In the context of the lighting design for the LCF (Air Defence and Command Frigate), a literature study was conducted in order to ascertain whether the application of low level red lighting (adaptation lighting) needs revisiting. In addition, light measurements were made on board of the M-Frigate Hr.Ms. Van Amstel, so as to get an impression of the present implementation of the red-light doctrine. The results of the literature search indicate that the advantage of red lighting, in terms of the gain in the recovery time for getting adequately dark adapted, is in the order of 1 to 2 minutes. The question is whether such a small difference in the recovery time of dark adaptation - much smaller than the normal individual variance - outweighs the reported disadvantages of working under red lighting. According to the results obtained in studies on vessels of the US Navy, the answer is negative. There it was shown that when it comes to the choice between red or white lighting, the crews that participated in the evaluation project (mostly from sonar submarine divisions) expressed a strong preference for low-level-white (LLW). This preference, as obtained from questionnaires taken after working under red and white light respectively, was expressed with respect to general well being as well as job performance. Since red light is also used for illuminating work areas on deck, also the aspect of ship concealment was addressed. From studies on the range of coloured signal lights it was concluded that red light is not a good choice from the viewpoint of detectibility by look-outs on enemy ships. One should also consider that image intensifiers are very sensitive to red light. A more logical choice would be LLW, or better still, blue light. The results of this literature study suggest that red adaptation lighting should be replaced by LLW, and also that, for work areas on deck, white or blue light would be the better choice. However, before dispensing with the red-light doctrine, it is advised to conduct additional research to confirm the validity and/or applicability of the results reported in the literature. (A)
Abstract