[failure] train defense

[vanatteveldt]

Inspired by the 'golden train' thread I wanted to make a train defense.

I decided against an 'eternal loop' setup since I want to have multiple trains running and I wanted to be able to refuel them.

I came up with this spiral solution:



Which works fine in peace time: there are a lot of signals at the bottom (presumably the 'safe' side) and they make good speed on the rest of the loop. I have two stations and set them to go to A and then B waiting 0 seconds at each. Of course, since we have no underground or bridges the spiral has to cross, so occasionally trains have to wait for the crossing. My idea was to have enough trains so there will always be a train ready to go.

Possible improvements:
- Maybe the crossing should be in the middle so that trains are never blocked from going on the 'active' loop
- Maybe having multiple separate loops works better than a spiral, could even use a number of concentric 'golden train' loops.

However, the main outcome of the experiment is that trains just don't have the stopping power to kill behemoth biters . They kill everything else easily, but when they hit a moth they stop. They continue to do damage per second, but since they are stopped they will now be attacked by other biters and die:



I tried making longer trains (4 engines chained together). This might give more damage, but unfortunately they switch to manual mode when one engine is killed, so they block the track until they're gone.

I guess you could have this as part of a defense setup, i.e. also have a number of laser turrets, but then, why not just have laser turrets?

Also, it is annoying that you can't deploy trains automatically, so this will always require manual 'reloading'.

My conclusion: trains are not part of a good defense setup . Anyone has a better idea to get this working?

[hansinator]

lol that's a nice experiment I like it

[kinnom]

tried putting cargo wagons at the front?

[Optera]

Funny idea, too bad it's ruined by Behemoths being imbalanced bullet sponges.

tried putting cargo wagons at the front?

When a train composition is changed the old train is removed and a new train in manual mode is created.....
See also my bug report about this odd behavior.

[TheVeteraNoob]

Oh hey cool I inspired somebody. This was actually the intention of the golden train initially, then i gave up because I got tied up with school. I wish i had some tips for you

[Deadly-Bagel]

I can see there being a use in Bob's Mods as large worms can spawn close to your walls and take out your defences from outside their range. There is an Armoured Train which you can fill with lasers and shields however as Bob sticks to vanilla balance they're still totally useless.

Not sure what they would do if they ran into a behemoth, I was killed by a regular MK3 train even through four MK2 shields but the laser towers would take care of anything on the tracks, the trains are more to take out any worms or nests that spawn nearby.

[HalfPastZulu]

What about maybe having blue belts between the tracks pushing bugs on the track and away from base?

[vanatteveldt]

What about maybe having blue belts between the tracks pushing bugs on the track and away from base?

That would be fun (although the main problem I had was the train stopping after hitting a behemoth).

I believe that a train with sufficient lenght (and nuclear fuel?) does not slow down after hitting a behemoth, so it could be worth a try...

[Adeon Hawkwood]

You can kill Behemoths with Trains, but you need a BIG train (15 locomotives).

From this reddit thread:
https://www.reddit.com/r/factorio/comme ... _mow_down/

Slight correction: Locomotives are twice the weight of cargo wagons, not equal weight. The actual weight to aim for is 15 locomotive equivalent, or 30000 weight, given that a locomotive weighs 2000, a cargo wagon weighs 1000, and a fluid tanker weighs 3000.

At 15 locomotive weight, a train will not slow down when hitting a single behemoth biter when running at full speed but will eventually stop(due to losing acceleration, which will cause it to lose enough kinetic energy that it no longer instakills) after hitting around 20-30 in a row. Which is difficult to find naturally unless you herd and wall them onto the train tracks for testing. It was... difficult to count the corpses. If the train is braking for a station or intersection, somewhere around the point of 200-250km/h it will stop when it hits a behemoth biter, as it lacks the momentum to deal enough damage to instakill combined with the fact that it is decelerating to begin with.

At 30 locomotive weight, the point where a decelerating train is unable to instakill a behemoth biter is around 100 km/h, meaning in my test map the train hit a behemoth biter and stopped about 10 blocks short of the station in the behemoth biter testing cage, where I ruthlessly ran over biters for fun in the name of science. The 30 locomotive train was also not stopping by itself prior to that point, despite the many, many hundreds of biters who valiantly tried to stop the train with their bodies. I didn't make a long enough testing ground to measure accurately.

[Optera]

Those numbers are outdated.
A while ago Tankers where brought down to weight 1000 same as cargo wagons.

[Koub]

viewtopic.php?p=327815#p327815

[adam_bise]

From my own personal testing the following trains will not be stopped by behemoth biters:

6 locos at top speed
5 locos and 2 wagons at top speed
4 locos and 3 wagons at top speed
2 locos, 4 wagons, 2 locos at top speed
2 locos, 6 wagons, 1 loco at top speed
3 locos and 6 wagons at top speed
2 locos and 7 wagons at top speed
2 locos and 10 wagons at 250km/h

[darkfrei]

From my own personal testing the following trains will not be stopped by behemoth biters:
6 locos at top speed
...
2 locos and 10 wagons at 250km/h

They are all have very big impact damage, while they have no resistance for it. So I've made this mod with the heavy wagon, that is enough heavy and has very high impact resistance. With two wagons you can goin through normal trains with high speed.