WesWorld

Here's a shallow-draft little thing that might get a couple of platoons of troops close to the beach, and give them a bit of fire support while its there. Is this too much displacement for about 80 troops?

Krokodil, Russia Large Amphibious assault ship laid down 1926

Displacement:
467 t light; 481 t standard; 518 t normal; 547 t full load

Dimensions: Length overall / water x beam x draught
196.85 ft / 196.85 ft x 31.17 ft x 3.94 ft (normal load)
60.00 m / 60.00 m x 9.50 m x 1.20 m

Armament:
1 - 3.94" / 100 mm guns in single mounts, 30.51lbs / 13.84kg shells, 1926 Model
Breech loading gun in deck mount
on centreline forward
6 - 1.46" / 37.0 mm guns (3x2 guns), 1.55lbs / 0.70kg shells, 1926 Model
Breech loading guns in deck mounts
on centreline, evenly spread, all raised mounts
12 - 0.30" / 7.6 mm guns in single mounts, 0.01lbs / 0.01kg shells, 1926 Model
Breech loading guns in casemate mounts
on side, evenly spread, 4 raised mounts
8 guns in hull casemates - Limited use in any sea
Weight of broadside 40 lbs / 18 kg
Shells per gun, main battery: 150

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 0.98" / 25 mm 196.85 ft / 60.00 m 6.56 ft / 2.00 m
Ends: Unarmoured
Upper: 0.98" / 25 mm 131.23 ft / 40.00 m 4.27 ft / 1.30 m
Main Belt covers 154 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.98" / 25 mm - -
2nd: 0.98" / 25 mm - -
3rd: 0.98" / 25 mm - -

- Armour deck: 0.39" / 10 mm, Conning tower: 1.18" / 30 mm

Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 1,015 shp / 757 Kw = 14.00 kts
Range 2,000nm at 12.00 kts (Bunkerage = 66 tons)

Complement:
53 - 70

Cost:
£0.087 million / $0.347 million

Distribution of weights at normal displacement:
Armament: 5 tons, 1.0 %
Armour: 117 tons, 22.6 %
- Belts: 71 tons, 13.8 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 6 tons, 1.2 %
- Armour Deck: 37 tons, 7.2 %
- Conning Tower: 2 tons, 0.3 %
Machinery: 32 tons, 6.3 %
Hull, fittings & equipment: 203 tons, 39.2 %
Fuel, ammunition & stores: 51 tons, 9.8 %
Miscellaneous weights: 110 tons, 21.3 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,670 lbs / 757 Kg = 54.7 x 3.9 " / 100 mm shells or 1.2 torpedoes
Stability (Unstable if below 1.00): 1.28
Metacentric height 1.4 ft / 0.4 m
Roll period: 11.2 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.04
Seaboat quality (Average = 1.00): 1.08

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.750
Length to Beam Ratio: 6.32 : 1
'Natural speed' for length: 14.03 kts
Power going to wave formation at top speed: 45 %
Trim (Max stability = 0, Max steadiness = 100): 65
Bow angle (Positive = bow angles forward): 0.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 6.96 ft / 2.12 m
- Forecastle (20 %): 6.96 ft / 2.12 m
- Mid (50 %): 6.96 ft / 2.12 m
- Quarterdeck (15 %): 6.96 ft / 2.12 m
- Stern: 6.96 ft / 2.12 m
- Average freeboard: 6.96 ft / 2.12 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 52.1 %
- Above water (accommodation/working, high = better): 128.4 %
Waterplane Area: 5,139 Square feet or 477 Square metres
Displacement factor (Displacement / loading): 156 %
Structure weight / hull surface area: 33 lbs/sq ft or 161 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.00
- Longitudinal: 1.01
- 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

Suggest changing the type of the 37mm and 0.30" guns from breech loading to anti-air ang machine gun, respectively

Looks good for a landing craft as used in WW2. I just wonder if you aren´t ahead of times with such a design in the mid-20s? IIRC, amphebious operations where more like sail-to-a-coast-with-a-large-ship-lower-many-small-boats-and-row-to-the-shore b ut I could be wrong. Technically it´s not a problem to build landing craft as you propose.

The Russians built landingcraft in WW1. The RN built 'X' and 'Y-lighters' too.

Cheers,

Before landing, the troops are held in the section protected by the upper belt armor, and when she runs aground, they come up and jump over the side. There's nothing so complicated as a ramp on her. She was developed from analysis of Gallipoli, where the use of ship's boats and other mechansms are seen as being too complicated to really work in such difficult situations as an opposed landing.

The 37mm aren't really intended for air defense. They're intended to take out machinegun nests and other light defensive emplacements. The 100mm is for destroying slightly bigger defensive emplacements. But thanks for the suggestion on the machineguns.