The K class were a prime candidate due to the large size of the grate.

It entered service the same year, as K class no. 19.

These were supplemented by 53 K class 2-8-0 locomotives, some of which had been built as recently as 1946.

As such, the building of further K class was not a desirable option.

The 3-cylinder principle was therefore applied to the K class.

No. 31806 is the only survivor of the K class rebuilds.

This proposal was accepted, and two locomotives were built in 1909, which became the K class.

The K class had to cope with 99' radius curves and 1 in 25 gradients.

In practice the K class were a constant problem and could not operate effectively with a fleet.

The conversion process was concurrent with that of the K class.