Bison Rail Systems provided checking and evaluation of vital railway signal relay logic and vital and non-vital software logic for the Neck 1, Neck 2 and Neck 3 interlockings.

Conducted a detailed analysis of existing interlocking operation and compared changes made to interlocking logic against Long Island Rail Road (LIRR) operational requirement engineering standards according to the LIRR Signal Engineering Operations Manual (SEOM).

Provided comprehensive drawing and software markups and report of findings.

Suggested circuit modifications and equipment modifications, where necessary to produce a proper working and safe design.