Site assessment of the quad light system used for the guidance of a tamper/liner (IM-SM-018)

On Sunday 1 Feb 76 the Research 4 Development Division's "quad light" equipment was demonstrated to Eastern Region representatives on the test site, Tollerton-Beningbrough (North of York). The equipment provides a straight datum line which was used to guide the lining chord adjustment at the front of a Plasser...