The drawings to the right illustrate the GRS compound lens style searchlight signal.� This signal is very similar to the US&S H-2 style searchlight signal.� Both have a compound lens design with a smooth non-prism outer lens.� They both accommodate this design by adding a front housing extension.� The housing extension of each signal also contains an adjustable close-up deflecting prism lens and a cover to access this lens.� The GRS signal attaches the cover with standard bolts, while the US&S signal uses bolts with wing-nut like tops.� The signal in the top drawing has a top of mast mounting assembly.� The lower drawing illustrates the elegant GRS side of mast mount.

GRS searchlight signals do not use �D� shaped washers on the front adjusting bolt, instead relying on a nut having rounded over edges.

While the sighting device appears similar to the device used on the US&S searchlight signals, there are a couple of differences.� The GRS signal uses a glass with a painted cross in the front standard whereas the cross in the US&S sighting device has no glass and consists of two heavy gauge wires.� Also, the factory adjustment is made on the GRS sighting device by loosening and moving the glass plate containing the cross on the front standard, whereas with the US&S sighting device, the adjustment is made by loosening and moving a metal plate which contains the pinhole on the rear standard.� Finally, the GRS sighting device is fitted onto studs extending out of the top of the housing and attached with two nuts, while the US&S device is simply attached to the top of the housing with two bolts.

Above.� The nuts shown in the drawing on the mounting stud would be removed before the stud is inserted into the mounting bracket.� Once the stud is inserted, the nuts would then be screwed onto the stud to secure the signal to the bracket.

Left.� �Side of mast mounted GRS SA stepped lens style searchlight signal.� Note the absence of the housing extension.�

To open the rear door of the GRS searchlight signal, a flanged nut securing the latch hook is loosened with a wrench-like handle.� Once loose, the wrench is then used as a lever to disengage the hook from a catch mounted on the top inside of the housing.� The US&S searchlight signals use a standard nut with a hinged handle welded on which performs similarly.

The back door seal is made from a rope like material which would be impregnated with wax to protect against moisture penetration.� US&S searchlight signals use the same type of gasket.� Gaskets on modern or upgraded units are made from neoprene, a synthetic rubber-like material used widely in automotive door seals.