Egyptian Design Studies 1912-1913

[ciders]

I don't know, I don't found any reliable informations about the Nil's depth. And I must consider the modern informations with caution. In 1918, the Nile is always a savage river.

But I think that 3 meters are a good draught. This ship is conceived to go from Aswan to Cairo ( 900 km ).

[Sachmle]

Under gunned, even for riverine duty. Too slow for DD rules (15kts), to weak for normal rules:
        Hull strength (Relative):
      - Cross-sectional: 0,73
      - Longitudinal: 1,61
      - Overall: 0,79

[Kaiser Kirk]

I did some poking about without great luck, as I have
a limited appetite for Nile research.

At this time frame the Assiut Barrage and Old Aswan dam were historically already built by the British, and the channel cut through the Sudd to allow navigation in Sudan to Omdurman. I presume Navalism echos that.

According to a site on river cruises, the maximum draft of current vessels is 1.5m.   http://www.cruisecritic.com/ports/article.cfm?ID=168

According to Wiki, the Assiut barrage has a lock 262.5 ft (80.0m) long and 52.8 ft (16.1m) wide " capable of passing the largest Nile cargo ships and barges"

I tried to find the lock dimensions for the Old Aswan dam, but other than that there was a 32m elevation difference and 5 locks, no idea.
http://books.google.com/books?id=cwuydax9e4AC&pg=PA600&lpg=PA600&dq=Nile+Navigation+draft+limits&source=bl&ots=JBZFla9RDQ&sig=JBydHq1PrGW4AsmVkSuPGi11G-o&hl=en&ei=MBafSqWTC4SqswOQm534Dw&sa=X&oi=book_result&ct=result&resnum=4#v=onepage&q=&f=false

[ciders]

1.5 m ? For the first river of the world ? ???

So, I must reduce the draft. If you have an idea for a transport ship, I listen.  :)

[Kaiser Kirk]

I'm sure it varies with flows and the subsurface strata, but that also represents the shallowest points, not the average or deepest. Still, since the Nile is not central to what I do, I didn't spend too much time looking.

Similarly,  I haven't come up with a Danube depth by Passau yet and I was annoyed to find similar depths for my section of the Rhine, 1000 ft wide and 4.5 feet deep near Strassbourg,  So much for the dream of US Civil war style ironclads.

Still, between the draft and the lock dimensions, you can field small monitors along the river. I think the Rhine river monitor with a 6" howitzer I recently posted would work, as would more armored versions with a 3-4" how.  This would both control riverine traffic and make it difficult for potential foes to camp on, or anchor a flank on, the Nile.

[ciders]

Egypt have yet 8 gunboats. The two most modern are bigger than the others : 2 m and 3.50 m of draft. But, for now, I think monitors are not a priority.

Egyptian territory is... large. 900 km bewteen Cairo and Aswan, 1200 km between Khartoum and Port-Sudan... and no railways. But I have the Nile. And six cataracts ( actually, the ships can go to the south of Aswan, at the second cataract, but no more after without transshipment )... If I can transport some thousands troops between Cairo and Aswan, and some guns and artillery, I would be relieved.

So, I'm trying to modify my ship, reduce the draft and increase the power of fire.

[The Rock Doctor]

The Colombian Condor class might offer inspiration.  They have 1.25 m draft, and function primarily as transports.

http://www.navalism.org/index.php?topic=52.msg17763#msg17763

[ciders]

Another try :

...

Courrier du Nil, Egypt River Auxiliary Ship laid down 1918 (Engine 1905)

Displacement:
   1 028 t light; 1 053 t standard; 1 165 t normal; 1 255 t full load

Dimensions: Length overall / water x beam x draught
   229,66 ft / 229,66 ft x 65,62 ft x 4,92 ft (normal load)
   70,00 m / 70,00 m x 20,00 m  x 1,50 m

Armament:
      1 - 3,00" / 76,2 mm guns in single mounts, 13,50lbs / 6,12kg shells, 1905 Model
     Breech loading gun in deck mount
     on centreline forward
      4 - 0,50" / 12,7 mm guns in single mounts, 0,06lbs / 0,03kg shells, 1905 Model
     Breech loading guns in deck mounts
     on side, evenly spread
   Weight of broadside 14 lbs / 6 kg
   Shells per gun, main battery: 150

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   0,98" / 25 mm   147,64 ft / 45,00 m   9,02 ft / 2,75 m
   Ends:   0,98" / 25 mm     82,02 ft / 25,00 m   9,02 ft / 2,75 m
   Upper:   0,98" / 25 mm     82,02 ft / 25,00 m   7,38 ft / 2,25 m
     Main Belt covers 99 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0,98" / 25 mm         -               -
   2nd:   0,39" / 10 mm         -               -

   - Armour deck: 0,39" / 10 mm

Machinery:
   Coal fired boilers, steam turbines,
   Direct drive, 2 shafts, 2 160 shp / 1 611 Kw = 15,00 kts
   Range 2 000nm at 10,00 kts
   Bunker at max displacement = 202 tons (100% coal)

Complement:
   99 - 129

Cost:
   £0,125 million / $0,501 million

Distribution of weights at normal displacement:
   Armament: 2 tons, 0,1 %
   Armour: 203 tons, 17,4 %
      - Belts: 124 tons, 10,7 %
      - Torpedo bulkhead: 0 tons, 0,0 %
      - Armament: 2 tons, 0,2 %
      - Armour Deck: 77 tons, 6,6 %
      - Conning Tower: 0 tons, 0,0 %
   Machinery: 180 tons, 15,4 %
   Hull, fittings & equipment: 294 tons, 25,2 %
   Fuel, ammunition & stores: 137 tons, 11,7 %
   Miscellaneous weights: 350 tons, 30,0 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1 762 lbs / 799 Kg = 130,5 x 3,0 " / 76 mm shells or 1,2 torpedoes
   Stability (Unstable if below 1.00): 1,85
   Metacentric height 7,2 ft / 2,2 m
   Roll period: 10,3 seconds
   Steadiness   - As gun platform (Average = 50 %): 65 %
         - Recoil effect (Restricted arc if above 1.00): 0,00
   Seaboat quality  (Average = 1.00): 1,31

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0,550
   Length to Beam Ratio: 3,50 : 1
   'Natural speed' for length: 15,15 kts
   Power going to wave formation at top speed: 45 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   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:      16,67 ft / 5,08 m
      - Forecastle (20 %):   10,60 ft / 3,23 m
      - Mid (50 %):      10,60 ft / 3,23 m
      - Quarterdeck (15 %):   10,60 ft / 3,23 m
      - Stern:      10,60 ft / 3,23 m
      - Average freeboard:   11,08 ft / 3,38 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 84,5 %
      - Above water (accommodation/working, high = better): 214,4 %
   Waterplane Area: 10 517 Square feet or 977 Square metres
   Displacement factor (Displacement / loading): 126 %
   Structure weight / hull surface area: 26 lbs/sq ft or 125 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,47
      - Longitudinal: 0,97
      - Overall: 0,50
   Caution: Hull subject to strain in open-sea
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is excellent
   Good seaboat, rides out heavy weather easily

[ctwaterman]

You might also look to make a few Dredges to patrol the Nile all the way to Aswan,  they can dredge up the Silt and pump it onto flat barges and sell it to farmers or simply dontate it to farmers not found directly on the flood plain.   

It would increase productivity of Farms and allow easier navigation of the Nile.

Charles

[ciders]

Good idea. But you know how create a dredge with Springsharp ?  :-[

[ctwaterman]

No But Im sure I can fake it....

A 500 Ton or so boat with lot of Misc Tonage for the Dredges and mayb 5 knots hmm.... lets give it a try.

Charles

[ctwaterman]

http://www.globalsecurity.org/military/systems/ship/dredge-dustpan-specs.htm
The Dredges shown here were built in 1932 & 33 and were repowered several times during their life time they are used on the Mississippi river by the US Army Corp of Engineer.

More realistically a simple Clam Shell Dredge would be used lower it into the water grab a handful of Sand and or Silt lift it out by a Crain and dump it on a barge.  Slow but steady.

Below is a crude approximation of a Dredge for the Nile River

Nile Dredge, Egypt Dredge laid down 1917 (Engine 1902)

Displacement:
   404 t light; 413 t standard; 416 t normal; 418 t full load

Dimensions: Length overall / water x beam x draught
   120.00 ft / 120.00 ft x 40.00 ft x 6.00 ft (normal load)
   36.58 m / 36.58 m x 12.19 m  x 1.83 m

Machinery:
   Coal fired boilers, simple reciprocating steam engines,
   Direct drive, 2 shafts, 259 ihp / 193 Kw = 10.00 kts
   Range 200nm at 5.00 kts
   Bunker at max displacement = 5 tons (100% coal)

Complement:
   45 - 59

Cost:
   £0.037 million / $0.149 million

Distribution of weights at normal displacement:
   Armament: 0 tons, 0.0 %
   Machinery: 45 tons, 10.8 %
   Hull, fittings & equipment: 109 tons, 26.3 %
   Fuel, ammunition & stores: 11 tons, 2.7 %
   Miscellaneous weights: 250 tons, 60.2 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     414 lbs / 188 Kg = 3.8 x 6 " / 152 mm shells or 0.5 torpedoes
   Stability (Unstable if below 1.00): 1.26
   Metacentric height 1.9 ft / 0.6 m
   Roll period: 12.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 48 %
         - Recoil effect (Restricted arc if above 1.00): 0.00
   Seaboat quality  (Average = 1.00): 0.91

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.505
   Length to Beam Ratio: 3.00 : 1
   'Natural speed' for length: 10.95 kts
   Power going to wave formation at top speed: 48 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   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:      5.05 ft / 1.54 m
      - Forecastle (80 %):   3.67 ft / 1.12 m
      - Mid (0 %):      3.67 ft / 1.12 m
      - Quarterdeck (20 %):   3.67 ft / 1.12 m
      - Stern:      3.67 ft / 1.12 m
      - Average freeboard:   4.11 ft / 1.25 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 100.7 %
      - Above water (accommodation/working, high = better): 49.9 %
   Waterplane Area: 3,213 Square feet or 298 Square metres
   Displacement factor (Displacement / loading): 122 %
   Structure weight / hull surface area: 31 lbs/sq ft or 152 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.95
      - Longitudinal: 1.59
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is extremely poor
   Poor seaboat, wet and uncomfortable, reduced performance in heavy weather

250T Clam Shell Crane and Dredge.

[The Rock Doctor]

Would the dredge be under steam the whole time - remaining stationary against river current - or would it anchor, dig, move, and anchor again?

If the former, I think the range might need an increase.

[ctwaterman]

Nope Anchor, and then when Coal is low simply have one of the Barges come back loaded with coal in 50 Lb bags and have the crew load them before filling the Barge with Silt.

Charles