Ditching my partner and going solo!
I understand and have been in a similar situation with another business I had. Please be smart about the situation. What to do with the yards, split them 50/50 or like they said buy them out. When purchasing the equipment did you purchase it with you own money and bring that into your books (accounting system) as an asset to the company? If you did this then you will probably have to find the best way to split this. Think about the money in the bank AND who had access to it. My previous partner and I both had access so when I told him I wanted to split he went and took out a much larger piece than was his. I had no idea he did this. So please be careful.
All in all it sounds like this needs to be done and fast. Don't wait if it's not working out because it will only get worse. Good luck and I hope it all works out