View Full Version : Solution to the Beachhead supply problems
OK, I think I found a solution to one of TOAWs scenario design challenges, which is how to simulate invasions, or more to the point, beachheads and their supply.
Most of the time designers will just put a friendly supply point on a beach hex, but that creates some problems, for example either the invasion army is unsupplied because the enemy managed to recapture exactly that hex, or an invasion army will be in supply despite his opponent having thrown up a formidable sea blockade which should have cut off any supply shippment. Also your invasion army is always at the maximum supply level, even if they had to land at ports which shouldn't allow full supply to be landed.
One solution was the invention of sea-supply-roads, but they had the negative side effect that units at the beach had a habbit of retreating onto this supply road instead of stubbornly defending the beaches. Another minus was that all beach hexes connected to this supply road network were automatically supplied, and no matter how strong the defenders airforce was, it was impossible to simuate destroying the merchant fleet by air to stop the supply from flowing.
I found a way which allows the player to choose exactly which beach he wants to supply, it even allows him to swicht his resupply efforts to a different beach during the game, it prevents landed units from beeing pushed back on supply roads and it even allows the destruction of the supply fleet and thereby to cut all supply to the beaches!
The solution is realtive simple, I created this sea-road network 2 hexes from the beaches, and put a super-river between the sea-road supply line and the beaches (these super rivers can't be seen, as they are masked by the deep sea hex), over which the sea-roads connected the supply point with the beaches. Than I destroyed all bridges over these super rivers and thereby cut all supply to the beaches.
If a player wants to get the supply flowing again, he has to move a special merchant-fleet/supply unit onto this destroyed-bridge hex (it is a ferry-bridging unit with some engineers and ferry-bridging squads), which will than work as a bridge (it should NOT repair the bridge, just stand there), allowing the supply to flow to the beach again. But if this merchant-fleet unit is destroyed, all supply will be stopped again.
And as this hex is treated as deep water, no unit can enter it from the land, not even a merchant-fleet unit should it for whatever reason beeing pushed off that hex. The only way to enter this hex is in embarked status.
This is the overview from a test scenario (scenario is attached to this post), it shows the supply road network and the blown-bridge hexes.
http://mitglied.lycos.de/berger50/supply-Overview.jpg
This is what happenes to a landing force without a supply unit to connect the beaches to the supply network, they are out of supply.
http://mitglied.lycos.de/berger50/supply-Landings_without_supply.jpg
This is the same landing, but now with a supply unit present to connect the beaches to the supply network.
http://mitglied.lycos.de/berger50/supply-Landings_with_supply_unit.jpg
Please note that the supply starts to flow even while the supply unit is still embarked, landing forces will thereby be supplied from day 1 of their invasion. This is also a pretty good simulation for supply that has to be landed onto the beaches, the embarked unit is pretty vulnerable to enemy air attacks and wont survive long without total air supremacy. Additionally it consumes shippment points, lowering the amount of troops that can be transported, as these ships are now used for supplys instead.
It's also still mobile, so should the need arrise to supply a different part of the landing zone (maybe because your units got cut off somewhere by a counterattack) you could simply move this supply fleet to a different part of the network, which of course always holds the risk that you'll leave your protective area and have to move out of fighter cover, putting your entire merchant fleet at risk.
To simulate the mulberry ports I suggest that the player disembarks this supply unit at this hex, supply will still flow, units still can't be pushed onto that hex, the mulberry is now stationarry and has a greater resistance against enemy air attacks.
Designers can also simulate difficult beaches where it would be hard to land supplies or which are too far away from your own harbors, and lower the supply to this locations by using +distance hexes.
This is a landing with a +1 distance put onto the hex where the supply unit is parked:
http://mitglied.lycos.de/berger50/supply-Distance(1).jpg
As you can see, the first few hexes are still in 50 supply.
Now the same situation with a +20 distance hex at the same location:
http://mitglied.lycos.de/berger50/supply-Distance(20).jpg
I hope this'll help to better simulate some of the difficulties planers had when preparing a seaborn invasion :)
Ben Turner
25 Jul 06, 10:24
Very nice. A number of variations available on this. For example enemy naval units standing astride the sea road would block supply.
Good idea. I've used sea railroads, adjacent but not connected to land hexes to prevent movement over the sea supply lines. I would like to test how it could work with your "supply convoy".
Please could someone explain why the cut-off units are still supplied? And yes, the position of the merchant fleet unit is intended. If the merchant fleet is out of the supply network they are not supplied, but as soon as it is anywhere inside the network all cut off units are supplied. This would mean tracing supply through enemy and/or unpassable (for supply) terrain without air transport capacity.
http://img127.imageshack.us/img127/416/supplytestrf3.png
Looks good. The ability to have different supply levels depending on the landing location is useful.
Secadegas
25 Jul 06, 12:18
Please could someone explain why the cut-off units are still supplied?
Good idea, Kraut
and good question, Telumar
Ben Turner
25 Jul 06, 12:25
This would mean tracing supply through enemy and/or unpassable (for supply) terrain without air transport capacity.
Supply can be traced through enemy territory. This has always been the case and is also the root of many erroneous claims that units are receiving supply by air.
Only terrain, enemy units and unoccupied enemy ZOCs block supply.
Good idea, Kraut
and good question, Telumar
Supply isn't determined by hex possesion. It's determined by whether there are enemy units around to block the supply lines. In the picture there are no enemy units to block the flow of supply.
Good idea, Kraut
and good question, Telumar
I wished i had not to ask this question. Kraut's idea is so brilliant. Any ideas yet?
Supply can be traced through enemy territory. This has always been the case and is also the root of many erroneous claims that units are receiving supply by air.
Only terrain, enemy units and unoccupied enemy ZOCs block supply.
You save the day, Ben. I will test it by sending force2 units to block supply.
Et voilá !
http://img127.imageshack.us/img127/3166/supplytest2hx6.png
Telumar, I think this is the situation you wanted to see (in your las picture the unit would be cut off in eitehr way as it is completely surrounded by enemy units:
http://mitglied.lycos.de/berger50/supply-cut_off_1.jpg
http://mitglied.lycos.de/berger50/supply-cut_off_2.jpg
The dark red marks where 've moved the enemy units, and the light red it a unit's ZOC through which no enemy supply can be traced.
This situation nicely demonstartes 2 beachheads who are seperated by force 2's troops, and only the beachhead with an assigned supply unit / merchant fleet will receive supply.
Panzer-War
25 Jul 06, 13:52
Quite clever, Kraut.
Yes, indeed. I am so glad that it works. Good work, Stefan. Can't wait to see it in game, and it would be such a nice and good solution for the WF 44-45 Szo edition scenario!
- der andere Stefan.
Kraut, you're a freakin genius. Like, wow. I mean...wow...EA coudl seriously benefit form this, as well as WF '44, and every other scenario with possible sea invasion...I can't put into words hwo impressed I am. Genius!
*Speechless*
Dicke Bertha
25 Jul 06, 21:03
I don't understand supply too well, so sorry if this is a silly question.
Is it the composition of the supply unit that will determine the total level/amount of supply available? What then for Westfront44 if we decide to land at Bordeaux instead of Calais. The supply possibility at Bordeaux should be worse (arguably) so will we need to have different supply units for different sectors? How do we factor in variations in the total available supply (suppose we make an other invasion, and thus 'dilute' the first invasion site's supply)?
I don't understand supply too well, so sorry if this is a silly question.
Is it the composition of the supply unit that will determine the total level/amount of supply available? What then for Westfront44 if we decide to land at Bordeaux instead of Calais. The supply possibility at Bordeaux should be worse (arguably) so will we need to have different supply units for different sectors? How do we factor in variations in the total available supply (suppose we make an other invasion, and thus 'dilute' the first invasion site's supply)?
Distance hexes?
Around Calais we have hexes distance X broduex X+5...
As to the second question: No idea.
The idea is very neat but in some cases it is very unforgiving. Probably it is best suited for scenarios which will see almost no opposition (like Normandy scenarios) and is reserved for giving the attacker more options and giving the scenario designers more ability to allocate different supply to different ports.
Some notable problems I found while playing around if used in a scenario where you want the give the opposition to actually hit your "supply ships".
1. It is an all or nothing unit. Damaging the unit has no effect on supply. I added air units to the test scenario and even with only 20 some odd ferrying squads left, the unit continued to channel full supply through the gap.
2. You need fairly high force recon to locate such a unit sitting at the point of the destroyed "road".
3. The attacker would most likely protect this supply ship unit with lots of AAA and Air superiority missions meaning that it is probably a very high risk attack you are making for your bombers.
This means the defender will have very real problems locating the "shipping", more so than is realistically it should have been (since there is no "fly out and look for ships option) unless you give the defender abnormally high force recon. Also once discovered, the defending player will probably have a tough call to make as any attack mission on such a unit will cost him a lot of aircraft but at the same time he needs to evaporate the unit or the entire effort was wasted.
It is also harsh on the attacker in that if the defender does pile on all indirect fire units possible and evaporates the unit, the entire invasion is basically off until reconstitution.
Not trying to ding the idea, just pointing out some difficulties that could arise. Certainly it is not a good idea for every invasion scenario.
The idea is very neat but in some cases it is very unforgiving. Probably it is best suited for scenarios which will see almost no opposition (like Normandy scenarios) and is reserved for giving the attacker more options and giving the scenario designers more ability to allocate different supply to different ports.
Well, I think every invasion should only be possible with overwhelming air and sea superiority, thats one of the reasons why the germans never tried Sealion, because they knew they couldn't risk it as long as the RAF and RN were still operational. So, any solution that requires such essential operational necesarities is a good solution IMHO ;)
With the old system of supply points at the beach an invasion could be successul without having anything in the air or sea, as there is no sea interdiction in TOAW and cutting off the supply to the invasion forces would be impossible.
1. It is an all or nothing unit. Damaging the unit has no effect on supply. I added air units to the test scenario and even with only 20 some odd ferrying squads left, the unit continued to channel full supply through the gap.
That is true, but sadly that's a direct result of TOAWs supply system. Within the current game system (that includes TOAW III) there simply is no way to dynamically limit the supply flow, it's all or nothing.
2. You need fairly high force recon to locate such a unit sitting at the point of the destroyed "road".
Well, theather recon is something the scenario designer controls, which could be anything from 100% (modern) to very low (WW1). So, depending on the scenario it'll be sometimes almost guaranteed, sometimes almost impossible to spot the supply fleet, but that's no real weakness of the supply model but rather an intended feature to reflect the capabilities of the simulated timeframe.
3. The attacker would most likely protect this supply ship unit with lots of AAA and Air superiority missions meaning that it is probably a very high risk attack you are making for your bombers.
... and he better does that, or suffer the consequences :D About the AAA: thats again a scenario designers decision, in WW2 merchant ships had a light AAA on board, so some AAs might be justified.
If the attacker would be indeed forced to keep a keen eye on his supply force, and has to keep a good portion of his air force on air superiority missions to protect them, that would make me really happy, because that's just what should happen. Just imagine what the german Ju-87s would have done to the dens stream of allied supply ships towards the D-Day beaches, had the allies not protected them with their own fighters :bite:
This means the defender will have very real problems locating the "shipping", more so than is realistically it should have been (since there is no "fly out and look for ships option) unless you give the defender abnormally high force recon. Also once discovered, the defending player will probably have a tough call to make as any attack mission on such a unit will cost him a lot of aircraft but at the same time he needs to evaporate the unit or the entire effort was wasted.
Discovering the supply units is already a little bit easier as it sits on a road, and road hexes have a higher chance of beeing revealed by theather recon. If the scenario designer really wants the fleet to be spotted he could add airports to those hexes as those have an even higher chance of beeing spotted.
About the evaporation: true, but than again, the scenario designer can easily influence how easily the supply unit will sink (evaporate) by assigning more/less equipment to its TO&E, or by changing the supply % of its formation to influence how quickly a supply unit recoveres from an attack. Such a unit at 1% formation supply would hardly receive any replacements, so if your planes destroy only 20% each turn, the supply unit will still get weaker every turn, as they'll get fewer replacements than necessary to replace the losses.
It is also harsh on the attacker in that if the defender does pile on all indirect fire units possible and evaporates the unit, the entire invasion is basically off until reconstitution.
True, but again, thats just how it should be :) Lose your merchant fleet and you'll be in deep trouble :shock:
If the scenario designer wants he can add a second or third supply fleet to the attackers OOB if he thinks that's justified, but than better start protecting them after you lost your first one :p
Not trying to ding the idea, just pointing out some difficulties that could arise. Certainly it is not a good idea for every invasion scenario.
Every feedback is welcome, and I don't really expect every scenario designer to blindly adept it, it's just ment to be another tool in the toolbox, use it if you like it, use something else if you are looking for a different 'effect' for your scenario :smoke:
Well, I think every invasion should only be possible with overwhelming air and sea superiority, thats one of the reasons why the germans never tried Sealion, because they knew they couldn't risk it as long as the RAF and RN were still operational. So, any solution that requires such essential operational necesarities is a good solution IMHO ;)
With the old system of supply points at the beach an invasion could be successul without having anything in the air or sea, as there is no sea interdiction in TOAW and cutting off the supply to the invasion forces would be impossible.
I think the tried and true interdiction model in the game which subjects penalties to supply probably would work better in contested cases. And resupply does occur in the face of enemy air onslaught. The destroyers supplying Tobruk garrison during the North African campaign and those which supplied the Japanese in Guadalcanal ran the gauntlet of air power frequently. The Italian merchant fleet supplied Rommel even under heavy sea and air interdiction. They took lots of losses but it wasn't as if the supply was squeezed dry.
... and he better does that, or suffer the consequences :D About the AAA: thats again a scenario designers decision, in WW2 merchant ships had a light AAA on board, so some AAs might be justified.
If the attacker would be indeed forced to keep a keen eye on his supply force, and has to keep a good portion of his air force on air superiority missions to protect them, that would make me really happy, because that's just what should happen. Just imagine what the german Ju-87s would have done to the dens stream of allied supply ships towards the D-Day beaches, had the allies not protected them with their own fighters :bite:
.....
About the evaporation: true, but than again, the scenario designer can easily influence how easily the supply unit will sink (evaporate) by assigning more/less equipment to its TO&E, or by changing the supply % of its formation to influence how quickly a supply unit recoveres from an attack. Such a unit at 1% formation supply would hardly receive any replacements, so if your planes destroy only 20% each turn, the supply unit will still get weaker every turn, as they'll get fewer replacements than necessary to replace the losses.
I agree that to some extent, but the fundamental problem of all or nothing is still there. I must make the decision to really pile on attack aircraft and risk a lot of my assets for a 100% win or I lose everything.
For example the hypothetical storm of every last Ju-87 on the beachheads might have produced catostrophic losses for the Germans but maybe it would have been worth it if they cut down the Allied supply to 50% by sinking half the transports.
In this case though, when I send my suicide storm of Ju-87s, 50% damage isn't going to cut it and I will have probably lost all my aircraft for 0 effect because I lost on the coinflip. Conversely if you lost the conflip, well game is over.
Even if we pad it so that you could chip away at the unit and then evaporate the ships over 4-5 turns of combat, I might really need the supply reduction now rather than later where 4-5 turns costs me a lot.
Every feedback is welcome, and I don't really expect every scenario designer to blindly adept it, it's just ment to be another tool in the toolbox, use it if you like it, use something else if you are looking for a different 'effect' for your scenario :smoke:
For sure. I just wanted to raise the point that using your trick as a method to try and simulate air (or sea) attacks on supply convoys probably isn't the way to go. Standard interdiction via aircraft or modeling naval intervention with events/theatre options might be a better way to go.
Your ability to create different supply values for different hexes using the +distance settings as well as the inherient flexibility of the system to let you restrict attackers to a certain number of beachheads by limiting how many "fleets" they have is really great though.
I think the tried and true interdiction model in the game which subjects penalties to supply probably would work better in contested cases. And resupply does occur in the face of enemy air onslaught. The destroyers supplying Tobruk garrison during the North African campaign and those which supplied the Japanese in Guadalcanal ran the gauntlet of air power frequently. The Italian merchant fleet supplied Rommel even under heavy sea and air interdiction. They took lots of losses but it wasn't as if the supply was squeezed dry.
Well, in theory you are correct, but again the game engine doesn't allow us to let it handle these aspects of the war, as it simply completely fails in doing it.
One reason is that interdiction is always simulated across the entire map, so if you have a map of western europe to play a game of 1944-45 western front, you cant restrict your interdiction to the D-Day landing beaches, it will always include Berlin, too. So, even with the allied superiority in the air their interdiction level will not rise above 2% (see the West Front 44-45 scenario) and therefore supply reduction by interdiction will remain meaningless really.
Next is that even if the german Luftwaffe would manage to fly interdiction missions a) their supply reduction to the allies would be meaningless, too, and b) they can't interdict anything at sea. Interdiction strikes only happen on units moving over land, I have never seen an interdiction strike on a sea convoy.
So this interdiction you describe which could stop sea movement / sea resupply... it is impossible to do with this game, it simply does not simulate any of this. Maybe with the development of TOAW III we'll see some improvement here sometime in the future, but at the moment it simply can't be done.
I agree that to some extent, but the fundamental problem of all or nothing is still there. I must make the decision to really pile on attack aircraft and risk a lot of my assets for a 100% win or I lose everything.
For example the hypothetical storm of every last Ju-87 on the beachheads might have produced catostrophic losses for the Germans but maybe it would have been worth it if they cut down the Allied supply to 50% by sinking half the transports.
In this case though, when I send my suicide storm of Ju-87s, 50% damage isn't going to cut it and I will have probably lost all my aircraft for 0 effect because I lost on the coinflip. Conversely if you lost the conflip, well game is over.
Even if we pad it so that you could chip away at the unit and then evaporate the ships over 4-5 turns of combat, I might really need the supply reduction now rather than later where 4-5 turns costs me a lot.
Well, your only chance is that if your all-out attack manages to sink 50% of his supply unit that your opponent might pull it back to prevent it from sinking. Besides that, there is indeed no way to simulate a reduced supply stream, but thats again a limitation of the game engine. It only checks whether supplies can flow from hex x to hex y, and the only supply drops appear after the set supply radius is reached or in muddy terrain. Supply will cross a super river at a 100% rate as long as the engineer unit has 10% major ferry capacity, and will drop to 0% supply as soon as the engineer unit dropps to 9% major ferry capacity.
So, again, to have this issue fixed there is nothing I can do, you can only wait whether the TOAW III developers will someday address this issue.
For sure. I just wanted to raise the point that using your trick as a method to try and simulate air (or sea) attacks on supply convoys probably isn't the way to go. Standard interdiction via aircraft or modeling naval intervention with events/theatre options might be a better way to go.
Well than, how would you simulate attacks on supply convoys by events? (as I already explained earlier, interdiction does not work) Give player Y a xx percent chance to sink player A's supply convoy? What if players y's navy was sunk already or is operating somewhere else, there is no way as to check this by events, so player 2 will still have this TO despite his navy beeing out somewhere else.
And what if the event succeeds, what do you do than... reduce player 1's supply level? well, that would affect the entire scenario, so in the case of a WW II scenario, reducing the supply because of an attacked D-Day landing foce would also reduce the supply of the soviet army, again, the supply model is global, it affects everything on the map.
I said it already but I will say it again, what you want to see simulated is sound and how it should work, but you are hitting the limitations of the game engine here, it simply can't be modeled with TOAW CoW or III at the current state of the game.
First we have to wait for a complete overhaul of the entire supply model, but the developers already said that such a thing should not be expected until TOAW IV, so until than we have to live with what we got now.
Ben Turner
05 Aug 06, 08:16
I think the tried and true interdiction model in the game which subjects penalties to supply probably would work better in contested cases.
Supply reduction due to interdiction is global. This won't work.
And resupply does occur in the face of enemy air onslaught. The destroyers supplying Tobruk garrison during the North African campaign and those which supplied the Japanese in Guadalcanal ran the gauntlet of air power frequently. The Italian merchant fleet supplied Rommel even under heavy sea and air interdiction. They took lots of losses but it wasn't as if the supply was squeezed dry.
To take just your last example, Malta was under more or less constant air attack during the period of Rommel's successes, making its ability to interdict supply to North Africa severely limited. As soon as Malta was given a chance to rebuild its offensive capability the supply situation became incredibly desperate. The Italians went to increasingly great lengths to avoid being attacked by the aircraft and submarines from Malta, but intelligence was always able to provide their routes and the aircraft and ships were generally able to find and sink them.
Even if we pad it so that you could chip away at the unit and then evaporate the ships over 4-5 turns of combat, I might really need the supply reduction now rather than later where 4-5 turns costs me a lot.
You do have a valid complaint. Kraut's solution is best for strategic scenarios where, more than the loss of supply at any one point, it is the loss of the landing craft to be able to carry out a major landing that is the point. For operational scenarios covering just one or two landings, one can generally cope with things using the event engine, because the number of possible situations is finite.
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