No date but we have a tractor backacter which possible predates JCB. If this is a water main it is either Cast iron, spun Iron or Pitch Fibre. Low land possibly near Swarkeston. This may be a sewer because the trench is very deep - watermains are normally laid to 3 feet (0.9 metres) cover.
Photo sent in by Malc Woodward whose father Cecil Woodward worked for SDWB and then STWA.