Simulation analysis of the King's Cross accident in London (1987) was conducted to determine and understand causes for observed fire behaviour and the extent of fatalities in the escalator shaft of the Piccadilly line.
An inert fire model was used with the thermal source of 1.6 MW. The fire started in the 45 m long Piccadilly line tunnel with an inclination angle of almost 45°. The performed transient CFD simulation included the discrete transfer thermal radiation model. Other parameters followed the original work [1].

The simulation results demonstrated the importance of the trench effect. Instead of moving vertically, the fire and the resulting hot gases aligned themselves with the slopped escalator due to local ventilation conditions (i.e. restricted side entrainment).