by George Muncaster

Power Supply

In 1942 the largest machines on the surface: the winders, fan and compressors were steam driven. Underground, whilst machinery at the shaft bottom was electrically driven, inbye machinery was driven by compressed air. Looking back it may seem odd that a steam and compressed air pit would be regarded as modern but steam was still commonly used in the 1920’s, in fact, the steam engine had been developed almost to perfection. Nostalgia for steam engines is common and the steam engines at the Morrison Busty provided good reason for it. The winding engines in particular were not only a pleasure to watch and listen to and smell when in motion but the paint work on them was a work of art too. Reliability was the most important requirement of machinery such as winders and fans and I never knew of them ever breaking down. It was the steam raising plant that required a lot of maintenance and was short lived.

The Boilers

The boilers at the Morrison Busty consisted of eight Lancashire boilers and one Babcock and Wilcox water tube boiler with a chain grate stoker operating at a steam pressure of 160 pounds per square inch [9]. Modern when they were installed, they were better than those at many other pits at the time of Nationalisation, so the ‘Busty’ had to wait to become fully electric.

The Lancashire boilers were fired by pulverised fuel from three pulverisers. Small coal was dropped through the bottom door of a truck into a hopper and taken by an elevator to hoppers above each of the pulverisers. A regulated feed of coal was supplied to the pulverisers, which were revolving steel drums about eight feet long and four feet diameter. As the drums rotated, steel balls, about two inches in diameter, inside the drums, pounded the coal into dust that was blown into the fires by fans. These boilers had economisers and superheaters.

Up till 1942 the boiler chimney was considered an environmental nuisance because too much of the pulverised coal did not get burnt by the fires, resulting in the chimney emitting a lot of black smoke.

There is an excellent novel “A North Country Maid” by Mary Craddock [10] about life in a Durham mining village in the depression years. It is almost certainly partly autobiographical and it is almost certain she lived in Annfield Plain in the ‘20s and ‘30s, although she called her village Rainton. Place names have been changed but those who know the district, as it used to be, will be able to identify the places she describes. She wrote about “the huge pit chimney at Rainton which scatters pit dust round the whole area” - almost certainly the Busty chimney.

In 1942, a dust extractor plant was built next to the boilers. This consisted of three fans taking the smoke from the chimney flue and extracting the dust by centrifugal action before passing the smoke to the chimney. It made a significant improvement.

The Power Station

The report of the visit to the Morrison Busty Pits by the Mining Engineers in 1925, said there were two alternators having a frequency of 40 hertz [6] but in 1942 there was only one generator and although the main switchboard had switches for two generators and space on the power station floor for another, the second had not been installed.

The frequency in 1942 was 50 hertz, because in the 1930’s (1936?) the North-Eastern Electricity Supply Company (NESCO) changed the frequency to 50 hertz. Whilst this involved changing electric motors it was not necessary to install a new alternator but only to increase its speed from 2400 revolutions per minute to 3000 revolutions per minute in order to generate at 50 hertz.

The 3000-volt, 1-megawatt alternator was not enough to supply all the needs of the colliery, nor would two have been enough, and most of the electrical energy came from the electricity supply company. To further ensure continuity of supply there was a ring main connecting with other pits belonging to the H.& S.M.C.

In the basement of the power station there were three, Bellis and Morcam, steam driven compressors, each capable of supplying 4000 cubic feet per minute at a pressure of 80 pounds per square inch. The high-pressure cylinders had a diameter of 23 inches and a stroke of 17 inches and the low-pressure cylinders were 33 inches diameter with a 17-inch stroke [9]. Between the power station and the heapstead, there were three compressed air receivers.

The power station and winding engine houses were a single building with a winding engine house at each end and although there was access to both winding engine houses from the power station there was a dividing wall between them. The winding engines were identical, having twin 26-inch diameter cylinders with a 48-inch stroke [9].

A photograph taken when the pits were being sunk shows the power station and winding engine houses under construction with the sinking engine houses on the south side of the shafts. When sinking was finished the steam driven sinking engines were retained as spare winders until the boiler plant was shut down in 1959.

The Fans

The fan building housed two ventilating fans. The main or working fan was installed on the north side of the fan house and driven by a 450 Horse Power steam engine [9]. In addition to the steam fan there was a 200 HP, electrically driven, standby fan with a rope drive between motor and fan pulley.

Digitised by George Muncaster

This is part of a series of projects, others are listed below:

Morrison Busty Colliery ( Part 1) - mainly memories

Morrison Busty Colliery ( Part 2 ) - ‘the baths’, ‘the heapstead’, and ‘the dry cleaner’

Morrison Busty Colliery ( Part 4 ) - underground

Morrison Busty Colliery ( Part 5 ) - the coal cutting machines

Morrison Busty Colliery ( Part 6 ) - modernisation on the surface

Morrison Busty Colliery ( Part 7 ) - references