Urban Designs

[eltf177]

For a ship this small the hoist would be simple, either a small elevator handing one shell at a time taking it from the magazine up to the deck or maybe some sort of block and tackle.

[Urban]

For a ship this small the hoist would be simple, either a small elevator handing one shell at a time taking it from the magazine up to the deck or maybe some sort of block and tackle.

That's very good to know, thank you! :)

I'd done some springsharp wrangling- I've dropped the main guns to 5.5" 40 cal ones, and added the hoists in order to keep a reasonable rate of fire up. To achieve the hoists 1 knot of top speed had to be sacrificed. Removing the hoists could allow the 14kt speed to be retained, but I think I'm happy with the slight speed reduction in order to get the ship closer fulfilling it's intended purpose a bit better.


RGB01,  River Gunboat laid down 1915

Displacement:
   531 t light; 559 t standard; 600 t normal; 632 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (220.00 ft / 220.00 ft) x 36.00 ft x (4.50 / 4.70 ft)
   (67.06 m / 67.06 m) x 10.97 m  x (1.37 / 1.43 m)

Armament:
      2 - 5.50" / 140 mm 40.0 cal guns - 79.73lbs / 36.16kg shells, 150 per gun
     Breech loading guns in deck and hoist mounts, 1915 Model
     1 x Single mount on centreline, forward deck centre
     1 x Single mount on centreline, aft deck centre
      2 - 3.00" / 76.2 mm 40.0 cal guns - 12.94lbs / 5.87kg shells, 175 per gun
     Quick firing guns in deck mounts, 1915 Model
     1 x Single mount on centreline, forward deck centre
      1 raised mount
     1 x Single mount on centreline, aft deck centre
      1 raised mount
      4 - 0.30" / 7.6 mm 80.0 cal guns - 0.02lbs / 0.01kg shells, 2,000 per gun
     Machine guns in deck mounts, 1915 Model
     4 x Single mounts on sides, evenly spread
      4 raised mounts
      Weight of broadside 185 lbs / 84 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   1.00" / 25 mm   143.50 ft / 43.74 m   2.10 ft / 0.64 m
   Ends:   0.45" / 11 mm     76.50 ft / 23.32 m   5.30 ft / 1.62 m
   Upper:   1.00" / 25 mm   220.00 ft / 67.06 m   4.20 ft / 1.28 m
     Main Belt covers 100 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1.00" / 25 mm   0.45" / 11 mm            -
   2nd:   0.45" / 11 mm         -               -

   - Armoured deck - single deck:
   For and Aft decks: 0.45" / 11 mm
   Forecastle: 0.37" / 9 mm  Quarter deck: 0.37" / 9 mm

   - Conning towers: Forward 1.00" / 25 mm, Aft 0.45" / 11 mm

Machinery:
   Oil fired boilers, complex reciprocating steam engines,
   Direct drive, 2 shafts, 765 ihp / 571 Kw = 13.00 kts
   Range 2,300nm at 10.00 kts
   Bunker at max displacement = 73 tons

Complement:
   59 - 78

Cost:
   £0.058 million / $0.231 million

Distribution of weights at normal displacement:
   Armament: 42 tons, 7.1 %
      - Guns: 42 tons, 7.1 %
   Armour: 111 tons, 18.5 %
      - Belts: 54 tons, 9.0 %
      - Armament: 9 tons, 1.6 %
      - Armour Deck: 45 tons, 7.5 %
      - Conning Towers: 2 tons, 0.4 %
   Machinery: 46 tons, 7.6 %
   Hull, fittings & equipment: 327 tons, 54.6 %
   Fuel, ammunition & stores: 68 tons, 11.4 %
   Miscellaneous weights: 5 tons, 0.8 %
      - Above deck: 5 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1,582 lbs / 718 Kg = 19.0 x 5.5 " / 140 mm shells or 1.4 torpedoes
   Stability (Unstable if below 1.00): 1.21
   Metacentric height 1.5 ft / 0.5 m
   Roll period: 12.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.15
   Seaboat quality  (Average = 1.00): 0.73

Hull form characteristics:
   Hull has raised forecastle,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.589 / 0.595
   Length to Beam Ratio: 6.11 : 1
   'Natural speed' for length: 14.83 kts
   Power going to wave formation at top speed: 36 %
   Trim (Max stability = 0, Max steadiness = 100): 96
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00 %,  6.50 ft / 1.98 m,  6.50 ft / 1.98 m
      - Forward deck:   30.00 %,  5.00 ft / 1.52 m,  5.00 ft / 1.52 m
      - Aft deck:   20.00 %,  5.00 ft / 1.52 m,  5.00 ft / 1.52 m
      - Quarter deck:   30.00 %,  5.00 ft / 1.52 m,  5.00 ft / 1.52 m
      - Average freeboard:      5.30 ft / 1.62 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 49.1 %
      - Above water (accommodation/working, high = better): 92.5 %
   Waterplane Area: 5,733 Square feet or 533 Square metres
   Displacement factor (Displacement / loading): 173 %
   Structure weight / hull surface area: 55 lbs/sq ft or 267 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 1.24
      - Longitudinal: 0.93
      - Overall: 1.00
   Excellent machinery, storage, compartmentation space
   Adequate accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Poor seaboat, wet and uncomfortable, reduced performance in heavy weather

Misc weights:
-- Above Deck
---- 5t 1915 Fire control for 5.5" guns
---- 0t Short range wireless set (100m range)

[Urban]

Time for something a little different, as an experiment I decided to see how well one of these gunboats could be converted into a tender to support the others on deployments. In the end a whole lot had to be stripped out, including the 5.5" guns and the majority of the armour, while retaining the same speed and the small 3" guns for self defence, though if this thing finds itself in combat something has probably gone rather wrong already. Also managed to fit a long range wireless set, the thought being that since the other gunboats lack long range sets of their own this allows messages to be passed along when they get resupplied. They can supply 2 of the larger river gunboats of the same class, or more lesser vessels.


RGBT01,  River Gunboat Tender laid down 1915

Displacement:
   545 t light; 559 t standard; 600 t normal; 632 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (220.00 ft / 220.00 ft) x 36.00 ft x (4.50 / 4.70 ft)
   (67.06 m / 67.06 m) x 10.97 m  x (1.37 / 1.43 m)

Armament:
      2 - 3.00" / 76.2 mm 40.0 cal guns - 12.94lbs / 5.87kg shells, 175 per gun
     Quick firing guns in deck mounts, 1915 Model
     1 x Single mount on centreline, forward deck centre
      1 raised mount
     1 x Single mount on centreline, aft deck centre
      1 raised mount aft
      4 - 0.30" / 7.6 mm 80.0 cal guns - 0.02lbs / 0.01kg shells, 2,000 per gun
     Machine guns in deck mounts, 1915 Model
     4 x Single mounts on sides, evenly spread
      4 raised mounts
      Weight of broadside 26 lbs / 12 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   0.45" / 11 mm   143.50 ft / 43.74 m   2.10 ft / 0.64 m
   Ends:   Unarmoured
   Upper:   0.45" / 11 mm   220.00 ft / 67.06 m   4.20 ft / 1.28 m
     Main Belt covers 100 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.45" / 11 mm         -               -

   - Conning towers: Forward 0.39" / 10 mm, Aft 0.39" / 10 mm

Machinery:
   Oil fired boilers, complex reciprocating steam engines,
   Direct drive, 2 shafts, 425 ihp / 317 Kw = 11.00 kts
   Range 2,300nm at 10.00 kts
   Bunker at max displacement = 73 tons

Complement:
   59 - 78

Cost:
   £0.035 million / $0.139 million

Distribution of weights at normal displacement:
   Armament: 5 tons, 0.8 %
      - Guns: 5 tons, 0.8 %
   Armour: 24 tons, 4.1 %
      - Belts: 21 tons, 3.6 %
      - Armament: 2 tons, 0.3 %
      - Conning Towers: 1 tons, 0.2 %
   Machinery: 25 tons, 4.2 %
   Hull, fittings & equipment: 310 tons, 51.8 %
   Fuel, ammunition & stores: 55 tons, 9.2 %
   Miscellaneous weights: 180 tons, 30.0 %
      - On freeboard deck: 180 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     4,233 lbs / 1,920 Kg = 313.6 x 3.0 " / 76 mm shells or 4.8 torpedoes
   Stability (Unstable if below 1.00): 1.12
   Metacentric height 1.3 ft / 0.4 m
   Roll period: 13.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0.03
   Seaboat quality  (Average = 1.00): 0.76

Hull form characteristics:
   Hull has raised forecastle,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.589 / 0.595
   Length to Beam Ratio: 6.11 : 1
   'Natural speed' for length: 14.83 kts
   Power going to wave formation at top speed: 28 %
   Trim (Max stability = 0, Max steadiness = 100): 93
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00 %,  6.50 ft / 1.98 m,  6.50 ft / 1.98 m
      - Forward deck:   30.00 %,  5.00 ft / 1.52 m,  5.00 ft / 1.52 m
      - Aft deck:   20.00 %,  5.00 ft / 1.52 m,  5.00 ft / 1.52 m
      - Quarter deck:   30.00 %,  5.00 ft / 1.52 m,  5.00 ft / 1.52 m
      - Average freeboard:      5.30 ft / 1.62 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 17.7 %
      - Above water (accommodation/working, high = better): 92.5 %
   Waterplane Area: 5,733 Square feet or 533 Square metres
   Displacement factor (Displacement / loading): 225 %
   Structure weight / hull surface area: 49 lbs/sq ft or 238 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 1.48
      - Longitudinal: 0.88
      - Overall: 1.00
   Excellent machinery, storage, compartmentation space
   Adequate accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Poor seaboat, wet and uncomfortable, reduced performance in heavy weather

Misc weights:
-- Above Deck
---- 0t Short range wireless set (100m range)
-- On deck
---- 100t - 1000t of resupply capacity
-- Hull above water
----80t - 800t of resupply capacity

(1800t total of resupply capacity)


I'm not sure these stripped down vessels would be a particularly good use of resources when other shallow draft cargo ships are probably available but they were fun to mess around with at least! Managed to finish the drawing for the main riverboat (appended to previous post) and also did one of these tenders too for fun. :D

[Jefgte]

Interesting ship with the possibility of taking marines or explorers.

[Urban]

Slowly working my way up tonnage wise, this time a fairly heavily armed fleet destroyer, the sacrifice being any additional utility in the form of ASW or minesweeping capability.


DD18-1,  Destroyer laid down 1918

Displacement:
   1,000 t light; 1,055 t standard; 1,200 t normal; 1,316 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (328.00 ft / 322.00 ft) x 27.50 ft x (11.00 / 11.73 ft)
   (99.97 m / 98.15 m) x 8.38 m  x (3.35 / 3.58 m)

Armament:
      5 - 5.00" / 127 mm 45.0 cal guns - 63.03lbs / 28.59kg shells, 140 per gun
     Quick firing guns in deck mounts, 1918 Model
     4 x Single mounts on centreline ends, evenly spread
      2 raised mounts - superfiring
     1 x Single mount on centreline, aft deck forward
      2 - 3.00" / 76.2 mm 45.0 cal guns - 13.62lbs / 6.18kg shells, 400 per gun
     Anti-air guns in deck mounts, 1918 Model
     2 x Single mounts on sides, forward deck aft
      2 raised mounts
      Weight of broadside 342 lbs / 155 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.45" / 11 mm         -               -
   2nd:   0.39" / 10 mm         -               -

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 24,768 shp / 18,477 Kw = 31.00 kts
   Range 3,900nm at 14.00 kts
   Bunker at max displacement = 261 tons

Complement:
   101 - 132

Cost:
   £0.272 million / $1.089 million

Distribution of weights at normal displacement:
   Armament: 60 tons, 5.0 %
      - Guns: 60 tons, 5.0 %
   Armour: 6 tons, 0.5 %
      - Armament: 6 tons, 0.5 %
   Machinery: 605 tons, 50.4 %
   Hull, fittings & equipment: 274 tons, 22.8 %
   Fuel, ammunition & stores: 200 tons, 16.7 %
   Miscellaneous weights: 55 tons, 4.6 %
      - On freeboard deck: 24 tons
      - Above deck: 31 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     263 lbs / 119 Kg = 4.2 x 5.0 " / 127 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.13
   Metacentric height 0.9 ft / 0.3 m
   Roll period: 12.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 67 %
         - Recoil effect (Restricted arc if above 1.00): 0.65
   Seaboat quality  (Average = 1.00): 1.01

Hull form characteristics:
   Hull has raised forecastle,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.431 / 0.443
   Length to Beam Ratio: 11.71 : 1
   'Natural speed' for length: 17.94 kts
   Power going to wave formation at top speed: 64 %
   Trim (Max stability = 0, Max steadiness = 100): 66
   Bow angle (Positive = bow angles forward): 10.00 degrees
   Stern overhang: 3.00 ft / 0.91 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   30.00 %,  17.00 ft / 5.18 m,  16.00 ft / 4.88 m
      - Forward deck:   30.00 %,  10.00 ft / 3.05 m,  10.00 ft / 3.05 m
      - Aft deck:   25.00 %,  10.00 ft / 3.05 m,  10.00 ft / 3.05 m
      - Quarter deck:   15.00 %,  10.00 ft / 3.05 m,  10.00 ft / 3.05 m
      - Average freeboard:      11.92 ft / 3.63 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 176.8 %
      - Above water (accommodation/working, high = better): 105.0 %
   Waterplane Area: 5,565 Square feet or 517 Square metres
   Displacement factor (Displacement / loading): 60 %
   Structure weight / hull surface area: 28 lbs/sq ft or 135 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.47
      - Overall: 0.55
   Cramped machinery, storage, compartmentation space
   Adequate accommodation and workspace room

Misc weights:
-- Above deck
---- 6t Fire control system (1918)
---- 0t Short range wireless set (100m)
---- 25t Long range wireless set (250+)
-- On deck
---- 24t - 6 (2x3) 21" inch torpedoes mounted on the centreline (No reloads, 4t torps)

Trial speed: 32kts



Also I forgot to offer this before, if anyone would like a small vessel "memorialised" in the style of my previous drawings just let me know! My drawing time is usually during work meetings that don't require my full attention (of which I have many) so it doesn't affect my time doing other stuff much. I'm going to concentrate on working on bigger ships in SS at the moment and so I'd be happy to work on some smaller drawings for others as I don't feel up to drawing bigger stuff just yet... ;)

[The Rock Doctor]

Note that you've got five main guns but only four single mounts for them...

[Desertfox]

I might take you up on the drawings, would be nice to see mine in a bigger more detailed scale. Perhaps the Toph Marus would be a good starting point.

Rocky, the fifth gun is there, its just on aft deck forward instead of ends.

[Urban]

Yep, 4 guns on the ends- 2 fore and 2 aft, and 1 roughly amidships!

And sure, shoot me a message with all the info on the Toph Marus you think is relevant and I'll get back to you tomorrow as it's rather late here. ;)

[The Rock Doctor]

D'oh!

[TacCovert4]

I've got one I'd like to see in a larger scale as well.  More of a light cruiser if you think you're up to it.  The jaguar class currently in construction. 6000t.  Has one or two interesting design points. 

[eltf177]

For the DD you might want to consider mount and hoist, those 5-inch shells get heavy in a hurry...

[TacCovert4]

For the DD you might want to consider mount and hoist, those 5-inch shells get heavy in a hurry...

From personal experience, a 120mm gets really heavy on mile 2 of the run.

[Urban]

Thanks for your comments all: hoists were considered from the start, however very early on they were found to have extreme deleterious effects on stability, seakeeping and recoil to the point that they were nixed from the design equally early! While they would be very nice to have from a rate of fire point of view, the design headaches they brought on a ship this size were judged not to be worth the potential benefits. But larger, future ships... Who knows? Might attempt another destroyer today and make hoists an absolute requirement and see what happens.

I've got one I'd like to see in a larger scale as well.  More of a light cruiser if you think you're up to it.  The jaguar class currently in construction. 6000t.  Has one or two interesting design points. 

Sure, 6000t is a fair bit bigger than anything I have experience with so far but I'm willing to give it a shot! I've found the design in the thread, send me a message with anything specific you want the design to have like quirks, historical inspiration and colour scheme and what have you- we can discuss from there!

[eltf177]

I have also noted the huge effects mount and hoist vs. mount has on small ships.

Don't completely understand it but them's the breaks on smaller vessels...

[TacCovert4]

I suspect the stability effects are because of the weight of the hoist distributed throughout the above-water portion of the ship all the way to the mount location.  And that the mount itself will be on a rotating plate rather than a pintle, so the mount itself has to be beefier and more complex to include the hoist mechanism.