Crash every 1-3 cycles, unclear how to reproduce

Other relevant information: I have really, really sketchy internet connection at the moment (bodging it with a 3G/4G dongle), not playing with any mods as far as I know, am using DLC vanilla and running on 3x speed.

Restarted Steam in offline mode. I don't appear to have had a crash for maybe 60 cycles now.

Could you try disabling data communications (Options -> Data Communication) and playing in Steam online mode to see if it's related to online functionality? Next time it happens please attach both your Player.log and Player-prev.log files before launching the game again.

Most recent logs attached without restart. Took longer with data communication turned off

Player.log Player-prev.log

This does not appear to be network related. 

If you load your attached save file and let it run without interacting with the game does it still crash? I ran it from cycle 39 to cycle 58 with no crash. I'm wondering if it's related to a specific action in game like building or connecting to pipes.

Something else you could try is running the Windows Memory Diagnostic Tool which comes with Windows 10. Have you adjusted memory settings in your bios? I'm not convinced it's a hardware error yet though.