Our next up in our Interlocking Walkthrough series is CI interlocking in Central Islip (everyone calls Central Islip “CI”.) This interlocking sits in the Main Line (aka Ronkonkoma Branch) and is rarely used besides during track-work. This interlocking is a very simple and consistent of two switch.
Switches
CI is a rather typical interlocking, that only consists of (going from east to west) a switch going from track 1 to track 2, then soon afterward, a switch going back to track 2. This is your typical mid-line LIRR interlocking, that’s used rarely.
Neighbors
CI Interlocking is bordered by BRENT interlocking to the west in Brentwood, and by KO interlocking to the east in Ronkonkoma.
The speed limit thru the area is 80 mph, which is fitting considering the long, straight stretch of track.