TPA or Thermal Protective aid
A TPA is a bag or suit made of waterproof material with low thermal conductance (thermal conductance of not more than 7,800 K⋅m2/W). Every survival craft should have 2 thermal protective aid suits or 10% of its total carrying capacity whichever is greater. The material used to make TPA is usually aluminized polyethylene suit with sealing to reduce both convective and evaporative heat loss from wearer’s body.
Additional Requirements for Thermal Protective Aid
A TPA shall
- be made of a waterproof material having a thermal conductance of not more than 7,800 K⋅m2/W and shall be so constructed that, when used to enclose a person, it shall reduce both the convective and evaporative heat loss from the wearer’s body.
- Cover the whole body of persons of all sizes wearing a lifejacket with the exception of the face. Hands shall also be covered unless permanently attached gloves are provided;
- Be capable of being unpacked and easily donned without assistance in a survival craft or rescue boat;
- Permit the wearer to remove it in the water in not more than 2 min, if it impairs the ability to swim.
The thermal protective aid shall function properly throughout an air temperature range -30°C to +20°C.
The aid is not recommended to be used in water, however, if the wearer enters the water, it can be removed quickly.