Prior to 1922, the ventilation fans were steam driven. The supply for the fan engines was obtained from a boiler range opposite the fan house complex at the SW end of the South pit heapstead. Originally, there were 2? 50psi Lancashire boilers facing the fan-houses with a single chimney to the rear. The coal supply arrangement for these  is not immediately obvious but may have been by cart.

In 1890, a pair of steam driven DC generators were installed in a building adjoining the fan house complex and, as addition electrically  Powered underground haulage motors were added, the steam demand increased accordingly.  By sometime after 1911, a new more powerful ventilation fan had been installed and the steam demand had increased even further. To cope with the increasing load, the boiler house appears to have been reconstructed at some point, this time housing 4 boilers, 3 in operation and 1 on standby or being serviced. 

By 1915, coal was being delivered by a short stretch of railway track along the front of the boiler house.  How the ash was dealt with is also unclear

  fan-houses and fan-boilers circa 1916 (JST)

View from  the SW around 1918  showing the ventilation fan boiler-house chimney  in the fore-ground

A water-colour painting of  the colliery shows the chimney for the ventilation-fan boilers to be somewhat different to those of the main boilers.  It looks to be round, it has banding and the base appears to be octagonal. The base plinth is  surmounted by stone round-nosed drip lintels like those on the other chimneys, but the chimney seems narrower and the plinth is noticeably different at its foot.  The over-sailing seems to be similar to that of the other chimneys, with the central stones round-nosed drip moulding.   This chimney is shown banded but the other chimneys did not have banding at this time.