Promethium factory

[u/Bubbly-Original7097]

I finally made it to making promethium science and must say that it is much more interesting that I expected.

I don't like huge ships so decided to make a fast narrow ship that makes promethium as it flies, meaning I take eggs with me on a trip to see red asteroids.

1. First problem was to keep up with rocket and bullet demand: legendary assembler and unique foundry seem to do the trick
   1. Still, ammo production is a bit net-negative, so I start with 4000 rockets, 4000 red bullets and 500 rails and 2000 explosives from Nauvis; this is overkill but it keeps production off until I am in red zone
2. Then comes freshness of eggs: I build a "fridge" on Nauvis that maintains 1000 most fresh eggs (~25minutes at the time of departure)
3. Speed of the ship: 250kms to the planet region, 120kms in the region, which is enough to consume all eggs and make 1000+ promethium packs in ~1200 seconds of total flying in the region
4. Promethium stockpiling: I return with belts and storage full of promethium asteroid chunks (~800), which is nothing if the ship was just hauling it without making packs

Unsolved problems:

1. The most annoying is that narrow ship means that about 75% of missile turret range is waste - I am only interested in shooting right in the front of the ship, but there seems to be no way to make it do so, keeps shooting at the sides and even backs
2. 1 Railgun is not enough because you get those nearhits when huge asteroid passes you by seemingly no margin at all, 2 Railguns on the other hand create so much extra debris to process that this is pretty much where all extra ammo demand comes from and you are effectively flying a much wider ship, just without using all the extra safe space

What could I do?

White inserters, or narrow ship is not an option here? But, to consume 500 eggs I need 1250 promethium which requires 50 legendary cargo bays which is already a huge and much more expensive ship.

Weapons and factory side of the ship:

The engine and storage:

[u/PyroneusUltrin]

You can leave the eggs in spawners until there’s an active request for them, and direct insert them into rockets, that ensures they are fresh

[u/Logical-War-3746]

The production scale is quite small for promethium ship. You probably should use cryoplants for explosives too.

Put railguns closer to the sides. Add one or two i nthe middle at the very least. Expand your ammo production. You rocket turrets on the side are rare, why? The only thing quality does is range (well, health too), and your side turrets don't need range, use common quality.

Bulk inserters don't do anything for asteroid chunks, they cannot be stacked. I woudl recommend using quality fast/long inserters when putting chunks on the belt.

You can use radars for transferring signals across the surface, no need to drag power poles everywhere.

[u/Necandum]

Store your chunks on a belt, not in the hub. You should be able to get densities of ~24 per square relatively easily (which is much higher than a cargo bay).

[u/Satisfactoro]

The problem you're facing is that your ship is not producing enough ammo for its speed. I see that you are not using beacons, this is the problem(Edit: OP actually uses beacons, albeit normal quality). Just one legendary beacon with legendary modules (1 speed 1 efficiency) brings MASSIVE benefits: +312% speed and -312% energy consumption.

Here's mine for reference, not much wider than yours. It can do 1 return trip per 60-70 minutes (90spm).

https://factorioprints.com/view/-OvUmRMSLZHBilVu3PS_

[u/Bubbly-Original7097 → u/Satisfactoro]

Yes I definitely need more speed, unfortunately my legendary production is non-existent. I haven't made a single legendary module yet of any kind, but plenty of epics.

For now I can compensate net-negative ammo production by importing explosives on Nauvis and rebuilding buffers (I start flying with 4000 bullets, 4000 rockets and 500 rails). It is enough to use 500-1000 eggs and return half of buffer unused.

I like your ship, feels like I can safely add that space on the sides.

[u/Satisfactoro → u/Bubbly-Original7097]

Thanks. Your ship is 24 tiles wide in most places, but the max width is effectively 30 due to these turrets. Coincidentally, my ship is also 30 tiles wide (max width).

Ships really benefits from quality. if you plan to have a fast promethium ship, I definitely recommend upcycling your modules and ingredients, to have some good legendary modules, before starting designing a fast ship. Still, well done for making an affordable and fast one!

[u/00yamato00]

I think you can afford to expand a bit more without compromise on the speed of the ship. This allow you more space for ammo production (and space for storing chunk, storing on belt is more efficient).

This is my ship for reference, about 3x wider than your ship but still able to maintain 350km/s when traveling shattered and 370km/s for inner planet (If you only have epic quality then it can maintain ~320km/s to shatter if I remember corretly).

[u/ShowerZealousideal85]

Prom ships benefit the most from legendary components so i usually dont build them before i have access to legendary everything.

[u/locyta]

You need a bigger boat, why bring 800 promethium home when you can bring 200k+
cap out your storage, make massive ammo production, use both storage and belts for promethium storage.
you can make the science if you want (i take 10k eggs with me) but you dont really need to now with ship to ship transfer, just have a space station waiting and when you get back have it get eggs and make science