Welcome. A good start on mono conversions. A few thoughts:
1. I'm not sure if it's a low resolution image or what, but it seems slightly soft overall to me. There are a couple of issues; the mono, while not bad is a bit mid-tone rich or muddy (There's too much grey, not enough black or white). I'd suggest taking this back into post and doing some work with levels and curves to bring a little more detail out in the dark areas and perhaps try to recover a little more range as well. From a composition point of view, I think it just missed. I find my eye following the double track from lower right, to the back of the image without really noticing the frieght cars on the siding. Lastly your sky is lacking. A graduated neutral density filter would have really helped this image and improved the contrast between the sky and the cloud.
2. Much better sky in this image and overall better exposure, but again, very muddy. I'm not really sure what the subject in this image is supposed to be. Is it the crane, the playground equipment or the houses image right? If it's the crane, I think perhaps a different perspective might work better, say from closer and looking up.
Overall, good work. Mono conversions are much more difficult that they look. The key to a good one is to start with a perfectly exposed image to begin with. Looking forward to seeing more.
Just my $00.02 worth - your mileage may vary.
~John