TYPE DT SIGNALS
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| The type DT line of signals were introduced sometime around 1952. Type DT or "Dust Tight" signals were very similar to the D line. The DT signals maintained for the most part the same design as the D line. The same design was still used and the same castings were used. There were however a few modifications made. The most notable is the "dust-tight optical system" This improvement was achieved by using gaskets at all openings between receptacle, reflector, lens and door. Dust or dirt entering the signal through the underground conduit or through the wire outlet cannot pass these barriers. For the DT line, the cast aluminum reflector spider used on the D line, was changed to a stamped aluminum reflector frame. The DT signals shared the same glass or aluminum reflectors and most of the accessories and mountings were still available from the D line. |
MORE INFORMATION AND PICTURES WILL BE DISPLAYED SOON. |