WesWorld

Quoted from "Hood"

What actual effect does the setting have in Subsim? Extra crew, heavier structure?

Yes, both of those; as part of the latter point, it changes the factors which it uses to calculate diving depths, so that oceanic subs get better diving limits. If I sim a design as a coastal sub and then change it to oceanic, I can lose about twenty percentage points of reserve buoyancy. That often is enough to take my designs from ~15% (which is almost ideal) to -5% (which is... not).

Quoted

What actual effect does the setting have in Subsim? Extra crew, heavier structure?

Playing around with my Ninja submarine, changing it from coastal to ocean-going...

- Crew goes from 54 to 59. This is because the baseline crew of 10 for coastal submarines becomes 15 for ocean-going submarines.
- No idea what D_body and T_sheet are supposed to be but they change from 5.4 and 1.8 respectively to 5.6 and 2.7.
- Weight for miscellaneous crew goes from ~10.45 tons per additional crew member to ~14.75 tons per additional crew member.
- Structure mass goes from 564.2 to 869.9.
- TT weight goes from 10 to 30 tons. A single TT on a coastal submarine is 5 tons and a single TT on an ocean-going submarine is 15 tons.

... and of course due to the weight changes, kerb weight and light weight change as well. Reserve buoyancy changes from 11% to -16%.

Quoted

When I think coastal or ocean going I think more in terms of the role rather than size, which itself is usually dictated by the role and the specifications set by the nation building it.

I think that that is probably dangerous as then one could go for something the size of a Typhoon with a 4,000nm@10kts range for coastal patrols and sim it as a coastal submarine because that is its role.

Quoted

Atlantis sort of mirrored the British desire to have subs fast enough to screen the battle fleet and, as the British did, labeled them fleet subs. Designers quickly gave up on this idea given the rate at which battleship design speeds were increasing while submarine propulsion systems couldn't keep up (historically the British didn't give up easy on this concept) but the term fleet sub remained.

Well, they could still be attached to fleets, just not the ones with fast ships. Looking at the Atlantean Amphibious Forces for example, there are quite a few 18 knot designs so it should not be too difficult for fleet submarines to tag along with an amphibious landing fleet when it is deemed necessary. The label 'fleet' could still be properly used.

Quoted

As a result Atlantean subs don't place a premium on submerged speed as much as offensive capabilities and range, though the latter is still a bit short by foreign standards.

Since you mentioned range, I thought I would look at that and see how the Atlantean submarines compare to the other submarines. I only looked at those of 1940 and later otherwise it becomes a big unwieldy mess for me to work with.

In order of displacement:
Shayú ----------- China ------- 1942 ----- 182t ----- 1600nm@8.25 kts
Dolphin --------- Thailand ---- 1940 ----- 288t ----- 5000nm@7 kts
Héroe ----------- Chile ------- 1940 ----- 325t ----- 3472nm@12 kts
M401 ------------ Russia ------ 1945 ----- 365t ----- 1390nm@12 kts
Gymnote --------- France ------ 1944 ----- 375t ----- 5000nm@10 kts
Europa ---------- Latvia ------ 1940 ----- 448t ----- 3916nm@12 kts
R1 -------------- SAE --------- 1942 ----- 479t ----- 5000nm@10 kts
Type XXIII ------ Germany ----- 1948 ----- 497t ----- 7593nm@8 kts
K-37 ------------ Netherlands - 1943 ----- 499t ----- 6157nm@10 kts
P1 -------------- SAE --------- 1940 ----- 500t ----- 5000nm@10 kts
Type IX --------- Germany ----- 1941 ----- 506t ----- 5250nm@12 kts (*)
S-6 ------------- GB ---------- 1942 ----- 523t ----- 5000nm@8 kts
I-314 ----------- Japan ------- 1947 ----- 571t ----- 3564nm@10 kts
Dolphin II ------ Thailand ---- 1941 ----- 600t ----- 7500nm@8 kts
Akula ----------- Bulgaria ---- 1940 ----- 615t ----- 7107nm@12 kts
Thetis ---------- France ------ 1943 ----- 675t ---- 10138nm@10 kts
Audaz ----------- Philippines - 1943 ----- 675t ---- 10138nm@10 kts
Yáomù ----------- China ------- 1943 ----- 690t ----- 6000nm@8 kts
V --------------- GB ---------- 1941 ----- 702t ----- 7500nm@10 kts
Walrus ---------- GB ---------- 1945 ----- 702t ----- 5505nm@10 kts
R-98 ------------ Atlantis ---- 1940 ----- 735t ----- 7640nm@10 kts
P-6 ------------- Peru -------- 1941 ----- 750t ----- 8000nm@10 kts
Tirador --------- Philippines - 1946 ----- 849t ---- 11308nm@10 kts
IN-1 ------------ Japan ------- 1948 ----- 915t ----- 4900nm@10 kts
Incheon --------- Chosen ------ 1942 ----- 922t ----- 5000nm@8.4 kts
Project 64 ------ Russia ------ 1941 ----- 923t ---- 17100nm@10 kts
SG-1 ------------ Iberia ------ 1946 ----- 952t ----- 7019nm@10 kts
T1 -------------- SAE --------- 1942 ----- 954t ---- 10000nm@12 kts
O-17 ------------ Netherlands - 1943 ----- 990t ---- 17999nm@10 kts
I-300 ----------- Japan ------- 1940 ---- 1069t ----- 5800nm@14 kts
Triton ---------- GB ---------- 1944 ---- 1194t ---- 11014nm@12 kts
Thames ---------- GB ---------- 1940 ---- 1199t ---- 12000nm@10 kts
Q1 -------------- SAE --------- 1940 ---- 1223t ---- 15000nm@12 kts
I-36 ------------ India ------- 1943 ---- 1320t ---- 11761nm@10 kts
Type VII -------- Germany ----- 1941 ---- 1385t ----- 8164nm@12 kts (*)
Roland Morillot - France ------ 1943 ---- 1450t ----- 8635nm@12 kts
B-1 ------------- Brazil ------ 1940 ---- 1470t ---- 12268nm@12 kts
Orca ------------ Canada ------ 1941 ---- 1500t ---- 10000nm@10 kts
I-34 ------------ India ------- 1942 ---- 1500t ---- 20000nm@10 kts
Oberon ---------- GB ---------- 1948 ---- 1533t ---- 14583nm@10 kts
Durjeya --------- India ------- 1945 ---- 1544t ---- 14000nm@10 kts
O-22 ------------ Netherlands - 1948 ---- 1545t ---- 13462nm@10 kts
Gato ------------ USA --------- 1941 ---- 1611t ---- 11000nm@10 kts
Salta I --------- Argentina --- 1947 ---- 1666t ---- 16159nm@10 kts
Type XXI -------- Germany ----- 1945 ---- 1720t ----- 8864nm@12 kts
Emeraude -------- France ------ 1945 ---- 1750t ----- 8864nm@12 kts
Type 42 --------- Atlantis ---- 1942 ---- 1900t ---- 14143nm@10 kts
Mako ------------ Philippines - 1940 ---- 1935t ---- 17717nm@10 kts
Project 78 ------ Russia ------ 1947 ---- 1950t ---- 10374nm@12 kts
Guìyú ----------- China ------- 1942 ---- 2004t ---- 14000nm@11 kts
SSH-1 ----------- Australia --- 1941 ---- 2010t ---- 12500nm@11 kts
Type 43 --------- Atlantis ---- 1940-44 - 2300t ---- 12576nm@10 kts
I-305 ----------- Japan ------- 1944 ---- 2671t ---- 15000nm@10 kts
I-310 ----------- Japan ------- 1946 ---- 3189t ---- 18342nm@10 kts
Shearwater ------ Canada ------ 1940 ---- 5000t ---- 11800nm@10 kts
I-402 ----------- Japan ------- 1946 ---- 5493t ---- 46756nm@10 kts
I-315 ----------- Japan ------- 1947 ---- 6591t ---- 22311nm@10 kts


(*) Says 'radius' but I assume that this is incorrect and should be 'range' instead.


Looking at the 3 Atlantean submarine designs from the 1940s, It actually does not look too bad though it can be hard to guess without using springsharp or subsim what the various ranges are that do not use 10 knots as cruising speed. I would guess, based on the conversions to 10 knots cruising speed of the Filipino and French coastal submarines a few posts back, that the Type VII, Roland Morillot, Type XXI and Emeraude have a similar range to the Type 42. Project 78 and SSH-1 probably have a similar range to the Type 43.

Quoted from "Rooijen10"

I would guess, based on the conversions to 10 knots cruising speed of the Filipino and French coastal submarines a few posts back, that the Type VII, Roland Morillot, Type XXI and Emeraude have a similar range to the Type 42. Project 78 and SSH-1 probably have a similar range to the Type 43.

Type XXI and Emeraude both have 12,477nm range at 10 knots.

Doesn't the depth of the waters your going to operate in influence the choice too?
For example, Belgium's subs are only designed to operate in the North Sea which is actually quite shallow and so the crush depth and hull structure could be less. Of course a heavier hull resists depth charges better but against the kind of impact-fuzed mortars now in use I don't think that matters too much as any structure is vulnerable.

Thanks for the list of subsim changes, some make sense and others less so. Not sure why the TT weight should change unless its adding weight for more complicated reload equipment?

Actually I can probably relax the Type 0 requirement and that makes things a little easier.
I think 0 = coastal is correct for this sim as subsim automatically sets the crush depth to 225m, which fits the Belgian requirements. 1 = 317.5 crush depth which is more than I require. So the structure weight should be correct for a sub only intended for operational in shallow waters.


The Dutch have proposed the following:

Belgian Destructeur de Sous-Marin Class
Date: 1948
Coastal
Armament:
- Guns: none
- Torpedoes: 8 21in torpedo tubes (all fore)
- Mines: 30 (simming 16x torpedoes)
Electric HP: 6,000hp
Diesel HP: 3,000hp
Crew: 45
Weight fuel & batts: 575 tons
Light Displacement: 1,316 tons
Loaded Displacement/Kerb Weight: 1,413 tons
Full Displacement: 1,742 tons
Reserve buoyancy: 19%
Max Surf Speed: 15.0 knots
Max Sub Speed: 18.0 knots

Length: 80.0 m
Beam: 6.7 m
Draft: 6.5 m
Crush depth: 225 m
Tons Oil: 65 tons
Tons Battery: 510 tons
Cruise speed: 6 knots
Submerged speed: 6 knots
Surface Range: 3,657nm@10 knots (minimum requirement 3360nm@10 knots)
Submerged Range: 447nm@6 knots (minimum requirement 18nm@18 knots + 48nm@6 knots)

Notes: 100 tons miscellaneous weight for radar, ASDIC, hydrophones, air conditioning equipment

Quoted from "Hood"

Doesn't the depth of the waters your going to operate in influence the choice too?

Quoted from "Hood"

Not sure why the TT weight should change unless its adding weight for more complicated reload equipment?

I think that's probably the case. Many of the postwar European coastal submarines I've looked at didn't actually carry any reloads (for example, look at the German Type XIII, the Type 201 class, and the Type 206; the Soviet Project 615 "Quebecs"; the French Daphne class).

Quoted from "Brockpaine"

Quoted from "Hood"

Not sure why the TT weight should change unless its adding weight for more complicated reload equipment?

I think that's probably the case. Many of the postwar European coastal submarines I've looked at didn't actually carry any reloads (for example, look at the German Type XIII, the Type 201 class, and the Type 206; the Soviet Project 615 "Quebecs"; the French Daphne class).

To me, that seems unlikely. Changing to 1939 and 1919 is a simple test, I get the same changes with torpedo tube weight and I am not sure that what you said about postwar coastal submarines also applies to <1946 coastal submarines. I think that the reload equipment is included in the weights, either as part of the TT weight or somehow calculated into the weights of the crew.

It seems more likely that the increased weight is not so much about the torpedo tubes themselves but the submarine's structure around the tubes which would need to be stronger if the submarine goes to deeper depths. After all, you are talking about holes in the pressure hull where the tubes are located.