As you seem to check your sites regularly ( some people post notes and then don't check replies) i thought I would give you a brief reply here. I have the Houghton-le-Spring register on fiche up to 1812 so I was able to check the details for William Dinning. He was born as you know to Thomas Dinning and Wife Margaret Wilson.born 12/4/1804 and baptised 2/12/1804 William was the first son. Thomas was a pitman, Native of Ryton (close to the main root of the Dinnings in the North) his wife is native of Ludworth, near Durham.At the time of this baptism the family lived at Philadelphia a pit village built near houghton-le-Spring.The other children I found were 22/8/1806. bap.29/3/1807.Ann. 2nd daughter. 22/4/1809. bap.4/3/1810. Margaret 3rd.daug. 31/7/1811. bap.22.12.1811 Thomas 2nd. son. All the other details were the same.As you can see the 1881 census confirms this family to be connected as William aged 77 is born in Philadelphia. His son born at South Shields is not particularly unusual as there was also a coal mine there.We do not know if he had any particular skills which would make him more likely to move. South Shields suffered a huge explosion so he may have had some skills for the aftermath. I will check out the dates.A Henry Dinning was in Houghton-le- Spring when Thomas was there and a Henry Dinning turns up in South Shields on the 1851 census. It is not a common name so there might be a link.I think your family would keep moving to the new pits as they opened. They moved in groups because they relied on each other because the job was so dangerous. They knew each other well and they had to trust their young boys to the care of these men. The boys would be down the pit on 12 hour shifts so you can imagine the need for care.Many major accidents were caused by little boys some as young as 5 falling asleep.I have the details for several accidents one or two at Philadelphia pit when the Dinnings were there. My interest in the Dinnings began nearly 20 years ago because my husband's grandmother was called Dinning. After making family trees of the north-eastern Dinnings he learnt that he was Irish. I think you will need further research into the Shadforth area. The Haswell pit area is a possibility. I could look for you but it would not be possible until we can get a booking in the Durham record office. We do have to go for other records so I will be going over the summer.