are then determined as follows the time necessary to heat the water and concreted taking into account the heat loss through the walls and infiltration loss from the building at steady state values is then calculated note that the heat loss through the dry dock walls and bottom are neglected since they are believed to be minimal the water is heated from an initial temperature of 30 u00b0 f to 160 u00b0 f equ9 with the ambient water bath temperature of 160 u00b0 f the time to heat the center line of the log to 132 u00b0 f u2248 56 u00b0 c is calculated this calculation assumes that water flow over the logs produces minimal external resistance to heat transfer when compared with internal heat transfer resistances this limiting case has the inverse biot number set equal to zero equ10 the thermal diffusivity of the logs is calculated in order to determine the internal temperature resistance of the logs utilizing the result for thermal diffusivity the time required to heat the center line of logs having diameters of 8 34 12 34 and 20 34 respectively in water having the ambient temperature of 160 u00b0 f is as follows equ11 u03c4 8 in 4 4 hr u03c4 12 in 10 hr the above calculation is repeated below using an ambient water temperature of 180 u00b0 f rather than 160 u00b0 f equ12 the time required to bring the center line.