ThomasRocksification has revealed via The Ultimate Diesel Guide book, the descriptions on the newbies, Norman and Paxton.
Norman is a Diesel engine who often breaks down. If he were fixed properly, he would show what a Really Useful Engine he is.
Paxton is a young Diesel who likes the steam engines, especially Thomas. He can be a bit gullible, enabling other Diesels to take advantage of him.
The Ultimate Diesel Guide hits book shelves later this year coinciding with the release of the Day of the Diesels special later in the Autumn.
Thanks to ThomasRocksification, Thomasfan and TTTE Wikia.