Tuesday, 24 November 2015 10:49

Appleby Castle

The Scheduled Monument of Appleby Castle is situated in the historic town of Appleby-in-Westmoreland, Cumbria, overlooking the River Eden. It consists of a 12th-century castle keep, known as Caesar's Tower, as well as a Jacobean mansion house. These, together with their associated buildings are set in a courtyard surrounded by curtain walls. 

S&CC Ltd has been working together with the owner, Mrs Nightingale, and Historic England (English Heritage) to investigate and monitor the distress in the keep. After S&CC Ltd recorded relative movement of 1.1mm in the foundations over a 5m-length of wall during a period of just 4 weeks in 2013, the team investigated further movement and looked at possible explanations. Although monitoring showed that movements have effectively stopped, repairs have been carried out that will allow for potential future movements. The conservation engineer has suggested a range of remedial measures, covering cost-effective interventions that eliminate potential contributory factors to the structural distress.

Monitoring

A range of monitoring techniques were used at the keep by S&CC Ltd. These proved to be crucial to the understanding of the nature of the movements and therefore their possible causes.

DETAIL

The key aspect in the monitoring methods is the use of laser-cut rulers as seen in the above image. (www.MovementGauge.com). These allow cost-effective levelling for relative vertical movements along the walls to ±0.1. Monitoring vertical movements to that accuracy provides results within weeks.

A range of crack-width gauges were used as a secondary source of data to confirm the scale of damage to the walls.