This Glasgow one is a telegraphist - with a wife, and a very young son - Graham ....but doesnt explain him being "single" on the passenger list though...
Back in a sec with a transcript so you can see....
517 Sauchichall Street, Glasgow.
Alice Park, Head, 53, Boarding House Keeper, born England
Alice M Nicholls, Daughter, 27, married 2 years, born Glasgow
Hope A Park, Daughter, 15, School, born Glasgow
William Nicholls, Son in Law, 29, Telegraphist Cable Company, born England
Graham Nicholls, Grandson, 1, born Glasgow