons of diesel fuel= 2352 Liters of fuel.  Easely transported, even with a horse drawn carriage.

The Rock Doctor