Trenches -- a bogging bug?

[MrSpkr]

In a recent PBEM, I defended against an Allied attack in the desert. As part of my defense, I used a lengthy (100m+) trench line as a forward position. I filled this with various infantry units, all of which were extremely short on AT weapons.

My opponent had a few light tanks. He proceeded to move one to the far right flank of my defensive position, then turned and drove his tank right down the length of the trench at full speed! My infantry (veterans and regulars all) reacted by crawling out of the trench (where they came under a hail of small arms fire). His tank never bogged, much less became immobilized, by this unusual manuever. I chalked it up to good luck on his part.

Then his tank turned around and did it again. Twice.

He never bogged, never immobilized, but certainly managed to force my troops out of the trench (and of course, I snuck them right back in) three times, at which point his infantry was able to swarm the trench and take it.

This bothered me, as I thought that a tank crossing a trench was supposed to have a much higher than normal chance of bogging or immbilization. I was particularly surprised to see that his light tank didn't even slow down significantly. I believed that a tank driving down the middle of a trench (not only visually, but as shown in the 'terrain type' window for that tank) might actually have a few problems, especially a small tank lacking the length or power to pop a track out of a trench.

So, being bored, I ran a test. I set up eleven trench lines, each about 200m-225m long. I selected fifteen MkVIb British tanks. Eleven would run the length of the trench line at top speed, while four would travel perpendicularly across the trenches at top speed. Each vehicle was to make ten passes, and the resulting bogs/immobilizations would be tracked accordingly. The ground was very dry, the weather, hot and clear, and the time, mid-day.

I was shocked at the results. After sixty turns, not one tank, either traveling along the trenches or across them, had so much as bogged, let alone become immobilized. The speed of the vehicles in the trenches was dramatically slower than the speed demon outside the trench, though this was relative (the small, fast vehicles on the trenches still moved at a reasonable speed, though the control vehicle was approximately five times faster).

Puzzled, I ran the test again. And again. Same result each time.

Then I consulted the CM manual -- it states "Only fully-tracked vehicles are allowed to enter or cross trenches, but do so very slowly and at great risk of bogging." CMAK Manual, p. 58 (emphasis added).

Really? You couldn't prove it by this experiment. I recognize the ground pressure of the MkVIb is significantly lower than the average vehicle (only .58 kg/sqcm), but I wouldn't think ground pressure would factor into bogging on trenches nearly as much as, say, bogging in soft ground or mud.

I ran additional tests using larger vehicles. I selected six Stuart IIs (ground pressure .72 kg/sqcm) and six Lee's (ground pressure .88 kg/sqcm); five of each would run along the trenches while one of each would run across the trenches.

In this one, the Stuarts all finished the course -- one bogged for less than 15 seconds. The Lees that moved along the trenches did not finish the course (apparently, 80 turns is not enough for them to run 2km of trenchlines); two of these tanks bogged, one for twenty five seconds; the other for less than 15 seconds. The Stuart and Lee running perpendicularly across the trenches both finished the course and never bogged.

Now I was concerned, a bit, so I decided to try using some heavyweights on the same map using 120 turns. I used the heaviest Allied ground-pressure vehicles I could find -- a dozen Matilda II's (ground pressure 1.12 kg/sqcm). NOW I would get some bogging and immobilizations, right?

Not really. On turn 57, two Matilda's running along the trenches bogged down. One became immobilized after 36 seconds; the other immobilized after 52 seconds. These were the first vehicles to bog or immobilize in this test. On turn 63, another Matilda running along the trenches bogged. On turn 64, another Matilda bogged. The first of this pair began moving after about 90 seconds; the other resumed moving after 214 seconds.

On turn 68, one of the Matildas that bogged earlier bogged again. It remained bogged for 155 seconds, then resumed movement.

On turn 88, the Matilda that had bogged twice previously bogged again for about six seconds, then resumed movement. Perhaps the driver stole some grog from the Royal Navy?

On turn 96, another Matilda moving along the trench bogged, then immobilized 72 seconds later.

On turn 115, one of the Matildas moving across the trenches bogged for 67 seconds, then resumed movement. This was the first vehicle in ANY of the tests that bogged moving perpendicularly across the trenches.

The clock ran out; none of the Matildas had finished the course; three were immobilized (25% of the force).

The final results are that eight of the Matildas bogged, resulting in three immobilizations.

I decided to run the test again, to see if these results were a fluke (particularly given the fact NONE of the Matildas bogged until turn 57!).

The second time around, one Matilda traveling along the trenches bogged on turn 6, then immobilized 76 seconds later.

On Turn 26, another Matilda (one going across the trenches) bogged; 273 seconds later, it resumed movement.

On turn 49, one of the Matildas moving along the trenches bogged; 40 seconds later, it resumed movement.

On turn 67, a Matilda moving along the trenches bogged; 217 seconds later, it resumed movement.

On turn 79, one Matilda moving along the trenches bogged; 27 seconds later, it resumed movement.

On turn 105, a Matilda moving along the trench bogged; 66 seconds later, it resumed moving.

None of the Matildas finished their routes in the 120 turns allotted.

In this test, then, over the course of 120 turns, six of the twelve Matildas bogged, resulting in one immobilization.

These results are vaguely disturbing. I would have expected the vehicles to bog more often, and immobilize slightly more. Instead, given these results, I believe vehicles are fairly safe running across, or even more importantly, ALONG the trenches to flush out enemy forces. Granted, had their been any infantry with AT weapons or grenade bundles in these trenches, I probably would have lost more tanks; however, the game seems to reward what seems to be a somewhat gamey tactic.

Thoughts, anyone? Is this a bug, or a feature?

Steve

[Boo Radley]

Are you asking if Jim Boggs is a bug, Steve?

I'd have to say, yes.

[MrSpkr]

No, Boo, you intellectually challenged matador.

Now begone to the Ohiosian swamp from whence you came -- I seek more serious answers here than the likes of you can provide.

Steve

[Treeburst155]

Very interesting, MrSpkr. I'd say your opponent stumbled onto a gamey tactic. I hope I get a chance to use it on you too.

Treeburst155 out.

[MrSpkr]

Originally posted by Treeburst155:

Very interesting, MrSpkr. I'd say your opponent stumbled onto a gamey tactic. I hope I get a chance to use it on you too.

Treeburst155 out.

Too late! My uberPanzer will keep you at bay. I hope.

Turn out later tonight, Mike.

Steve

[xerxes]

Ugh, that's rather bad and certainly does sound like quite a bug.

[Jim Boggs]

You should maybe post this in the Official Bug Thread, as it would seem to counter what is said in the manual.

Just curious:

How wide was the average trench?

Is it conceivable that the width of the tank would allow it to bracket it lengthwise?

Did you do any tests other than desert terrain?

[MrSpkr]

Originally posted by Jim Boggs:

You should maybe post this in the Official Bug Thread, as it would seem to counter what is said in the manual.

Just curious:

How wide was the average trench?

Is it conceivable that the width of the tank would allow it to bracket it lengthwise?

Did you do any tests other than desert terrain?

1) I don't know -- the width of the standard trench in CMAK, whatever that is. The trenches were a little less than perfectly straight (some were not laid precisely end to end), but the vehicles traveled straight as arrows, so I would think they would have had to drop a tread in the trench at some point (and if that is not a problem, why would the vehicle speeds slow so much -- I mean, yeah, a MkIVb might be significantly slowed from it's speedy top speed, but why would a Matilda slow down all that much if the only consideration is keeping the tread out of the trench -- Matildas move slow anyway, right?).

2) Possibly, though in the case of the MkVIb, that means we have extremely narrow trenches.

3) No, though I am going to (and going to test Axis vehicles AND test in Italy). I will also test in normal and damp ground conditions.

I haven't seen the bug thread in a while, which is why I posted this one here. If you post link, I'll copy this one to it.

Steve

[Sergei]

Since tanks tend to be ~3m wide, it should be possible. Just getting into/out of the position would be hard, and curves might be dangerous as well.

But if the men want to crawl out of the trenches, then it would seem to offer room for a gamey, ahistorical exploit. In reality a tank above you couldn't really do anything to you except drop grenades from hatches or hope for the trench to collapse, while it would certainly have been an easy target for any AT weapon there was at hand. But infantry TacAI doesn't recognise the benefits of staying in trenches or foxholes.

[MrSpkr]

Originally posted by Sergei:

Since tanks tend to be ~3m wide, it should be possible. Just getting into/out of the position would be hard, and curves might be dangerous as well.

But if the men want to crawl out of the trenches, then it would seem to offer room for a gamey, ahistorical exploit. In reality a tank above you couldn't really do anything to you except drop grenades from hatches or hope for the trench to collapse, while it would certainly have been an easy target for any AT weapon there was at hand. But infantry TacAI doesn't recognise the benefits of staying in trenches or foxholes.

That would seem to be the source of the bug. In addition, I would suspect they would have a higher than normal chance of bogging while travelling along the trench (rather than just across it) due to the chance of a tread slipping into the trench (particularly given the 'blind' nature of driving under fire). However, the game does not appear to reflect either reality.

Steve

[Jim Boggs]

Originally posted by Sergei:

In reality a tank above you couldn't really do anything to you except drop grenades from hatches or hope for the trench to collapse, while it would certainly have been an easy target for any AT weapon there was at hand. But infantry TacAI doesn't recognise the benefits of staying in trenches or foxholes.

When I was in the service during AIT we had to crouch in a pre-made foxhole and allow a tank to run over us, then jump out of the hole and throw a simulated satchel charge on the back deck of the tank.

Needless to say, the guys who were scared had to be dragged out of the foxhole by the Drill Instructor. They had curled up in the bottom and weren't going anywhere!

[MrSpkr]

Originally posted by Jim Boggs:

When I was in the service during AIT we had to crouch in a pre-made foxhole and allow a tank to run over us, then jump out of the hole and throw a simulated satchel charge on the back deck of the tank.

You accountants have all the fun!

Needless to say, the guys who were scared had to be dragged out of the foxhole by the Drill Instructor. They had curled up in the bottom and weren't going anywhere!

So that's how you met Boo, right?

In all seriousness, though, has anyone else encountered this tactic?

Steve

[Seanachai]

I'd say that as long as it's only used against MrSpkr, it's a feature, not a bug.

It's also the funniest thing I've heard of in a long time. Do it again, do it again!

[Brent Pollock]

Stumbled indeed, as I did it as a desperation move to distract the ditch-dwellers. I'd read the manual (as quoted by MrSpkr) and fully expected my little AFV to bog pronto - didn't happen, much to my joy. It continued to cause problems even though it had run out of ammo.

Originally posted by Treeburst155:

Very interesting, MrSpkr. I'd say your opponent stumbled onto a gamey tactic. I hope I get a chance to use it on you too.

Treeburst155 out.

[MrSpkr]

Originally posted by Seanachai:

I'd say that as long as it's only used against MrSpkr, it's a feature, not a bug.

It's also the funniest thing I've heard of in a long time. Do it again, do it again!

You only say that because, if you stand on your tippy-toes, the tank brushes the top of your hat as it crosses the trench, tickling what little hair you have left.

Steve

[MikeyD]

I've seen some photos of ETO U.S. light tanks with small bullet deflector squares welded just below and in front of the bow mg. If you depress the mg all the way the bullets hit the deflector and go straight down. These were specifically designed for trench/foxhole clearing.

But in the real world no tanker in his right mind would straddle a trench and joy-ride down the length of it! That's a fatal accident waiting to happen.

Plus, in CM I had a buttoned Stug killled by 'defenseless' troops when he got too close just last week. All it took was two grenades.

[Jim Boggs]

Originally posted by MrSpkr:

In all seriousness, though, has anyone else encountered this tactic?

Steve

Thanks to you, I'll probably encounter it tonight! :mad: :mad: :mad:

[Slappy]

Here's my mechanics grog take on this. As we all know (or probably should) some fortifications in CM actually change the way the underlying terrain manifests itself. The classic example is barbed wire in woods. LOS across wire is longer in woods than not across wire. As far as I can tell, the wire actually changes the terrain it sits on to open ground for some purposes. My guess is that the same thing happens for trenches w/r/t bogging. That is the trench is assumed to be open ground for some purposes and that one of those is bogging. I've read the manual as well and agree that this seems unintentional (aka a bug).

[MrSpkr]

Originally posted by Brent Pollock:

Stumbled indeed, as I did it as a desperation move to distract the ditch-dwellers. I'd read the manual (as quoted by MrSpkr) and fully expected my little AFV to bog pronto - didn't happen, much to my joy. It continued to cause problems even though it had run out of ammo.

</font><blockquote>quote:</font><hr />Originally posted by Treeburst155:

Very interesting, MrSpkr. I'd say your opponent stumbled onto a gamey tactic. I hope I get a chance to use it on you too.

Treeburst155 out.

</font>

[gibsonm]

Originally posted by MikeyD:

But in the real world no tanker in his right mind would straddle a trench and joy-ride down the length of it! That's a fatal accident waiting to happen.

Probably not, but Engineers seem happy to do it. I seem to remember in Gulf War 2* a US Engineer drove a CEV along a trench offering Iraqi’s the option of getting out and surrendering or a free burial.

*

Gulf War 1 = Iran Vs Iraq

Gulf War 2 = Liberation of Kuwait

Gulf War 3 = Latest effort

[Brent Pollock]

Actually, MrSpkr omitted what was, to me, the best part of the whole trench overrun foray: the tank's initial run at the trench was aimed at scrunching an ATG that was set up therein: mission accomplished, thanks to plenty of surpressing fire.

Crushing ATGs under my tank's tracks has to be my favourite CM past time...accomplishing that little gem is always victory enough, regardless of the final score.

[Holman]

We know that CM includes certain abstractions. Given that no WW2 tanker in his right mind would ever drive down the length of a trench in this way (who knows when the ground might crumble from the edge?), we should probably assume that the tank in question is driving close but alongside the trench in question. This is regardless of the fact that the model is sitting right in top of the trench.

What other choice do you have?

[MrSpkr]

Originally posted by Martyr:

We know that CM includes certain abstractions. Given that no WW2 tanker in his right mind would ever drive down the length of a trench in this way (who knows when the ground might crumble from the edge?), we should probably assume that the tank in question is driving close but alongside the trench in question. This is regardless of the fact that the model is sitting right in top of the trench.

Then why does the manual state there is an increased chance of bogging or immobilization? Additionally, why would veteran infantry in good order then sneak/crawl out of the trench in plain view of the enemy just because a tank drove alongside the trench? Sorry, but there is a bug in here, maybe more than one, involving the behavior of infantry in those circumstances and the chances of bogging or immobilizing your tank by running it through the area.

Steve