Something terribly wrong with convoy speed

[Dan1109]

Yet another post about ship speed, but I offer concrete data to back some things up. Now part of the problem MIGHT be that due to the sea zone maps, that ships don't travel in a straight line, but honestly that should have maybe only a 20% reduction in destination times.

My source from this is from the US Navy, declassified information regarding WW2 convoy routing. Don't know when it was written, sometime after the war (and it was original classified as Secret), but this looks like a solid source:
https://www.history.navy.mil/resear...abetically/h/history-convoy-routing-1945.html

So, to begin withI've often complained about Transports going at 12kmph, or 6.5kn. Liberty Ships went twice as fast, but there are many aspects to factor in: zig zagging, convoy is only as fast as its slowest ship, route taken, etc. So to simplify the debate I am going to compare authentic US Navy data of convoy timings, to in game troop transfers. Why troop transfers? Well, they show the exact route, and the speed (12kmph). There is a stark difference between in game and reality of going 12kmph/6.5kn.

Let's get slow ships out of the way first. The above screen shot from the document describes SC convoys, being the slowest, at 8 knots and then states the reality was up to 1knot slower. So, 7 knots. Ok, PDS may be right in describing convoys at 12kmph, 6.5kn (still a bit on the slow side, especially if you assume every convoy in the world has one ship which is the slowest in the world). But more importantly is the time. 15-17 days between Halifax and Liverpool.

The above picture shows a ship (troop transfer, because it SHOWs the speed) going from Liverpool to Halifax in 28 days. The difference ratio is 28 days / 16 days = 1.75.

Now let's look at USA -> North Africa:

Cape Henry and Europa point BTW is Norfolk and Gibraltar. Now let's look at HOI4:

OK, it was raining. Let me adjust it to 28.25 days. Difference ratio in route: 28.25 days / 16.5 days = 1.71

Now let's look at the Pacific:

OK, San Francisco to Pearl, above table says 10 days. In HOI4, much slower:

18.84 days / 10 days = 1.89 difference ratio

Now SF to Guam:

36.25 days (* by .95 to eliminate rain delay) / 15 days = 2.4 difference ratio

Now, since all of these examples of troop transports, let's show some data on troop transports:

19 to 20 knots for troop transports, thats ~37kmph. Heh, it even states that not only was not a single troop transport lost in the Atlantic, but not a single troop!! I'll need @Axe99 to verify troop transport losses at sea for the the UK and the Commonwealth, but I assume this is for US and Canadian troops. Yes, I would not be surprised to learn than troops were lost in the Pacific, by some arbitrary sub raids. JAP subs in fact sank carriers, and even sank the Indianapolis, fortunately after it delivered the atomic bomb to a forward staging base (heh, it could have been the first use of a nuclear depth charge, lol).

So, in conclusion, something seems terribly wrong. The times for transports are definitely off by a factor of 1.7 to 2.4. Maybe this has something to do with knots:kmph being a 1.85 ratio. Maybe this has something to do with PDS nearly "doubling" ship speed in 1.6.2 (warship speed only, not convoy speed).

I don't care what the exact posted speeds are. Its immersion to create a ship with the proper speed or see my invasion force being displayed to move at the appropriate speed. Warship ship speed reduction can be argued going from port to port, they did not go at flank speed. Fine, we need to find examples of how long it took Task Force X to go from port Y to port Z. But if so, what speed are warships using in combat, where they use max fuel consumption?? And wouldn't convoys use flank speed in combat as well, ya think?

What matters most to me is how long these troops are on the water, which is dead wrong, seen from tables from the US Naval document. It contributes to troops dying in the Atlantic (which they NEVER did) and horrendous troop transfer times limiting the Allied naval mobility, which helped them win the war.

 

[Dan1109]

After some additional tests a big part of the problem is naval pathing. I’m finding convoy routes, warship routes, and troop transfer routes to all be different. For the same port to port route. Why??

Further, as each sea zone must be traversed, one at a time, there is a LOT of inefficiency, compared to going in a straight line. Can’t say there is an easy fix to this, the most logical would be to increase the sea zones in a sea region by a massive amount, but that’s a lot of work, and would put much increased stress on the current naval pathing algo.

On the other hand, perhaps an algo could be made to determine the true distance of the route, then determine how long the naval pathing route is, and adjust the speed of the TF or troop transfer or invasion force so that when following the naval pathing route, the time of transfer is the same as going in a straight line. It would get a bit more complex when destination is not a straight line, but I don’t seeing it being that difficult, just need to code in several ‘way points’ (after 2-3 sea zones, if the angle of trajectory has changed over 60 degrees that should be a way point).This can be done whenever an order is given, so it would not give an unfair advantage to short routes and make long routes more realistic.

Of course the sloppy and easy fix would be to increase convoy speed overall. This would of course be unfair for short routes. But maybe a linear speed buff from x1.0 to x2.0, based on the route length would be more ideal. This problem is certainly exacerbated by the length of the route. This would be the cheapest and most effective solution to the problem.

 

[Tacticus101]

Your troops also land as a full division, with all their equipment and fuel. The speed is an abstraction, whilst it IS probably a bit slow even considering that, there is no easy way to represent the waiting and organising freshly landed divisions would have to do.

Also, there were troop ships sunk a-plenty during the second world war. Not generally the big ocean ones, but even the USA lost some in the Mediterranean and i know the British lost quite a few. The Japanese were even worse off.

 

[elektrizikekswerk]

there is no easy way to represent the waiting and organising freshly landed divisions would have to do.

Well, troops do have low org after unloading...

 

[Dan1109]

Your troops also land as a full division, with all their equipment and fuel. The speed is an abstraction, whilst it IS probably a bit slow even considering that, there is no easy way to represent the waiting and organising freshly landed divisions would have to do.

this is already represented by the loss off all org when arriving at a port. This works fine and is fairly realistic, although by no means perfect - it’s good enough. The same goes for land based strategic relocation.

Also, there were troop ships sunk a-plenty during the second world war. Not generally the big ocean ones, but even the USA lost some in the Mediterranean and i know the British lost quite a few. The Japanese were even worse off.

Of course the Japanese lost troop convoys, but they were the only ones stupid enough to send them unescorted through hostile waters (as well the Tokyo Express, DDs carrying small amounts of troops and supplies isn’t modeled at all).

The underlying point is that naval pathing is highly inaccurate. For years I laugh when people look at a deficiency in this game and try to justify it abstractly with another missing mechanic.

Yes, naval pathing is highly cpu taxing but there needs to be a solution. I can cross the Atlantic in my 36’ sailboat, tacking repeatedly into a headwind (including navigation around weather), about as fast as the game allows troop transports to move.

 

[Jorgen_CAB]

To be honest the loss of organization is not even near enough to account for all the logistical problems nations faced with shipping large quantities of troops around the ocean. The slow speed is at least making the time from departure to combat readiness somewhat realistic.

We are allowed to move FAR too much troops around on the ocean from what they were capable of during the actual war, so I see no real issue with this.

 

[Dan1109]

Except being in the water in HOI is far more dangerous than being at port. For some nations, it’s the majority of manpower loss.

That’s my over arching concern about raiding vs escorts. The game has far too long allowed for a stupid amount of convoy, equipment, and manpower loss observed on the first day of game launch almost 3 years ago. If not addressed in their first and probably their last naval exclusive DLC, when???

 

[Brooklyn666]

Your troops also land as a full division, with all their equipment and fuel. The speed is an abstraction, whilst it IS probably a bit slow even considering that, there is no easy way to represent the waiting and organising freshly landed divisions would have to do.

It's the literally game mechanic called "organization", and troops already have basically no org after landing.

 

[currylambchop]

Posts like these, with similar evidence, have been made all the time, at least weekly. There isn't a need to have so many posts about this. The slow transports are a design decision, given so the Axis can have a chance without being swarmed by the Allies.

It's also historical that nukes are more powerful than in game, but as a design decision the Devs chose to make nukes cheaper than in real life, and also weaker. This was to prevent an arms race gameplay where the nation which got nukes first, would automatically win. Another decision the Devs made that was ahistorical, but for gameplay purposes, was German industry being ahistorically strong.

Most people don't complain about those design decisions, and I don't see why they would complain about this one.

The Devs have almost certainly read these posts, and decide that it would be imbalanced to change the speed values.

 

[Karapis]

Most people don't complain about those design decisions, and I don't see why they would complain about this one.

Well there is nothing unsusal about some game design decisions being good and some not good

 

[Aeon221]

I feel like there should be a speed difference between troop transports, freight transports and amphibious assault transports. There should probably also be different equipment for each. The game already distinguishes between freight and troop in the code as can be seen with the different spotting values so it wouldn't be a world ender to pull off.

Troop transports would be standard friendly port to friendly port transports. They'd be pretty quick and tough for subs to catch or spot. This would allow Axis to maintain a force in Africa and Allies to move units around globally without a massacre. IMO this would do a lot to improve the Allied and Japanese AI as they could adjust force allocations without getting mutilated. Good quality late game surface raiders and subs could interdict them (keep in mind that Japanese transport losses only started going crazy in 43/44 after US torpedo issues were fixed)

Freight transports would be pokey and easy to spot. We're talking 6-8kts at most. This would be the stuff early game raiders and subs hunt.

Amphibious transports would be the most vulnerable and the pokiest. You'd want a fleet to escort them the whole way and you'd want to launch them from the shortest distance possible. This would ensure that amphibious invasions are still a giant struggle and naval/air attack is hugely threatening to them.

I feel like these changes would improve the game immensely without breaking the Germany game.

 

[Tacticus101]

Well, troops do have low org after unloading...

It's the literally game mechanic called "organization", and troops already have basically no org after landing.

this is already represented by the loss off all org when arriving at a port. This works fine and is fairly realistic, although by no means perfect - it’s good enough. The same goes for land based strategic relocation.

Was it really necessary for all three of you to reply with almost the exact same thing?


"Organising" was probably a poor choice of wording.
There is no easy way to represent that fact that a division can land completely intact, with hundreds of tanks, all their equipment and men arranged in one place and healthy after half a month at sea. The fact they land with low Organisation does not sufficiently cover it, especially given that some nations or doctrines can recover that incredibly quickly.

Yes, historically a convoy could cross the Atlantic significantly faster than in the game, and modern troops ships even faster. However, those divisions generally took a few days to unload, far longer to get the division properly organised with all their equipment. Then, their supplies and reinforcements or replacements would take even longer to turn up. Many of the problems armies, especially the British, had when fighting abroad was when things like spare parts simply didnt arrive, meaning month long delays.

I DO think that troops transfer speed is a little slow and could benifit from a slight improvement. But currently you can shift a million strong American army, complete with 10,000 tanks, across the Atlantic and have them ready to fight a day after landing. You cant pick and choose what you want to be realistic in a majorly abstracted mechanic.

 

[Aeon221]

I DO think that troops transfer speed is a little slow and could benifit from a slight improvement. But currently you can shift a million strong American army, complete with 10,000 tanks, across the Atlantic and have them ready to fight a day after landing. You cant pick and choose what you want to be realistic in a majorly abstracted mechanic.

You could, but they'd choke on the supply limit in any zone they landed in and get cleaned up pretty trivially. And if you or the AI spent the minimal effort required to interdict incoming freight supply with subs they'd hit a supply limit of near zero and die really fast.

This actually happened to me during my first game with the new patch. The Italian AI went ape on my supply into Sicily via Palermo in the Tyrrhenian sea (oh lawd them spells) with subs, causing my supply limit to drop to nothing which fatally weakened my units, forcing me to evac.

So while the Allies can in theory flood a landing zone with unholy hordes, in practice existing mechanics already mitigate or eliminate that issue as a serious concern.

 

[I_am_Nemo]

Yes, historically a convoy could cross the Atlantic significantly faster than in the game, and modern troops ships even faster. However, those divisions generally took a few days to unload, far longer to get the division properly organised with all their equipment. Then, their supplies and reinforcements or replacements would take even longer to turn up. Many of the problems armies, especially the British, had when fighting abroad was when things like spare parts simply didnt arrive, meaning month long delays.

Maybe divisions could land with a significant strength penalty of some sort? Say, have half their equipment be missing, and have it slowly trickle back to them over the course of a week. (Could either return to stockpile on convoy landing, or be placed into a separate holding pool). That would allow the actual transport (and dangerous period) to be over with quickly, while still imposing a significant delay between landing and combat readiness.

Don't know how viable that would be in terms of processing power/implementation, though.

 

[Tacticus101]

You could, but they'd choke on the supply limit in any zone they landed in and get cleaned up pretty trivially. And if you or the AI spent the minimal effort required to interdict incoming freight supply with subs they'd hit a supply limit of near zero and die really fast.

This actually happened to me during my first game with the new patch. The Italian AI went ape on my supply into Sicily via Palermo in the Tyrrhenian sea (oh lawd them spells) with subs, causing my supply limit to drop to nothing which fatally weakened my units, forcing me to evac.

So while the Allies can in theory flood a landing zone with unholy hordes, in practice existing mechanics already mitigate or eliminate that issue as a serious concern.

Depends on how large a front they are landing over. If i am trying to land in a single supply zone with a million men? yeah, you have supply issues.
If i am trying to pour troops in France, or Russia, or India or China or any large front then it is far less of an issue.

You are kind of comparing apples to oranges here though. I am not criticising the ability of the Allies (or Axis) to flood a landing zone with troops, that has supply consequences. I am criticising the fact that you can have a million men at sea at the same time, that doesnt.

Maybe divisions could land with a significant strength penalty of some sort? Say, have half their equipment be missing, and have it slowly trickle back to them over the course of a week. (Could either return to stockpile on convoy landing, or be placed into a separate holding pool). That would allow the actual transport (and dangerous period) to be over with quickly, while still imposing a significant delay between landing and combat readiness.

Don't know how viable that would be in terms of processing power/implementation, though.

That would work. Currently the ability of divisions to recover equipment is quite fast though, so it would probably have to be reduced overall for that to work. Not a bad change to have in general though, as well as making supply convoys higher in number.

 

[Aeon221]

Maybe divisions could land with a significant strength penalty of some sort? Say, have half their equipment be missing, and have it slowly trickle back to them over the course of a week. (Could either return to stockpile on convoy landing, or be placed into a separate holding pool). That would allow the actual transport (and dangerous period) to be over with quickly, while still imposing a significant delay between landing and combat readiness.

Don't know how viable that would be in terms of processing power/implementation, though.

But this isn't accurate. Divisions didn't ship to warzones without kit. They did ship to England piecemeal, but that's because the US Army was using England as a giant supply dump and training area. In game terms the US was deploying troops early, sending them to Southeast England at green experience and without full kit, then teained them to regulars while their kit showed up.

Units landed in North African ports after Torch shipped in combat loaded with their kit. Same with pretty much any power deploying units into an overseas combat zone absent extenuating circumstances.

 

[Aeon221]

Depends on how large a front they are landing over. If i am trying to land in a single supply zone with a million men? yeah, you have supply issues.
If i am trying to pour troops in France, or Russia, or India or China or any large front then it is far less of an issue.

You are kind of comparing apples to oranges here though. I am not criticising the ability of the Allies (or Axis) to flood a landing zone with troops, that has supply consequences. I am criticising the fact that you can have a million men at sea at the same time, that doesnt.

Well the US Army _was_ shipping millions of men overseas. Over 3 million were shipped into England for Overlord and then deployed into Normandy. It'd probably take until 44 to do that in game too.

The limit on troop transfer to friendly ports is sealift, which thanks to the enormous US shipping industry was not a binding constraint. Other nations are simply able to build way too many convoys relative to history, and can use these absurd numbers of convoys without paying a huge manpower cost.

 

[Jorgen_CAB]

Well the US Army _was_ shipping millions of men overseas. Over 3 million were shipped into England for Overlord and then deployed into Normandy. It'd probably take until 44 to do that in game too.

The limit on troop transfer to friendly ports is sealift, which thanks to the enormous US shipping industry was not a binding constraint. Other nations are simply able to build way too many convoys relative to history, and can use these absurd numbers of convoys without paying a huge manpower cost.

Yes... another thing is also that you can't use every ship for shipping men and equipment and the ships have to travel both there and back again. At least ships needed to be prepared to ship troops rather than just supplies or natural resources. These conversions took time and then time to convert back again for regular convoy duty.

Just the huge task of organizing forces on the scale of Operation Overlord was massive at took allot of time and effort to set in place. There were pretty much no other country except the US who was able or had the resources to do anything like that in WW2.

The game could very well have made the actual transportation of the troops faster at the expense of both loading and unloading preparations taking time to reflect all the other difficulties and logistical problems.

There could be four different convoy values, one for supplies and raw materials, one for fuel and one for troop transports and one for amphibious landings. Now you could convert regular cargo transports into troop transport when necessary (even tankers but at a higher conversion cost rate), could even happen automatically when needed but it would take dockyard capacity like repairing or refitting ships.

Only Marine units could use naval invasion using regular transports while regular units need amphibious ships to do naval invasions.

 

[Tacticus101]

Units landed in North African ports after Torch shipped in combat loaded with their kit. Same with pretty much any power deploying units into an overseas combat zone absent extenuating circumstances.

The units landing in Operation Torch needed 500 transport ships. The 35,000 (3 divisions) that were shipped directly from the US needed over 100 ships in convoy to acount for all their equipment (including the tanks). This is all with complete allied naval cover, having already won the battle of the Atlantic quite comprehensively, which is why none were lost.

Operation torch also saw 6 troopship lost despite all this.

Well the US Army _was_ shipping millions of men overseas. Over 3 million were shipped into England for Overlord and then deployed into Normandy. It'd probably take until 44 to do that in game too.

The limit on troop transfer to friendly ports is sealift, which thanks to the enormous US shipping industry was not a binding constraint. Other nations are simply able to build way too many convoys relative to history, and can use these absurd numbers of convoys without paying a huge manpower cost.

The US shipped a million men overseas. They did not have a million men and all their equipment at sea at the same time. Its a major difference.

 

[Aeon221]

I think three is sufficient, with a single convoy ship type. They just need different spotting values and speeds.

As far as the lack of a serious logistics system, I think everyone feels that keenly. But it's a little weird to say that seaborne movement should have a massive handicap due to the gaping hole where a proper logistics system should be while massive land movement and offensives are privileged and do not face similar constraints.

Like, there's absolutely no doubt that strategic movement should return all heavy equipment to the reserve and then resupply on arrival. Or that offensives should require more logistical prep work than move division - > hit go. But neither of those things are necessary, so why do it to sealift?