How to move tanks without being detected?

[Bulletpoint]

When I move my tanks, I don't want my enemy to hear them and get sound contacts. I think I once read that if I use SLOW, tanks make less noise, is that correct?

What if I use MOVE, QUICK, or FAST, does noise go up with each new speed, or is it a case of SLOW = quiet and all other movement types = noisy?

And is there any rule of thumb about how close to the enemy I can drive my tanks without being heard?

Edited January 18, 2016 by Bulletpoint

[Bud Backer]

I'd like to see some more experienced opinions or knowledge brought forward on what you are asking. My understanding from mentions in other threads was that sound is not changed based on movement speed in any way. In fact, in one thread I recall being told that Hide for vehicles only works in CMBS, making the command useless in WWII titles. I hoped that isn't true. Perhaps some of the experienced testers can elaborate this. 

[RockinHarry]

I´d guess vehicle noises, particularly tanks with all that usual rattling and squeaking can be heard at several kilometers distance. Night time and particular weather conditions can either amplify or diminish noises, of which plain engine noises are more dependent on actual engine speed and gears. But I´d say that movement speed shouldn´t make that much of a difference, as the ever present rattling and squeaking is the more prominent type of noises from the full spectrum and can only be suppressed by not moving at all. Wheeled vehicles would obviously not have that particular problem and I´d suppose that different tanks and tank types might also differ in general noise footprint, composed of engine and mechanical noise sources. Would be interesting to know for sure whether that all is modelled in the game. I´d make a test setup, possibly on a 1x4km size map, various (enemy) tank types and a single FO as listening post, that does not have LOS on the map. Also fiddling with weather conditions and time of day, should then give some basic answers. Other possible noise making factors could be terrain types, vehicle crew experience and maybe experience of the listener. Preferably someone around here has the answer already...

[Vanir Ausf B]

The distance for sound contacts for moving vehicles is about 225-230 meters. Movement speed makes no difference (IIRC it does make a difference for moving infantry, however). For stationary vehicles it is 120 meters or 60 meters with a Hide command (which does presently only work in Black Sea, but it will work in Final Blitzkrieg and I assume the other WW2 games when they are patched).

Also, vehicle units can't obtain sound contacts on enemy units.

Edited January 18, 2016 by Vanir Ausf B

[Bud Backer]

The distance for sound contacts for moving vehicles is about 225-230 meters. Movement speed makes no difference (IIRC it does make a difference for moving infantry, however). For stationary vehicles it is 120 meters or 60 meters with a Hide command (which does presently only work in Black Sea, but it will work in Final Blitzkrieg and I assume the other WW2 games when they are patched).

Also, vehicle units can't obtain sound contacts on enemy units.

Thank you, Vanir. That is exactly the sort of answer I hoped for.

 

[RockinHarry]

That´s pretty short distances (compared to RL) I´d say, but otherwise and for gaming reasons the contact marker stuff somehow needs to fit a map and some direction/location. So thanks, good to know, although in a game I wouldn´t rely or plan with it I think.

[Vanir Ausf B]

So thanks, good to know, although in a game I wouldn´t rely or plan with it I think.

No point against the AI, but I do use it to plan in PBEMs.

[Bulletpoint]

The distance for sound contacts for moving vehicles is about 225-230 meters. Movement speed makes no difference (IIRC it does make a difference for moving infantry, however). For stationary vehicles it is 120 meters or 60 meters with a Hide command (which does presently only work in Black Sea, but it will work in Final Blitzkrieg and I assume the other WW2 games when they are patched).

Also, vehicle units can't obtain sound contacts on enemy units.

 

Your answer is surprising, because in my recent game, I thought I was being very sneaky with my tanks that just arrived as reinforcements.

But then my opponent tells me on game chat "Oh it seems like you just got 3-4 tanks". I'm pretty sure I was way more than 230 metres away from him, and for sure I was out of LOS as there was a slope on the map.

Thanks for answering though. I'm disappointed my moving around on SLOW speed made no difference. I thought that tank engines in real life made more noise when they work harder.

Edited January 18, 2016 by Bulletpoint

[Badger73]

<snipped>

I thought that tank engines in real life made more noise when they work harder.

<snipped>

In real life they did.  Noise increased with engine RPM; either revving when idle or incurring movement loads.  Track noise and rattle also increases with movement speed depending on types of terrain.

What I've read about WW2 indicates that tank noise was usually "masked" instead, not hidden.  Tanks could go undetected when the a sounds of driving rain, howling wind, or artillery impacts were loud enough locally to conceal their movement when such conditions existed.

I do not know how the game treats this kind of ambient noise for AI or H2H play.  Others say that the game does not account for position of the sun as a factor for visibility (meaning that you cannot use a sunrise or sunset behind your troops to degrade enemy observations).  I susepct that "Sound", like "Lighting", is likely not accounted for in such ways (yet) by CMx2.

Great question.  Good answers.  Thanks for asking.

[Pak40]

The distance for sound contacts for moving vehicles is about 225-230 meters. Movement speed makes no difference (IIRC it does make a difference for moving infantry, however). For stationary vehicles it is 120 meters or 60 meters with a Hide command (which does presently only work in Black Sea, but it will work in Final Blitzkrieg and I assume the other WW2 games when they are patched).

Also, vehicle units can't obtain sound contacts on enemy units.

Why would a hide command make a vehicle more quite? Are they actually turning off their engine in that case?

[Bud Backer]

Why would a hide command make a vehicle more quite? Are they actually turning off their engine in that case?

That was my assumption. 

What I think one easily can not consider in terms of sound contacts is that you most likely can hear tanks more than 250m (depending on terrain) away  but will you get a clear idea of where they are that you could localize them within say, 10m of their location? 

To give you a real life example, I was shovelling snow from my drive a few days ago. A dump truck with plough was clearing the roads in the neighbouring street. When I thought it would appear at the end of my street based on noise...it didn't. Gauging its location was trickier than it seemed, and what appeared under those conditions to be a lot closer wasn't. It was also moving, which is the example of the tanks were discussing. That too is a factor that complicates localization - sound travels and propagates at a speed that is not instantaneous, and bouncing off terrain, snowbanks and houses can make it harder to be as precise as I expected to be. 

Just something to consider  

[Bulletpoint]

What I think one easily can not consider in terms of sound contacts is that you most likely can hear tanks more than 250m (depending on terrain) away  but will you get a clear idea of where they are that you could localize them within say, 10m of their location?

Good point, and very important one. In the distance, even the biggest tank in the world would just make a background noise that would be impossible to pinpoint. You might be able to say "I think there's armour coming from the east", but not say "there's some heavy tank lurking behind that farmhouse", which is what we get with the CM contact icons.

[Bulletpoint]

 

Great question.  Good answers.  Thanks for asking.

Well, thank you for sharing your experience.

They say one fool can ask more than ten wise men can answer. On this forum, I'm doing a lot of asking, so I'm always happy to get good answers 

[Bud Backer]

 You might be able to say "I think there's armour coming from the east", but not say "there's some heavy tank lurking behind that farmhouse", which is what we get with the CM contact icons.

Yes, that's it exactly!

In a sense, one could almost consider it fair play to say to an opponent "you may or may not have contact icons, but your men should be able to hear engines of vehicles"

So that if they don't have contact icons, they still know that indeed, this is not an infantry-only force they are facing. Given the rarity of those types of battles, it's probably a superfluous idea. 

[A Canadian Cat]

The distance for sound contacts for moving vehicles is about 225-230 meters. Movement speed makes no difference (IIRC it does make a difference for moving infantry, however). For stationary vehicles it is 120 meters or 60 meters with a Hide command (which does presently only work in Black Sea, but it will work in Final Blitzkrieg and I assume the other WW2 games when they are patched).

Also, vehicle units can't obtain sound contacts on enemy units.

Interesting.  Are we sure about tank crews never getting sound contacts?  What about AT gun fire?  I know that tank commanders not not hear other moving tanks easily - their own engines drown out much of the enemy tank's sound but I have seen tanks with ? contacts for AT guns firing at them.  I figured that was mostly due to sound.  But it could be flash and movement too I suppose.

Of course the do get ? contacts from information passing though.

 

Why would a hide command make a vehicle more quite? Are they actually turning off their engine in that case?

No, just idling.  Crews did not turn off engines because many tanks of that era required crews to dismount to start the engine and even those that did not the start sequence as not as smooth as we are used to with our modern cars.  So, crews would *not* turn of engines in close proximity to the enemy.

Edited January 18, 2016 by IanL

[Michael Emrys]

Hmmm, FWIW, recently I played a game pitting two platoons of Shermans against one platoon of Marders. In it I was sometimes able to get sound contacts against the Marders before they fired at ranges of 700+ meters. No foot soldiers involved. Shermans were all unbuttoned.

Michael

Edited January 18, 2016 by Michael Emrys

[Vanir Ausf B]

Interesting.  Are we sure about tank crews never getting sound contacts?  What about AT gun fire?

Let's just say that if tanks can hear other vehicles it is only at very short ranges. I have driven tanks within 70 meters of each other without a sound contact.

Keep in mind that the UI does not distinguish between sound contacts and uncertain visual contacts. Also, my testing was only for sound contacts from movement. Sound contacts from weapons firing could have much longer range.

Page 46 of the game engine manual says that slow movement should make "the vehicle less likely to appear as a sound contact to the enemy." The fact that it doesn't may be a bug, or the manual could just be wrong. I'll report it and let Charles sort it out

[RockinHarry]

Did some quick tests with single Sherman M4 late, vs some german infantry. Map all grass with one paved road. Germans had no LOS to anywhere the Sherman was about to move (from 2000m straight toward the germans at the other end of the map). 2 player hotseat, iron mode. CMBN all modules, V3.11

Observations:

Germans got a vehicle contact marker first time at:

~220m when conscript
~250m when regular
~280m when elite

Error margin lays somewhere between 5 to 10m

I could not observe any effects from (listener) leader rating, vehicle movement speed, terrain (road, non road), wind strength and direction, time of day/night, precipitation/fog, ground condition, number of pixeltroopers in the listener unit (FO for one test, Plt HQ + 1 full strength squad in another). Results were all the same as figures above.

I did not test different vehicles, vehicle crew experience (was regular, leader 0), lateral movements, info sharing capabilities for the listeners (listening units where close together in directly adjoining AS), as well as another method to block LOS for the germans to anywhere on the map (a 2m high parapet did the LOS blocking). No vehicle vs vehicle tests. 

[Vanir Ausf B]

That's interesting regarding the effect of experience. IIRC all of my tests were with Regular troops.

[RockinHarry]

That's interesting regarding the effect of experience. IIRC all of my tests were with Regular troops.

Yep and it´s only from some observations for the mentioned test cases. Can´t hurt if somebody else yet can give some confirmation on the unit experience-sound contact range relation, but it seems that the 250m range is something that one can at least take as a "base". Other test situations yet can include spotter/listener suppression levels and different terrain types, i.e beeing in a building which in RL might yield some very special problems locating and estimating a sound source. (although anyway I do not believe that any that advanced sound physics like that are and should be modelled in the game)

[Bulletpoint]

Did some quick tests with single Sherman M4 late, vs some german infantry. Map all grass with one paved road. Germans had no LOS to anywhere the Sherman was about to move (from 2000m straight toward the germans at the other end of the map). 2 player hotseat, iron mode. CMBN all modules, V3.11

Observations:

Germans got a vehicle contact marker first time at:

~220m when conscript
~250m when regular
~280m when elite

Error margin lays somewhere between 5 to 10m

I could not observe any effects from (listener) leader rating, vehicle movement speed, terrain (road, non road), wind strength and direction, time of day/night, precipitation/fog, ground condition, number of pixeltroopers in the listener unit (FO for one test, Plt HQ + 1 full strength squad in another). Results were all the same as figures above.

I did not test different vehicles, vehicle crew experience (was regular, leader 0), lateral movements, info sharing capabilities for the listeners (listening units where close together in directly adjoining AS), as well as another method to block LOS for the germans to anywhere on the map (a 2m high parapet did the LOS blocking). No vehicle vs vehicle tests. 

Thank you. Spitzenklasse.

[Bulletpoint]

Page 46 of the game engine manual says that slow movement should make "the vehicle less likely to appear as a sound contact to the enemy." The fact that it doesn't may be a bug, or the manual could just be wrong. I'll report it and let Charles sort it out

Maybe I read it in the manual then. I knew I had seen it somewhere. Much appreciated that you pass it on.

It would (arguably) be more realistic to have slow moving armour be more stealthy, and also it would create new gameplay choices. Do you go slow to avoid detection, or full throttle to get a jump on the enemy?

Edited January 19, 2016 by Bulletpoint

[MOS:96B2P]

Observations:

Germans got a vehicle contact marker first time at:

~220m when conscript
~250m when regular
~280m when elite

Error margin lays somewhere between 5 to 10m

I could not observe any effects from (listener) leader rating, vehicle movement speed, terrain (road, non road), wind strength and direction, time of day/night, precipitation/fog, ground condition, number of pixeltroopers in the listener unit (FO for one test, Plt HQ + 1 full strength squad in another). Results were all the same as figures above.

Interesting information.  Thanks for once again taking the time to test and share. 

[rocketman]

While on the topic of sound contacts - I wonder if FB will simulate that sound is significantly muffled and travels less far in areas with deep snow and snow covered trees?