Rough Service Lamp
An incandescent lamp so constructed as to withstand mechanical shocks and vibrations.
Note: In the U.S.A., Vibration Service Incandescent Lamp designates a lamp to withstand vibrations while burning.
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
Celsius (previously Centigrade)
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM