Bogging data

[TheVulture]

I did finally get around to getting some hard data on road-side bogging, and it is fairly dramatic.

The test

I have four platoons of identical panthers (each platoon is 5 pathers). The map is completely flat wet grass, with some roads overlaid.

Platoon 1 drives over the flat wet grass for 2km

Platoon 2 drives along dirt toads for 2km, staying in the middle of the road

Platoon 3 drives half-on, half-off dirt roads for 2 km, staying on the edge of the road / over the side ditch for the whole distance

Platoon 4 has roads laterally across their path every tile, so they drive on to a road (at 90 degrees) and off again every 8 meters for 2 km (roads are east-west, tanks drive north across 250 separate dirt roads.

All vehicles have a single fast movement order plotted.

Results

Platoon 1 on wet grass has 4 bogs. 3 of the vehicles recover, 1 is immobilised. Boggings occur at 638, 1598, 1622 and 1694 metres. 4 of 5 vehicles complete the 2km track (in 209 seconds for the unbogged vehicles).

Platoon 2 on wet dirt roads has 1 bog (at 1554 metres) which recovers. All 5 vehicles complete the 2km course (in 192 seconds for the unbogged vehicles).

Platoon 3 driving along the edges of roads didn't fare well. There were 10 total bogging events and all tanks ended up immobilised. Boggings occurred every 44 meters on average, and the tanks were immobilised after 4, 12, 12, 24 and 384 metres. Average distance to immobilisation was 87 metres.

Platoon 4 did a little better. All 5 tanks again ended up immobilised, and they accumulated 21 total bogging events. Average distance between boggings was 120 metres, and average distance to immobilisation was 500 metres (immobilisations at 120, 244, 248, 936, 950 metres).

I suspect platoon 4 did so much better than platoon 3 because they only spend some of their time in the half-on half-off state, since some of the time they were entirely on a road or entirely on the grass. But that is just a guess.

Summary

For driving in wet ground conditions on level grass / dirt road combinations we get the following distances between boggings and immobilisation

On Road Bogging: ~10km Immobilisation >> 10km

On Grass Bogging ~2km Immobilisation ~10km

Entering/leaving road Bogging 0.12km Immobilisation 0.5km

Partially on road Bogging 0.04km Immobilisation 0.09km

So basically, driving with one side of a vehicle on the road and one off, you will bog roughly 100 times more frequently than driving purely on the road or on the grass.

So the lesson to learn from this is simple: do everything you can to avoid moving on to or off roads (at leats dirt roads). if you have to do so, get off the road as quickly as possible. If you are driving along a road, be extremely careful to make sure you stay precisely on the road and don't put a wheel or track off the side.

[anton meise]

Interesting, what would be the oncome if the tanks move with normal/slow speed?

[Magpie_Oz]

So the lesson to learn from this is simple: do everything you can to avoid moving on to or off roads (at leats dirt roads). if you have to do so, get off the road as quickly as possible. If you are driving along a road, be extremely careful to make sure you stay precisely on the road and don't put a wheel or track off the side.

Sounds pretty much like Real life

[SlowMotion]

"driving with one side of a vehicle on the road and one off, you will bog roughly 100 times more frequently than driving purely on the road or on the grass."

This was a very useful test from you.

[winkelried]

@TheVulture

interesting test. how many times did you run the test? with my own testing (just plain grass in different states) i run the tanks on 16 km stretch and found that the distribution of the bogs/immo is not very linear. so with a relatively short drive of 2 km you could see some artefacts. you would need longer distances to get statistically reliable data.

[thejetset]

Thanks for the info!

[Chainsaw]

this can explain why some people notice bogging more then others. I am one of those who rarely get bogged vehicles. BUT Im pretty detailed when putting my waypoints down (detail nerd) so they move ON the road. So those that get boggs frequently are a bit "sloppier" and sets the waypoints "wrong" so the vehicles move allot more on the road verge and get stuck.

thanks for the data!

[Redwolf]

So the German army broke down every 10 km during Barbarossa?

AAA must have been busy.

[SlowMotion]

The part that I have trouble understanding is that tanks would immobilize 100 times more often just because one track is on dirt road and one track on grass - if both tracks are at same level. I do understand fording and serious mud, but not this. If the road was like most modern roads - road clearly higher than surrounding ground - then it would make sense to me. But if the road is more like a path in forest, maybe 10 cm deeper than ground around it....

[winkelried]

So the German army broke down every 10 km during Barbarossa?

AAA must have been busy.

i don't think that this is the right interpretation of the data. have a look at http://www.battlefront.com/community/showthread.php?t=101135&highlight=bogging&page=5 where we have more data points. there you can conclude, that on dry ground a tank would bog once and would go immobile also once every 880 kms on dry ground. not too bad IMHO. Especially interesting is the graph on http://www.battlefront.com/community/showthread.php?t=101135&highlight=bogging&page=7

[DavidFields]

This would in essence be a penalty for AFVs using the road, imposed on those who are less detail oriented. That is not exactly, in my opinion, what this game needs.

If the data in this thread is correct...perhaps the idea is to dissuade people from using the fast command all the time on roads? But, is this really a critical, and interesting, detail decision that a player should be pre-ocuppied with? Even if IRL one bogs more by having one wheel/track on the road and one off, IRL one has a dedicated driver maneuvering the machine, and I am not sure we should be taking the time to be every driver in the simulation. IRL the driver is going to slow down at turns, and generally drive responsibly. To require extremely detailed way-points to simply move a vehicle seems unfun.

If I had 5 Panthers in a scenario--a very exciting thought, as I have yet to play with much german armor, almost delaying it out of anticipation of how much fun it will be--, and 4 of them bogged at 4, 12, 12, 24 meters because I happen to set them up with a track off the road, with a fast order because I was moving them into attack position (particularly with a Panther, with its supposed maneuverability), I would be unhappy.

If is was, like, turn 30, and I had received the 5 as a reinforcement, I would be particularly unhappy--particularly if I did not know exactly what mistake I had made--that I should have just put them in the grass.

Not that we need to be happy all the time, but it does not seem reasonable to make players pointlessly unhappy, without explanation.

[Sgt Schultz]

I agree it is a harsh penalty to pay for driving along a ditch. But the test was at Fast. Imagine throwing a track because you caught a few rocks in the ditch. It is not so much you got stuck, but "bog" also simulates throwing a track. Go Fast on Rocky and see what happens. You ain't bogged... you ate a rock.

What you may want to look at is how long the tanks last with a Slow order along the ditch.

Once I got stuck in a ditch I just made sure I kept the units either ON or OFF the road.

Where is our resident Sherman crewman(retired)??

Which is more prone to throw a track at high speed driving in a ditch along a road.... tiny wheeled Christie or big wheeled Tiger suspension??

[Erwin]

Foe what it's worth I find I have a high rate of bogging/immobilizations moving carefully and SLOW. The problem caused by being partly on and off the road is interesting. Will try and avoid that in future. But, as Rankorian said, is this irritating/annoying detail really needed in CM2? Is this CM: TANK DRIVER SCHOOL?

[Redwolf]

To me looks like some complicated piece of code that would make the game better if it was simply turned off.

[YankeeDog]

To me looks like some complicated piece of code that would make the game better if it was simply turned off.

I agree.

It is technically true that driving with one side of a vehicle on a hard, good traction surface (like a road), and the other one a soft, loose surface (like a gravel verge or drainage ditch paralleling a road) is a great way to get stuck. The vehicle tends to yaw and skid in this situation due to the difference in traction on each side of the vehicle, making it more difficult to control.

However, as Erwin excellently put it, this is not "CM: Tank Driver School", and I don't think it is desirable to expect the player to micromanage the path of vehicles to this degree of fidelity. Furthermore, it's not actually very easy to micromanage in this way even if you want to -- CM's movement controls aren't really set up to give the player this fine a degree of control over precise path.

So yeah, put me in the "turn it off" column. I think we can abstractly assume that tank drivers know better than to drive along with one track in the drainage ditch by the side of the road.

[LongLeftFlank]

Platoon 2 drives along dirt toads for 2km, staying in the middle of the road.

Your typo reminds me of a tale from my Lonely Planet backpacker days. One night early in the monsoon season I was riding a motorbike in Northern Thailand. The tarmac roads were wet but still warm from the sun which seemed to make them irresistible to hordes of tiny yellow frogs. So there I am, driving through the paddies watching one frog after another take a magnificent leap in my headlight to land perfectly in front of my tire -- Pop! Pop! Pop! for miles on end, grossing me out the entire way. So if we are indeed reincarnated, I'm pretty sure I know what I'm coming back as in the next life. Selah!

[sburke]

Your typo reminds me of a tale from my Lonely Planet backpacker days. One night early in the monsoon season I was riding a motorbike in Northern Thailand. The tarmac roads were wet but still warm from the sun which seemed to make them irresistible to hordes of tiny yellow frogs. So there I am, driving through the paddies watching one frog after another take a magnificent leap in my headlight to land perfectly in front of my tire -- Pop! Pop! Pop! for miles on end, grossing me out the entire way. So if we are indeed reincarnated, I'm pretty sure I know what I'm coming back as in the next life. Selah!

Man I just ate breakfast, damn glad it wasn't frog's legs.

[TheVulture]

I ran the test on slow when I had a few minutes spare. There were minor variations, but the results were pretty much the same as for fast. This time all panthers completely on grass or completely on road got to the end of the 2km with no immobilisations and occasional boggings among the platoon. The half on, half off platoon averaged about 100 metres before becoming immobilised. The ones driving across perpendicular roads averaged about 500 metres before becoming immobilised.

The stats certainly aren't high enough to show any difference between slow and fast moves; they bog at approximately the same rate, and any difference is far, far smaller than the difference of where you drive.

As others have said, what it all amounts to is that you have to be very careful driving on roads to make sure you never put a wheel off the side of the road. For tanks navigating turns on narrow roads, this could be quite a problem...

[thejetset]

Anyone have any info on how wheeled vehicles do when driving on railroad tracks??

[SlowMotion]

...you have to be very careful driving on roads to make sure you never put a wheel off the side of the road. For tanks navigating turns on narrow roads, this could be quite a problem...

Or tanks going around another vehicle in front of them, possibly because it has been destroyed or immobilized in the middle of the road...

[Kanonier Reichmann]

It seems clear from the test that some serious study from the Beta testers would be highly desirable.

Regards

KR

[A Canadian Cat]

So basically, driving with one side of a vehicle on the road and one off, you will bog roughly 100 times more frequently than driving purely on the road or on the grass.

So the lesson to learn from this is simple: do everything you can to avoid moving on to or off roads (at leats dirt roads). if you have to do so, get off the road as quickly as possible. If you are driving along a road, be extremely careful to make sure you stay precisely on the road and don't put a wheel or track off the side.

Wow those are significant results. 100 times more likely just because of the road grass interface. That explains that there are many people posting about becoming immobilized on the edge of roads.

The test you created is pretty much like the one I was working on except I was not planning to drive perpendicular across road tiles - good idea.

To me that seems wrong I suppose I could be convinced that it is a risky moment with ditches involved but 100 times more risky that does not seem right. Even if the number was 10 times more risky I would still think it seemed high.

[Chek]

It seems to me that one is going to sink more uniformly on soft ground as the weight of the vehicle is distributed more evenly,thus taking longer or becoming less likely to get to the point where you can't move.

When half on half off,the road will be higher upsetting the centre of gravity placing more weight on the lower softer side causing it to sink faster and become immobilised faster due to the belly of the vehicle coming into contact with the firm edge of the road.

Plus the vehicle being slewed to one side and as previously mentioned various rocks and debri on the roadside increasing a track being thrown.

Of course these are all just musings from the comfort of an armchair.

I don't have a problem with it being awkward or frustrating as long as it models reality as accurately as possible which to me this appears to be doing.

[Kanonier Reichmann]

I don't have a problem with it being awkward or frustrating as long as it models reality as accurately as possible which to me this appears to be doing.

The test the OP ran produced the following results when running Panther tanks half on, half off the road. I'll quote... Boggings occurred every 44 meters on average, and the tanks were immobilised after 4, 12, 12, 24 and 384 metres. Average distance to immobilisation was 87 metres.

One could quite rightly argue that the 384 metre distance was the outlier in this test. If so and with the outlier discarded, the average distance before becoming bogged would be just 13 metres. I find this just a tad absurd for a Panther tank that was widely regarded as having one of the best suspension, flotation, ground pressure characteristics of any tank in WW II.

Regards

KR

[Redwolf]

The test the OP ran produced the following results when running Panther tanks half on, half off the road. I'll quote... Boggings occurred every 44 meters on average, and the tanks were immobilised after 4, 12, 12, 24 and 384 metres. Average distance to immobilisation was 87 metres.

One could quite rightly argue that the 384 metre distance was the outlier in this test. If so and with the outlier discarded, the average distance before becoming bogged would be just 13 metres. I find this just a tad absurd for a Panther tank that was widely regarded as having one of the best suspension, flotation, ground pressure characteristics of any tank in WW II.

People would have never bothered with those tank things, any tank, in the first place if that was accurate.