Convoy spacing in new missions

[TG626]

I've noted a tendency, even when the ships are well over 300m apart, for convoys to freak and scatter at the beginning of a mission. How far apart is "normal"? How far apart do they need to be to not panic in fear of collision which is what I assume they are doing...

[TorpX]

Originally Posted by TG626

I've noted a tendency, even when the ships are well over 300m apart, for convoys to freak and scatter at the beginning of a mission. How far apart is "normal"? How far apart do they need to be to not panic in fear of collision which is what I assume they are doing...

Good question.

I, more or less, assumed that they were supposed to 'freak and scatter', when it hit the fan. Especially, the merchants. I figured this was more to evade torpedoes than to avoid collision. The spacing of the ships in convoys, in the game, is much less than what it was in RL. That's all I really know. The way I play, I mostly encounter singles and small convoys.

Enemy AI behavior leaves a lot to be desired. It was better in SHCE.

[Admiral Halsey]

Originally Posted by TorpX

Enemy AI behavior leaves a lot to be desired.

You could say that with most games really.

[TG626]

So what was it in real life? This is for mission MAKING so I have control over it...

[Hitman]

This is from another post I readed here long ago (Sorry not being able to quote the author), and for allied convoys, but gives you a reference:

Convoys during the war sailed in formations that were much wider than they were long eg a 45 ship convoy would be in nine columns of five, even a 14 vessel convoy would travel in seven columns of two. There were several reasons for this formation:

1. U-boats would much prefer to attack a target side on and this presented fewer opportunities than a long snaking column stretching for several miles.
2. Escorts could travel from front to back of the convoy (and back again) much more quickly.
3. Escorts on the flanks could keep both the front and back of the formation in sight without having to change station. This also helped with signalling.
4. Stragglers slipping behind with engine problems would be spotted much sooner by escorts in the rear.
5. In a large convoy, ships in the middle columns would be out of range from torpedo attacks fired from outside the escort screen.

Station keeping distances for vessels was 3 cables (600 yards) between ships in columns and 5 cables (half a mile) between columns. In practice of course, merchant ships were rarely able to stay this close in anything like rough weather and escorts would inevitably be chasing back and forth signalling frantically to herd up stragglers as darkness approached. The downside of a large spread out convoy was that the best attacking position for a u-boat was to actually surface at night within the central columns where merchant lookouts were much less vigilant and they would be all but invisible to escorts.

[TG626]

So in meters, that's

658 meters front to back
1097 meters side to side

Thanks! That's exactly what I wanted to know! Now we'll see how that works in game...

[TG626]

Ok, ran a test. I "auto arranged" the convoy into 3 columns of 2 ships each with a spacing of 1km and they seem to be quite happy. They steamed toward their waypoint without becoming a floating bunch of billard balls.

[Hitman]

You can find in Lurker's RSRD campaign very accurate convoys, and in the readme and in the starting post he lists a huge amount of sources. If I remember correctly, there was a link to a web that had lots of detailed info about japanese convoys: frequency, typichal composition, formations, etc

[tater]

The largest failing is the lack of an organic "zig-zag" capability in any of the game engines. Not the "constant helming" we see, but legit patterns of course changes for the entire group every XX minutes. The patterns were not /\/\/\/\/, either, but very complex shapes that look more like bizarre sinusoids.

We tried in both my campaign, and lurker's RSRDC to have /\/\/\ zigzags created by the Automated Campaign Editor program, but too many slows the game down a great deal (a single convoy can then have 10s of thousands of waypoints).

Originally Posted by TG626

Ok, ran a test. I "auto arranged" the convoy into 3 columns of 2 ships each with a spacing of 1km and they seem to be quite happy. They steamed toward their waypoint without becoming a floating bunch of billard balls.

that's good news

if you take a group of ships, out of 15 or 20 in a convoy there will most of the time be 3 or 4 that turn away while the others are quite happy and content holding the formation at "reasonable" distance. i think for most people, what "looks" like safe spacing distance can be too close by game standards as well as RL distances.

I think some ships also have the collision distances set too far out so they spook too easy fearing collision. so one may turn away at 600m while the next might not turn away until 500m. that one of the biggest peeves i have with the game is most similar ships don't share basic uniform behaviors and tendencies as they should.

[TorpX]

Originally Posted by tater

The largest failing is the lack of an organic "zig-zag" capability in any of the game engines.
...........

I agree. This would be a very big step up, in the realism dept.

[Hitman]

if you take a group of ships, out of 15 or 20 in a convoy there will most of the time be 3 or 4 that turn away while the others are quite happy and content holding the formation at "reasonable" distance. i think for most people, what "looks" like safe spacing distance can be too close by game standards as well as RL distances.

One often overlooked thing is that ships on the external columns should have the capability of running much faster than the set convoy speed. Otherwise they will never be able to keep station on the big circle they have to make around the convoy's pivot point when it changes direction.

SH4 does not recognize the difference between zig-zagging as a simple heading change pivoting on the same point, and a true course change of the whole convoy. It always asumes the latter, hence setting zig zagging patterns in the capmpaign files is not effective and tends to break up convoys.

[LGN1]

Originally Posted by Hitman

...It always asumes the latter, hence setting zig zagging patterns in the capmpaign files is not effective and tends to break up convoys.

Hi Hitman,

what do you mean with this I extensively use zigzagging convoys in my SH3 installation and it's quite effective (around every 16km and an angle variation of +/-25°). I've also never seen a broken convoy

Cheers, LGN1

[TorpX]

Originally Posted by LGN1

Hi Hitman,

what do you mean with this I extensively use zigzagging convoys in my SH3 installation and it's quite effective (around every 16km and an angle variation of +/-25°). I've also never seen a broken convoy

Cheers, LGN1

Any vessel on the outside of a formation, that makes a pivot must move faster or fall behind. The same problem existed with heavy bomber formations when they turned.

One zig every 16 km isn't really a tactical zig pattern. At 8 kts., that's only about once per hour. One zig in 6 min. was more the norm in RL.

***

Perhaps, limiting the number of columns to 2 or 3 would help?

Personally, I would be content to have fewer large convoys in exchange for more zigging. However, Ducimus said that frequent zigs taxed the computer and slowed things down. How much of a problem was this?

[LGN1]

Hi,

I understand this, but I have never seen any problem with this Maybe because I limit the convoy speed and the max. column size and thus, the outer ships can always easily catch up

I agree that it's not like a historical zigzag pattern, however, it makes the game significantly harder at least for me. Attacking/Shadowing a late-war convoy in the Atlantic without map updates and many escorts with radar is now really tough.

Cheers, LGN1