TUMBLER DRYER FIRES
Before we get into the actual operation of the tumbler dryer, let's discuss the potential fire hazards involved in drying clothing and other textile materials in standard shipboard tumbler dryers. The principal cause of shipboard laundry fires is spontaneous combustion of residual soil in clothing (particularly paint and drying or edible oils) and/ or polymeric elastic waistband materials. Most laundry dryer fires are caused by human error or negligence. Many of the causes are listed below:

1 In Leaving clothing or linen unattended in the dryer
1 Not properly washing, rinsing, or extracting clothes
1 Overdrying because of imbalance in loading (heavy items included with light items)
1 Placing divisional laundry bags in the dryer
1 Not cooling down dryer loads for 10 minutes with dampers set to deliver room temperature after drying
1 Improper cleaning of primary and secondary lint traps Improper use of the timer on the dryer
1 Unclean steam coils on the dryer addition, operators must be familiar with safety devices and report faulty equipment to maintenance personnel. Investigations of shipboard fires have revealed the following conditions in laundry tumbler dryer safety devices:
1 Clogged, damaged, or missing lint traps
1 Missing or inoperative thermometers
1 Thermometers that do not indicate tem-peratures above 220 F, although the equipment can be operated above this temperature
1 No automatic temperature control
1 No automatic timing device to control drying time
1 No automatic cool-down cycle
1 No fire sensing and smothering device
1 When the above conditions exist on board your ship, be extra careful when operating the tumbler dryer.

A Prevent Laundry Dryer and Hamper Fires placard (fig. 5-29) should be posted on the front of each dryer. Placards are available through the supply system and should be mounted on the door of every dryer.

OPERATING THE TUMBLER DRYER
The procedures for operation of the dryer are as follows:

1. Load the dryer, not exceeding rated capacity.
2. Set dampers to the desired position. Most loads can run in the HOT position.
3. Set thermometer regulator to desired temperature (140-160 F). The actual dryer temperature will be indicated on the thermometer.
4. Set drying time for approximately 20 minutes.
5. Set the cool-down timer for 10 minutes to cool the load to approximately 120 F during the cool-down cycle.

6. Push the start button. Drying time depends upon steam condition, weight and texture of load, and the amount of moisture left in the load after it was extracted. Standard tumbler performance should not exceed 1 minute per pound (dry weight). NOTE: During the cool-down cycle, move dampers to the cool position.

Figure 5-29.- Prevent Laundry Dryer and Hamper Fires placard.

7. Remove clothes from the dryer.
Never allow laundered items to remain in the dryer after completion of the drying cycle.
Laundry personnel should store freshly dried clothing loosely and remain in the laundry after the last dryer load to make sure there is no residual buildup of heat in the clothing.