HISTORY UNEARTHED: Rig operators from subcontractor Aspin Foundations found themselves bringing out stonework from a 12th century castle when they installed steel pin foundations at Northampton station in the East Midlands. The castle was demolished in 1662 on the order of Charles II, because of the town's parliamentarian support during the civil war.
Four tubular pins with a wall thickness of 16mm are supporting a new portal signal gantry and a signal post on the Network Rail site, going to depths of 16m and 19m for the gantry and 9m for the post. The site was made challenging by overhead power lines and difficult ground conditions.
Under a £90,000 contract to Carillion, Aspin spun the 457mm diameter thread ended pins into the ground using a high-torque mast connected to a road-railer. Although this fast, non-vibratory technique normally has no wet process, grouting was necessary to stiffen the ground.
The gantry was due to be finished this autumn.