I am fairly new to Paradox Studio's Hearts of Iron 3 which is a lot overwhelming than CK2, EU 4 or Victoria for me. So it might just be something silly on my part but here goes:
For context, I launched an invasion of Germany in a Two-Pronged attack from East and West. Western Divisions were supposed to break German Defenders along the Danish Peninsula and Follow the Coast to East. While Eastern Force was going to land at Konigsburg, Prussia and advance along the coast to West while annihilating opposition and capturing coastal belt. Both Forces were supposed to meet at Rostock in Pomerania region.
The Western attack failed and units were bogged down at Danish-German border, still trying to overpower the numerous hordes of Wehrmacht. (But that's okay since after taking Kiel with Eastern Force, I will be able to take the Germans on Danish border in rear and flanks. I'd be on Risk of being flanked myself but I don't see any such threat looming as other available units of Wehrmacht are being tied down by other Allied forces in France and Low countries). The Eastern Sea-borne force met with success and achieved its targets as far as Danzig since most of regional German forces were defending against Western force. Now the Eastern attack has stalled because my units have run out of supplies in Prussia and they are in a very vulnerable position there. I am trying to keep the Germans busy in Kiel & Leck (Western Side Force) to keep them off my starving troops in East but I don't know how long will they last.
Prior to launching the invasion, I destroyed almost all resources in Prussia with strategic bombing campaign lasting for weeks so that can be a factor in low supply.
Resources I have at hands for supply and escort duties:
- Transport Ships: 12
- Airborne Transport Airplanes: 12-14
- Two strong flotillas (Mixed forces of Heavy Cruisers, Light Cruisers and Destroyers) guarding the entry into Danish waters and Baltic Sea in General.
- 8 Wings of Interceptors and MRFs (Gloster Gauntlets and Spitfires) providing aerial umbrella.
- Ample resources in terms of Supply and fuel.
Despite having such superiority, I don't know how do I get supplies transported to my men.
My order of battle is:
->Main HQ[Army level] (Located in Copenhagen)
|
-->Western Invasion Force[Corps level] (HQ Located in Arhaus Denmark)
|
-->Eastern Invasion Force[Corps level] (HQ located in Konigsburg, Occupied Germany)
Now my understanding was that main HQ can supply troops as far as 2000 KM. Konigsburg is only 626 KM from Copenghagen which is why I undertook the invasion in the first place . What seems to be the problem?
Then I assumed maybe if I gained superiority of Baltic sea, that would open sealanes to my forces. So I intercepted the German fleet, gave battle, won and what remained of German Baltic fleet is currently hiding in Kiel which is constantly under port strikes from my tactical bombers. (I don't think any German naval units managed to make it across the sound and to safety of Wilhelmshaven. Either way, I have Kiel invested with a flottila in case the Germans decide to get out of the port and a submarine patrolling from Wilhelmshaven to Dutch Coast).
It never worked.
Failing to get automatic supply after I had gained control of Baltic sea as I assumed, I turned to other options. When I try to use Naval Transports to act as supply vassals, they don't get an option to supply or base in occupied territories even though I have built naval bases there.
Then I tried to use Aerial assets and they don't get any option either. All options are greyed out.
What else can I do to resupply the stranded divisions? Or am I doing something wrong in methods I have already tried?
UPDATE
After losing the Eastern Force to low supplies, I raised another army and augmented Western Force with it. They broke through successfully and even after expanding southwards, I haven't yet faced low supply issue. Which makes me think, Is land connection between your HQ and forces needed for supply?
Best Answer
Use the supply map mode. You want provinces to be green or blue (green = in supply, blue = generating surplus)
Supply calculation is a bit obtuse in HoI3. It is not really clear how it is calculated from a first look. There is an intrinsic system of depots, and then you need unbroken lines between those and the provinces supplied by them. Look at the supply map mode, and click on a province, to see what source it draws it supply from.
An interesting side note is that supplies stacked in a province (unused supplies) will be kept, until next day shift, where it will be sent back to the initial depot (surplus supplies) meaning you may use this time, to move units to the province and still have enough supply.
As for how the unit is supplied, it is from the province it is standing in. This means it will trace back, in an unbroken line, towards the listed "depot" through all connected provinces, so it "bubbles" up from the central, to your unit. The supply movement rate is one province per day.
This is then modified by the infrastructure levels in the provinces along the path.
So to make sure your units are still in supply, make sure they have unbroken paths of supply back to the depot (using the supply map), then make sure to upgrade infrastructure at key points in that link, to get bonus. Never allow the link to the listed depot be broken, as that would put your units out of supply.
Also, turn on auto-convoys as it helps. For naval supply to work, you need an unbroken connection from the desgnated depot, to a port, then from that port, to an open land route to your units (unless they are actually IN the province that has a port).
So check your supply map, to see where the problems lie, it makes it a lot easier to overview where your supply is cut, and where it chokes.