O dziewiętnastej czasu pokładowego zeszedłem, mijając stojących wokół studni, po metalowych szczeblach do wnętrza zasobnika.
As literal as I can get to the original and just be a little awkward rather than flat out wrong.
At nineteen hundred hours ship's time I descended, passing by those standing around the shaft, by the metal rungs into the interior of the capsule.
Massaged a bit for the benefit of English syntax:
At nineteen hundred hours ship's time, I moved past those standing around the shaft and climbed down the metal rungs into the interior of the capsule.
And while here, I thought "zeszedłem" was an error and should be "zszedłem" is the non-standard form used on purpose?