WesWorld

go about designing a floating drydock??

Thoughts please!

With difficulty.

1. Decide how large the ship are that you want to dock so that you don't place the ends of long ones under unnecessary strain.

2. How heavy are the ships that you want to lift?

3. How heavy does the drydock need to be to hold the above load.

4. Total weight is 2+3

CG,

Very large floating drydocs are modular in design. There are a number of pieces, they are towed to the site and there the dock is assembled. More pieces maybe added if larger ships are to be accomodated.

Here's a pic of West Virginia in a floating drydock:



You'll note the craft alongside, probably holding machine shops, berthing, stores, etc for the dock, and the cranes. They're a part of the dock and added as the dock assembled. Also, not the shape of the sections, to make moving them easier.

I'd say you'd have to sim some kind of power plant into the dock to provide power for the accessories, pumps and ship(s) in dock.

I think RA has a good forumula for the dock's capability. I'm not sure how you'd simulate the ability to submerge and lift though beyond miscellaneous weight. Or perhaps as a torpedo bulkhead, to ge the weight lower in the design.

You can see a lot more of ABSD-1 here:

http://www.navsource.org/archives/09/2801.htm

Regards,
Big Rich

Pics don't show up Rich!

Odd, for me it does. The link doesn't work, though.

As with Hrolf, the pic is working for me.

The link to Navsource isn't right now; I keep getting a network error...

Wikipedia has a pretty good article here on the drydock shown in the picture, including displacement of 10 sections of the dock (38,500 tons). There's also a link on that page to the navsource site, which IS working now and gives segment length, beam, and draft.


Ah, I've figured out the problem with the "link" previously shown: it's not really a link.

Thanks Hrolf. The link in the body of my first post is corrected.

The Wikipedia article is essentially the same information as the Navsource site...

Regards,

Something like this capable of lifting a 40,000tons (deep load) ship. Should probably add at least 1000tons for machinery, lifting stuff, floatation systems...


Dry Dock, laid down 1932

Displacement:
58,678 t light; 59,876 t standard; 59,876 t normal; 59,876 t full load

Dimensions: Length overall / water x beam x draught
853.02 ft / 853.02 ft x 131.23 ft x 19.69 ft (normal load)
260.00 m / 260.00 m x 40.00 m x 6.00 m

Machinery:
Immobile floating battery

Complement:
1,913 - 2,488

Cost:
£9.335 million / $37.341 million

Distribution of weights at normal displacement:
Armament: 0 tons, 0.0 %
Machinery: 0 tons, 0.0 %
Hull, fittings & equipment: 18,678 tons, 31.2 %
Fuel, ammunition & stores: 1,198 tons, 2.0 %
Miscellaneous weights: 40,000 tons, 66.8 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
117,926 lbs / 53,490 Kg = 1,091.9 x 6 " / 152 mm shells or 6.3 torpedoes
Stability (Unstable if below 1.00): 1.09
Metacentric height 8.9 ft / 2.7 m
Roll period: 18.4 seconds
Steadiness - As gun platform (Average = 50 %): 81 %
- Recoil effect (Restricted arc if above 1.00): 0.00
Seaboat quality (Average = 1.00): 1.62

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.951
Length to Beam Ratio: 6.50 : 1
'Natural speed' for length: 29.21 kts
Power going to wave formation at top speed: 0 %
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: 32.81 ft / 10.00 m
- Forecastle (20 %): 32.81 ft / 10.00 m
- Mid (50 %): 32.81 ft / 10.00 m
- Quarterdeck (15 %): 32.81 ft / 10.00 m
- Stern: 32.81 ft / 10.00 m
- Average freeboard: 32.81 ft / 10.00 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 73.2 %
- Above water (accommodation/working, high = better): 368.5 %
Waterplane Area: 112,807 Square feet or 10,480 Square metres
Displacement factor (Displacement / loading): 150 %
Structure weight / hull surface area: 138 lbs/sq ft or 672 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.00
- Longitudinal: 1.00
- 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
Excellent seaboat, comfortable, rides out heavy weather easily