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Vi hørte på radioen at toget skulle krydse et andet tog ved Smiths, og at der skulle køre endnu et tog mod øst kort tid efter, og . Vi besluttede at vi havde nok billeder fra Vicksburg, så vi kørte i forvejen til et krydsningssporet ved navn Smiths.

Strækningen er i princippet uden signaler (dvs. uden automatisk linieblok og uden fjernstyring), så trafikken dirigeres ved hjælp af radiotilladelser. Hvilket jo er bekvemt når man skal finde ud af hvad der foregår. Krydsningssporene er udstyret med elektriske sporskifter som stilles af togene selv ved hjælp af radioen.

Ovenfor er "vores" tog på vej mod os gennem krydsningssporet, og får radiotilladelse til at køre videre fra "East Smiths". Sporskiftet står i normalstillingen, dvs. til hovedsporet, og sporskiftesignalet røde lys viser at det ikke er blevet låst for et tog. Et øjeblik senere taster togpersonalet en talkode på radioen og...:

We had heard on the scanner that the train was set up for a meet at Smiths, and that another eastbound was to follow shortly. We decided that we had enough pictures from Vicksburg and hit the road to Smiths siding.

The line is "unsignaled", i.e. without automatic block signaling and without CTC, so traffic is controlled by Track Warrant Control. Which of course is convenient for railfans. The siding switches are electric, remote controlled from the trains via the radio.

On the photo above"our" eastbound is pulling through the siding, and gets a Track Warrant to continue from "East Smiths". The switch is in its neutral position, i.e. lined normal, but the red light in the switch signal indicates the switch is not locked for a train. A moment later the train crew punches numbers on the radio, and...:

...sporskiftet stiller om til krydsningssporet og signalet skifter til gult. På radioen høres en indtalt stemme rapportere sporskiftestillingen: "KCS East Smiths, milepost one-twenty-four dot two, switch is in reverse, switch is in reverse, KCS East Smiths out".

Hvis sporskiftet var kaldt til lige spor så ville signalet vise grønt og stemmen rapportere "...switch is normal, switch is normal...". Sporskiftet er låst et stykke tid efter at være kaldt op, men oplåses efter togets passage. Sporskifter i afvigende stilling stiller automatisk tilbage efter toget (sporskifter i hovedspor skal altid efterlades til kørsel i hovedsporet når strækningen ikke har linieblok/sikringsanlæg).

...switch reverses and the signal changes to yellow. A pre-recorded message is heard on the scanner: "KCS East Smiths, milepost one-twenty-four dot two, switch is in reverse, switch is in reverse, KCS East Smiths out".

Had the switch been called for the main track, the signal would have changed to green and the message had said "...switch is normal, switch is normal...". The switch is locked some time after being called but is unlocked by a train passing over it. Switches in reverse are automatically lined back as switches in "unsignaled" territory are required to be lined back to normal after use.