In 1862, Sigl manufactured five 2-2-2 express locomotives for the KFNB. They were named “RaketeII”, “BlitzII”, “KometII”, “VestaII” and “NeptuneII”. They were initially classified as type IVa and renamed Ia in 1869. They were characterized by an outside frame and outside cylinders.
“KometII” with driver's cab
When they were used for conventional passenger trains after the economic downturn in 1873, the single driving axle proved to be an obstacle. In 1882 and 1883, all locomotives were rebuilt into the IIb 1, which now had the 2-4-0 wheel arrangement but the same driving wheel diameter. The “KometII” came to the kkStB in 1906 as class 407 and survived until 1913.