(continuing on the first part of my mail which I already sent by accident)
Additional there are two more joints without the possibility of expansion. We can define:
• metallurgical welds
• glued insulated joints
These links provide the information and graphics from the book:
http://puu.sh/iyZLs/9a7d6ab8e0.jpg
http://puu.sh/iyZMR/e3b874c9bb.jpg
http://puu.sh/iyYSE/c9742ad52a.jpg
More information on the book can be found at http://esveld.com/MRT.html.
Depending on what Michael needs, I advice him to choose expansion joint or expansion device (the difference is in the occurence of a glide plane). I think that "adjustment switch" is too specific for the British situation.