Abstract: Cables are widely used in urban buildings and industrial sites. Once the cable is ignited, it will cause serious consequences. The cable is not only one when laying, so this paper takes the parallel double cables in the horizontal direction as the research object. By analyzing the three thermal transfer modes in the combustion process, a mathematical model for predicting the flame spread rate is established. An experimental study on the flame spread of parallel double cables in the horizontal direction is carried out and the influence of cable spacing on flame spread characteristics are analyzed. The flame width and the flame height increased first and then decreased with the increasing of the cable distance, the flame spread rate also increased first and then decreased with the increasing of the cable spacing. The experimental results are in good agreement with the model prediction results.

Key words: parallel double cables, cable spacing, thermal transfer, flame spread rate, flame size