This is a two part bug report. the first part covers the creation of steel upon the damaging of bunker doors by a rocket engine. The second part covers the deletion of the bunker door's heat after collision.I do no know if these are specific to the steam engine or not.
When a landing rocket breaks through bunker doors, it results in the creation of steel, which falls from the broken doors. Fig. 1 displays my pre-landing steel supplies of 4050kg. Fig. 2 shows the steel dropped by the broken doors, and fig. 3 shows the broken doors in the process of being deconstructed and reconstructed. It is worth noting that, while these doors dropped steel, their mass did not change and deconstructing them awarded the full 500kg. Figf 4, which happens after the doors have been rebuilt, shows that my steel supply is 4925, meaning I gained an additional 875kg, roughly 146kg per each of the 6 doors. I did not have any steel production or deconstruction of other steel buildings occur at this time.
A second bug is caused by the damaging of the doors. Initialy, the doors were somewhere close to 300C (fig. 5). Some of the doors dropped to absolute zero upon being hit (fig. 6) only to immediately reheat soon after (fig, 7). Some of the hit doors then cool back down to absolute zero (fig. 8), giving me the "not 0K but pretty cool" achievement. I do not know what factor determines which doors heat or cool. The absolute zero doors, when deconstructed, drop their steel at 19.9C (fig. 9)
Steps to Reproduce
Land a steam engine-powered rocket through closed or closing bunker doors
This issue has not been confirmed by a developer yet.