When we arrived in Denver two days ago they were announcing on the Amtrak Califrornia Zephyr that there had been a track washout and that trains were being re-routed through Wyoming. We had assumed that, as would be the case in other countries, the washout would take a while to repair. (To give you an idea of the sort of forces the raildroads have to deal with, our train went around ‘Big 10 Curve’ where the winds can be so strong that hopper cars filled with sand and welded to the rails have been parked on an adjacent railway line to act as a windbreak.) But not in America. We had underestimated the importance of King Coal. Not only was the track through the Rockies repaired, but our train this morning was pretty much on time. We were given another reminder of the importance of King Coal as we approach the impressive Moffat Tunnel. Nearby Wyoming has a number of vast open cast coal mines. The coal is loaded onto carriages that are formed up into vast trains and sent east to Denver and beyond. As we toiled our way up to the western entrance to the tunnel we were informed that a coal train was unfortunately coming the other way and that, as a result, we would have to wait in a siding until the train had passed. This took quite a while, but the passing of the train in question took even longer. These vast trains are made up of well over a hundred fully-laden coal wagons. Frequently, they are pulled and pushed by two diesel locomotives, with another two situated in the middle of the train for good measure. Once the train had finally passed, we had to wait another fifteen minutes for the tunnel to ‘vent’ and then, when we finally set off, we were warned to stay in our carriages and not to cross between them. The filth on our windows when we finally emerged on the other side of the Continental Divide inidcated why such strictures are necessary. It’s not just a question of venting the tunnel of the diesel fumes from six toiling locomotives. The coal trucks are open and each time a train passes is engulfed in a cloud of coal dust. The 10 kilometre tunnel, which opened in 1928 and at last provided Denver with a more direct route to the west, is an impressive achievement. It stands at 2,800 metres above sea-level and took prodigious quantities of financing and of engineering.