Black frost

The question was raised because of the trawlers of the lost Hull trawlers Lorella and Roderigo, which, it has been suggested, were not adequately warned of the freak black frost conditions by shore-based radio stations.

‘Black Frost is like a dense mist and when it lifts it leaves ice all over the ship the ropes round the masts are sometimes 1½ feet in diameter. When black frost hits a ship men are allowed to drink rum by the bottle to keep themselves warm.’

The air temperature is most important and a sudden drop may well indicate imminent icing conditions. This drop is often made obvious by the formation of Arctic frost-smoke fog, or ‘black frost’ as it is known by fishermen. It occurs quite frequently in these waters when a sea-air temperature difference exceeds 10 degC and is regarded by fishermen with some apprehension, but there seems little justification for this unless the portent of icing conditions developing is the reason.

[…] "black frost" may extend above the observer covering the whole ship. The reduction in horizontal visibility will depend on the height above the sea to which the phenomenon extends. Trawlers heavily iced due to black frost have been known to capsize in Arctic fishing grounds.

The dreaded black frost, that penetrated into every part of ones body and the ship, that enveloped everything, spread a thick coating of ice on rigging, stays and all it embraced, running up the masts, surmounting the superstructure and even the very clothes we wore.

The ship was iced up worse than Dai had ever known it and a heavy swell was running, so when the black frost began to rise from the water everyone had been too busy to notice it. You can't see black frost, but you can feel it; it is black frost which causes each breath you take to include tiny particles of ice, and ice in the lungs can kill a man.