The repeated shortages of coal for railways use and the restriction of less essential railway services were discussed in Chapter 15. Because of its key position in the transport industry, and the extremely heavy extra wartime load it had to carry, the Railways Department needed a high priority for available coal. Nevertheless page 427 its coal supplies continued to be uncertain. After the war, it was to convert many of its locomotives to oil burners, but during the war the Department remained predominantly dependent on coal.
Coal used for ships bunkering decreased over the war years from 159,000 tons in 1939 to 118,000 tons in 1945. It was to continue to decrease after the war. There was an increasing tendency for ships to burn oil instead of coal.
Supplies of coal remaining for civilian and other purposes fluctuated around 1,000,000 tons from about 1934 right through until well after the war; this in spite of the fact that the population increased by nearly one-fifth between 1934 and 1948. There were recurring shortages of coal for domestic use, but electricity, because of its extra convenience, was steadily being substituted for coal for space heating, in spite of the fact that some authorities considered electricity to be less economical than coal for this purpose.
Irregularities in coal production, as well as the extra convenience of electricity for heating and power, encouraged the growing tendency for electricity to take over. There were shortages of electricity, too, in the war years, but supplies were more reliable than coal supplies. Up to 1945, coal production increased each year. However, it could not keep pace with the demand from railways, factories and gasworks, all of which were hampered by inadequate stocks and uncertain arrivals of coal.