Since the KRB had challenging lines with successive inclines and declines, they decided to order even passenger locomotives with the wheel arrangement 0-6-0. 15 were built by Sigl in 1868 and 1869 and got odd running numbers between 1 and 29. They had relatively large wheels with a diameter of 1,495 mm (4 ft 11 in), a short wheel base, inside valve gear and outside frames and cylinders.

In 1884, they became class 29 of the kkStB, what was changed to 929 in 1912. From 1895, some got new boilers which were a bit smaller, but were operated at a higher pressure. In 1913 and 1914, two were sold to the NÖLB and got the numbers 5.01 and 5.02. Withdrawals had begun in 1903 and were completed in 1923. After World War I, four were to be taken over by the BBÖ, but only one made it actually briefly into the inventory of the BBÖ.