1930s Mercantile Marine vessels

[Kaiser Kirk]

A very long time ago, I researched and posted a version of the 'Hog Island' WWI freighter.

In my personal concept, there are likely only a few passenger liners in existence.  without the huge industrial economy and immigrant flow of the United States, the historical ocean liners probably do not exist in the same numbers. I expect there are some, giving fast, luxurious and expensive travel options for those that can afford it.

Historically there were 'cargo liners' which were slower and carried some passengers and mostly freight. It appears passenger numbers were limited to 12 due to a British rule on the threshold for requiring a doctor on board. There is no reason for that rule to exist here, so they could easily carry more. These could also be the 'tramp' steamers.


For Wars, I figure there are 3 general size classes - small coastal, 'cargo-liner' like these, and 'big freighter/tanker'. It takes 20-30 such vessels to make a 'Deployment point' sufficient to move a Land Point, aka a BP. So losses in commerce raiding get scaled against that. All colonial IC/BP have to make it to the homeland, which dictates the amount of traffic on the routes, About 10%-20% of homeland IC/BP is dependent on overseas trade to NPCs/PCs. All of which I try to pencil out when figuring out the ship traffic, which effects the ability of raiders to find them.


I have long wanted to find a follow up design to the Hog Island, and I want to investigate Q-ships off that basis, so I looked for a 'modern' steamship.

I found the Marwarri, given as an example of a modern steamship and completed in 1935 as a cargo liner.

www.shippingwondersoftheworld.com/marwarri.html

www.uboat.net/allies/merchants/56.html


Hull dimensions are given, but instead of draft, the height of the hull. I scaled the draft at roughly 24feet. Based the fore/aft off adding an 8ft deck.

It gave 10,250t, but I don't know if that is light, standard, normal, or Gross (which is volumetric), while the Uboat net gave 8,000. So I made that light.
I could then use the SHP given to find the maximum speed, and set the cruise speed at the 13.5 knots cited.

Range I really had to guess.
Fairly simple to increase the range, and just expand the BC until the tonnage is right again.

There are a bunch of guesses, the question is - does it make a reasonable Cargo-Liner for our purposes ?

If so, then I'll worry about other size classes.

Alternately at the bottom of the shipping wonders page, there are links to 'Canada' which is slightly larger and faster, with 56 passengers.
The 'Klipparen' in the link may be a good model for smaller ships.

Marwarri, Mercantile Marine Frieghter-Liner laid down 1934

Displacement:
    10,250 t light; 10,468 t standard; 10,921 t normal; 11,283 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
    (472.52 ft / 470.00 ft) x 62.75 ft x (24.00 / 24.64 ft)
    (144.02 m / 143.26 m) x 19.13 m  x (7.32 / 7.51 m)

Machinery:
    Oil fired boilers, steam turbines,
    Geared drive, 1 shaft, 5,201 shp / 3,880 Kw = 14.61 kts
    Range 4,130nm at 13.50 kts
    Bunker at max displacement = 815 tons

Complement:
    533 - 694

Cost:
    £1.864 million / $7.456 million

Distribution of weights at normal displacement:
    Armament: 0 tons, 0.0 %
    Machinery: 150 tons, 1.4 %
    Hull, fittings & equipment: 2,345 tons, 21.5 %
    Fuel, ammunition & stores: 671 tons, 6.1 %
    Miscellaneous weights: 7,755 tons, 71.0 %
      - Hull below water: 6,600 tons
      - Hull void weights: 50 tons
      - Hull above water: 750 tons
      - On freeboard deck: 320 tons
      - Above deck: 35 tons

Overall survivability and seakeeping ability:
    Survivability (Non-critical penetrating hits needed to sink ship):
      14,812 lbs / 6,719 Kg = 137.1 x 6 " / 152 mm shells or 2.1 torpedoes
    Stability (Unstable if below 1.00): 1.86
    Metacentric height 6.7 ft / 2.1 m
    Roll period: 10.2 seconds
    Steadiness    - As gun platform (Average = 50 %): 70 %
            - Recoil effect (Restricted arc if above 1.00): 0.00
    Seaboat quality  (Average = 1.00): 1.76

Hull form characteristics:
    Hull has raised forecastle, raised quarterdeck ,
      a normal bow and a cruiser stern
    Block coefficient (normal/deep): 0.540 / 0.543
    Length to Beam Ratio: 7.49 : 1
    'Natural speed' for length: 21.68 kts
    Power going to wave formation at top speed: 28 %
    Trim (Max stability = 0, Max steadiness = 100): 40
    Bow angle (Positive = bow angles forward): 6.00 degrees
    Stern overhang: -5.00 ft / -1.52 m
    Freeboard (% = length of deck as a percentage of waterline length):
                Fore end,    Aft end
      - Forecastle:    24.00 %,  24.00 ft / 7.32 m,  18.75 ft / 5.72 m
      - Forward deck:    30.00 %,  10.75 ft / 3.28 m,  10.75 ft / 3.28 m
      - Aft deck:    31.00 %,  10.75 ft / 3.28 m,  10.75 ft / 3.28 m
      - Quarter deck:    15.00 %,  18.75 ft / 5.72 m,  18.75 ft / 5.72 m
      - Average freeboard:        14.37 ft / 4.38 m

Ship space, strength and comments:
    Space    - Hull below water (magazines/engines, low = better): 78.1 %
        - Above water (accommodation/working, high = better): 75.8 %
    Waterplane Area: 19,741 Square feet or 1,834 Square metres
    Displacement factor (Displacement / loading): 136 %
    Structure weight / hull surface area: 77 lbs/sq ft or 375 Kg/sq metre
    Hull strength (Relative):
        - Cross-sectional: 0.98
        - Longitudinal: 1.22
        - Overall: 1.00
    Excellent machinery, storage, compartmentation space
    Cramped accommodation and workspace room
    Ship has slow, easy roll, a good, steady gun platform
    Excellent seaboat, comfortable, rides out heavy weather easily

Warning: Beam between bulkheads too wide

This ship is patterned on the british steamship Marwarri, completed 1935.

www.shippingwondersoftheworld.com/marwarri.html

www.uboat.net/allies/merchants/56.html

Reserve :
50t

AD:
25t  LR Radio
10t  SR Radio

OD :
320t - Accomodations

HAW :
750t - individual cargo.

HBW :
6600t - Bulk cargo

[Kaiser Kirk]

shipping types

Here is the index to that site.

[TacCovert4]

Weirdly enough, I think there'd be more, but smaller, passenger liners. 

Large European Imperial powers such as Rome, Vilnius, and then Byzantium and Parthia, all with extensive holdings quite far from home, would encourage passenger travel, probably a combination of passenger/mail travel on packet steamers.  Even the Aztecs would likely have a number of 25+kt mail/passenger steamers on various lines to ensure the wheels of commerce keep going.  Then you'd have slower cargo ships with passenger space that would handle things like families moving to a new nation, Parthian Families coming to the 'new world' for instance, Aztecs going to Zealand, and so on....immigration rather than commercial transit.

Those would likely take care of the needs to send various people around the globe on commercial ventures.  But then when you look at the Norse, Romans, and Vilnius specifically, they have significant Western-Hemisphere holdings just one ocean away from their homelands.  In those circumstances, I'd opine it extremely likely that there'd be a notable number of larger passenger liners.  The Mississippi River cities of Nova Roma, the Trans-Eryka Canal region, the massive Norse Holdings in North America, all of these would likely have the sort of significant movement of people and goods to justify large passenger liners, maybe with strikedown spaces that could be steerage on one leg of the trip for immigrants or workers, and converted to carry crated goods on another leg.

My two cents since we don't have anything ready for trans-Atlantic flight yet.

[Kaiser Kirk]

Weirdly enough, I think there'd be more, but smaller, passenger liners. 

A) Large European Imperial powers such as Rome, Vilnius, and then Byzantium and Parthia, all with extensive holdings quite far from home, would encourage passenger travel, probably a combination of passenger/mail travel on packet steamers.  Even the Aztecs would likely have a number of 25+kt mail/passenger steamers on various lines to ensure the wheels of commerce keep going. 

B)   Then you'd have slower cargo ships with passenger space that would handle things like families moving to a new nation, Parthian Families coming to the 'new world' for instance, Aztecs going to Zealand, and so on....immigration rather than commercial transit.

Actually the above vessel would fit in the "B" part of your musing. I was thinking they would handle the majority of commerce and immigration.   

The "A" part isn't far off what I was saying about there would still be some liners. But speed is costly, so that would be richer folks and higher priority cargoes, which by nature would be fewer. Rome would have one to Cuba and back. Azteca would have 1 to Japan/China, one to Vilnus/Norse and 1 to the Med.

The smaller coastal freighters would be the last link in the pickup/delivery system between the local ports and the "A" and "B" oceanic frieghters.

However that view of mine could be horrible off what everyone else thinks.
So it's interesting to discuss.

[Kaiser Kirk]

For a larger "A" type liner, how about something modeled on MS Marnix van Sint Aldegonde or Hikawa Maru both 1929.
- just wiki them.

The Dutch carried passengers and cargo from Netherlands to Indonesia, the Japanese from Japan to Seattle. Both seem about right. 

For the "B" ship, either the one posted, or the slightly larger 'Canada', which is #8 on that above link.
What I used was #34, an Indian-US cargo-liner.
Alternately, other versions would be the #2 Nora Maersk, or #21 Peebles both which would be more of Hog Island size.

The "C" ship the small freighter, something along the line of the #29 Hyogo Maru or #34 Ophir