Fire chief Matt Morton was on his day off and heading to the beach with his family, but responded to the call for the fire brigade.
"They looked and started digging, and you could only just see Robin with his hands straight up."
Rescuers used bits of wood to stabilise the hole, as standing a few feet away caused sand to fall in.
"They were digging and after a while they'd dug an awful lot of sand away. Then I heard them say 'put your shovels down and dig by hand'."
Mrs Loomes didn't realise until she was bathing Robin later that day, but as the firefighters dug they had grazed his neck with the shovel.
"But anyway, he came out all right. He was as good as gold."
Mrs Loomes thought "half the street" turned up to watch the rescue effort.
She said she "wasn't that anxious" at the time, and only realised later "how bad it could've been".
After the rescue, Robin was given a ride in the fire engine.
Robin, who is now 56 and living in Christchurch, can still remember his mouth being "full of sand".
"For a long time afterwards, I could always taste sand in my mouth.
"I remember the fire chief Morton reaching down to me all the time and pushing boards down around me to stop the hole collapsing over me entirely. I remember him talking to me quite a bit and I think I remember his face was very... had a very grave expression."
Mr Loomes said he didn't remember being scared at the time. "It was just something that was happening. I don't feel that I was panicking at any stage."
Chief Morton, who pulled Robin from the hole, died a few years later battling a house fire, but Mr Loomes remembers the fire brigade keeping in touch with him and his family over the years.
"I remember they bought me a toy fire engine," he said.
Fifty-two years later, Mrs Loomes still lives at the same Gonville property, but instead of a hole in the ground, the spot is covered up with a small patch of garden.