Monitoring the Condition of the Pier Extensions. SBC’s engineering consultant, Royal Haskoning, recommended in 2009 that rectification of the High Priority defects on the pier extensions (void filling and new scour protection works) should begin in April 2011. This did not happen.
Following the emergency repairs to the huge void on the landward end of the East Pier Extension in 2010/11, Royal Haskoning issued a further report in May 2012. In order to give higher priority to the works on the Main Piers, they advised that it could be possible to defer the start of the remaining void filling and scour protection works on the Extensions to 2032.
However, this relaxation came with two conditions:
a: Dive surveys were to be conducted every 5 years between 2012 and 2032. This was to “ensure that any significant deterioration (such as large voids) is reported in order to allow the timing of the repair work to be re-evaluated if required.” It should be emphasised that the annual walkover surveys cannot provide the data required.
b: Due to concerns regarding the poor quality of the concrete at the lower level of the extensions, Royal Haskoning recommended that horizontal core samples should be taken in order to provide a better understanding of the erosion process. The cores were to be taken during the design phase of the main piers, which at that time was anticipated to be 2014.
Question 10: Has SBC conducted any dive surveys on the Extensions since 2012?
Question 11: If so, please would you provide details of the findings in respect of the extent and location of the excessively corroded steel sheet piling, the number and location of holes in the pile pans and the size and location of the voids?
Question 12: How is SBC monitoring the inevitable deterioration of the existing scour protection, the occurrence of new voids and the enlargement of the existing ones?
Question 13: Has SBC commissioned the taking of horizontal cores in the foundations of the extensions?
Question 14: If so, may we have copies of their subsequent analysis?
Question 15: If SBC has not commissioned any cores, may we know the reason why?
[Extract from Open Letter from Fight4Whitby to SBC, sent 3rd April 2017. To be continued…]