The application of the Harwell field model, FLOW3D, to model compartment fires is investigated. Two experiments are chosen to model numerically. The first experiment is a single room fire where the vertical structure of the ceiling jet produced by the fire is measured and the temperature response of simulated fusible links to the ceiling jet is available. The second experiment consists of three rooms with a fire. Temperature measurements using thermocouples are available in each of the three rooms as well as in the corridors connecting the rooms. These two experiments provide an opportunity to investigate both two and three dimensional field modeling of fires. It is found that the numerical results using the field model are in reasonable agreement with the experimental data. FLOW3D has been enhanced by the addition of a simple fusible link algorithm previously used in the zone fire model LAVENT. This algorithm used in conjunction with the field model produces good agreement with the measured fusible link temperatures found in the single room experiment.