South foundation ... west ... 1953 ... South foundation.
South foundation ... AMS 156 Horizontal (normal) ... 19 Jun 1931 ... South foundation.
North-south foundation trench ... north Horizontal (normal) ... 21 Mar 1934 ... North-south foundation trench.
North-south foundation trench ... AMS north Horizontal (normal) ... 21 Mar 1934 ... North-south foundation trench.