AI logistics ( especially Japan )

[datachild]

During my game as germany i got problems with the logistic of my 2 main allies, italy and japan.
Japan did a realy bad job in china in this game. While it didn't gain much space in china ( after Vichy, vietnam, etc. was lost to china within half a year ) it didn't do anything else in the pacific region at all. ok they did in fact capture 2 provinces of the philippines.
UK made a landing on a more or less undefended main island in 1943. After this i accepted a peace offer from china, to prevent japan from total collapse. The following years japan build up troops ( 10+ stacks on the island ) but didn't do anything else for more than 2 years. I was wondering and checked with an older savegame. The result in 1943!!!:
0 Convoys
0 Transports
Same goes for Italy by the way.
I totaly understand the fact, that the convoys in the mediterranean sea are cut to pieces by the allies, until both suez and gibralta are into axies hands. However Japan as the dominant naval power in this region should have done a better job.

Now they are in this bad situation, how to change it. Eventually the ai ordered tons of transports and convoys. The problem is that they don't prioritize this build. It will take 4-6 years until the other oders in the list are completed and the first convoy is even build. And i have no doubt, that this 10 convoys won't even last a month.
Is this normal or just bad luck?

 

[macscarfe]

However Japan as the dominant naval power in this region should have done a better job.

If i remember what i have read and watched (yes i'm a lazy history buff) this isn't far from the reality of the situation. Japan's merchant navy was appauling, no convoy system and no real escort service. The US subs had a field day and almost completely obliterated all large and medium merchant ships in that area .... was dominance achieved as early as '43? Not sure.

 

[Hagar]

If i remember what i have read and watched (yes i'm a lazy history buff) this isn't far from the reality of the situation. Japan's merchant navy was appauling, no convoy system and no real escort service. The US subs had a field day and almost completely obliterated all large and medium merchant ships in that area .... was dominance achieved as early as '43? Not sure.

1943 is a bit early, in reality the rats were really into the woodwork in 1944. But in 1943 Guadalcanal and it's aftermath were sending Japanese transport capabilities into a downward spiral. You can see this US Navy article for instance... Basically this quote (from the forementioned article) pretty much sums it up.

The entire merchant marine (including that shipping throughout the empire that was not convoyed) had a loss of "carrying efficiency" of 8% between January 1942 and January 1944 with a further reduction of 21% by 1945.(35) However, on the critical line between Singapore and Japan, efficiency declined by 45% between May 1943 and May 1944, with further substantial declines later.(36) Not only did Japan have too few ships, but their ships took longer and longer throughout the war to carry badly needed cargoes the same distances.

 

[Denniss]

In my game as GER the JAPs were almost ouf of convoys in late 1942 - they DOW'ed USA in very late 1941 and were then invited into the Axis by me. AI preferred to finish of China first (don in mid 1942) but doing nothing in Hong Kong (stack of about 10 divs from various allied nations there - should not be there). Some JAP invasion agains Phillippine islands (from the south). As usual the AI looses transports at an alarming rate.
JAP had a so low rate of convoy transports to be only able to convert two transports. It's now building many convoy transports and transport divisions but they are all arriving very late. I had to edit them 500 transports in to be at least able to maintain their supply and resource convoys.

In short: JAP is in bad need of convoy transports from early on. What about using the mobilisation events to give naval nations some more convoy transports from interned or confiscated, formerly private-owned, ships.

 

[HistoryMan]

The convoy numbers are based on the total merchant shipping tonnage registered for the country in question - there are no "extra" privately owned ships, as they are already included in the totals. I did consider reducing the initial numbers of convoys, and then adding some back with the mobilisation events, but the way the game works, the Netherlands (for example) needs a lot of convoys just to establish the route from the DEI to Europe, regardless of how much they actually need to transport, so we left all the convoys in from day 1.

Japan being short of convoys is pretty accurate, essentially - they were poorly organised and short of ships, even early on, by and large, to actually get the required resources back to the home islands. Arguably, the sea route to Korea/Formosa was pretty safe, and you could maybe justify an impassable link (or, perhaps, a "sea" link - like Denmark to Sweden) across here, though this would allow Japan to get pretty much all her mainland resources across. She'd still need convoys for the DEI & Phillippines, of course, plus anywhere that wasn't linked to Korea on the mainland.

Tim

 

[datachild]

One way or another, at the moment japan collapses to fast. She should be able to hold the mainland, korea and the nothern provinces of china, at least for a while ( 2 years+). It is just unrealistic if GB takes korea 1 year after war ( with 1 division ) and japan with no change to respond to this threat.
If i didn't cancel the war with china japan would have been out of the war after 1,5 years with all japan divisons dead because of starvation.
The main problem is the sovjet union. As soon as japan enters the war on my side the soviets crush manchuria and thereby the last suplyline of the nothern troops. This means that japan is somehow a no-go for a german alliance.

 

[unmerged(101225)]

A lack of convoys might make sense in a game where fighting efficiency was gradually lost to simulate rationed or prioritized supplies and ammunition, but in HOI2 its either in supply or out of supply with a -50 bonus, which is game breaking. You cannot build up supplies so while the AI might launch an attack on a day where it is in supply, the next day the attack will fail because the convoys ran a different route that day.

Better option might be having the UK\JAP\ITA spend their industry on building a larger transport fleet prewar and during the war; distracting productions from other areas like upgrading and reinforcing.

 

[Bakta]

In my one JAP game, I noticed some really odd pathing, with convoys being sunk around Pearl Harbour or other odd places where there should be no reason at all for them to be.

This may explain the lack of conv/escort, above and beyond historical reasons mentioned above.

 

[Hagar]

Well the EXE is renowned for making poor decisions regarding naval missions. We can tell it that certain areas are off-limits, but aren't in full control in what area the AI sends ships to. So sometimes it's a bit like 'against all odds'.