Thanks for all your help, Allan. It looks now as if William Reveley TENCH senior lived in a number of places and was only in Garston for the lengthof time it took to complete his engineering contract. He may well have been employed by Joseph RAWLINSON and Sons Ltd, who were widening the railway stations from Edge Hill to Speke in the 1890s. Yes, Isabel is the youngest child born in 1892 in Garston
In 1881, when he and the family were in Ipswich (with the help of Ann), he may well have been involved in the construction of a viaduct there. I've contacted a railway enthusiast to gain more information, hopefully.
Living in Newcastle upon Tyne, in 1901, and describing himself as a pier erector, I think he could have been working for PJ Messant's engineering firm either finishing off the original North Pier at Tynemouth or reconstructing it when it was damaged badly by a storm in 1897. It took 14 years to complete.
I've lots more to do now and I could be barking up the wrong tree but...onward and upward
Regards
Pat