Chicago, Burlington & Quincy (Burlington Route) class O-5

In 1930, the Burlington Route got eight Northerns from Baldwin, which they designated class O-5. While the first six were designed to burn lignite, the last two had changes in the firebox to burn bituminous coal. One got a special ashpan to make space for a trailing truck booster. They had Timken roller bearings only on the carrying axles. There are reports of a single O-5 hauling 82 mail cars.

Between 1936 and 1940, the Burlington Route built 26 more in their own shops in West Burlington. These had roller bearings on all axles of the locomotive and tender and other improvements. They were now called class O-5a, as were some of the 1930 locomotives which were rebuilt to the same standard. The last batch that got Boxpok drivers was called O-5b.

Later a total of six O-5a and O-5b were rebuilt to oil-burners. Here a renaming took place, so that all oil-burners became O-5b and even the coal-burning O-5b became O-5a. Today four O-5 are surviving, none of which is operational.