Hi Tony,
Your Grandfather would have sailed to Boulogne on either the Michigan or Herschel depending on which Company he served in. Headquarters Company, 'A' Company, 'B' Company, Machine Gun Section and Headquarters Detail were on the 'Lake Michigan' and 'C' Company, 'D' Company, Transport Officer, Quarter Master and Headquarters Detail on the 'Herschel'.
The following details I have for your Grandfather on the database:
Private 12585 Walter Hubert Rollings.
Born 1899. He was groom to Captain Senhouse-Clarke at the time of the battle of Gheluvelt. Died aged 76 20th March 1966 Kidderminster.
Disembarked 12.08.1914 (from MIC).
As you will appreciate the 2nd Battalion Worcesters were involved in many actions and much movement in France and Belgium, too much to type out on this posting. The best reference I can suggest is 'The Worcestershire Regiment in the Geart War' by Captain H. FitzM. Stacke (a copy may be available at your local reference library) or the 2nd Battalion War Diary 1914 (a copy can be requested from the Regimental Museum for a small fee, see this website for details). Another good book for reference to the Worcesters (1st, 2nd and 3rd Battalions) for 1914 is Ray Westlakes 'British Battalions in France and Belgium 1914'(Leo Cooper 1997). Again your local library may have a copy otherwise a search on AbeBooks for a second hand copy is worth while. A reprint in two volumes (SB) of Stackes book can be obtained from 'The Naval & Military Press Ltd. (Price £65)
www.naval-military-press.co.uk
I hope this is of some help to you.
Regards