We used to have a few around here that were all welded shut so the only part accessible was the platforms. Now they're all gone and replaced by the converted flatcars you see in jpwisc's photo above. Cabooses weigh about 40,000 lbs. if I remember correctly, which is enough heft that you can shove them with some air set and the wheels won't slide. That's in contrast to the shove platforms made from flatcars which will slide with a half-hearted handbrake or a minimum set. As a consequence, the wheels on those things become covered in flat spots in no time and are very difficult to use at speeds above 10 mph because of the noise. We also have a local agreement in effect here that allows for a penalty claim when making a movement that would have required a caboose in years past. When you have to hang onto a car for a shove of a mile or more and a caboose would have been available to avoid hanging onto the car prior to the cabooses being eliminated, you are entitled to a penalty claim. If it's a lumber car or a tank car, I'd rather have the caboose than the money.