UGEARS STEAM EXPRESS 2.5D PUZZLESteam Express 2. 5D puzzle The Steam Express' three perspectives include a side view of the locomotive, with driving wheels and connecting and coupling rods all synched thanks to mechanical wooden gearing. There's also a front view of the locomotive, with a cattle guard and hinged smokebox hatch that opens to reveal a latticed air intake. The third perspective is a side view of a passenger car, with a secret mechanism that lets you slide open the