"Had" being the correct terminology, the vaults were filled in many years ago. They were stored in the open by the tower for nearly a year before they were installed into the shelters. Great sport winding up the RAF(P) as well by driving into the HAS and parking on the vault and waiting for the phone call asking you to remove your vehicle! The same vaults were also installed in the first generation HAS at Bruggen as well.Didn't realise Marham had them installed.
Regards