As a CSX employee, they have free work boots available, or, more appropriately, one orders them online using your CSX employee number. The boots offered are from several manufacturers and styles and range in retail price to, perhaps, $125. CSX will only pay up to a specific amount (I don't recall the number), and, if you want a 'better' boot, you have to make up the difference. You might have to come up with $25 or so. At a minimum, you'll need a steel-toe, waterproof boot. Some are electrical shock insulated as well. They'll be delivered to your door via UPS within a week. The biggest warning I can give you is that if the boot you are interested in does not specifically say WATERPROOF, IT'S ==NOT==!! I learned that the hard way with the first pair of boots I ordered through them.
I'm not sure about boots when you hire on. I had my own from a previous job that were still in good condition. I suspect you are required to report and have the required steel-toe boots in your possession the first day. If you have to go buy a pair, keep the receipt. They may reimburse you some or all of the price.
One of the reasons employees can get a free pair of boots each year is they don't last much longer in an outdoor environment. I started there with a cheapo I bought locally and after perhaps 13-14 months, the sole came off and they had lost their waterproof capability. Foolishly, I bought another pair just like them (locally) and sold the CSX supplied boots to a friend which covered most of my cost. When those failed, I went back to the same local shoe store and they put me into a good quality Chippewa boot...I think it's their Logger model. After more than 4 years in them, I finally replaced them about a month ago with the same model when the waterproofing stopped working. I paid $175. That was a far better deal than the $89 pair good for about a year.