I think that Victor may have forgotten one very important fact when comparing reconstruction times between the Aylesbury Arm lock and Tardebigge Top Lock, writes Roger Fox.
The two locks have different planning status with Tardebigge being a listed structure and Aylesbury not listed.
The requirement to obtain listed building approval before the commencement of works can add weeks to any such application and approval will often include stipulations about materials which have to be used, which themselves can add time through procurement delays.
Contrast this with the Aylesbury example which is unlikely not to have had any bureaucratic delays other than discussions about whether the nearby dairy was responsible for the collapse and whether they might pay for the re-instatement.