Saw this at the weekend in Smyths. currently available at Amazon for £32.51 and Tesco for £49.99?! (although i think that may include another train)
It says it's compatible with the standard wooden trains sets (brio etc). Description from the Smyths website:
Drive Thomas and Stanley up and down Quarry Mountain or roll the boulder down the chute, spin the crane to pick up and load the boulder and the engines can then deliver and pick up passengers to the station. Includes Thomas and Cargo Car, Stanley, 3 trackstiles, 2 boulders and a variety of destinations.
NOTE: for some reason the direct link goes to just the Smyths homepage, a quick search for "thomas quarry" will bring it up