WHAT SANK THE TITANIC? THE POSSIBLE CONTRIBUTION OF THE BUNKER FIRE

The Titanic sank as the result of hitting an iceberg when steaming at full speed in the middle of the night through an iceberg field, in spite of radio warnings. Unanswered is: Why was the ship at full speed under those conditions? It was not trying to set a cross-Atlantic speed record.; the ship was designed for luxury, not speed. The answer may be a smoldering fire in coal bunker # 6. Spontaneous ignition of coal in seams, culm banks, and bunkers is well-known with a long history. At the time of the Titanic sailing, it was known as a chronic, but not an acute problem. The most effective containment solution involved sailing at full speed to drawdown the coal in the bunker until the smoldering coal could be extracted and fed into the boiler. This may be why the Titanic proceeded at full throttle through the ice field. Bunker fires being a chronic problem, fire control teams were common in port and on many ships, including the Titanic. The Titanic fire was under attention by Port fire control teams at Southampton before sailing, and at the stop in Cherbourg, with continuing control actions during the voyage; but full speed steaming was evidently not sufficient for adequate draw-down in the ship. Using data supplied by Harland and Wolf, the builders in Belfast, the bunker was evidently only partly filled with about 800 tons of coal and with the fire probably in the top half of the bunker. From this capacity, the maximum rate of drawdown is estimated to have been ~2 in. per hour, in agreement with an estimate from firing densities and grate areas, boiler thermal efficiencies, and engine HP. By comparison, minimum rates of upward flame spread at ¼-in/hr for small particles were measured in laboratory experiments at Sheffield University in the 1950’s which extrapolate to ½ to 1 in/hour for particles of the size onboard the Titanic. At full speed, the bunker fire would have had a net drawdown rate of the order of 1-in/hr. At this rate, a fire that originated in the top half of the bunker would still have been in the bunker at the time of collision. Two dimensional computer models for the initiation of fires in coal piles are used show a possible behavior pattern relevant to the Titanic bunker fire.