How long are you "experimenting" with B&W ? You seem to be all over the place without real concept of own style yet. "Black & White happened" has, IMO, poor tonal separation which causes me, as a viewer to lose sense of third dimension and subsequently sense of the shape of the subject. "Standstill" is on the other end, tones are weak, or rather "unsure" of themselves, which makes the picture just to gray or to monotonous. This was maybe not so easy subject at the moment in probably weak, morning light. And then we go to "Solitude". A composition, which could easily be of Adams or Weston. Good dynamic range from pure black to pure white. A lot of enticing details to hang eye on, this is a picture, which is not boring to look at. And has own spirit. Apart from few details like mentioned by Maria over sharpening (I don't know, I am a film photographer

) and a bit to small dof to get the front plane details acceptably sharp, this is something to print large (small print will not do here) and hang on the wall.
So keep going, but with purpose. Try first to impress yourself before you do something to only impress us. Good luck.